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Irandoust S, Whitton RC, Muir P, Henak CR. Subchondral bone fatigue injury in the parasagittal condylar grooves of the third metacarpal bone in thoroughbred racehorses elevates site-specific strain concentration. J Mech Behav Biomed Mater 2024; 155:106561. [PMID: 38678748 DOI: 10.1016/j.jmbbm.2024.106561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 04/17/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Condylar stress fracture of the distal end of the third metacarpal/metatarsal (MC3/MT3) bones is a major cause of Thoroughbred racehorse injury and euthanasia worldwide. Functional adaptation to exercise and fatigue damage lead to structural changes in the subchondral bone that include increased modeling (resulting in sclerotic bone tissue) and targeted remodeling repair (resulting in focal resorption spaces in the parasagittal groove). Whether these focal structural changes, as detectable by standing computed tomography (sCT), lead to elevated strain at the common site of condylar stress fracture has not been demonstrated. Therefore, the goal of the present study was to compare full-field three-dimensional (3D) strain on the distopalmar aspect of MC3 bone specimens with and without focal subchondral bone injury (SBI). Thirteen forelimb specimens were collected from racing Thoroughbreds for mechanical testing ex vivo and underwent sCT. Subsequently, full-field displacement and strain at the joint surface were determined using stereo digital image correlation. Strain concentration was observed in the parasagittal groove (PSG) of the loaded condyles, and those with SBI in the PSG showed higher strain rates in this region than control bones. PSG strain rate in condyles with PSG SBI was more sensitive to CT density distribution in comparison with condyles with no sCT-detectable injury. Findings from this study help to interpret structural changes in the subchondral bone due to fatigue damage and to assess risk of incipient stress fracture in a patient-specific manner.
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Affiliation(s)
- Soroush Irandoust
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - R Christopher Whitton
- Equine Centre, Melbourne Veterinary School, University of Melbourne, Werribee, Vic, 3030, Australia
| | - Peter Muir
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Corinne R Henak
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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2
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Hewitt-Dedman CL, Kershaw LE, Schwarz T, Del-Pozo J, Duncan J, Daniel CR, Cillán-García E, Pressanto MC, Taylor SE. Preliminary study of proton magnetic resonance spectroscopy to assess bone marrow adiposity in the third metacarpus or metatarsus in Thoroughbred racehorses. Equine Vet J 2024. [PMID: 38699829 DOI: 10.1111/evj.14086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 03/07/2024] [Indexed: 05/05/2024]
Abstract
BACKGROUND Magnetic resonance spectroscopy (MRS) has been used to investigate metabolic changes within human bone. It may be possible to use MRS to investigate bone metabolism and fracture risk in the distal third metacarpal/tarsal bone (MC/MTIII) in racehorses. OBJECTIVES To determine the feasibility of using MRS as a quantitative imaging technique in equine bone by using the 1H spectra for the MC/MTIII to calculate fat content (FC). STUDY DESIGN Observational cross-sectional study. METHODS Limbs from Thoroughbred racehorses were collected from horses that died or were subjected to euthanasia on racecourses. Each limb underwent magnetic resonance imaging (MRI) at 3 T followed by single-voxel MRS at three regions of interest (ROI) within MC/MTIII (lateral condyle, medial condyle, proximal bone marrow [PBM]). Percentage FC was calculated at each ROI. Each limb underwent computed tomography (CT) and bone mineral density (BMD) was calculated for the same ROIs. All MR and CT images were graded for sclerosis. Histology slides were graded for sclerosis and proximal marrow space was calculated. Pearson or Spearman correlations were used to assess the relationship between BMD, FC and marrow space. Kruskal-Wallis tests were used to check for differences between sclerosis groups for BMD or FC. RESULTS Eighteen limbs from 10 horses were included. A negative correlation was identified for mean BMD and FC for the lateral condyle (correlation coefficient = -0.60, p = 0.01) and PBM (correlation coefficient = -0.5, p = 0.04). There was a significant difference between median BMD for different sclerosis grades in the condyles on both MRI and CT. A significant difference in FC was identified between sclerosis groups in the lateral condyle on MRI and CT. MAIN LIMITATIONS Small sample size. CONCLUSIONS 1H Proton MRS is feasible in the equine MC/MTIII. Further work is required to evaluate the use of this technique to predict fracture risk in racehorses.
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Affiliation(s)
- Charlotte L Hewitt-Dedman
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Lucy E Kershaw
- BHF Centre for Cardiovascular Science and Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | - Tobias Schwarz
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Jorge Del-Pozo
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Juliet Duncan
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Carola R Daniel
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Eugenio Cillán-García
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Maria Chiara Pressanto
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
| | - Sarah E Taylor
- Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Roslin, UK
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3
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Bergstrom TC, Spriet M, Carpenter RS, Jacques KL, Stover SM. Condylar fracture location is correlated to exercise history in Thoroughbred racehorses. Equine Vet J 2024. [PMID: 38584321 DOI: 10.1111/evj.14091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 03/14/2024] [Indexed: 04/09/2024]
Abstract
BACKGROUND Condylar fractures are a major cause of morbidity and mortality in Thoroughbred racehorses. Condylar fractures have a variety of fracture configurations that suggest there may be differences in aetiopathogenesis. OBJECTIVE To determine if exercise history differs with condylar fracture location in a population of Thoroughbred racehorses. STUDY DESIGN Retrospective analysis of clinical and exercise data. METHODS Exercise history of Thoroughbred racehorses that had condylar fracture repair between 1 January 2018 and 28 February 2021 was compared between racehorses that had fractures located radiographically either within the parasagittal groove (PSG) or abaxial to the PSG (non-PSG). Age, sex, and last event (race, timed work) matched control groups were compared between the PSG and non-PSG groups. Additionally, exercise history variables of both groups were each compared with a group-specific control population, each consisting of three control racehorses of equivalent age and sex matched to each affected racehorse by last event (race or official timed work) before fracture. RESULTS Eighty-two horses with 84 fractures (45 PSG, 39 non-PSG) met inclusion criteria. Age was not different between groups (PSG: 3.4 ± 1.3 years [mean ± SD], non-PSG: 3.7 ± 1.3, p = 0.3). Number of races (PSG: 5.3 ± 7.1, non-PSG: 11.4 ± 8.9, p < 0.001), total race furlongs (PSG: 38.2 ± 54.7, non-PSG: 79.2 ± 64, p = 0.003), and number of active days (PSG: 304 ± 224, non-PSG: 488 ± 314, p = 0.003) before fracture were greater; while mean number of layups was fewer (PSG: 1.0 ± 1.2, non-PSG: 0.5 ± 0.7, p = 0.02) in horses with non-PSG fracture. Horses with non-PSG fracture had more differences compared with their respective control group than horses with PSG fractures. Outcomes following fracture repair were not different between groups. MAIN LIMITATIONS Retrospective study, one regional racehorse population, two-dimensional imaging and potential inherent bias for fracture localisation, low statistical power for return to performance analysis. CONCLUSIONS Thoroughbred racehorses with non-PSG condylar fractures have a more extensive exercise history than horses with PSG condylar fractures, suggesting differences in fracture aetiopathogenesis.
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Affiliation(s)
- Thomas C Bergstrom
- William R. Prichard Veterinary Medical Teaching Hospital, University of California, Davis, California, USA
| | - Mathieu Spriet
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, USA
| | | | - Kevin L Jacques
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Susan M Stover
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California, USA
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Costa da Silva RG, Sun TC, Mishra AP, Boyde A, Doube M, Riggs CM. Intracortical remodelling increases in highly loaded bone after exercise cessation. J Anat 2024; 244:424-437. [PMID: 37953410 PMCID: PMC10862154 DOI: 10.1111/joa.13969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 11/14/2023] Open
Abstract
Resorption within cortices of long bones removes excess mass and damaged tissue and increases during periods of reduced mechanical loading. Returning to high-intensity exercise may place bones at risk of failure due to increased porosity caused by bone resorption. We used point-projection X-ray microscopy images of bone slices from highly loaded (metacarpal, tibia) and minimally loaded (rib) bones from 12 racehorses, 6 that died during a period of high-intensity exercise and 6 that had a period of intense exercise followed by at least 35 days of rest prior to death, and measured intracortical canal cross-sectional area (Ca.Ar) and number (N.Ca) to infer remodelling activity across sites and exercise groups. Large canals that are the consequence of bone resorption (Ca.Ar >0.04 mm2 ) were 1.4× to 18.7× greater in number and area in the third metacarpal bone from rested than exercised animals (p = 0.005-0.008), but were similar in number and area in ribs from rested and exercised animals (p = 0.575-0.688). An intermediate relationship was present in the tibia, and when large canals and smaller canals that result from partial bony infilling (Ca.Ar >0.002 mm2 ) were considered together. The mechanostat may override targeted remodelling during periods of high mechanical load by enhancing bone formation, reducing resorption and suppressing turnover. Both systems may work synergistically in rest periods to remove excess and damaged tissue.
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Affiliation(s)
| | - Tsim Christopher Sun
- Sydney School of Veterinary ScienceUniversity of SydneyCamperdownNew South WalesAustralia
| | - Ambika Prasad Mishra
- Department of Infectious Diseases and Public HealthCity University of Hong KongKowloonHong Kong
| | - Alan Boyde
- Barts and The London School of Medicine and DentistryQueen Mary University of LondonLondonUK
| | - Michael Doube
- Department of Infectious Diseases and Public HealthCity University of Hong KongKowloonHong Kong
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McPhee S, Kershaw LE, Daniel CR, Peña Fernández M, Cillán-García E, Taylor SE, Wolfram U. QCT-based computational bone strength assessment updated with MRI-derived 'hidden' microporosity. J Mech Behav Biomed Mater 2023; 147:106094. [PMID: 37741181 DOI: 10.1016/j.jmbbm.2023.106094] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/10/2023] [Accepted: 08/26/2023] [Indexed: 09/25/2023]
Abstract
Microdamage accumulated through sustained periods of cyclic loading or single overloading events contributes to bone fragility through a reduction in stiffness and strength. Monitoring microdamage in vivo remains unattainable by clinical imaging modalities. As such, there are no established computational methods for clinical fracture risk assessment that account for microdamage that exists in vivo at any specific timepoint. We propose a method that combines multiple clinical imaging modalities to identify an indicative surrogate, which we term 'hidden porosity', that incorporates pre-existing bone microdamage in vivo. To do so, we use the third metacarpal bone of the equine athlete as an exemplary model for fatigue induced microdamage, which coalesces in the subchondral bone. N = 10 metacarpals were scanned by clinical quantitative computed tomography (QCT) and magnetic resonance imaging (MRI). We used a patch-based similarity method to quantify the signal intensity of a fluid sensitive MRI sequence in bone regions where microdamage coalesces. The method generated MRI-derived pseudoCT images which were then used to determine a pre-existing damage (Dpex) variable to quantify the proposed surrogate and which we incorporate into a nonlinear constitutive model for bone tissue. The minimum, median, and maximum detected Dpex of 0.059, 0.209, and 0.353 reduced material stiffness by 5.9%, 20.9%, and 35.3% as well as yield stress by 5.9%, 20.3%, and 35.3%. Limb-specific voxel-based finite element meshes were equipped with the updated material model. Lateral and medial condyles of each metacarpal were loaded to simulate physiological joint loading during gallop. The degree of detected Dpex correlated with a relative reduction in both condylar stiffness (p = 0.001, R2 > 0.74) and strength (p < 0.001, R2 > 0.80). Our results illustrate the complementary value of looking beyond clinical CT, which neglects the inclusion of microdamage due to partial volume effects. As we use clinically available imaging techniques, our results may aid research beyond the equine model on fracture risk assessment in human diseases such as osteoarthritis, bone cancer, or osteoporosis.
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Affiliation(s)
- Samuel McPhee
- School of Engineering and Physical Sciences, Institute of Mechanical, Process and Energy Engineering, Heriot-Watt University, Edinburgh, UK
| | - Lucy E Kershaw
- Centre for Cardiovascular Sciences and Edinburgh Imaging, The University of Edinburgh, Edinburgh, UK
| | - Carola R Daniel
- Royal (Dick) School of Veterinary Studies and the Roslin Institute, The University of Edinburgh, Edinburgh, UK
| | - Marta Peña Fernández
- School of Engineering and Physical Sciences, Institute of Mechanical, Process and Energy Engineering, Heriot-Watt University, Edinburgh, UK
| | | | - Sarah E Taylor
- Royal (Dick) School of Veterinary Studies and the Roslin Institute, The University of Edinburgh, Edinburgh, UK
| | - Uwe Wolfram
- School of Engineering and Physical Sciences, Institute of Mechanical, Process and Energy Engineering, Heriot-Watt University, Edinburgh, UK.
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Wong ASM, Morrice-West AV, Hitchens PL, Whitton RC. The association between Thoroughbred racehorse training practices and musculoskeletal injuries in Victoria, Australia. Front Vet Sci 2023; 10:1260554. [PMID: 37941814 PMCID: PMC10628463 DOI: 10.3389/fvets.2023.1260554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 08/29/2023] [Indexed: 11/10/2023] Open
Abstract
Catastrophic musculoskeletal injuries (CMI) in horses are associated with both too little and too much high-speed exercise. In order to advise trainers on training and management strategies that minimize the risk of musculoskeletal injury (MSI), a better understanding of how training practices affect MSI in racehorses is needed. Data from prospective studies relating training data and MSI are complicated by the gradual development of pathology and the effect of this on the ability of horses to train consistently prior to the identification of an injury. To circumvent this, 66 Australian Thoroughbred trainers were surveyed on their intended training practices, including rest, pre-training, and race-fit practices. Associations between intended training practices and catastrophic and non-catastrophic race day MSI outcomes in two-year-old and mature (≥three-year-old) horses were assessed using multivariable negative binomial regression models. The incidence of two-year-old race day MSI was lower for trainers who preferred shorter times (weeks) to trial, less time in fast work pre-trial (p = 0.003), shorter, more frequent rest periods (p < 0.01) and higher amounts of fast work at 15.5-16.7 m/s once race-fit (p = 0.001). The incidence of mature horse race day MSI was lower for trainers who preferred longer rest periods (p = 0.026) and a high-volume pre-trial training strategy comprising a high volume of slower speed gallop training and longer times to trial compared to fast and light training programs (p = 0.004) for their mature horses, in addition to higher amounts of fast work at 15.5-16.7 m/s for their race-fit two-year-olds (p = 0.012). Race day CMI incidence was lower for trainers who preferred lower volumes of fast gallop work for their race-fit mature horses (p < 0.05). These results suggest that two-year-old training practices could affect MSI risk later in a horse's career, and that age and stage in training (pre-trial, race-fit) are important considerations when developing training practices to minimize the risk of MSI.
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Affiliation(s)
- Adelene S. M. Wong
- Equine Lameness and Imaging Centre, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC, Australia
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7
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Noordwijk KJ, Chen L, Ruspi BD, Schurer S, Papa B, Fasanello DC, McDonough SP, Palmer SE, Porter IR, Basran PS, Donnelly E, Reesink HL. Metacarpophalangeal Joint Pathology and Bone Mineral Density Increase with Exercise but Not with Incidence of Proximal Sesamoid Bone Fracture in Thoroughbred Racehorses. Animals (Basel) 2023; 13:ani13050827. [PMID: 36899684 PMCID: PMC10000193 DOI: 10.3390/ani13050827] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023] Open
Abstract
Proximal sesamoid bone (PSB) fracture is the leading cause of fatal musculoskeletal injury in Thoroughbred racehorses in Hong Kong and the US. Efforts are underway to investigate diagnostic modalities that could help identify racehorses at increased risk of fracture; however, features associated with PSB fracture risk are still poorly understood. The objectives of this study were to (1) investigate third metacarpal (MC3) and PSB density and mineral content using dual-energy X-ray absorptiometry (DXA), computed tomography (CT), Raman spectroscopy, and ash fraction measurements, and (2) investigate PSB quality and metacarpophalangeal joint (MCPJ) pathology using Raman spectroscopy and CT. Forelimbs were collected from 29 Thoroughbred racehorse cadavers (n = 14 PSB fracture, n = 15 control) for DXA and CT imaging, and PSBs were sectioned for Raman spectroscopy and ash fraction measurements. Bone mineral density (BMD) was greater in MC3 condyles and PSBs of horses with more high-speed furlongs. MCPJ pathology, including palmar osteochondral disease (POD), MC3 condylar sclerosis, and MC3 subchondral lysis were greater in horses with more high-speed furlongs. There were no differences in BMD or Raman parameters between fracture and control groups; however, Raman spectroscopy and ash fraction measurements revealed regional differences in PSB BMD and tissue composition. Many parameters, including MC3 and PSB bone mineral density, were strongly correlated with total high-speed furlongs.
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Affiliation(s)
- Kira J. Noordwijk
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Leyi Chen
- Department of Materials Science and Engineering, College of Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Bianca D. Ruspi
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Sydney Schurer
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Brittany Papa
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Diana C. Fasanello
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Sean P. McDonough
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Scott E. Palmer
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Ian R. Porter
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Parminder S. Basran
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Eve Donnelly
- Department of Materials Science and Engineering, College of Engineering, Cornell University, Ithaca, NY 14853, USA
- Correspondence: (E.D.); (H.L.R.)
| | - Heidi L. Reesink
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- Correspondence: (E.D.); (H.L.R.)
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8
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Posukonis MN, Daglish J, Wright IM, Kawcak CE. Novel computed tomographic analysis demonstrates differences in patterns of bone mineral content between fracture configurations in distal condylar fractures of the third metacarpal/metatarsal bones in 97 Thoroughbred racehorses. Am J Vet Res 2022; 83:ajvr.22.03.0060. [DOI: 10.2460/ajvr.22.03.0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
OBJECTIVE
To evaluate bone mineral content patterns between fracture configurations using novel CT image analysis.
ANIMALS
CT images from 97 Thoroughbred racehorses with third metacarpal/tarsal condyle fractures provide the case population for analysis.
PROCEDURES
Fractures were grouped by radiographic appearance. Image analysis objectively measured area of highly attenuating pixels (aHAP), areal density of highly attenuating pixels (dHAP) utilizing novel convex hull analysis, and subjective assessment of apparent attenuation intensity ranking (AAIR) for each fracture. Differences between fracture configuration groups were evaluated.
RESULTS
Analysis of dHAP identified lower-density regions of highly attenuating pixels in propagating fractures and higher-density regions of highly attenuating pixels in unicortical fractures (P = .028). Complete and incomplete configurations were almost indistinguishable in dHAP (P = 1.000). The ratio of dHAP between fractured and nonfractured condyles revealed higher density gradients between condyles in unicortical (P = .040) and incomplete (P = .031) fractures than propagating fractures.
CLINICAL RELEVANCE
Differences in patterns of bone mineral content were identified between propagating, bicortical (incomplete and complete), and unicortical fractures of third metacarpal/tarsal bone condyles. Computer-assisted geometric measurement of dHAP identified on CT images could help to assess fracture risk in equine athletes. This application may have greater relevance as standing CT screening becomes more available.
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Affiliation(s)
- Megan N. Posukonis
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO
| | | | | | - Christopher E. Kawcak
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO
- Gail Holmes Equine Orthopaedic Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO
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9
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Pearce DJ, Hitchens PL, Malekipour F, Ayodele B, Lee PVS, Whitton RC. Biomechanical and Microstructural Properties of Subchondral Bone From Three Metacarpophalangeal Joint Sites in Thoroughbred Racehorses. Front Vet Sci 2022; 9:923356. [PMID: 35847629 PMCID: PMC9277662 DOI: 10.3389/fvets.2022.923356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Fatigue-induced subchondral bone (SCB) injury is common in racehorses. Understanding how subchondral microstructure and microdamage influence mechanical properties is important for developing injury prevention strategies. Mechanical properties of the disto-palmar third metacarpal condyle (MCIII) correlate poorly with microstructure, and it is unknown whether the properties of other sites within the metacarpophalangeal (fetlock) joint are similarly complex. We aimed to investigate the mechanical and structural properties of equine SCB from specimens with minimal evidence of macroscopic disease. Three sites within the metacarpophalangeal joint were examined: the disto-palmar MCIII, disto-dorsal MCIII, and proximal sesamoid bone. Two regions of interest within the SCB were compared, a 2 mm superficial and an underlying 2 mm deep layer. Cartilage-bone specimens underwent micro-computed tomography, then cyclic compression for 100 cycles at 2 Hz. Disto-dorsal MCIII specimens were loaded to 30 MPa (n = 10), while disto-palmar MCIII (n = 10) and proximal sesamoid (n = 10) specimens were loaded to 40 MPa. Digital image correlation determined local strains. Specimens were stained with lead-uranyl acetate for volumetric microdamage quantification. The dorsal MCIII SCB had lower bone volume fraction (BVTV), bone mineral density (BMD), and stiffness compared to the palmar MCIII and sesamoid bone (p < 0.05). Superficial SCB had higher BVTV and lower BMD than deeper SCB (p < 0.05), except at the palmar MCIII site where there was no difference in BVTV between depths (p = 0.419). At all sites, the deep bone was stiffer (p < 0.001), although the superficial to deep gradient was smaller in the dorsal MCIII. Hysteresis (energy loss) was greater superficially in palmar MCIII and sesamoid (p < 0.001), but not dorsal MCIII specimens (p = 0.118). The stiffness increased with cyclic loading in total cartilage-bone specimens (p < 0.001), but not in superficial and deep layers of the bone, whereas hysteresis decreased with the cycle for all sites and layers (p < 0.001). Superficial equine SCB is uniformly less stiff than deeper bone despite non-uniform differences in bone density and damage levels. The more compliant superficial layer has an important role in energy dissipation, but whether this is a specific adaptation or a result of microdamage accumulation is not clear.
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Affiliation(s)
- Duncan J. Pearce
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, VIC, Australia
| | - Peta L. Hitchens
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, VIC, Australia
| | - Fatemeh Malekipour
- Department of Biomedical Engineering, The University of Melbourne, Parkville, VIC, Australia
| | - Babatunde Ayodele
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, VIC, Australia
| | - Peter Vee Sin Lee
- Department of Biomedical Engineering, The University of Melbourne, Parkville, VIC, Australia
| | - R. Chris Whitton
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, VIC, Australia
- *Correspondence: R. Chris Whitton
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10
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Luedke LK, Ilevbare P, Noordwijk KJ, Palomino PM, McDonough SP, Palmer SE, Basran PS, Donnelly E, Reesink HL. Proximal sesamoid bone microdamage is localized to articular subchondral regions in Thoroughbred racehorses, with similar fracture toughness between fracture and controls. Vet Surg 2022; 51:952-962. [PMID: 35672916 DOI: 10.1111/vsu.13816] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 01/04/2022] [Accepted: 02/24/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine whether proximal sesamoid bone (PSB) microdamage and fracture toughness differ between Thoroughbred racehorses sustaining PSB fracture and controls. STUDY DESIGN Cadaveric case-control. ANIMALS Twenty-four Thoroughbred racehorses (n = 12 PSB fracture, n = 12 control). METHODS Proximal sesamoid bones were dissected, and gross pathological changes and morphological measurements were documented. High-speed exercise history data were evaluated. Microdamage was assessed in fracture, fracture-contralateral limb (FXCL) and control PSBs using whole bone lead uranyl acetate (LUA) staining with micro-CT imaging or basic fuchsin histological analysis. Fracture toughness mechanical testing was carried out in 3-point-bending of microbeams created from PSB flexor cortices. Data were analyzed using ordinal logistic and linear regression models. RESULTS Microdamage was detected most commonly in the articular subchondral region of PSBs via LUA micro-CT and basic fuchsin histology. There were no differences in microdamage between FXCL and control PSBs. Fracture toughness values were similar for FXCL (1.31 MPa√m) and control (1.35 MPa√m) PSBs. Exercise histories were similar except that horses sustaining fracture spent a greater percentage of their careers in rest weeks. CONCLUSION Microdamage was detected in the articular region of PSBs but was not greater in horses sustaining catastrophic PSB fracture. Fracture toughness of PSB flexor cortices did not differ between FXCL and control PSBs. CLINICAL SIGNIFICANCE Although uncommon, microdamage is localized to the articular region of Thoroughbred racehorse PSBs. Catastrophic PSB failure is not associated with lower PSB flexor cortex fracture toughness.
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Affiliation(s)
- Lauren K Luedke
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, Ithaca, New York, USA
| | - Phoebe Ilevbare
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, Ithaca, New York, USA
| | - Kira J Noordwijk
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, Ithaca, New York, USA
| | - Pablo M Palomino
- Cornell University College of Engineering, Department of Biomedical Engineering, Ithaca, New York, USA
| | - Sean P McDonough
- Cornell University College of Veterinary Medicine, Department of Biomedical Sciences, Ithaca, New York, USA
| | - Scott E Palmer
- Cornell University College of Veterinary Medicine, Department of Population Medicine and Diagnostic Sciences, Ithaca, New York, USA
| | - Parminder S Basran
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, Ithaca, New York, USA
| | - Eve Donnelly
- Cornell University College of Engineering, Department of Materials Science and Engineering, Ithaca, New York, USA
| | - Heidi L Reesink
- Cornell University College of Veterinary Medicine, Department of Clinical Sciences, Ithaca, New York, USA
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11
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Malek G, Richard H, Beauchamp G, Laverty S. An in vitro model for discovery of osteoclast specific biomarkers towards identification of racehorses at risk for catastrophic fractures. Equine Vet J 2022; 55:534-550. [PMID: 35616632 DOI: 10.1111/evj.13600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 05/12/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Focal bone microcracks with osteoclast recruitment and bone lysis, may reduce fracture resistance in racehorses. As current imaging does not detect all horses at risk for fracture, the discovery of novel serum biomarkers of bone resorption or osteoclast activity could potentially address this unmet clinical need. The biology of equine osteoclasts on their natural substrate, equine bone, has never been studied in vitro and may permit identification of specific biomarkers of their activity. OBJECTIVES 1) Establish osteoclast cultures on equine bone, 2) Measure biomarkers (tartrate resistant acid phosphatase isoform 5b (TRACP-5b) and C-terminal telopeptide of type I collagen (CTX-I)) in vitro and 3) Study the effects of inflammation. STUDY DESIGN In vitro experiments. METHODS Haematopoietic stem cells, from 5 equine sternal bone marrow aspirates, were differentiated into osteoclasts and cultured either alone or on equine bone slices, with or without pro-inflammatory stimulus (IL-1β or LPS). CTX-I and TRACP-5b were immunoassayed in the media. Osteoclast numbers and bone resorption area were assessed. RESULTS TRACP-5b increased over time without bone (p < 0.0001) and correlated with osteoclast number (r = 0.63, p < 0.001). CTX-I and TRACP-5b increased with time for cultures with bone (p = 0.002; p = 0.02 respectively), correlated with each other (r = 0.64, p < 0.002) and correlated with bone resorption (r = 0.85, p < 0.001; r = 0.82, p < 0.001 respectively). Inflammation had no measurable effects. MAIN LIMITATIONS Specimen numbers limited. CONCLUSIONS Equine osteoclasts were successfully cultured on equine bone slices and their bone resorption quantified. TRACP-5b was shown to be a biomarker of equine osteoclast number and bone resorption for the first time; CTX-I was also confirmed to be a biomarker of equine bone resorption in vitro. This robust equine specific in vitro assay will help the study of osteoclast biology.
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Affiliation(s)
- Gwladys Malek
- Comparative Orthopaedic Research Laboratory, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, St-Hyacinthe, QC, Canada
| | - Hélène Richard
- Comparative Orthopaedic Research Laboratory, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, St-Hyacinthe, QC, Canada
| | - Guy Beauchamp
- Comparative Orthopaedic Research Laboratory, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, St-Hyacinthe, QC, Canada
| | - Sheila Laverty
- Comparative Orthopaedic Research Laboratory, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, St-Hyacinthe, QC, Canada
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12
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Marsiglia MF, Yamada ALM, Agreste FR, Rose Marques de Sá L, Nieman RT, Lopes Correia Silva LC. Morphological analysis of third metacarpus cartilage and subchondral bone in Thoroughbred racehorses: An ex vivo study. Anat Rec (Hoboken) 2022; 305:3385-3397. [PMID: 35338614 DOI: 10.1002/ar.24918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/24/2022] [Accepted: 03/07/2022] [Indexed: 11/05/2022]
Abstract
Racehorses are exposed to repetitive overload during training and competition, causing joint hyperextension, tissue fatigue, and ultimately skeletal failure. Some degree of bone changes, such as sclerosis, are expected in equine athletes, as adaptation to the biomechanical rigors of training and racing. Understanding the imaging characteristics of the equine joint surface and subchondral bone would allow earlier detection of injuries or adaptation, improving prognosis and training programs. This study sought to describe the joint surface structural patterns and the periarticular structures of the third metacarpal bone (MC3). Both forelimbs of eight horses engaged in daily training programs, aged 3 to 5 years, which were euthanized for reasons unrelated to the metacarpophalangeal (MCP) joints, were collected. Specimens were evaluated through macroscopic inspection, radiography, ultrasonography, and microscopic examinations, such as optical microscopy and microtomography. Analysis of the microtomography images showed that 50% of the samples had higher trabecular thickness in the lateral condyle. Comparison of each imaging examination revealed that ultrasound images were most closely related to the histological examination (p = 0.29) in terms of sensitivity, while macroscopic and radiographic examinations differed most between evaluators. Finally, the irregularities and modifications observed in the articular cartilage surface and subchondral bone were normal adaptations of the anatomical structures of trained racehorses, which should be considered during clinical examination.
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13
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Palmer AL, Rogers CW, Stafford KJ, Gal A, Bolwell CF. Risk-Factors for Soft-Tissue Injuries, Lacerations and Fractures During Racing in Greyhounds in New Zealand. Front Vet Sci 2021; 8:737146. [PMID: 34926634 PMCID: PMC8678076 DOI: 10.3389/fvets.2021.737146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 11/05/2021] [Indexed: 11/13/2022] Open
Abstract
Recognition of injuries in racing animals is essential to identify potential risk factors so actions can be taken to reduce or mitigate the cause of the injury to safeguard the animal. Racing greyhounds are subject to musculoskeletal injuries associated with athletic pursuit, in particular soft-tissue injuries, lacerations, and fractures. The objective of this study was therefore to determine risk factors for soft-tissue injuries, lacerations and fractures occurring during racing, using a cohort of greyhounds racing in New Zealand between 10th September 2014 and 31st July 2020. Dog-level, race-level and track-level risk factors for each outcome were assessed using mixed-effects multivariable logistic regression including trainer as a random effect. Throughout the study period there were 218,700 race starts by 4,914 greyhounds, with a total of 4,385 injuries. Of these, 3,067 (69.94%) were classed as soft-tissue injuries, 641 (14.62%) were reported as lacerations, and 458 (10.44%) were fractures. Greyhounds with a low racing frequency (racing more than 7 days apart) had 1.33 [95% confidence interval (CI): 1.06-1.67] times the odds of fracture compared to those racing more frequently. Older greyhounds had a greater odds of fracture compared with younger greyhounds. Racing every 7 days had a lower odds of soft-tissue injury compared with racing more than once a week. Dogs over 39 months had 1.53 (95% CI: 1.35-1.73) times the odds of sustaining a soft-tissue injury compared to the younger dogs. Greyhounds originating from Australia had a higher odds of fracture and laceration compared with New Zealand dogs. Better performing dogs (higher class) had a greater odds of fracture and laceration whilst maiden dogs had a higher odds of soft-tissue injury. Greyhounds starting from the outside box had a higher odds of fracture. There was considerable variation in the odds of soft-tissue injury at different racetracks. In conclusion, although the incidence of soft-tissue injuries was higher than other injury types, the repercussion of such injuries was less than those for fractures. The results from this study will help to inform intervention strategies aimed at reducing the rate of injuries in racing greyhounds, enhancing racing safety and greyhound welfare.
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Affiliation(s)
- Anna L Palmer
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Chris W Rogers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand.,School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Kevin J Stafford
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Arnon Gal
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Charlotte F Bolwell
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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14
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Crawford KL, Finnane A, Greer RM, Barnes TS, Phillips CJC, Woldeyohannes SM, Bishop EL, Perkins NR, Ahern BJ. Survival Analysis of Training Methodologies and Other Risk Factors for Musculoskeletal Injury in 2-Year-Old Thoroughbred Racehorses in Queensland, Australia. Front Vet Sci 2021; 8:698298. [PMID: 34796223 PMCID: PMC8593238 DOI: 10.3389/fvets.2021.698298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Musculoskeletal injuries remain a global problem for the Thoroughbred racing industry and there is conflicting evidence regarding the effect of age on the incidence of injuries. The ideal time to commence race training is strongly debated, with limited supporting literature. There is also conflicting evidence regarding the effect of high-speed exercise on musculoskeletal injuries. There is a strong interest in developing training and management strategies to reduce the frequency of injuries. The types of musculoskeletal injuries vary between 2-year-old and older horses, with dorsal metacarpal disease the most common injury in 2-year-old horses. It is likely that risk factors for injury in 2-year-old horses are different than those for older horses. It is also likely that the risk factors may vary between types of injury. This study aimed to determine the risk factors for musculoskeletal injuries and dorsal metacarpal disease. We report the findings of a large scale, prospective observational study of 2-year-old horses in Queensland, Australia. Data were collected weekly for 56-weeks, from 26 trainers, involving 535 2-year-old Thoroughbred racehorses, 1, 258 training preparations and 7, 512-weeks of exercise data. A causal approach was used to develop our statistical models, to build on the existing literature surrounding injury risk, by incorporating the previously established causal links into our analyses. Where previous data were not available, industry experts were consulted. Survival analyses were performed using Cox proportional hazards or Weibull regression models. Analysis of musculoskeletal injuries overall revealed the hazard was reduced with increased exposure to high-speed exercise [Hazard ratio (HR) 0.89, 95% Confidence Interval (CI) 0.84, 0.94, p < 0.001], increased number of training preparations (HR 0.58, 95% CI 0.50, 0.67, p < 0.001), increased rest before the training preparation (HR 0.89, 95% CI 0.83, 0.96, p = 0.003) and increased dam parity (HR 0.86, 95% CI 0.77, 0.97, p = 0.01). The hazard of injury was increased with increasing age that training commenced (HR 1.13, 95% CI 1.06, 1.19, p < 0.001). Analyses were then repeated with the outcome of interest dorsal metacarpal disease. Factors that were protective against dorsal metacarpal disease and musculoskeletal injuries overall included: increased total cumulative distance (HR 0.89, 95% CI 0.82, 0.97, p = 0.001) and total cumulative days exercised as a gallop (HR 0.96, 95% CI 0.92, 0.99, p = 0.03), the number of the training preparations (HR 0.43, 95% CI 0.30, 0.61, p < 0.001). The age that training commenced was harmful for both dorsal metacarpal disease (HR 1.17, 95% CI 1.07, 1.28, p < 0.001 and overall musculoskeletal injuries.). The use of non-ridden training modalities was protective for dorsal metacarpal disease (HR 0.89, 95% CI 0.81, 0.97, p = 0.008), but not musculoskeletal injuries overall. The male sex increased the hazard of DMD compared to females (HR 2.58, 95% CI 1.20, 5.56, p = 0.02), but not MSI overall. In summary, the hazard of musculoskeletal injury is greatest for 2-year-old horses that are born from uniparous mares, commence training at a later age, are in their first training preparation, have undertaken little high-speed exercise or had limited rest before their training preparation. The hazard of dorsal metacarpal disease is greatest for 2-year-old horses that are males, commence training at a later age, are in their first training preparation, have undertaken little high-speed exercise or had limited use of non-ridden training modalities. Close monitoring of these high-risk horses during their training program could substantially reduce the impact of MSI. Furthermore, an understanding of how training methodologies affect the hazard of MSI facilitates modification of training programs to mitigate the risk impact of injury. The strengths of this study include a large sample size, a well-defined study protocol and direct trainer interviews. The main limitation is the inherent susceptibility to survival bias.
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Affiliation(s)
- Kylie L Crawford
- School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.,School of Public Health, The University of Queensland, Herston, QLD, Australia
| | - Anna Finnane
- School of Public Health, The University of Queensland, Herston, QLD, Australia
| | - Ristan M Greer
- Torus Research, Bridgeman Downs, QLD, Australia.,Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Tamsin S Barnes
- School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.,Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Gatton, QLD, Australia
| | - Clive J C Phillips
- Curtin University Sustainability Policy (CUSP) Institute, Curtin University, Perth, WA, Australia
| | | | - Emma L Bishop
- Garrards Equine Veterinary Practice, Albion, QLD, Australia
| | - Nigel R Perkins
- School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia
| | - Benjamin J Ahern
- School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia
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15
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Fortin-Trahan R, Lemirre T, Santschi EM, Janes JG, Richard H, Fogarty U, Beauchamp G, Girard CA, Laverty S. Osteoclast density is not increased in bone adjacent to radiolucencies (cysts) in juvenile equine medial femoral condyles. Equine Vet J 2021; 54:989-998. [PMID: 34716940 DOI: 10.1111/evj.13530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/02/2021] [Accepted: 10/18/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND There is a knowledge gap about how equine MFC subchondral radiolucencies (SR) arise and evolve. Osteoclasts are believed to have a role but have not been studied in situ. OBJECTIVES To measure and compare osteoclast density and the percentage of chondroclasts in healthy and MFC SR specimens from juvenile Thoroughbreds. STUDY DESIGN Cadaveric study. METHODS Medial femoral condyles (MFC) from a tissue bank of equine stifles were studied. Inclusion criteria were MFCs (≤8 months old) with a computed tomography SR lesion and histological focal failure of endochondral ossification (L group). Contralateral, lesion-free, MFCs were a control group (CC). Osteochondral slabs were cut through the lesion (L), a healthy site immediately caudal to the lesion, (internal control; IC) and the contralateral, site-matched controls (CC). Histological sections were immunostained with Cathepsin K for osteoclast counting. Osteoclasts in contact with the growth cartilage (chondroclasts) were also counted. The sections were segmented into regions of interest (ROI) at different depths in the subchondral bone: ROI1 (0-1 mm), ROI2 (1-3 mm) and ROI3 (3-6 mm). Osteoclasts were counted and the bone area was measured in each ROI to calculate their density. Chondroclasts were counted in ROI1 . RESULTS Sections were studied from L and IC (n = 6) and CC sites (n = 5). Osteoclast density was significantly higher in ROI1 when compared with ROI3 in all groups. Although higher osteoclast density was measured in ROI1 in the L group, no significant differences were detected when compared with control ROIs. The proportion of chondroclasts in ROI1 was lower in the L sections when compared with controls but no significant differences were detected. MAIN LIMITATIONS Limited sample size. CONCLUSIONS Osteoclasts are important actors in MFC subchondral bone development, digesting both growth cartilage (chondroclasts) and bone, but the pathophysiology of early MFC SRs cannot be explained solely by an increased osteoclast presence in the subchondral bone.
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Affiliation(s)
- Rosalie Fortin-Trahan
- Comparative Orthopaedic Research Laboratory, Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Thibaut Lemirre
- Comparative Orthopaedic Research Laboratory, Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Elizabeth M Santschi
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA
| | - Jennifer G Janes
- Department of Veterinary Science, University of Kentucky, Lexington, Kentucky, USA
| | - Hélène Richard
- Comparative Orthopaedic Research Laboratory, Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | | | - Guy Beauchamp
- Comparative Orthopaedic Research Laboratory, Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Christiane A Girard
- Comparative Orthopaedic Research Laboratory, Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Sheila Laverty
- Comparative Orthopaedic Research Laboratory, Département de Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
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16
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Abstract
This review describes results obtained with tissue from prior studies of equine and human osteoarthritis (OA). The main methods considered are scanning electron microscopy, novel methods in light microscopy and X-ray Micro-tomography. The same samples have been re-utilised in several ways. The tissues described are hyaline articular cartilage (HAC; or substitutes), with its deep layer, articular calcified cartilage (ACC), whose deep surface is resorbed in cutting cone events to allow the deposition of subchondral bone (SCB). Multiple tidemarks are normal. Turnover at the osteochondral (ACC-HAC-SCB) junction is downregulated by overload exercise, conversely, during rest periods. Consequent lack of support predisposes to microfracture of the ACC-SCB plate, in the resorption-related repair phase of which the plate is further undermined to form sink holes. The following characteristics contribute to the OA scenario: penetrating resorption canals and local loss of ACC; cracking of ACC and SCB; sealing of cracks with High-Density Mineral Infill (HDMI); extrusion of HDMI into HAC to form High-Density Mineral Protrusions (HDMP) in HAC which may fragment and contribute to its destruction; SCB marrow space infilling and densification with (at first) woven bone; disruption, fibrillation and loss of HAC; eburnation; repair with abnormal tissues including fibrocartilage and woven bone; attachment of Sharpey fibres to SCB trabeculae and adipocyte-moulded extensions to trabeculae (excrescences).
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Affiliation(s)
- Alan Boyde
- Dental Physical Sciences Imaging Unit, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Campus, London, E1 4NS, UK.
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17
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A Prospective Study of Training Methods for Two-Year-Old Thoroughbred Racehorses in Queensland, Australia, and Analysis of the Differences in Training Methods between Trainers of Varying Stable Sizes. Animals (Basel) 2021; 11:ani11040928. [PMID: 33805873 PMCID: PMC8064321 DOI: 10.3390/ani11040928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Musculoskeletal injuries present significant concerns for the global Thoroughbred racing industry. The development of training and management strategies to reduce injuries has been challenging due to conflicting findings about the risk factors for injury, and limited understanding of the role of different training methodologies. There is little published data on patterns of rest periods and exercise data and how these vary between trainers and between different racing jurisdictions. We describe training methodologies for 535 two-year-old horses providing 1258 training preparations and 7512 weeks of exercise. We investigated the variation in training methodologies between trainers from small, medium and large stable sizes. Significant differences were observed between trainers, with horses from larger stables accumulating a greater high-speed exercise volume, attaining training milestones more frequently and taking less time to reach their training milestones. We also highlight similarities and differences in training methods used in Queensland, Australia, and those previously reported from other geographic locations. A better understanding of training methods is an essential step towards reducing the impact of injuries. Abstract Worldwide, musculoskeletal injuries remain a major problem for the Thoroughbred racing industry. There is a strong interest in developing training and management strategies to reduce the impact of musculoskeletal injuries, however, progress has been limited by studies reporting conflicting findings, and a limited understanding of the role of different training methods in preventing injury. There is little data on patterns of rest periods and exercise data and how these vary between trainers. This prospective study of two-year-old racehorses was conducted in Queensland, Australia and involved weekly personal structured interviews with 26 trainers over 56 weeks. Detailed daily exercise data for 535 horses providing 1258 training preparations and 7512 weeks at risk were collected. Trainers were categorised into three groups by the mean number of two-year-old horses that they had in work each week over the study duration: (1) Small stables with five or less, (2) Medium stables with 6 to 15 and (3) Large stables with greater than 15 horses in training. Differences between trainers with small, medium and large stable sizes were evaluated using linear regression, Kruskal–Wallis equality-of-populations rank test if linear models were mis-specified or Chi-squared tests for categorical variables. Significant differences were observed between trainers, with horses from larger stables accumulating a greater high-speed exercise volume (p < 0.001), attaining training milestones more frequently (p = 0.01) and taking less time to reach their training milestones (p = 0.001). This study provides detailed data to which training practices from other locations can be compared. Presenting actual training data rather than trainers’ estimation of a typical program provides a more accurate assessment of training practices. Understanding how training practices vary between regions improves comparability of studies investigating risk factors and is an important step towards reducing the impact of musculoskeletal injuries.
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18
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Crawford KL, Finnane A, Phillips CJC, Greer RM, Woldeyohannes SM, Perkins NR, Kidd LJ, Ahern BJ. The Risk Factors for Musculoskeletal Injuries in Thoroughbred Racehorses in Queensland, Australia: How These Vary for Two-Year-Old and Older Horses and with Type of Injury. Animals (Basel) 2021; 11:ani11020270. [PMID: 33494508 PMCID: PMC7910838 DOI: 10.3390/ani11020270] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/08/2021] [Accepted: 01/18/2021] [Indexed: 11/25/2022] Open
Abstract
Simple Summary Musculoskeletal injuries (MSI) continue to affect Thoroughbred racehorses internationally, despite over thirty years of research into this problem. Studies of risk factors for musculoskeletal injuries report inconsistent findings. Consequently, developing training strategies to mitigate the risk of MSI is difficult. We identified factors associated with particularly high odds of injury in this population of racehorses. Two-year-old horses from primiparous mares (first foals born) are at increased odds of MSI, particularly dorsal metacarpal disease (“shinsoreness”). Two-year-old horses that have had a total preparation length of between 10 and 14 weeks also have increased odds of injury. Horses of all ages that travelled a total distance of 2.4–3.8 km (12–19 furlongs) at a gallop (faster than 15 m/s; 13 s/furlong; 900 m/min; 55 km/h) in the last four weeks and horses three years and older that travelled 3.0–4.8 km (15–24 furlongs) at three-quarter pace and above (faster than 13 m/s; 15 s/furlong; 800 m/min; 48 km/h) also have increased odds of injury. We recommend that these horses should be monitored closely for impending signs of injury. We also observed a non-linear relationship between high-speed exercise and musculoskeletal injuries. This highlights the importance of high-speed exercise to enable tissue adaptation to training. Finally, in some situations, increasing the number of days worked at a slow pace may be more effective for preventing MSI, if horses are perceived at a higher risk, than resting the horse altogether. Early identification of horses at increased risk of injury and appropriate intervention could substantially reduce the impact of musculoskeletal injuries in Thoroughbred racehorses. Abstract Musculoskeletal injuries (MSI) continue to affect Thoroughbred racehorses internationally. There is a strong interest in developing training and management strategies to reduce their impact, however, studies of risk factors report inconsistent findings. Furthermore, many injuries and fatalities occur during training rather than during racing, yet most studies report racing data only. By combining racing and training data a larger exposure to risk factors and a larger number of musculoskeletal injuries are captured and the true effect of risk factors may be more accurately represented. Furthermore, modifications to reduce the impact of MSI are more readily implemented at the training level. Our study aimed to: (1) determine the risk factors for musculoskeletal injuries and whether these are different for two-year-old and older horses and (2) determine whether risk factors vary with type of injury. This was performed by repeating analyses by age category and injury type. Data from 202 cases and 202 matched controls were collected through weekly interviews with trainers and analysed using conditional logistic regression. Increasing dam parity significantly reduced the odds of injury in horses of all age groups because of the effect in two-year-old horses (odds ratio (OR) 0.08; 95% confidence interval (CI) 0.02, 0.36; p < 0.001). Increasing total preparation length is associated with higher odds of injury in horses of all ages (OR 5.56; 95% CI 1.59, 19.46; p = 0.01), but particularly in two-year-old horses (OR 8.05; 95% CI 1.92, 33.76; p = 0.004). Increasing number of days exercised at a slow pace decreased the odds of injury in horses of all ages (OR 0.09; 95% CI 0.03, 0.28; p < 0.001). The distance travelled at three-quarter pace and above (faster than 13 m/s; 15 s/furlong; 800 m/min; 48 km/h) and the total distance travelled at a gallop (faster than 15 m/s; 13 s/furlong; 900 m/min; 55 km/h) in the past four weeks significantly affected the odds of injury. There was a non-linear association between high-speed exercise and injury whereby the odds of injury initially increased and subsequently decreased as accumulated high-speed exercise distance increased. None of the racing career and performance indices affected the odds of injury. We identified horses in this population that have particularly high odds of injury. Two-year-old horses from primiparous mares are at increased odds of injury, particularly dorsal metacarpal disease. Two-year-old horses that have had a total preparation length of between 10 and 14 weeks also have increased odds of injury. Horses of all ages that travelled a total distance of 2.4–3.8 km (12–19 furlongs) at a gallop in the last four weeks and horses three years and older that travelled 3.0–4.8 km (15–24 furlongs) at three-quarter pace and above also have increased odds of injury. We recommend that these horses should be monitored closely for impending signs of injury. Increasing the number of days worked at a slow pace may be more effective for preventing injury, if horses are perceived at a higher risk, than resting the horse altogether. Early identification of horses at increased risk and appropriate intervention could substantially reduce the impact of musculoskeletal injuries in Thoroughbred racehorses.
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Affiliation(s)
- Kylie L. Crawford
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (L.J.K.); (B.J.A.)
- School of Public Health, The University of Queensland, Herston 4006, Australia;
- Correspondence:
| | - Anna Finnane
- School of Public Health, The University of Queensland, Herston 4006, Australia;
| | - Clive J. C. Phillips
- Curtin University Sustainability Policy (CUSP) Institute, Curtin University, Perth 6845, Australia;
| | - Ristan M. Greer
- Torus Research, Bridgeman Downs 4035, Australia;
- School of Medicine, The University of Queensland, Herston 4006, Australia
| | - Solomon M. Woldeyohannes
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (L.J.K.); (B.J.A.)
| | - Nigel R. Perkins
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (L.J.K.); (B.J.A.)
| | - Lisa J. Kidd
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (L.J.K.); (B.J.A.)
| | - Benjamin J. Ahern
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (L.J.K.); (B.J.A.)
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Crawford KL, Finnane A, Greer RM, Phillips CJC, Woldeyohannes SM, Perkins NR, Ahern BJ. Appraising the Welfare of Thoroughbred Racehorses in Training in Queensland, Australia: The Incidence, Risk Factors and Outcomes for Horses after Retirement from Racing. Animals (Basel) 2021; 11:ani11010142. [PMID: 33440666 PMCID: PMC7827103 DOI: 10.3390/ani11010142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/29/2020] [Accepted: 01/07/2021] [Indexed: 11/16/2022] Open
Abstract
There is international public concern regarding retirement of racehorses, including the reason for retirement and the outcome for horses after racing. However, there are currently no prospective studies investigating these factors. A recent independent inquiry in Queensland, Australia, highlighted that the true outcomes for horses after retirement from racing are largely unknown. Furthermore, there are currently no measures to monitor the outcome for racehorses and their welfare once they have left the care of the trainer. This study investigated these gaps in knowledge through a weekly survey conducted over a 13-month period. We aimed to evaluate: (1) the incidence of retirement, (2) the reasons and risk factors for retirement and (3) the medium-term (greater than 6 months) outcomes for horses after retirement. Data were collected through personal structured weekly interviews with participating trainers and analysed using negative binomial and logistic regression. There was a low incidence of retirements, namely 0.4% of horses in training per week. The season and training track did not affect the incidence of retirement. Musculoskeletal injuries were the most common reason for retirement (40/110 horses, 36%). Involuntary retirements accounted for 56/100 (51%) of retirements, whereby musculoskeletal injuries, respiratory or cardiac conditions and behavioural problems prevented the horse from racing The odds of voluntary retirement, whereby the horse was retired due to racing form or impending injury, increased with each additional race start (OR 1.05; p = 0.01) and start/year of racing (OR 1.21; p = 0.03) but decreased with increasing percentage of first, second and third places (OR 0.94; p < 0.001). Medium-term follow-up (median 14 months, IQR 11, 18, range 8-21) revealed that most horses (108/110; 98%) were repurposed after retirement, almost half as performance horses (50/110; 46%). Horses that voluntarily retired had 2.28 times the odds of being repurposed as performance horses than those retired involuntarily (p = 0.03). Whether retirement was voluntary or involuntary did not influence whether horses were used for breeding or pleasure. The primary limitation of this study is that our results reflect retirement in racehorses in South East Queensland, Australia, and may not be globally applicable. Furthermore, we were unable to monitor the long-term outcome and welfare of horses in their new careers. It is vital that the industry is focused on understanding the risks for voluntary rather than involuntary retirement and optimising the long-term repurposing of horses. There is a need for traceability and accountability for these horses to ensure that their welfare is maintained in their new careers.
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Affiliation(s)
- Kylie L. Crawford
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
- School of Public Health, The University of Queensland, Herston 4006, Australia;
- Correspondence:
| | - Anna Finnane
- School of Public Health, The University of Queensland, Herston 4006, Australia;
| | - Ristan M. Greer
- Torus Research, Bridgeman Downs 4035, Australia;
- School of Medicine, The University of Queensland, Herston 4006, Australia
| | - Clive J. C. Phillips
- Curtin University Sustainability Policy (CUSP) Institute, Curtin University, Perth 6845, Australia;
| | - Solomon M. Woldeyohannes
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
| | - Nigel R. Perkins
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
| | - Benjamin J. Ahern
- School of Veterinary Science, The University of Queensland, Gatton 4343, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
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Ayodele BA, Hitchens PL, Wong ASM, Mackie EJ, Whitton RC. Microstructural properties of the proximal sesamoid bones of Thoroughbred racehorses in training. Equine Vet J 2020; 53:1169-1177. [PMID: 33244781 DOI: 10.1111/evj.13394] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/14/2020] [Accepted: 11/19/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND Proximal sesamoid bone fractures are common catastrophic injuries in racehorses. Understanding the response of proximal sesamoid bones to race training can inform fracture prevention strategies. OBJECTIVES To describe proximal sesamoid bone microstructure of racehorses and to investigate the associations between microstructure and racing histories. STUDY DESIGN Cross-sectional. METHODS Proximal sesamoid bones from 63 Thoroughbred racehorses were imaged using micro-computed tomography. Bone volume fraction (BVTV) and bone material density (BMD) of the whole bone and four regions (apical, midbody dorsal, midbody palmar and basilar) were determined. Generalised linear regression models were used to identify the associations between bone parameters and race histories of the horses. RESULTS The mean sesamoid BVTV was 0.79 ± 0.08 and BMD was 806.02 ± 24.66 mg HA/ccm. BVTV was greater in medial sesamoids compared with lateral sesamoids (0.80 ± 0.07 vs 0.79 ± 0.08; P < .001) predominantly due to differences in the apical region (medial-0.76 ± 0.08 vs lateral-0.72 ± 0.07; P < .001). BVTV in the midbody dorsal region (0.86 ± 0.06) was greater than other regions (midbody palmar-0.79 ± 0.07, basilar-0.78 ± 0.06 and apical-0.74 ± 0.08; P < .001). BVTV was greater in sesamoids with more microcracks on their articular surface (Coef. 0.005; 95% CI 0.001, 0.009; P = .01), greater extent of bone resorption on their abaxial surface (Grade 2-0.82 ± 0.05 vs Grade 1-0.80 ± 0.05 or Grade 0-0.79 ± 0.06; P = .006), in horses with a low (0.82 ± 0.07) or mid handicap rating (0.78 ± 0.08) compared with high rating (0.76 ± 0.07; P < .001), in 2- to 5-year-old horses (0.81 ± 0.07) compared with younger (0.68 ± 0.08) or older horses (0.77 ± 0.08; P < .001) and in horses that commenced their racing career at less than 4 years of age (0.79 ± 0.08 vs 0.77 ± 0.77; P < .001). BMD was greater in the midbody dorsal (828.6 ± 19.6 mg HA/ccm) compared with other regions (apical-805.8 ± 21.8, midbody palmar-804.7 ± 18.4 and basilar-785.0 ± 17.1; P < .001), in horses with a handicap rating (low-812.1 ± 20.0, mid-821.8 ± 21.3 and high-814.6 ± 19.4) compared with those with no rating (791.08 ± 24.4, P < .001), in females (806.7 ± 22.0) and geldings (812.2 ± 22.4) compared with entires (792.7 ± 26.2; P = .02) and in older horses (<2-year-old-763.7 ± 24.8 vs 2- to 5-year-old-802.7 ± 23.4, and 6- to 12-year-old-817.8 ± 20.0; P = .002). MAIN LIMITATIONS Data were cross-sectional. CONCLUSIONS Densification of the proximal sesamoid bones is associated with the commencement of racing in younger horses and the presence of bone fatigue-related pathology. Lower sesamoid BVTV was associated with longevity and better performance.
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Affiliation(s)
- Babatunde A Ayodele
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Peta L Hitchens
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Adelene S M Wong
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Eleanor J Mackie
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - R Christopher Whitton
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, VIC, Australia
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Crawford KL, Finnane A, Greer RM, Phillips CJC, Woldeyohannes SM, Perkins NR, Ahern BJ. Appraising the Welfare of Thoroughbred Racehorses in Training in Queensland, Australia: The Incidence and Type of Musculoskeletal Injuries Vary between Two-Year-Old and Older Thoroughbred Racehorses. Animals (Basel) 2020; 10:ani10112046. [PMID: 33167429 PMCID: PMC7694396 DOI: 10.3390/ani10112046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Musculoskeletal injuries (MSI) remain a concerning cause of racehorse morbidity and mortality with serious ethical and welfare consequences. Previous research examining risk factors for injuries report inconsistent findings. Age is thought to affect the risk of injury, but, to date, there have been no prospective studies specifically comparing injuries between two-year-old versus older horses. We aimed to: (1) determine the incidence of injuries for two-year-old and older horses, and whether this was affected by training track, season, or rainfall, and (2) determine the types of injuries affecting two-year-old and older horses, and whether horses trialled or raced after injury. Data were collected through personal structured weekly interviews with participating trainers over a 13-month period. Data were analysed using Poisson regression. The incidence of MSI in the current study was low (0.6%). The incidence of MSI in two-year-old horses was higher than older horses. Types of MSI varied between two-year-old and older horses and affected whether horses subsequently trialled or raced from 11 to 23 months after injury. A larger proportion of two-year-old horses had dorsal metacarpal disease and traumatic lacerations. A smaller proportion of two-year-old horses had suspensory desmitis, superficial digital flexor tendonitis, proximal sesamoid bone fractures, and fetlock joint injuries than older horses. Training track and rainfall did not affect the incidence of injuries. The season affected the incidence of injuries in two-year-old horses but not in older horses. Abstract Musculoskeletal injuries (MSI) remain a concerning cause of racehorse morbidity and mortality with important ethical and welfare consequences. Previous research examining risk factors for MSI report inconsistent findings. Age is thought to affect MSI risk, but, to date, there have been no prospective studies comparing MSI in two-year-old versus older horses. This study aimed to: (1) determine the incidence of MSI for two-year-old and older horses, and whether this was affected by training track, season, or rainfall, and (2) determine the types of MSI affecting two-year-old and older horses, and whether horses trialled or raced after injury. A prospective survey was conducted with data collected through personal structured weekly interviews with participating trainers over a 13-month period. Data were analysed using Poisson regression. The incidence of MSI in the current study was low (0.6%). The incidence of MSI in two-year-old horses was higher than older horses (p < 0.001). Types of MSI varied between two-year-old and older horses (p < 0.001) and affected whether horses subsequently trailed or raced from 11 to 23 months after injury (p < 0.001). A larger proportion of two-year-old horses had dorsal metacarpal disease and traumatic lacerations. A smaller proportion of two-year-old horses had suspensory ligament desmitis, superficial digital flexor tendonitis, proximal sesamoid bone fractures, and fetlock joint injuries than older horses. Training track and rainfall did not affect MSI. The season affected MSI in two-year-old horses (p < 0.001) but not older horses. The major limitation was that trainers in this study were metropolitan (city) and our findings may not be generalisable to racehorses in regional (country) areas. Another significant limitation was the assumption that MSI was the reason for failure to trial or race after injury. In conclusion, the incidence of MSI was low in the current study and the types and the risk factors for MSI are different for two-year-old and older horses.
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Affiliation(s)
- Kylie L. Crawford
- School of Veterinary Science, The University of Queensland, 4343 Gatton, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
- School of Public Health, The University of Queensland, 4006 Herston, Australia;
- Correspondence:
| | - Anna Finnane
- School of Public Health, The University of Queensland, 4006 Herston, Australia;
| | - Ristan M. Greer
- Torus Research, 4035 Bridgeman Downs, Australia;
- School of Medicine, The University of Queensland, 4006 Herston, Australia
| | - Clive J. C. Phillips
- Curtin University Sustainability Policy (CUSP) Institute, Curtin University, 6845 Perth, Australia;
| | - Solomon M. Woldeyohannes
- School of Veterinary Science, The University of Queensland, 4343 Gatton, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
| | - Nigel R. Perkins
- School of Veterinary Science, The University of Queensland, 4343 Gatton, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
| | - Benjamin J. Ahern
- School of Veterinary Science, The University of Queensland, 4343 Gatton, Australia; (S.M.W.); (N.R.P.); (B.J.A.)
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Basran PS, Gao J, Palmer S, Reesink HL. A radiomics platform for computing imaging features from µCT images of Thoroughbred racehorse proximal sesamoid bones: Benchmark performance and evaluation. Equine Vet J 2020; 53:277-286. [PMID: 32654167 DOI: 10.1111/evj.13321] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/08/2020] [Accepted: 07/02/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND Proximal sesamoid bone (PSB) fractures are the most common fatal musculoskeletal injury in North American racehorses. Computed tomography has the potential to detect morphological changes in bone structure but can be challenging to analyse reliably and quantitatively. OBJECTIVES To develop a radiomics platform that allows the comparison of features from micro-CTs (µCT) of PSBs in horses that sustained catastrophic fractures with horses that did not. To compare features calculated with a radiomics approach with features calculated from a previously published study that used quantitative µCT in the same specimens. STUDY DESIGN Retrospective study of cadaver specimens of µCT images of PSBs using prospectively applied radiomics. METHODS Radiomics features were computed on standardised CT datasets to benchmark the software. Features from µCT images of PSBs from eight horses that sustained PSB fracture and eight controls were computed using the contralateral, intact forelimb from horses sustaining PSB fracture (cases, n = 19) and all available forelimbs for controls (n = 30). Two-hundred and fifteen radiomic features were calculated, and similar or comparable features were compared with those reported in a previous study that used the same specimens. RESULTS Morphologic features computed with the radiomics approach, such as volume, minor axis dimensions and anisotropy were highly correlated with previously published data. A high number of imperceptible radiomic features, such as entropy, coarseness and histogram features were also found to be significantly different (P < .01). The extent of the differences in image features for the cases and controls PSBs depends on radiomic calculation settings. MAIN LIMITATIONS Only datasets obtained from cadaver specimens were included in the study. CONCLUSIONS A radiomics approach for analysing µCT images of PSBs was able to identify and reproduce differences in image features in cases and controls. Furthermore, radiomics revealed many more imperceptible image features between cases and control PSBs.
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Affiliation(s)
| | - Jonathan Gao
- Clinical Sciences, Cornell University, Ithaca, NY, USA
| | - Scott Palmer
- Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Heidi L Reesink
- Clinical Sciences, Cornell University, Ithaca, NY, USA.,Equine and Farm Animal Hospital, Cornell University, Ithaca, NY, USA
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Distribution of mechanical strain in equine distal metacarpal subchondral bone: A microCT-based finite element model. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2020. [DOI: 10.1016/j.medntd.2020.100036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Thoroughbred Racehorse Welfare through the Lens of ‘Social License to Operate—With an Emphasis on a U.S. Perspective. SUSTAINABILITY 2020. [DOI: 10.3390/su12051706] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review addresses the question of whether Thoroughbred horse racing is sustainable in the context of current social values. A recently acknowledged framework, known as ‘Social License to Operate’ (SLO), provides us with a lens through which to view and assess racehorse welfare. In multiple surveys of the general public, the horse owning public, and university students, the primary topics of concern regarding Thoroughbred racing show considerable concordance: concern about catastrophic injuries—particularly as related to track surfaces, concern over the racing of two-year-olds, whip use by jockeys, drug/medication policies, and aftercare opportunities for retired Thoroughbred racehorses. Legitimacy of an industry, consent from industry stakeholders, and trust between the community players, are all essential to have and maintain SLO. In the current era of 24/7 global media access, and the proliferation of social media providing an interactive platform for all interested parties, a dramatic change has occurred in commentary related to racehorse welfare concerns. The situation at Santa Anita (California, USA) from late December 2018 through mid-November 2019 demonstrated just how tenuous the SLO for horse racing is. This article will provide a brief review of what ‘Social License to Operate’ is, along with a brief literature review of five of the areas of primary concern voiced by stakeholders.
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Gilday R, Richard H, Beauchamp G, Fogarty U, Laverty S. Abundant osteoclasts in the subchondral bone of the juvenile Thoroughbred metacarpus suggest an important role in joint maturation. Equine Vet J 2020; 52:733-742. [PMID: 31972056 DOI: 10.1111/evj.13235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 12/12/2019] [Accepted: 01/11/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND The administration of bisphosphonate medications, which target osteoclastic-bone remodelling, to juvenile and adult racehorses is a matter of debate owing to concerns that these molecules remain bound to the bone-mineralised matrix and may interfere with subsequent bone growth, adaptation to exercise and healing of bone microdamage in equine athletes. Osteoclasts participate in endochondral ossification, subchondral bone remodelling and bone repair. There is a knowledge gap on the role of equine osteoclast biology in the growth and maturation of joint surfaces and this information is important to inform judicious bisphosphonate use. OBJECTIVES Measure and compare the osteoclast density in the subchondral bone of Thoroughbred (TB) distal third metacarpi (McIII) at different sites, varying depths from the articular surface and with age (0-84 months). STUDY DESIGN Ex vivo cadaveric study. METHODS McIIIs from foals, yearlings and adults were collected, fixed in formaldehyde and stored at 4°C. Sections were cut from the lateral hemi-metacarpus, stained and scored for cartilage degeneration. Osteoclasts were counted on immunohistochemically (Cathepsin K) stained sections. Osteoclast density was compared in regions of interest (ROIs-the sagittal ridge, axial and abaxial condyle) and also at two depths (0-3 mm and 3-6 mm) into the subchondral bone below the osteochondral junction. RESULTS The osteoclast density was consistently highest in the subchondral cortical bone plate (0-3 mm) when compared with the deeper trabecular bone in all age groups. Furthermore, the osteoclast density was significantly higher in juvenile Thoroughbreds (foals and yearlings) within both sites in the subchondral bone when compared with adults. MAIN LIMITATIONS The number of specimens available for study was restricted. CONCLUSIONS Osteoclasts are important in normal McIII epiphyseal and articular surface maturation and have a propensity to localise at the osteochondral junction and subchondral cortical bone plate zone in juvenile Thoroughbreds.
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Affiliation(s)
- Rebecca Gilday
- Comparative Orthopaedic Research Laboratory, Département des Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Hélène Richard
- Comparative Orthopaedic Research Laboratory, Département des Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | - Guy Beauchamp
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
| | | | - Sheila Laverty
- Comparative Orthopaedic Research Laboratory, Département des Sciences Cliniques, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, Quebec, Canada
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Martig S, Hitchens PL, Lee PVS, Whitton RC. The relationship between microstructure, stiffness and compressive fatigue life of equine subchondral bone. J Mech Behav Biomed Mater 2019; 101:103439. [PMID: 31557658 DOI: 10.1016/j.jmbbm.2019.103439] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 10/26/2022]
Abstract
Subchondral bone injuries often precede articular cartilage damage in osteoarthritis and are common in thoroughbred racehorses due to the accumulation of fatigue damage from high speed racing and training. Thus, racehorses provide a model to investigate the role of subchondral bone in joint disease. We assessed the association of horse and racing related factors and micro-CT based micromorphology of three separate subchondral bone layers with the initial stiffness and compressive fatigue life of bone plugs. Furthermore, we investigated three different definitions of fatigue failure of subchondral bone during compressive fatigue testing. Initial stiffness was 2,362 ± 443 MPa (mean ± standard deviation). Median compressive fatigue life during cyclic loading to -78 MPa was 16,879 (range 210 to 57,064). Subchondral bone stiffness increased over a median of 24% (range 3%-42%) of fatigue life to a maximum of 3,614 ± 635 MPa. Compressive fatigue life was positively associated with bone volume fraction in the deeper layers of subchondral bone, maximal stiffness, and the number of cycles to maximal stiffness. Initial stiffness was positively associated with tissue mineral density in the deeper layers and bone volume fraction in the superficial layer. Most specimens with a fatigue life of less than 5,500 cycles fractured grossly before reaching 30% reduction of maximal stiffness. Cycles to 10% reduction of maximal stiffness correlated strongly with cycles to lowest recorded stiffness at gross fracture and thus is a valid alternative failure definition for compressive fatigue testing of subchondral bone. Our results show that subchondral bone sclerosis as a result of high speed exercise and measured as bone volume fraction is positively associated with compressive fatigue life and thus has a protective effect on subchondral bone. Further research is required to reconcile this finding with the common collocation of fatigue damage in sclerotic subchondral bone of racehorses.
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Affiliation(s)
- Sandra Martig
- U-Vet Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Highway, Werribee, VIC, 3030, Australia.
| | - Peta L Hitchens
- U-Vet Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Highway, Werribee, VIC, 3030, Australia.
| | - Peter V S Lee
- Melbourne School of Engineering, Department of Biomedical Engineering, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - R Chris Whitton
- U-Vet Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Highway, Werribee, VIC, 3030, Australia.
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Malekipour F, Whitton CR, Lee PVS. Stiffness and energy dissipation across the superficial and deeper third metacarpal subchondral bone in Thoroughbred racehorses under high-rate compression. J Mech Behav Biomed Mater 2018; 85:51-56. [DOI: 10.1016/j.jmbbm.2018.05.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 05/16/2018] [Accepted: 05/21/2018] [Indexed: 11/15/2022]
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Wulster KB. Diagnosis of Skeletal Injury in the Sport Horse. Vet Clin North Am Equine Pract 2018; 34:193-213. [DOI: 10.1016/j.cveq.2018.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Anne-Archard N, Martel G, Fogarty U, Richard H, Beauchamp G, Laverty S. Differences in third metacarpal trabecular microarchitecture between the parasagittal groove and condyle at birth and in adult racehorses. Equine Vet J 2018; 51:115-122. [DOI: 10.1111/evj.12980] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 06/04/2018] [Indexed: 11/30/2022]
Affiliation(s)
- N. Anne-Archard
- Comparative Orthopaedic Research Laboratory; Département des Sciences Cliniques; Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe Quebec Canada
| | - G. Martel
- Comparative Orthopaedic Research Laboratory; Département des Sciences Cliniques; Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe Quebec Canada
| | - U. Fogarty
- Irish Equine Centre; Johnstown Co Kildare Ireland
| | - H. Richard
- Comparative Orthopaedic Research Laboratory; Département des Sciences Cliniques; Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe Quebec Canada
| | - G. Beauchamp
- Département de Pathologie et Microbiologie; Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe Quebec Canada
| | - S. Laverty
- Comparative Orthopaedic Research Laboratory; Département des Sciences Cliniques; Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe Quebec Canada
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Martig S, Hitchens PL, Stevenson MA, Whitton RC. Subchondral bone morphology in the metacarpus of racehorses in training changes with distance from the articular surface but not with age. J Anat 2018; 232:919-930. [PMID: 29446086 DOI: 10.1111/joa.12794] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2018] [Indexed: 02/04/2023] Open
Abstract
The repetitive large loads generated during high-speed training and racing commonly cause subchondral bone injuries in the metacarpal condyles of racehorses. Adaptive bone modelling leads to focal sclerosis at the site of highest loading in the palmar aspect of the metacarpal condyles. Information on whether and how adaptive modelling of subchondral bone changes during the career of a racehorse is sparse. The aim of this cross-sectional study was to describe the changes in subchondral bone micromorphology in the area of highest loading in the palmar aspect of the metacarpal condyle in thoroughbred racehorses as a function of age and training. Bone morphology parameters derived from micro-CT images were evaluated using principal component analysis and mixed-effects linear regression models. The largest differences in micromorphology were observed in untrained horses between the age of 16 and 20 months. Age and duration of a training period had no influence on tissue mineral density, bone volume fraction or number and area of closed pores to a depth of 5.1 mm from the articular surface in 2- to 4-year-old racehorses in training. Horses with subchondral bone injuries had more pores in cross-section compared with horses without subchondral bone injuries. Differences in bone volume fraction were due to the volume of less mineralised bone. Tissue mineral density increased and bone volume fraction decreased with increasing distance from the articular surface up to 5.1 mm from the articular surface. Further research is required to elucidate the biomechanical and pathophysiological consequences of these gradients of micromorphological parameters in the subchondral bone.
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Affiliation(s)
- Sandra Martig
- Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic., Australia
| | - Peta L Hitchens
- Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic., Australia
| | - Mark A Stevenson
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Vic., Australia
| | - R Chris Whitton
- Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic., Australia
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Hitchens PL, Pivonka P, Malekipour F, Whitton RC. Mathematical modelling of bone adaptation of the metacarpal subchondral bone in racehorses. Biomech Model Mechanobiol 2018; 17:877-890. [PMID: 29344755 DOI: 10.1007/s10237-017-0998-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 12/23/2017] [Indexed: 02/02/2023]
Abstract
In Thoroughbred racehorses, fractures of the distal limb are commonly catastrophic. Most of these fractures occur due to the accumulation of fatigue damage from repetitive loading, as evidenced by microdamage at the predilection sites for fracture. Adaptation of the bone in response to training loads is important for fatigue resistance. In order to better understand the mechanism of subchondral bone adaptation to its loading environment, we utilised a square root function defining the relationship between bone volume fraction [Formula: see text] and specific surface [Formula: see text] of the subchondral bone of the lateral condyles of the third metacarpal bone (MCIII) of the racehorse, and using this equation, developed a mathematical model of subchondral bone that adapts to loading conditions observed in vivo. The model is expressed as an ordinary differential equation incorporating a formation rate that is dependent on strain energy density. The loading conditions applied to a selected subchondral region, i.e. volume of interest, were estimated based on joint contact forces sustained by racehorses in training. For each of the initial conditions of [Formula: see text] we found no difference between subsequent homoeostatic [Formula: see text] at any given loading condition, but the time to reach equilibrium differed by initial [Formula: see text] and loading condition. We found that the observed values for [Formula: see text] from the mathematical model output were a good approximation to the existing data for racehorses in training or at rest. This model provides the basis for understanding the effect of changes to training strategies that may reduce the risk of racehorse injury.
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Affiliation(s)
- Peta L Hitchens
- Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, VIC, 3030, Australia.
| | - Peter Pivonka
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Fatemeh Malekipour
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, 3010, Australia
| | - R Chris Whitton
- Equine Centre, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, VIC, 3030, Australia
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32
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Janes JG, Kennedy LA, Garrett KS, Engiles JB. Common lesions of the distal end of the third metacarpal/metatarsal bone in racehorse catastrophic breakdown injuries. J Vet Diagn Invest 2017; 29:431-436. [PMID: 28681688 DOI: 10.1177/1040638717717948] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Equine catastrophic skeletal breakdown injury is a serious issue within the racing industry, given the impact on equine and human health. The metacarpo- and metatarso-phalangeal (fetlock) joints are common sites of catastrophic injury. However, lesions involving articular cartilage, subchondral bone, and synovium are commonly identified within the fetlock of the contralateral limb; hence, it is imperative that lesions in both limbs are evaluated and characterized during postmortem examination. Bone and articular cartilage changes typically occur in specific locations, related to cyclic fetlock load and overextension during high-speed exercise. Associations between preexisting degenerative fetlock lesions and catastrophic injury are a focus of continued research. These lesions often occur because of adaptive failure related to cumulative damage. Further investigation of these lesions is imperative to determine their impact on equine performance or injury. Ultimately, consistent documentation of catastrophic versus non-catastrophic osteochondral lesions provided by pathologists, in the context of training history, diagnostic imaging, and the presence or absence of catastrophic injury, will contribute to further understanding of skeletal responses associated with catastrophic failure.
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Affiliation(s)
- Jennifer G Janes
- Departments of Veterinary Science and Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY (Janes, Kennedy).,Rood and Riddle Equine Hospital, Lexington, KY (Garrett).,Departments of Pathobiology and Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, PA (Engiles)
| | - Laura A Kennedy
- Departments of Veterinary Science and Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY (Janes, Kennedy).,Rood and Riddle Equine Hospital, Lexington, KY (Garrett).,Departments of Pathobiology and Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, PA (Engiles)
| | - Katherine S Garrett
- Departments of Veterinary Science and Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY (Janes, Kennedy).,Rood and Riddle Equine Hospital, Lexington, KY (Garrett).,Departments of Pathobiology and Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, PA (Engiles)
| | - Julie B Engiles
- Departments of Veterinary Science and Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY (Janes, Kennedy).,Rood and Riddle Equine Hospital, Lexington, KY (Garrett).,Departments of Pathobiology and Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, PA (Engiles)
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Corsi A, Ippolito E, Robey PG, Riminucci M, Boyde A. Bisphosphonate-induced zebra lines in fibrous dysplasia of bone: histo-radiographic correlation in a case of McCune-Albright syndrome. Skeletal Radiol 2017; 46:1435-1439. [PMID: 28660402 PMCID: PMC5709201 DOI: 10.1007/s00256-017-2698-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/30/2017] [Accepted: 06/07/2017] [Indexed: 02/02/2023]
Abstract
Bisphosphonates (BPs) are currently used in the treatment of diverse bone diseases including fibrous dysplasia of bone (FD). In pediatric patients, a radiographic consequence of cyclical administration of BPs is the development of apo-, epi-, and meta-physeal sclerotic bands, otherwise known as zebra lines, which result from the temporary inhibition of osteoclastic activity at the time of drug treatment. We report here on a child with McCune-Albright syndrome (FD in addition to hyperfunctioning endocrinopathies and skin hyperpigmentation) treated with cyclical intravenous infusions of pamidronate in which conventional radiography, contact microradiography, histology, and backscattered electron image analysis demonstrated that zebra lines formed only where bone was normal, were arrested at the boundary between FD-unaffected and FD-affected bone where bone is sclerotic, and were absent within the undermineralized FD bone. Moreover, in spite of the treatment, the FD lesions continued to expand. This case report is unique because no previously published studies correlated the radiographic and the histologic features of BP-induced zebra lines in the metaphysis of an FD-affected long bone of the limbs.
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Affiliation(s)
- Alessandro Corsi
- Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Ernesto Ippolito
- Department of Orthopaedic Surgery, University of Rome Tor Vergata, Rome, Italy
| | - Pamela G. Robey
- Skeletal Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Mara Riminucci
- Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Alan Boyde
- Dental Physical Sciences, Queen Mary University of London, London E1 4NS, UK
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Bani Hassan E, Mirams M, Mackie EJ, Whitton RC. Prevalence of subchondral bone pathological changes in the distal metacarpi/metatarsi of racing Thoroughbred horses. Aust Vet J 2017; 95:362-369. [DOI: 10.1111/avj.12628] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 11/14/2016] [Accepted: 12/01/2016] [Indexed: 11/29/2022]
Affiliation(s)
- E Bani Hassan
- Faculty of Veterinary and Agricultural Sciences; University of Melbourne; 250 Princes Hwy Werribee 3030 Victoria Australia
- Australian Institute for Musculoskeletal Science (AIMSS) and Department of Medicine-Western Health, Melbourne Medical School; The University of Melbourne; Australia
| | - M Mirams
- Faculty of Veterinary and Agricultural Sciences; University of Melbourne; 250 Princes Hwy Werribee 3030 Victoria Australia
| | - EJ Mackie
- Faculty of Veterinary and Agricultural Sciences; University of Melbourne; 250 Princes Hwy Werribee 3030 Victoria Australia
| | - RC Whitton
- Faculty of Veterinary and Agricultural Sciences; University of Melbourne; 250 Princes Hwy Werribee 3030 Victoria Australia
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Leitch VD, Di Cosmo C, Liao XH, O’Boy S, Galliford TM, Evans H, Croucher PI, Boyde A, Dumitrescu A, Weiss RE, Refetoff S, Williams GR, Bassett JHD. An Essential Physiological Role for MCT8 in Bone in Male Mice. Endocrinology 2017; 158:3055-3066. [PMID: 28637283 PMCID: PMC5659673 DOI: 10.1210/en.2017-00399] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 06/12/2017] [Indexed: 11/19/2022]
Abstract
T3 is an important regulator of skeletal development and adult bone maintenance. Thyroid hormone action requires efficient transport of T4 and T3 into target cells. We hypothesized that monocarboxylate transporter (MCT) 8, encoded by Mct8 on the X-chromosome, is an essential thyroid hormone transporter in bone. To test this hypothesis, we determined the juvenile and adult skeletal phenotypes of male Mct8 knockout mice (Mct8KO) and Mct8D1D2KO compound mutants, which additionally lack the ability to convert the prohormone T4 to the active hormone T3. Prenatal skeletal development was normal in both Mct8KO and Mct8D1D2KO mice, whereas postnatal endochondral ossification and linear growth were delayed in both Mct8KO and Mct8D1D2KO mice. Furthermore, bone mass and mineralization were decreased in adult Mct8KO and Mct8D1D2KO mice, and compound mutants also had reduced bone strength. Delayed bone development and maturation in Mct8KO and Mct8D1D2KO mice is consistent with decreased thyroid hormone action in growth plate chondrocytes despite elevated serum T3 concentrations, whereas low bone mass and osteoporosis reflects increased thyroid hormone action in adult bone due to elevated systemic T3 levels. These studies identify an essential physiological requirement for MCT8 in chondrocytes, and demonstrate a role for additional transporters in other skeletal cells during adult bone maintenance.
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Affiliation(s)
- Victoria D. Leitch
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Caterina Di Cosmo
- Department of Medicine, The University of Chicago, Chicago, Illinois 60637
| | - Xiao-Hui Liao
- Department of Medicine, The University of Chicago, Chicago, Illinois 60637
| | - Sam O’Boy
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Thomas M. Galliford
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - Holly Evans
- Sheffield Myeloma Research Team, University of Sheffield, Sheffield S10 2RX, United Kingdom
| | - Peter I. Croucher
- The Garvan Institute of Medical Research and St. Vincent’s Clinical School, University of New South Wales Medicine, Sydney, New South Wales 2010, Australia
| | - Alan Boyde
- Queen Mary University of London, Oral Growth and Development, Bart’s and The London School of Medicine and Dentistry, London E1 4NS, United Kingdom
| | | | - Roy E. Weiss
- Department of Medicine, University of Miami, Miami, Florida 33136
| | - Samuel Refetoff
- Department of Medicine, The University of Chicago, Chicago, Illinois 60637
- Department of Pediatrics, The University of Chicago, Chicago, Illinois 60637
- Committee on Genetics, The University of Chicago, Chicago, Illinois 60637
| | - Graham R. Williams
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
| | - J. H. Duncan Bassett
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London W12 0NN, United Kingdom
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Pinilla M, Tranquille C, Blunden A, Chang Y, Parkin T, Murray R. Histological Features of the Distal Third Metacarpal Bone in Thoroughbred Racehorses, With and Without Lateral Condylar Fractures. J Comp Pathol 2017; 157:1-10. [DOI: 10.1016/j.jcpa.2017.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/31/2017] [Accepted: 04/07/2017] [Indexed: 10/19/2022]
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37
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Liley H, Davies H, Firth E, Besier T, Fernandez J. The effect of the sagittal ridge angle on cartilage stress in the equine metacarpo-phalangeal (fetlock) joint. Comput Methods Biomech Biomed Engin 2017; 20:1-10. [PMID: 28631937 DOI: 10.1080/10255842.2017.1339795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/05/2017] [Indexed: 10/19/2022]
Abstract
Fatigue failure of bones of the metacarpo-phalangeal (fetlock, MCP) joint is common in thoroughbred racehorses. Stresses within the fetlock joint cartilages are affected by the morphology of the third metacarpal bone (MC3) and proximal phalangeal bone, and the steepness of the median sagittal ridge of MC3 is believed to be associated with fracture. This study investigated the influence of the steepness of the sagittal ridge on cartilage stress distribution using a finite element model of the joint. Changes to the steepness of the sagittal ridge were made by applying a parabolic function to the mesh, creating four different models with sagittal ridge angles ranging from 95° to 105°. In the fetlock joint of Thoroughbred racehorses, sagittal ridge angles of >100° were associated with higher Von Mises stresses in cartilage at the palmar aspect of the condylar groove than such stresses in joints with sagittal ridge angles of <100°. Stresses were high in the specific region where fractures are known to originate in MC3. This aspect of morphology of the fetlock joint thus appears to play an important role in the magnitude and distribution of cartilage stresses, which, when acting on the underlying hard tissues of the articular calcified cartilage and subchondral bone may play a role in the initiation of fatigue fracture in the third metacarpal bone.
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Affiliation(s)
- Helen Liley
- a Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - Helen Davies
- b Faculty of Veterinary and Agricultural Sciences , University of Melbourne , Melbourne , Australia
| | - Elwyn Firth
- a Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
- c Department of Exercise Sciences , University of Auckland , Auckland , New Zealand
| | - Thor Besier
- a Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
- d Department of Engineering Science , University of Auckland , Auckland , New Zealand
| | - Justin Fernandez
- a Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
- d Department of Engineering Science , University of Auckland , Auckland , New Zealand
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Abstract
Bone, despite its relatively inert appearance, is a tissue that is capable of adapting to its environment. Wolff’s law, first described in the 19th century, describes the ability of bone to change structure depending on the mechanical forces applied to it. The mechanostat model extended this principle and suggested that the amount of strain a bone detects depends on bone strength and the amount of muscle force applied to the bone. Experimental studies have found that low-magnitude, high-frequency mechanical loading is considered to be the most effective at increasing bone formation. The osteocyte is considered to be the master regulator of the bone response to mechanical loading. Deformation of bone matrix by mechanical loading is thought to result in interstitial fluid flow within the lacunar–canalicular system, which may activate osteocyte mechanosensors, leading to changes in osteocyte gene expression and ultimately increased bone formation and decreased bone resorption. However, repetitive strain applied to bone can result in microcracks, which may propagate and coalesce, and if not repaired predispose to catastrophic fracture. Osteocytes are a key component in this process, whereby apoptotic osteocytes in an area of microdamage promote targeted remodeling of the damaged bone. If fractures do occur, fracture repair can be divided into 2 types: primary and secondary healing. Secondary fracture repair is the most common and is a multistage process consisting of hematoma formation and acute inflammation, callus formation, and finally remodeling, whereby bone may return to its original form.
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Loughridge AB, Hess AM, Parkin TD, Kawcak CE. Qualitative assessment of bone density at the distal articulating surface of the third metacarpal in Thoroughbred racehorses with and without condylar fracture. Equine Vet J 2016; 49:172-177. [DOI: 10.1111/evj.12544] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 11/24/2015] [Indexed: 12/01/2022]
Affiliation(s)
- A. B. Loughridge
- Orthopaedic Research Center Department of Clinical Sciences College of Veterinary Medicine and Biomedical Sciences Colorado State University Fort Collins USA
| | - A. M. Hess
- Department of Statistics College of Natural Sciences Colorado State University Fort Collins USA
| | - T. D. Parkin
- Weipers Equine Centre School of Veterinary Medicine College of Medical, Veterinary and Life Sciences University of Glasgow UK
| | - C. E. Kawcak
- Orthopaedic Research Center Department of Clinical Sciences College of Veterinary Medicine and Biomedical Sciences Colorado State University Fort Collins USA
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Remoli C, Michienzi S, Sacchetti B, Consiglio AD, Cersosimo S, Spica E, Robey PG, Holmbeck K, Cumano A, Boyde A, Davis G, Saggio I, Riminucci M, Bianco P. Osteoblast-specific expression of the fibrous dysplasia (FD)-causing mutation Gsα(R201C) produces a high bone mass phenotype but does not reproduce FD in the mouse. J Bone Miner Res 2015; 30:1030-43. [PMID: 25487351 PMCID: PMC5526456 DOI: 10.1002/jbmr.2425] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/26/2014] [Accepted: 12/04/2014] [Indexed: 12/20/2022]
Abstract
We recently reported the generation and initial characterization of the first direct model of human fibrous dysplasia (FD; OMIM #174800), obtained through the constitutive systemic expression of one of the disease-causing mutations, Gsα(R201C) , in the mouse. To define the specific pathogenetic role(s) of individual cell types within the stromal/osteogenic system in FD, we generated mice expressing Gsα(R201C) selectively in mature osteoblasts using the 2.3kb Col1a1 promoter. We show here that this results in a striking high bone mass phenotype but not in a mimicry of human FD. The high bone mass phenotype involves specifically a deforming excess of cortical bone and prolonged and ectopic cortical bone remodeling. Expression of genes characteristic of late stages of bone cell differentiation/maturation is profoundly altered as a result of expression of Gsα(R201C) in osteoblasts, and expression of the Wnt inhibitor Sost is reduced. Although high bone mass is, in fact, a feature of some types/stages of FD lesions in humans, it is marrow fibrosis, localized loss of adipocytes and hematopoietic tissue, osteomalacia, and osteolytic changes that together represent the characteristic pathological profile of FD, as well as the sources of specific morbidity. None of these features are reproduced in mice with osteoblast-specific expression of Gsα(R201C) . We further show that hematopoietic progenitor/stem cells, as well as more mature cell compartments, and adipocyte development are normal in these mice. These data demonstrate that effects of Gsα mutations underpinning FD-defining tissue changes and morbidity do not reflect the effects of the mutations on osteoblasts proper.
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Affiliation(s)
- Cristina Remoli
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Stefano Michienzi
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | | | | | - Stefania Cersosimo
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Emanuela Spica
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Pamela G Robey
- Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Kenn Holmbeck
- Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Ana Cumano
- Lymphopoiesis Unit, INSERM, Pasteur Institute, Paris, France
| | - Alan Boyde
- Dental Physical Sciences, Queen Mary University of London, London, UK
| | - Graham Davis
- Dental Physical Sciences, Queen Mary University of London, London, UK
| | - Isabella Saggio
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, and IBPM CNR, Rome, Italy
| | - Mara Riminucci
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Paolo Bianco
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
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Shaw KA, Dunoski B, Mardis N, Pacicca D. Knee morphometric risk factors for acute anterior cruciate ligament injury in skeletally immature patients. J Child Orthop 2015; 9:161-8. [PMID: 25821086 PMCID: PMC4417740 DOI: 10.1007/s11832-015-0652-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 03/17/2015] [Indexed: 02/03/2023] Open
Abstract
STUDY DESIGN Retrospective, case-control. PURPOSE Knee morphometric risk factors for noncontact anterior cruciate ligament (ACL) injury have been a popular topic with skeletally mature patients. Little research has focused on the skeletally immature, with conflicting conclusions. This study performs a comprehensive analysis of identified parameters thought to predispose to ACL injury in a skeletally immature cohort. METHODS A retrospective review of pediatric patients undergoing knee magnetic resonance imaging (MRI) was performed over a 4-year period. Inclusionary criteria included mid-substance ACL disruption, skeletal immaturity, noncontact injury, without associated ligamentous disruption, and no medical condition associated with ligamentous laxity. MRI studies were analyzed by a pediatric musculoskeletal radiologist, measuring identified bony parameters, and compared with an age-matched control group without ligamentous injury. Data were analyzed using unpaired t-tests and logistic regression. RESULTS One hundred and twenty-eight patients sustained an ACL disruption, 39 met all inclusionary criteria (66 excluded for associated ligamentous disruption, 23 skeletally mature, three traumatic mechanisms, one with Marfan syndrome). When compared to an age-matched control cohort, the notch width index (NWI) was found to be significantly smaller in the ACL-injured group (p = 0.046). Subgroups analysis demonstrated significant differences in morphometric parameters between subjects with isolated ACL injuries and concomitant medial collateral ligament (MCL) strain. CONCLUSIONS The NWI was significantly smaller in the ACL injury group. Significant differences were noted between isolated ACL injuries and ACL injuries with an MCL strain. This study further highlights the need for incorporating associated injury patterns when investigating the influence of morphometric factors for ACL injury in the skeletally immature. LEVEL OF EVIDENCE Level III.
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Affiliation(s)
- K. Aaron Shaw
- Department of Orthopaedic Surgery, Dwight D. Eisenhower Army Medical Center, 300 East Hospital Road, Fort Gordon, GA 30905 USA
| | - Brian Dunoski
- Department of Radiology, Children’s Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108 USA
| | - Neil Mardis
- Department of Radiology, Children’s Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108 USA
| | - Donna Pacicca
- Division of Orthopaedic Surgery, Children’s Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108 USA
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Holmes JM, Mirams M, Mackie EJ, Whitton RC. Thoroughbred horses in race training have lower levels of subchondral bone remodelling in highly loaded regions of the distal metacarpus compared to horses resting from training. Vet J 2014; 202:443-7. [PMID: 25296852 DOI: 10.1016/j.tvjl.2014.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 08/31/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022]
Abstract
Bone is repaired by remodelling, a process influenced by its loading environment. The aim of this study was to investigate the effect of a change in loading environment on bone remodelling by quantifying bone resorption and formation activity in the metacarpal subchondral bone in Thoroughbred racehorses. Sections of the palmar metacarpal condyles of horses in race training (n = 24) or resting from training (n = 24) were examined with light microscopy and back scattered scanning electron microscopy (BSEM). Bone area fraction, osteoid perimeter and eroded bone surface were measured within two regions of interest: (1) the lateral parasagittal groove (PS); (2) the lateral condylar subchondral bone (LC). BSEM variables were analysed for the effect of group, region and interaction with time since change in work status. The means ± SE are reported. For both regions of interest in the training compared to the resting group, eroded bone surface was lower (PS: 0.39 ± 0.06 vs. 0.65 ± 0.07 per mm, P = 0.010; LC: 0.24 ± 0.04 vs. 0.85 ± 0.10 per mm, P < 0.001) and in the parasagittal groove osteoid perimeter was higher (0.23 ± 0.04% vs. 0.12 ± 0.02%). Lower porosity was observed in the subchondral bone, reflected by a higher bone area fraction in the LC of the training group (90.8 ± 0.6%) compared to the resting group (85.3 ± 1.4%, P = 0.0010). Race training was associated with less bone resorption and more bone formation in the subchondral bone of highly loaded areas of the distal metacarpus limiting the replacement of fatigued bone. Periods of reduced intensity loading are important for facilitating subchondral bone repair in Thoroughbred racehorses.
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Affiliation(s)
- J M Holmes
- Faculty of Veterinary Science, University of Melbourne, 250 Princes Hwy, Werribee 3030, Australia
| | - M Mirams
- Faculty of Veterinary Science, University of Melbourne, 250 Princes Hwy, Werribee 3030, Australia
| | - E J Mackie
- Faculty of Veterinary Science, University of Melbourne, 250 Princes Hwy, Werribee 3030, Australia
| | - R C Whitton
- Faculty of Veterinary Science, University of Melbourne, 250 Princes Hwy, Werribee 3030, Australia.
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Trope GD, Ghasem-Zadeh A, Anderson GA, Mackie EJ, Whitton RC. Can high-resolution peripheral quantitative computed tomography imaging of subchondral and cortical bone predict condylar fracture in Thoroughbred racehorses? Equine Vet J 2014; 47:428-32. [DOI: 10.1111/evj.12312] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 06/19/2014] [Indexed: 11/26/2022]
Affiliation(s)
- G. D. Trope
- Faculty of Veterinary Science; University of Melbourne; Werribee Victoria Australia
| | - A. Ghasem-Zadeh
- Department of Endocrinology and Medicine, Austin Health; University of Melbourne; Parkville Victoria Australia
| | - G. A. Anderson
- Faculty of Veterinary Science; University of Melbourne; Werribee Victoria Australia
| | - E. J. Mackie
- Faculty of Veterinary Science; University of Melbourne; Werribee Victoria Australia
| | - R. C. Whitton
- Faculty of Veterinary Science; University of Melbourne; Werribee Victoria Australia
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Bogers SH, Rogers CW, Bolwell CF, Roe WD, Gee EK, McIlwraith CW. Impact of race training on volumetric bone mineral density and its spatial distribution in the distal epiphysis of the third metatarsal bone of 2-year-old horses. Vet J 2014; 201:353-8. [DOI: 10.1016/j.tvjl.2014.06.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 06/09/2014] [Accepted: 06/26/2014] [Indexed: 11/25/2022]
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Affiliation(s)
- Peter Muir
- School of Veterinary Medicine; Department of Surgical Sciences; University of Wisconsin-Madison; Madison Wisconsin 53706 USA
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Martig S, Chen W, Lee PVS, Whitton RC. Bone fatigue and its implications for injuries in racehorses. Equine Vet J 2014; 46:408-15. [DOI: 10.1111/evj.12241] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/26/2014] [Indexed: 11/30/2022]
Affiliation(s)
- S. Martig
- Faculty of Veterinary Science; The University of Melbourne; Werribee Victoria Australia
| | - W. Chen
- Department of Mechanical Engineering, Melbourne School of Engineering; The University of Melbourne; Parkville Victoria Australia
| | - P. V. S. Lee
- Department of Mechanical Engineering, Melbourne School of Engineering; The University of Melbourne; Parkville Victoria Australia
| | - R. C. Whitton
- Faculty of Veterinary Science; The University of Melbourne; Werribee Victoria Australia
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Martig S, Lee PVS, Anderson GA, Whitton RC. Compressive fatigue life of subchondral bone of the metacarpal condyle in thoroughbred racehorses. Bone 2013; 57:392-8. [PMID: 24063945 DOI: 10.1016/j.bone.2013.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 09/13/2013] [Accepted: 09/14/2013] [Indexed: 11/23/2022]
Abstract
In racehorses, fatigue related subchondral bone injury leads to overt fracture or articular surface collapse and subsequent articular cartilage degeneration. We hypothesised that the fatigue behaviour of equine subchondral bone in compression follows a power law function similar to that observed in cortical and trabecular bone. We determined the fatigue life of equine metacarpal subchondral bone in-vitro and investigated the factors influencing initial bone stiffness. Subchondral bone specimens were loaded cyclically in compression [54MPa (n=6), 66MPa (n=6), 78MPa (n=5), and 90MPa (n=6)] until failure. The fatigue life curve was determined by linear regression from log transformed number of cycles to failure and load. A general linear model was used to investigate the influence of the following variables on initial Young's Modulus: age (4-8years), specimen storage time (31-864days), time in training since most recent rest period (6-32weeks), limb, actual density (1.6873-1.8684g/cm(3)), subchondral bone injury grade (0-3), and cause of death (fatigue injury vs. other). Number of cycles to failure was (median, range) 223,603, 78,316-806,792 at 54MPa; 69,908, 146-149,855 at 66MPa; 13204, 614-16,425 at 78MPa (n=3); and 4001, 152-11,568 at 90MPa. The fatigue life curve was σ=112.2-9.6 log10Nf, (R(2)=0.52, P<0.001), where Nf is number of cycles to failure and σ is load. Removal of the three horses with the highest SCBI grade resulted in: σ=134.2-14.1 log10Nf, (R(2)=0.72, P<0.001). Initial Young's Modulus (mean±SD) was 2500±494MPa (n=22). Actual density (ρ) was the only variable retained in the model to describe initial Young's Modulus (E): E=-8196.7+5880.6ρ, (R(2)=0.34, P=0.0044). The fatigue behaviour of equine subchondral bone in compression is similar to that of cortical and trabecular bone. These data can be used to model the development of SCBI to optimize training regimes.
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Affiliation(s)
- Sandra Martig
- Faculty of Veterinary Science, The University of Melbourne, 250 Princes Highway, Werribee, VIC 3030, Australia.
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Whitton RC, Mirams M, Mackie EJ, Anderson GA, Seeman E. Exercise-induced inhibition of remodelling is focally offset with fatigue fracture in racehorses. Osteoporos Int 2013; 24:2043-8. [PMID: 23371360 DOI: 10.1007/s00198-013-2291-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 12/14/2012] [Indexed: 11/26/2022]
Abstract
UNLABELLED Bone remodelling is inhibited by high repetitive loading. However, in subchondral bone of racehorses in training, eroded surface doubled in association with fatigue fracture and there was greater surrounding trabecular bone volume suggesting trabecular modelling unloads the bone focally, allowing damage repair by remodelling. INTRODUCTION Remodelling replaces damaged bone with new bone but is suppressed during high magnitude repetitive loading when damage is most likely. However, in cortical bone of racehorses, at sites of fatigue fracture, focal porosity, consistent with remodelling, is observed in proportion to the extent of surrounding callus. Focal areas of porosity are also observed at sites of fatigue damage in subchondral bone. We hypothesised that fatigued subchondral bone, like damaged cortical bone, is remodelled focally in proportion to the modelling of surrounding trabecular bone. METHODS Eroded and mineralizing surfaces and bone area were measured using backscattered scanning electron microscopy of post-mortem specimens of the distal third metacarpal bone in 11 racehorses with condylar fractures (cases) and eight racehorses in training without fractures (controls). RESULTS Cases had a two-fold greater eroded surface per unit area at the fracture site than controls (0.81 ± 0.10 vs. 0.40 ± 0.12 mm(-1), P = 0.021) but not at an adjacent site (0.22 ± 0.09 vs. 0.30 ± 0.11 mm(-1), P = 0.59). Area fraction of surrounding trabecular bone was higher in cases than controls (81 ± 2 vs. 72 ± 2 %, P = 0.0020) and the eroded surface at the fracture site correlated with the surrounding trabecular area (adjusted R (2) = 0.63, P = 0.0010). CONCLUSION In conclusion, exercise-induced inhibition of remodelling is offset at sites of fatigue fracture. Modelling of trabecular bone may contribute to unloading these regions, allowing repair by remodelling.
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Affiliation(s)
- R C Whitton
- Faculty of Veterinary Science, Equine Centre, University of Melbourne, 250 Princes Hwy, Werribee, Victoria 3030, Australia.
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Hamann N, Zaucke F, Dayakli M, Brüggemann GP, Niehoff A. Growth-related structural, biochemical, and mechanical properties of the functional bone-cartilage unit. J Anat 2012; 222:248-59. [PMID: 23083449 DOI: 10.1111/joa.12003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2012] [Indexed: 12/26/2022] Open
Abstract
Articular cartilage and subchondral bone act together, forming a unit as a weight-bearing loading-transmitting surface. A close interaction between both structures has been implicated during joint cartilage degeneration, but their coupling during normal growth and development is insufficiently understood. The purpose of the present study was to examine growth-related changes of cartilage mechanical properties and to relate these changes to alterations in cartilage biochemical composition and subchondral bone structure. Tibiae and femora of both hindlimbs from 7- and 13-week-old (each n = 12) female Sprague-Dawley rats were harvested. Samples were processed for structural, biochemical and mechanical analyses. Immunohistochemical staining and protein expression analyses of collagen II, collagen IX, COMP and matrilin-3, histomorphometry of cartilage thickness and COMP staining height were performed. Furthermore, mechanical testing of articular cartilage and micro-CT analysis of subchondral bone was conducted. Growth decreased cartilage thickness, paralleled by a functional condensation of the underlying subchondral bone due to enchondral ossification. Cartilage mechanical properties seem to be rather influenced by growth-related changes in the assembly of major ECM proteins such as collagen II, collagen IX and matrilin-3 than by growth-related alterations in its underlying subchondral bone structure. Importantly, the present study provides a first insight into the growth-related structural, biochemical and mechanical interaction of articular cartilage and subchondral bone. Finally, these data contribute to the general knowledge about the cooperation between the articular cartilage and subchondral bone.
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Affiliation(s)
- Nina Hamann
- Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Germany
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Bassett JHD, Logan JG, Boyde A, Cheung MS, Evans H, Croucher P, Sun XY, Xu S, Murata Y, Williams GR. Mice lacking the calcineurin inhibitor Rcan2 have an isolated defect of osteoblast function. Endocrinology 2012; 153:3537-48. [PMID: 22593270 DOI: 10.1210/en.2011-1814] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Calcineurin-nuclear factor of activated T cells signaling controls the differentiation and function of osteoclasts and osteoblasts, and regulator of calcineurin-2 (Rcan2) is a physiological inhibitor of this pathway. Rcan2 expression is regulated by T(3), which also has a central role in skeletal development and bone turnover. To investigate the role of Rcan2 in bone development and maintenance, we characterized Rcan2(-/-) mice and determined its skeletal expression in T(3) receptor (TR) knockout and thyroid-manipulated mice. Rcan2(-/-) mice had normal linear growth but displayed delayed intramembranous ossification, impaired cortical bone formation, and reduced bone mineral accrual during development as well as increased mineralization of adult bone. These abnormalities resulted from an isolated defect in osteoblast function and are similar to skeletal phenotypes of mice lacking the type 2 deiodinase thyroid hormone activating enzyme or with dominant-negative mutations of TRα, the predominant TR isoform in bone. Rcan2 mRNA was expressed in primary osteoclasts and osteoblasts, and its expression in bone was differentially regulated in TRα and TRβ knockout and thyroid-manipulated mice. However, in primary osteoblast cultures, T(3) treatment did not affect Rcan2 mRNA expression or nuclear factor of activated T cells c1 expression and phosphorylation. Overall, these studies establish that Rcan2 regulates osteoblast function and its expression in bone is regulated by thyroid status in vivo.
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Affiliation(s)
- J H Duncan Bassett
- Molecular Endocrinology Group, Department of Medicine, Imperial College London, Hammersmith Campus, London W12 0NN, United Kingdom
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