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Koshyk A, Pohl AJ, Takahashi Y, Scott WM, Sparks HD, Edwards WB. Influence of microarchitecture on stressed volume and mechanical fatigue behaviour of equine subchondral bone. Bone 2024; 182:117054. [PMID: 38395248 DOI: 10.1016/j.bone.2024.117054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 02/18/2024] [Accepted: 02/19/2024] [Indexed: 02/25/2024]
Abstract
Fractures of the equine metacarpophalangeal (MCP) joint are among the most common and fatal injuries experienced by racehorses. These bone injuries are a direct result of repetitive, high intensity loading of the skeleton during racing and training and there is consensus that they represent a mechanical fatigue phenomenon. Existing work has found the fatigue life of bone to be strongly determined by bone microarchitecture and the resulting stressed volume (i.e., the volume of bone stressed above assumed yield). The purpose of this study was to quantify the influence of bone microarchitecture on the mechanical fatigue behaviour of equine subchondral bone from the MCP joint across a wide variety of sample types. Forty-eight subchondral bone samples were prepared from the third metacarpal (MC3) and proximal phalanx (P1) of 8 horses and subsequently imaged using high resolution micro-computed tomography (μCT) to quantify microarchitectural features of interest, including bone volume fraction, tissue mineral density, pore size, pore spacing, and pore number. Samples were cyclically loaded in compression to a stress of 70 MPa, and fatigue life was defined as the number of cycles until failure. Finite element models were created from the μCT images and used to quantify stressed volume. Based on the expected log point-wise predictive density, stressed volume was a strong predictor of fatigue life in both the MC3 and P1. A regional analysis indicated fatigue life was more strongly associated with bone volume fraction in the superficial (r2 = 0.32, p < 0.001) and middle (r2 = 0.70, p < 0.001) regions of the subchondral bone, indicating the prominent role that the cortical plate played in the fatigue resistance of equine subchondral bone. By improving our understanding of the variance in fatigue life measurements, this research helps clarify the underlying mechanisms of the mechanical fatigue process and provides a basic understanding of subchondral bone injuries in the equine fetlock joint.
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Affiliation(s)
- Andrew Koshyk
- Department of Biomedical Engineering, University of Calgary, Calgary, Canada; McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada.
| | - Andrew J Pohl
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - Yuji Takahashi
- Sports Science Division, Equine Research Institute, Shimotsuke, Tochigi, Japan
| | - W Michael Scott
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Holly D Sparks
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - W Brent Edwards
- Department of Biomedical Engineering, University of Calgary, Calgary, Canada; McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada
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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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Young N, Corletto F, Wright I. Predicting return to racing after repair of fractures of the metacarpal/metatarsal condyles in Thoroughbred racehorses. Vet Surg 2022; 51:753-762. [DOI: 10.1111/vsu.13820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/28/2022] [Accepted: 04/15/2022] [Indexed: 11/30/2022]
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Labbe KA, Pigott JH. Radiographic technique to improve diagnosis of sagittal axial sesamoid fracture in racing Thoroughbreds with lateral condylar fracture. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- K. A. Labbe
- Cornell Ruffian Equine Specialists Elmont New York USA
| | - J. H. Pigott
- Cornell Ruffian Equine Specialists Elmont New York USA
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Goldstein DM, Engiles JB, Rezabek GB, Ruff CB. Locomotion on the edge: Structural properties of the third metacarpal in Thoroughbred and Quarter Horse racehorses and feral Assateague Island ponies. Anat Rec (Hoboken) 2020; 304:771-786. [PMID: 32805766 DOI: 10.1002/ar.24485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 11/09/2022]
Abstract
The elongated, distally tapered limbs of horses are adapted for high-speed locomotion. Because these traits are artificially selected for in modern racehorses, they operate at a morphological extreme with a high risk of fracture. Racehorses are subject to different training and racing regimes depending on their breed and gait, and are therefore an interesting model to examine bone functional adaptation under variable biomechanically intense conditions. This study compares bone structural properties in the third metacarpal (MCIII) of Thoroughbred (n = 9) and Quarter Horse (n = 11) racehorses, using feral Assateague Island ponies (n = 6) as an untrained/unraced outgroup, to determine whether structural properties reflect variable racing and training regimes. Geometric section properties and bone mineral densities were determined using peripheral quantitative CT at two diaphyseal sites and through the distal epiphysis. Diaphyseal strength of the MCIII in all three breeds does not differ relative to body size, but in the mid-diaphyseal region Thoroughbreds have higher antero-posterior relative to medio-lateral bending strength than Quarter Horses, as well as higher bone mineral densities in left MCIII epiphyses (particularly in the lateral condyle). Interestingly, all breeds have lower bone mineral densities in the lateral versus medial condyle, an inherent structural feature that may influence predisposition to fracture when running around turns. Our results suggest that despite subtle differences in bone structure between different racehorse breeds, basic morphology of the third metacarpus is relatively similar among racing and non-racing horses, possibly reflecting intense selection (natural and artificial) across domestic equids for similar structural features within distal limb elements.
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Affiliation(s)
- Deanna M Goldstein
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland, USA
| | - Julie B Engiles
- University of Pennsylvania, School of Veterinary Medicine, Department of Pathobiology, New Bolton Center, Kennett Square, Pennsylvania, USA
| | - Grant B Rezabek
- Oklahoma State University, OK Animal Disease Diagnostic Laboratory, Stillwater, Oklahoma, USA
| | - Christopher B Ruff
- The Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland, USA
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Boorman S, Richardson DW, Hogan PM, Stefanovski D, Levine DG. Racing performance after surgical repair of medial condylar fracture of the third metacarpal/metatarsal bone in thoroughbred racehorses. Vet Surg 2020; 49:648-658. [PMID: 32133662 DOI: 10.1111/vsu.13403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/18/2020] [Accepted: 02/15/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To report the performance of thoroughbred racehorses after surgical repair of a medial condylar fracture of the third metacarpal/metatarsal bone. STUDY DESIGN Retrospective cohort study. SAMPLE POPULATION Forty-three horses surgically treated for medial condylar fractures, 30 with previous racing experience, 13 without previous racing experience (nonexperienced). METHODS Medical records (2009-2017) were reviewed for signalment, radiographic fracture characteristics, repair technique, and postoperative morbidity and mortality. Each experienced horse was matched with two horses randomly selected from its most recent race to serve as healthy controls. Racing performance parameters (race rating, competitive level, speed rating, performance index) and career racing statistics were compared with multiple regression models between injured experienced horses and controls. The career racing statistics for nonexperienced horses were evaluated. Reasons for nonreturn to racing were obtained. RESULTS The median duration of follow-up was 6 years (minimum 2, maximum 10). Twenty-one of 43 (49%) horses raced again as well as 18 of 30 (60%) experienced horses and three of 13 (23%) nonexperienced horses. Experienced horses were five times more likely than nonexperienced horses to return to racing (95% confidence interval = 0.07-0.58, P = .003). Higher preoperative racing performance parameters were associated with return to racing. Racing performance parameters were lower after the date of fracture in injured horses compared with controls. CONCLUSION Experienced horses were more likely to return to racing after medial condylar fracture repair, although their performance was generally lower than that of comparably uninjured horses. CLINICAL SIGNIFICANCE Owners should be aware that horses with medial condylar fractures likely will race at a lower level than their uninjured peers.
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Affiliation(s)
- Sophie Boorman
- Department of Clinical Science, JT Vaughan Large Animal Teaching Hospital, College of Veterinary Medicine, Auburn University, Auburn, Alabama
| | - Dean W Richardson
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, Pennsylvania
| | | | - Darko Stefanovski
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, Pennsylvania
| | - David G Levine
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, Pennsylvania
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Moulin N, François I, Coté N, Alford C, Cleary O, Desjardins MR. Surgical repair of propagating condylar fractures of the third metacarpal/metatarsal bones with cortical screws placed in lag fashion in 26 racehorses (2007-2015). Equine Vet J 2018; 50:629-635. [PMID: 29350412 DOI: 10.1111/evj.12811] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 01/10/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Despite the recommendation of plate fixation for propagating condylar fractures of the third metacarpal (McIII) or third metatarsal bone (MtIII), lag screw fixation can be a viable surgical option. OBJECTIVES To evaluate short-term outcome and long-term racing performance of horses that underwent lag screw fixation of long condylar fractures of the McIII/MtIII. STUDY DESIGN Retrospective case series. METHODS Medical records, post-surgical racing performance and outcome of 26 horses with propagating fractures of the medial and/or lateral condyle of McIII/MtIII were reviewed. Medical information included were age, breed, sex, physical examination at admission, circumstances of fracture, radiographic evaluation, anaesthesia and recovery records, surgical and post-operative management, as well as complications. Outcome included racing data and information from telephone interviews. RESULTS Twenty-six horses (9 Standardbreds and 17 Thoroughbreds) were admitted with a long condylar fracture of the McIII/MtIII. Fore- and hindlimbs were equally represented with the left hindlimb being more frequently involved. Most of the fractures had a spiralling component (76%) and four (15%) were comminuted. Fifteen (58%) horses raced post-surgery including nine Standardbreds (100%) and six Thoroughbreds (35%). Twelve of them were placed in at least one race and 11 won at least once. One horse sustained a severe complication in recovery. No significant difference was observed in the racing performances before and after surgery. MAIN LIMITATIONS Follow-up method and duration were not standardised and there is a low number of cases with six surgeons. CONCLUSIONS Long condylar fractures can be repaired using lag fashion technique combined with a half-limb or full-limb tight cast for recovery as a good surgical alternative. Similar results to plate fixation can be expected, with a return to racing of more than 50%, and the prognosis being even better for pacers.
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Affiliation(s)
- N Moulin
- Pole Equin, Vetagro Sup, Lyon, France
| | - I François
- Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - N Coté
- Ontario Veterinary College, Guelph, Ontario, Canada
| | - C Alford
- Turtle Valley Equine Hospital, Delavan, Wisconsin, USA
| | - O Cleary
- Ontario Veterinary College, Guelph, Ontario, Canada
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Cole R, Wilborn R, Gillen A, Newton J, Walz H. Bilateral Catastrophic Metacarpal Fractures in a Quarter Horse Gelding. J Equine Vet Sci 2016. [DOI: 10.1016/j.jevs.2016.02.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Bogers SH, Rogers CW, Bolwell C, Roe W, Gee E, McIlwraith CW. Quantitative comparison of bone mineral density characteristics of the distal epiphysis of third metacarpal bones from Thoroughbred racehorses with or without condylar fracture. Am J Vet Res 2016; 77:32-8. [DOI: 10.2460/ajvr.77.1.32] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Dubois MS, Morello S, Rayment K, Markel MD, Vanderby R, Kalscheur VL, Hao Z, McCabe RP, Marquis P, Muir P. Computed tomographic imaging of subchondral fatigue cracks in the distal end of the third metacarpal bone in the thoroughbred racehorse can predict crack micromotion in an ex-vivo model. PLoS One 2014; 9:e101230. [PMID: 25077477 PMCID: PMC4117462 DOI: 10.1371/journal.pone.0101230] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/04/2014] [Indexed: 11/22/2022] Open
Abstract
Articular stress fracture arising from the distal end of the third metacarpal bone (MC3) is a common serious injury in Thoroughbred racehorses. Currently, there is no method for predicting fracture risk clinically. We describe an ex-vivo biomechanical model in which we measured subchondral crack micromotion under compressive loading that modeled high speed running. Using this model, we determined the relationship between subchondral crack dimensions measured using computed tomography (CT) and crack micromotion. Thoracic limbs from 40 Thoroughbred racehorses that had sustained a catastrophic injury were studied. Limbs were radiographed and examined using CT. Parasagittal subchondral fatigue crack dimensions were measured on CT images using image analysis software. MC3 bones with fatigue cracks were tested using five cycles of compressive loading at -7,500N (38 condyles, 18 horses). Crack motion was recorded using an extensometer. Mechanical testing was validated using bones with 3 mm and 5 mm deep parasagittal subchondral slots that modeled naturally occurring fatigue cracks. After testing, subchondral crack density was determined histologically. Creation of parasagittal subchondral slots induced significant micromotion during loading (p<0.001). In our biomechanical model, we found a significant positive correlation between extensometer micromotion and parasagittal crack area derived from reconstructed CT images (SR = 0.32, p<0.05). Correlations with transverse and frontal plane crack lengths were not significant. Histologic fatigue damage was not significantly correlated with crack dimensions determined by CT or extensometer micromotion. Bones with parasagittal crack area measurements above 30 mm2 may have a high risk of crack propagation and condylar fracture in vivo because of crack micromotion. In conclusion, our results suggest that CT could be used to quantify subchondral fatigue crack dimensions in racing Thoroughbred horses in-vivo to assess risk of condylar fracture. Horses with parasagittal crack arrays that exceed 30 mm2 may have a high risk for development of condylar fracture.
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Affiliation(s)
- Marie-Soleil Dubois
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Samantha Morello
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kelsey Rayment
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Mark D. Markel
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ray Vanderby
- Department of Orthopedics & Rehabilitation, School of Medicine & Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Vicki L. Kalscheur
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Zhengling Hao
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ronald P. McCabe
- Department of Orthopedics & Rehabilitation, School of Medicine & Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Patricia Marquis
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Gulfstream Park, Hallandale Beach, Florida, United States of America
| | - Peter Muir
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Turley SM, Thambyah A, Riggs CM, Firth EC, Broom ND. Microstructural changes in cartilage and bone related to repetitive overloading in an equine athlete model. J Anat 2014; 224:647-58. [PMID: 24689513 DOI: 10.1111/joa.12177] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2014] [Indexed: 11/30/2022] Open
Abstract
The palmar aspect of the third metacarpal (MC3) condyle of equine athletes is known to be subjected to repetitive overloading that can lead to the accumulation of joint tissue damage, degeneration, and stress fractures, some of which result in catastrophic failure. However, there is still a need to understand at a detailed microstructural level how this damage progresses in the context of the wider joint tissue complex, i.e. the articular surface, the hyaline and calcified cartilage, and the subchondral bone. MC3 bones from non-fractured joints were obtained from the right forelimbs of 16 Thoroughbred racehorses varying in age between 3 and 8 years, with documented histories of active race training. Detailed microstructural analysis of two clinically important sites, the parasagittal grooves and the mid-condylar regions, identified extensive levels of microdamage in the calcified cartilage and subchondral bone concealed beneath outwardly intact hyaline cartilage. The study shows a progression in microdamage severity, commencing with mild hard-tissue microcracking in younger animals and escalating to severe subchondral bone collapse and lesion formation in the hyaline cartilage with increasing age and thus athletic activity. The presence of a clearly distinguishable fibrous tissue layer at the articular surface immediately above sites of severe subchondral collapse suggested a limited reparative response in the hyaline cartilage.
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Affiliation(s)
- Sean M Turley
- Tissue Mechanics Laboratory, Department of Chemical and Materials Engineering, University of Auckland, Auckland, New Zealand
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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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Goodrich LR, Nixon AJ, Conway JD, Morley PS, Bladon BM, Hogan PM. Dynamic compression plate (
DCP
) fixation of propagating medial condylar fractures of the third metacarpal/metatarsal bone in 30 racehorses: Retrospective analysis (1990–2005). Equine Vet J 2014; 46:695-700. [DOI: 10.1111/evj.12184] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Accepted: 08/22/2013] [Indexed: 11/30/2022]
Affiliation(s)
- L. R. Goodrich
- Department of Clinical Sciences Colorado State University Fort Collins USA
| | - A. J. Nixon
- Department of Clinical Sciences Cornell University Ithaca New York USA
| | - J. D. Conway
- Department of Clinical Sciences Colorado State University Fort Collins USA
| | - P. S. Morley
- Department of Clinical Sciences Colorado State University Fort Collins USA
| | | | - P. M. Hogan
- Hogan Equine @ Fair Winds Farm Cream Ridge New Jersey USA
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15
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Dymock DC, Pauwels FET. Investigation into the morphology of the third metacarpal bone in the horse. N Z Vet J 2012; 60:223-7. [PMID: 22512622 DOI: 10.1080/00480169.2011.651056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
AIMS To describe key morphological attributes of the third metacarpal bone (Mc3) of horses and to determine whether or not the symmetry of the Mc3 varied significantly between limbs of the same horse. METHODS Ten pairs of metacarpi were collected from slaughter facilities. The age and breed of the horses were recorded. Fixed points and axes that could be easily reproduced between bones were identified on high-quality photographic images of each bone. Using image analysis, three angles were measured. Angle gamma measured the rotation around the long axis of the diaphysis of Mc3, angle delta the angle between the dorsal long axis of the cannon bone and the surface of the condyle of Mc3, and angle theta the angle between the surface of the condyle and the long axis of the sagittal ridge of the condyle of Mc3. These angles represent some of the characteristic morphologic relationships within the equine Mc3. RESULTS The coefficient of variation for angles gamma, delta and theta and were 1.2%, 0.2% and 0.5%, respectively. Angle gamma was larger in the left compared with the right limb (p=0.041). Angles delta and theta were larger in the right compared with the left limb (p=0.001 and p=0.003, respectively). There was a single outlier in a left limb for angle gamma. When this was excluded from the analysis, angle gamma in the left limb was still larger than in the right limb. Angle delta was consistently greater than 90° in 19/20 metacarpi. CONCLUSIONS There were significant morphological differences in the Mc3 between the left and right limbs of the 10 horses examined. These findings provide some reliable reference data for future investigation. Further work is required to document these differences in a larger population of horses and to determine whether the morphology of the Mc3 is influenced by age or other factors such as use of the animal.
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Affiliation(s)
- D C Dymock
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
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16
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Payne RJ, Compston PC. Short- and long-term results following standing fracture repair in 34 horses. Equine Vet J 2012; 44:721-5. [PMID: 22506811 DOI: 10.1111/j.2042-3306.2012.00569.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
REASONS FOR PERFORMING STUDY Standing fracture repair in the horse is a recently described surgical procedure and currently there are few follow-up data. This case series contains 2 novel aspects in the standing horse: repair of incomplete sagittal fractures of the proximal phalanx and medial condylar repair from a lateral aspect. OBJECTIVES To describe outcome in a case series of horses that had lower limb fractures repaired under standing sedation at Rossdales Equine Hospital. METHOD Case records for all horses that had a fracture surgically repaired, by one surgeon at Rossdales Equine Hospital, under standing sedation and local anaesthesia up until June 2011, were retrieved. Hospital records, owner/trainer telephone questionnaire and the Racing Post website were used to evaluate follow-up. RESULTS Thirty-four horses satisfied the inclusion criteria. Fracture sites included the proximal phalanx (incomplete sagittal fracture, n = 14); the third metacarpal bone (lateral condyle, n = 12, and medial condyle, n = 7); and the third metatarsal bone (lateral condyle, n = 1). One horse required euthanasia due to caecal rupture 10 days post operatively. Twenty horses (66.7% of those with available follow-up) have returned to racing. Where available, mean time from operation to return to racing was 226 days (range 143-433 days). CONCLUSIONS Standing fracture repair produced similar results to fracture repair under general anaesthesia in terms of both the number of horses that returned to racing and the time between surgery and race. POTENTIAL RELEVANCE Repair of lower limb fracture in the horse under standing sedation is a procedure that has the potential for tangible benefits, including avoidance of the inherent risks of general anaesthesia. The preliminary findings in this series of horses are encouraging and informative when discussing options available prior to fracture repair.
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Affiliation(s)
- R J Payne
- Rossdales Equine Hospital, Exning, Newmarket, UK
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17
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Jacklin BD, Wright IM. Frequency distributions of 174 fractures of the distal condyles of the third metacarpal and metatarsal bones in 167 Thoroughbred racehorses (1999-2009). Equine Vet J 2012; 44:707-13. [DOI: 10.1111/j.2042-3306.2012.00558.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tranquille CA, Parkin TDH, Murray RC. Magnetic resonance imaging-detected adaptation and pathology in the distal condyles of the third metacarpus, associated with lateral condylar fracture in Thoroughbred racehorses. Equine Vet J 2012; 44:699-706. [DOI: 10.1111/j.2042-3306.2011.00535.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lewis AJ, Sod GA, Burba DJ, Mitchell CF. Compressive forces achieved in simulated equine third metacarpal bone lateral condylar fractures of varying fragment thickness with Acutrak Plus screw and 4.5 mm AO cortical screws. Vet Surg 2010; 39:78-82. [PMID: 20210949 DOI: 10.1111/j.1532-950x.2009.00612.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To compare compression pressure (CP) of 6.5 mm Acutrak Plus (AP) and 4.5 mm AO cortical screws (AO) when inserted in simulated lateral condylar fractures of equine 3rd metacarpal (MC3) bones. STUDY DESIGN Paired in vitro biomechanical testing. SAMPLE POPULATION Cadaveric equine MC3 bones (n=12 pair). METHODS Complete lateral condylar osteotomies were created parallel to the midsagittal ridge at 20, 12, and 8 mm axial to the epicondylar fossa on different specimens grouped accordingly. Interfragmentary compression was measured using a pressure sensor placed in the fracture plane before screw placement for fracture fixation. CP was acquired and mean values of CP for each fixation method were compared between the 6.5 mm (AP) and 4.5 mm (AO) for each group using a paired t-test within each fracture fragment thickness group with statistical significance set at P<.05. RESULTS AO screw configurations generated significantly greater compressive pressure compared with AP configurations. The ratio of mean CP for AP screws to AO screws at 20, 12, and 8 mm, were 21.6%, 26.2%, and 34.2%, respectively. CONCLUSION Mean CP for AP screw fixations are weaker than those for AO screw fixations, most notably with the 20 mm fragments. The 12 and 8 mm groups have comparatively better compression characteristics than the 20 mm group; however, they are still significantly weaker than AO fixations. CLINICAL RELEVANCE Given that the primary goals of surgical repair are to achieve rigid fixation, primary bone healing, and good articular alignment, based on these results, it is recommended that caution should be used when choosing the AP screw for repair of lateral condylar fractures, especially complete fractures. Because interfragmentary compression plays a factor in the overall stability of a repair, it is recommended for use only in patients with thin lateral condyle fracture fragments, as the compression tends to decrease with an increase in thickness.
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Affiliation(s)
- Andrew J Lewis
- Department of Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803, USA.
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Russell TM, Maclean AA. Standing surgical repair of propagating metacarpal and metatarsal condylar fractures in racehorses. Equine Vet J 2010; 38:423-7. [PMID: 16986602 DOI: 10.2746/042516406778400664] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Repair of spiral and long diaphyseal metacarpal and metatarsal fractures under anaesthesia can be problematic and associated with a high incidence of complications, including fracture propagation necessitating euthanasia. OBJECTIVE To report on a practical repair technique for which general anaesthesia is not required. METHODS Thirteen racehorses with a spiral/propagating condylar fracture had the fracture repaired using local anaesthesia and sedation, without the need for general anaesthetic. RESULTS Ten of the horses returned to training and 8 raced again. Two horses were retired directly to stud. One horse had propagation of the fracture 3 days post surgery, and was subjected to euthanasia. CONCLUSIONS AND POTENTIAL RELEVANCE Results achieved were comparable to those gained using standard repair techniques under general anaesthesia. The described technique removes the need for general anaesthesia for repair of selected condylar fractures.
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Affiliation(s)
- T M Russell
- Goulburn Valley Equine Hospital, Shepparton, Victoria, Australia
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Perez-Olmos JF, Schofield WL, Mcgovern F, Dillon H, Sadlier M. Standing surgical treatment of spiral longitudinal metacarpal and metatarsal condylar fractures in 4 horses. EQUINE VET EDUC 2010. [DOI: 10.1111/j.2042-3292.2006.tb00467.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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SMITH LEWISCR, GREET TIMOTHYRC, BATHE ANDREWP. A Lateral Approach for Screw Repair in Lag Fashion of Spiral Third Metacarpal and Metatarsal Medial Condylar Fractures in Horses. Vet Surg 2009; 38:681-8. [DOI: 10.1111/j.1532-950x.2009.00503.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Diagnostic imaging of the equine fetlock region using radiography and ultrasonography. Part 2: The bony disorders. Vet J 2009; 181:123-36. [DOI: 10.1016/j.tvjl.2008.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2007] [Revised: 01/26/2008] [Accepted: 01/31/2008] [Indexed: 11/21/2022]
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25
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WRIGHT IANM, SMITH MATTHEWRW. A Lateral Approach to the Repair of Propagating Fractures of the Medial Condyle of the Third Metacarpal and Metatarsal Bone in 18 Racehorses. Vet Surg 2009; 38:689-95. [DOI: 10.1111/j.1532-950x.2009.00562.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Murray RC, Walters JM, Snart H, Dyson SJ, Parkin TDH. Identification of risk factors for lameness in dressage horses. Vet J 2009; 184:27-36. [PMID: 19369100 DOI: 10.1016/j.tvjl.2009.03.020] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 03/02/2009] [Accepted: 03/14/2009] [Indexed: 11/19/2022]
Abstract
The aim of this study was to describe the prevalence of illness and lameness at different anatomical sites in registered United Kingdom dressage horses and to identify risk factors for lameness. A questionnaire was sent to all 11,363 registered members of British Dressage in 2005, with one questionnaire assigned per horse. Four multivariable logistic regression models were developed for each section of the questionnaire. A final mixed effects logistic regression model was developed which combined the results from all prior models. Owners reported that 33% of horses had been lame at some time during their career, with 24% of these within the previous 2 years. A number of factors were associated with the occurrence of lameness in the last 2 years, including age, height, indoor arenas, horse-walkers, lunging (as protective), back problems, arenas that become deeper in wet conditions and sand-based arenas. These factors were included as variables in a final model to provide information for selection of horses, development of safer arenas and more effective training regimens to minimise the onset of lameness.
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Affiliation(s)
- Rachel C Murray
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
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Rubio-Martínez LM, Cruz AM, Gordon K, Hurtig MB. Structural characterization of subchondral bone in the distal aspect of third metacarpal bones from Thoroughbred racehorses via micro–computed tomography. Am J Vet Res 2008; 69:1413-22. [DOI: 10.2460/ajvr.69.11.1413] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Lloyd D, Johanson C, Phillips TJ. Treatment of medial condylar fractures of the third metatarsus in three horses with fibreglass casts under standing neuroleptanalgesia. Vet Rec 2008; 162:586-9. [DOI: 10.1136/vr.162.18.586] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- D. Lloyd
- Liphook Equine Hospital; Forest Mere Liphook Hampshire GU30 7JG
| | - C. Johanson
- Western Counties Equine Clinic; Culmstock Cullompton Devon EX15 3LA
| | - T. J. Phillips
- Liphook Equine Hospital; Forest Mere Liphook Hampshire GU30 7JG
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James FM, Richardson DW. Minimally invasive plate fixation of lower limb injury in horses: 32 cases (1999-2003). Equine Vet J 2006; 38:246-51. [PMID: 16706280 DOI: 10.2746/042516406776866291] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Complications of osteosynthesis including superficial and deep infections continue to affect adversely outcome in equine surgery of the lower limb. OBJECTIVE To describe a technique for minimally invasive plate fixation in horses and evaluate clinical results of the technique. HYPOTHESIS Lower complication rates would occur in horses treated with a minimally invasive approach compared with conventional techniques. METHODS Cases of minimally invasive plate fixation from January 1999 to December 2003 were evaluated. Case records, radiographs and race records for horses that sustained distal third metacarpal/metatarsal (Mc/tIII) condylar fractures were assessed. Follow-up information was obtained and results analysed. In addition, results for horses that received arthrodesis by a conventional, open approach during the same period were evaluated and statistical analysis was performed. RESULTS Thirty-two cases of minimally invasive plate fixation were identified (22 incomplete distal Mc/tIII condylar fractures with a spiralling or diaphyseal component, 10 metacarpophalangeal arthrodeses and 4 pastern arthrodeses). For both types of arthrodesis, surgery times and infection rates were lower and survival rates higher in the minimally invasive group, but no statistical difference was found. Spiralling condylar fractures were successfully managed, without catastrophic fracture. CONCLUSIONS AND POTENTIAL RELEVANCE Minimally invasive percutaneous plate osteosynthesis (MIPPO) can be successfully used for select applications in horses, and may reduce morbidity and mortality in equine fracture repair.
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Affiliation(s)
- F M James
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, 382 West Street Road, Kennett Square, Pennsylvania 19348-1692, USA
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Carpenter RS, Galuppo LD, Stover SM. Effect of diameter of the drill hole on torque of screw insertion and pushout strength for headless tapered compression screws in simulated fractures of the lateral condyle of the equine third metacarpal bone. Am J Vet Res 2006; 67:895-900. [PMID: 16649927 DOI: 10.2460/ajvr.67.5.895] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare variables for screw insertion, pushout strength, and failure modes for a headless tapered compression screw inserted in standard and oversize holes in a simulated lateral condylar fracture model. SAMPLE POPULATION 6 pairs of third metacarpal bones from horse cadavers. PROCEDURE Simulated lateral condylar fractures were created, reduced, and stabilized with a headless tapered compression screw by use of a standard or oversize hole. Torque, work, and time for drilling, tapping, and screw insertion were measured during site preparation and screw implantation. Axial load and displacement were measured during screw pushout. Effects of drill hole size on variables for screw insertion and screw pushout were assessed by use of Wilcoxon tests. RESULTS Drill time was 59% greater for oversize holes than for standard holes. Variables for tapping (mean maximum torque, total work, positive work, and time) were 42%, 70%, 73%, and 58% less, respectively, for oversize holes, compared with standard holes. Variables for screw pushout testing (mean yield load, failure load, failure displacement, and failure energy) were 40%, 40%, 47%, and 71% less, respectively, for oversize holes, compared with standard holes. Screws could not be completely inserted in 1 standard and 2 oversize holes. CONCLUSIONS AND CLINICAL RELEVANCE Enlarging the diameter of the drill hole facilitated tapping but decreased overall holding strength of screws. Therefore, holes with a standard diameter are recommended for implantation of variable pitch screws whenever possible. During implantation, care should be taken to ensure that screw threads follow tapped bone threads.
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Affiliation(s)
- Ryan S Carpenter
- JD Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Parkin TDH, Clegg PD, French NP, Proudman CJ, Riggs CM, Singer ER, Webbon PM, Morgan KL. Catastrophic fracture of the lateral condyle of the third metacarpus/metatarsus in UK racehorses – fracture descriptions and pre-existing pathology. Vet J 2006; 171:157-65. [PMID: 16427592 DOI: 10.1016/j.tvjl.2004.10.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2004] [Indexed: 11/22/2022]
Abstract
The characteristics of, and pre-existing pathology associated with 75 cases of fatal lateral condylar fracture sustained by Thoroughbreds while racing in the UK were described. Cases were identified from 220 cases of fatal distal limb fracture submitted as part of studies designed to identify risk factors for all fatal distal limb fractures. Fractures were most common in hurdle races and affected the right forelimb twice as often as the left forelimb. Fracture dimensions were similar to previous reports, however there was a much greater prevalence of articular and diaphyseal comminution and of concurrent fractures in the current report. Pre-existing pathology was particularly common in the medial and lateral parasagittal grooves of the distal articular surfaces of the third metacarpus/metatarsus. The degree of this pathology was not associated with horse age, length of career or number of career starts.
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Affiliation(s)
- T D H Parkin
- Department of Veterinary Clinical Science, University of Liverpool Veterinary Teaching Hospital, Leahurst, Neston CH64 7TE, UK.
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Radtke CL, Danova NA, Scollay MC, Santschi EM, Markel MD, Da Costa Gómez T, Muir P. Macroscopic changes in the distal ends of the third metacarpal and metatarsal bones of Thoroughbred racehorses with condylar fractures. Am J Vet Res 2003; 64:1110-6. [PMID: 13677388 DOI: 10.2460/ajvr.2003.64.1110] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine changes in the distal ends of the third metacarpal and metatarsal bones (MCIII and MTIII) of Thoroughbred racehorses that had sustained a catastrophic condylar fracture during high-speed exercise. SAMPLE POPULATION Fractured and contralateral MCIIIs and MTIIIs from 11 Thoroughbred racehorses that sustained a displaced condylar fracture during racing, both MCIIIs from 5 Thoroughbred racehorses euthanatized because of a catastrophic injury other than a condylar fracture, and both MCIIIs from 5 horses of other breeds that had not been professionally trained or raced. PROCEDURE Macroscopic observations were made of the distal ends of the bones before and after digestion of the articular cartilage with NaOH. RESULTS In all 11 racehorses with a displaced condylar fracture, the fracture was associated with a branching array of cracks in the condylar groove. In this region, fracture margins were smooth, and there was loss of subchondral bone. Comminution of the dorsal cortex was also seen. Parasagittal linear wear lines in the articular cartilage, erosions in the articular cartilage of the condyles, loss of the underlying subchondral bone, and cracking of condylar grooves were all more severe in the Thoroughbred racehorses than in the horses that had not been professionally trained or raced. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that condylar fractures in horses are pathologic fatigue or stress fractures that arise from a preexisting, branching array of cracks in the condylar groove of the distal end of MCIII or MTIII.
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Affiliation(s)
- Catherine L Radtke
- Comparative Orthopaedic Research Laboratory, Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA
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Le Jeune SS, Macdonald MH, Stover SM, Taylor KT, Gerdes M. Biomechanical investigation of the association between suspensory ligament injury and lateral condylar fracture in thoroughbred racehorses. Vet Surg 2003; 32:585-97. [PMID: 14648539 DOI: 10.1111/j.1532-950x.2003.00585.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Objective-To determine whether partial transection of the medial branch of the suspensory ligament (MBSL) alters equine third metacarpal bone (MC3) condylar surface strains and forelimb, distal joint angles in a manner consistent with promotion of lateral condylar fracture. Study Design-In vitro biomechanical experiment. Sample Population-Right forelimbs from 7 Thoroughbred horse cadavers. Methods-Lateral and medial MC3 condylar, dorsal and abaxial, bone surface strains and distal joint angles were measured both before and after partial transection of the MBSL during in vitro axial limb compression. Dorsal, principal bone strains and abaxial, uniaxial, and proximodistal strains were compared before and after MBSL partial transection at 1,400-, 3,000-, and 5,600-N loads. Results-Bone strains increased in all locations with increasing axial load. All lateral condylar bone strains were significantly higher, and abaxial surface medial condylar bone strain was significantly lower, after partial transection of the MBSL. Respective distal joints became more flexed or extended as axial load increased but were not significantly different after partial transection of the MBSL. Conclusions-Partial transection of the MBSL increases in vitro MC3 lateral condylar bone surface strains. Clinical Relevance-Loss of integrity of the medial branch of the suspensory ligament could increase the risk for lateral condylar fracture in Thoroughbred horses by amplifying bone strain in the lateral condyle.
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Affiliation(s)
- Sarah S Le Jeune
- Veterinary Medical Teaching Hospital, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Ellis D. Fractures--a preventable hazard of racing thoroughbreds. Vet J 2002; 163:5-6. [PMID: 11749131 DOI: 10.1053/tvjl.2001.0609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Fractures are a common cause of loss among Thoroughbred racehorses. A large proportion of these injuries occurs in the absence of a specific traumatic event and show typical characteristics of stress fractures. The fractures show a high degree of consistency in their morphology; they frequently share the same locations as incomplete cracks and they are often associated with pre-existing pathology (periosteal and endosteal new bone formation and intracortical remodelling). Bone is able to adapt to changes in its mechanical environment. Studies of the Thoroughbred racehorse show modification of the geometric properties of the third metacarpal bone in response to training. These modifications are associated with reduced bone strains. Intense training before the adaptive response is completed and bone strain reduced increases the risk of fatigue damage. Fatigue of bone is associated with progressive microdamage, which is important in the pathogenesis of stress fractures. However, the biological repair mechanism of bone (remodelling) is also instrumental in the development of stress fractures. Horses exercised before bone repair is complete are likely to be at significantly greater risk of sustaining a catastrophic stress fracture. A number of key questions regarding the importance of microdamage, remodelling and training schedules in the prevention of stress fractures are addressed in this review.
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Affiliation(s)
- C M Riggs
- Oakey Veterinary Hospital, Oakey, Queensland, 4401, Australia.
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Martin GS. Factors associated with racing performance of Thoroughbreds undergoing lag screw repair of condylar fractures of the third metacarpal or metatarsal bone. J Am Vet Med Assoc 2000; 217:1870-7. [PMID: 11132895 DOI: 10.2460/javma.2000.217.1870] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate effects of sex, fracture configuration, affected limb, and screw placement on outcome of Thoroughbreds with condylar fractures involving the third metacarpal or metatarsal bone. DESIGN Cohort study. Animals-56 horses. PROCEDURE Age, sex, affected limb, fracture configuration, fracture length, fracture fragment width, and distance of the most distal screw from the articular surface were analyzed in logistic regression models. RESULTS Females were more likely to have displaced fractures and race in fewer races after surgery than males. Sex and fracture configuration were associated with number of postoperative races. Among horses that returned to racing, those with thicker fracture fragments were 11 times as likely as horses with thinner fracture fragments to win a race after surgery. Horses with longer fractures and older horses had fewer postoperative races. Horses in which the most distal screw had been placed further from the joint surface had more races. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that female horses with displaced condylar fractures and male horses with nondisplaced condylar fractures are more likely to be referred for treatment. The effect of sex on outcome for these horses cannot be clearly separated from the effect of fracture configuration. When adjusted for fracture configuration, males were 6 times as likely as females to race after surgery. When adjusted for sex, horses with nondisplaced fractures were 17 times as likely as horses with displaced fractures to race after surgery. Results suggest that the most distal screw should be placed above the epicondylar fossa.
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Affiliation(s)
- G S Martin
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803, USA
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Zekas LJ, Bramlage LR, Embertson RM, Hance SR. Results of treatment of 145 fractures of the third metacarpal/metatarsal condyles in 135 horses (1986-1994). Equine Vet J 1999; 31:309-13. [PMID: 10454089 DOI: 10.1111/j.2042-3306.1999.tb03822.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The objectives of this study were to correlate condylar fracture characteristics and type of treatment with subsequent capacity for athletic ability, and to determine the characteristics of healing that affect prognosis after fracture fixation. Medical records, post operative radiographic studies and race records were examined for 135 horses sustaining 145 fractures. Sixty-five percent of horses overall started in a race post injury (SPI) in a mean time of 9.7 months with a mean of 13.7 races post injury. Having raced pre-injury did not confer an advantage to starting post injury, though nonstarters pre-injury tended to take longer to return. For horses starting pre- and post injury, 66% improved or maintained their race class level after injury, whereas 64.2% decreased their race earnings post injury. Eighty-five percent of the fractures received internal fixation, of which 70% were complete fractures. Eighty-seven percent of horses with incomplete-nondisplaced fractures treated conservatively raced post injury. The percent SPI for incomplete-nondisplaced, complete-nondisplaced and complete-displaced fractures treated with internal fixation were 74%, 58%, and 60%, respectively. Males (72%) raced post injury more frequently than fillies (53%), and may represent a truer probability of SPI. Spiral fractures tended to take longer until their first start (mean 13.3 months). Fifty-two percent of horses with articular fragments were able to race post injury. Horses were more likely to start if 2-4 month radiographic healing revealed no evidence of the fracture except the presence of lag screws. Based on this series of cases, the majority of horses, with proper treatment, were able to return to racing regardless of fracture characteristic. Prognosis appeared to be affected by the severity of the injury to the joint, the presence of articular comminution and the quality of surgical repair.
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Affiliation(s)
- L J Zekas
- Rood and Riddle Equine Hospital, Lexington, Kentucky 40580-2070, USA
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Zekas LJ, Bramlage LR, Embertson RM, Hance SR. Characterisation of the type and location of fractures of the third metacarpal/metatarsal condyles in 135 horses in central Kentucky (1986-1994). Equine Vet J 1999; 31:304-8. [PMID: 10454088 DOI: 10.1111/j.2042-3306.1999.tb03821.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The objective of this retrospective study was to provide a detailed description of the characteristics of condylar fractures represented in a population of 135 horses who sustained 145 fractures. Records and radiographic studies were examined. Fifty-nine percent of the horses were male and the majority Thoroughbreds. The distribution of fractures was 37% incomplete-nondisplaced, 30% complete-nondisplaced and 32% complete-displaced. The right front was more likely to sustain a complete-displaced fracture, whereas the left front was more likely to sustain an incomplete-nondisplaced fracture. Forelimbs (81%) and lateral condyles (85%) were more likely to be involved. Contrary to previous studies, the right forelimb was slightly more often involved than the left. Fractures tended to involve the middle portion of the condyle (59%). The mean length of all fractures was 75+/-3.8 mm. Axial fractures and medial condyle fractures tended to be longer. Fifteen percent of the fractures had definitive articular comminution. Ninety-five percent of fractures with articular comminution were associated with complete fractures. When fractures entered the middle area of the condyle, 23% had articular comminution. Eight of the fractures spiralled, all involved forelimbs. Concurrent lesions included proximal phalanx chip fractures, sesamoid fractures, sesamoiditis, proximal phalanx fractures, 'splint' bone periostitis and ligamentous injuries. The complete description of the fractures in this group of horses allows us better to define the condylar fracture, compare these fractures to previous studies and establish new data for use in defining prognosis.
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Affiliation(s)
- L J Zekas
- Rood and Riddle Equine Hospital, Lexington, Kentucky 40580-2070, USA
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Riggs CM, Whitehouse GH, Boyde A. Pathology of the distal condyles of the third metacarpal and third metatarsal bones of the horse. Equine Vet J 1999; 31:140-8. [PMID: 10213426 DOI: 10.1111/j.2042-3306.1999.tb03807.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study examined material from Thoroughbred horses, the majority of which had been in race training, for evidence of pathology in the third metacarpal (McIII) and third metatarsal (MtIII) bones which might be related to the occurrence of distal condylar fractures. Whole bone samples were studied and documented by macrophotography prior to macroradiography and computed tomographic (CT) imaging. Microradiographs were made from 100 microm thick mediolateral sections cut perpendicular to the dorsal and palmar/plantar articular surfaces of distal condylar regions of McIII and MtIII. Blocks were prepared for morphological imaging using the backscattered electron mode of scanning electron microscopy (BSE SEM). Linear defects in mineralised articular cartilage and subchondral bone were found in the palmar/plantar aspects of the condylar grooves adjacent to the sagittal ridge. These were closely related to the pattern of densification of the subchondral bone and were associated with intense focal remodelling of the immediately adjacent and subjacent bone. Parasagittal fractures of the condyles originated in similar defects. A unifying hypothesis for the aetiopathogenesis of these fractures is presented.
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Affiliation(s)
- C M Riggs
- Department of Veterinary Clinical Science, University of Liverpool, Neston, UK
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Boyde A, Haroon Y, Jones SJ, Riggs CM. Three dimensional structure of the distal condyles of the third metacarpal bone of the horse. Equine Vet J 1999; 31:122-9. [PMID: 10213424 DOI: 10.1111/j.2042-3306.1999.tb03805.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study examined the three-dimensional (3D) microarchitecture of regions of the equine third metacarpal bone (McIII) commonly involved in distal condylar fractures. Limbs were obtained from Thoroughbred horses (neonates to age 24 years) destroyed for inoperable fractures and a variety of other conditions. Beams, blocks and sections were cut in the principal axes, some embedded in PMMA and others examined unembedded. Several methods were used to study the 3D structure, including conventional and confocal optical microscopy, scanning electron microscopy (SEM) and radiography. The mineralised articular cartilage tends to cleave in the sagittal plane. Proximal to the subchondral bone, the main trabeculae are robust plates running in the sagittal direction with less significant mediolateral connections. Small blood vessel canals lie inside the sagittal plates. This structure gives maximum strength and protection in the sagittal plane in which the bone rotates, but offers minimal resistance to fracture propagation in this plane. The anatomical course of the common distal condylar fractures of the third metacarpal bones can be explained by underlying anisotropic structural features of the mineralised tissues.
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Affiliation(s)
- A Boyde
- Department of Anatomy and Developmental Biology, University College London, UK
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Riggs CM. Aetiopathogenesis of parasagittal fractures of the distal condyles of the third metacarpal and third metatarsal bones--review of the literature. Equine Vet J 1999; 31:116-20. [PMID: 10213423 DOI: 10.1111/j.2042-3306.1999.tb03803.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fractures are the cause of considerable morbidity and mortality among Thoroughbred racehorses. A significant proportion of these injuries occur in the absence of any particular traumatic incident. Evidence of prefracture pathology interpreted as fatigue damage has been identified in some such cases, but the aetiology of many of these so-called 'spontaneous' fractures remains obscure. Parasagittal fractures of the third metacarpal (McIII) and third metatarsal (MtIII) bones are one of the more common fractures to affect Thoroughbred racehorses. The configuration of each of these fracture types is highly consistent, suggesting a predisposition of the bones to these injuries. Several theories have been proposed to explain the aetiopathogenesis of these fractures although none has so far stood up to critical examination. The current paper reviews the literature relating to parasagittal fractures of McIII and MtIII.
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Affiliation(s)
- C M Riggs
- Department of Veterinary Clinical Science and Animal Husbandry, University of Liverpool, Neston, UK
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