1
|
Song L, Golman M, Abraham AC, Zelzer E, Thomopoulos S. A role for TGFβ signaling in Gli1+ tendon and enthesis cells. FASEB J 2024; 38:e23568. [PMID: 38522021 PMCID: PMC10962263 DOI: 10.1096/fj.202301452r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 02/16/2024] [Accepted: 03/07/2024] [Indexed: 03/25/2024]
Abstract
The development of musculoskeletal tissues such as tendon, enthesis, and bone relies on proliferation and differentiation of mesenchymal progenitor cells. Gli1+ cells have been described as putative stem cells in several tissues and are presumed to play critical roles in tissue formation and maintenance. For example, the enthesis, a fibrocartilage tissue that connects tendon to bone, is mineralized postnatally by a pool of Gli1+ progenitor cells. These cells are regulated by hedgehog signaling, but it is unclear if TGFβ signaling, necessary for tenogenesis, also plays a role in their behavior. To examine the role of TGFβ signaling in Gli1+ cell function, the receptor for TGFβ, TbR2, was deleted in Gli1-lineage cells in mice at P5. Decreased TGFβ signaling in these cells led to defects in tendon enthesis formation by P56, including defective bone morphometry underlying the enthesis and decreased mechanical properties. Immunohistochemical staining of these Gli1+ cells showed that loss of TGFβ signaling reduced proliferation and increased apoptosis. In vitro experiments using Gli1+ cells isolated from mouse tail tendons demonstrated that TGFβ controls cell proliferation and differentiation through canonical and non-canonical pathways and that TGFβ directly controls the tendon transcription factor scleraxis by binding to its distant enhancer. These results have implications in the development of treatments for tendon and enthesis pathologies.
Collapse
Affiliation(s)
- Lee Song
- Department of Orthopedic Surgery, Columbia University, New York, NY10032, USA
| | - Mikhail Golman
- Department of Orthopedic Surgery, Columbia University, New York, NY10032, USA
- Department of Biomedical Engineering, Columbia University, New York, NY10027, USA
| | - Adam C. Abraham
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Elazar Zelzer
- Department of Molecular Genetics, Weizmann Institute of Science, Israel
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University, New York, NY10032, USA
- Department of Biomedical Engineering, Columbia University, New York, NY10027, USA
| |
Collapse
|
2
|
Luzzi AJ, Ferrer X, Fang F, Golman M, Song L, Marshall BP, Lee AJ, Kim JJ, Hung CT, Thomopoulos S. Hedgehog Activation for Enhanced Rotator Cuff Tendon-to-Bone Healing. Am J Sports Med 2023; 51:3825-3834. [PMID: 37897335 PMCID: PMC10821775 DOI: 10.1177/03635465231203210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/30/2023]
Abstract
BACKGROUND Rotator cuff repair is a common orthopaedic procedure, yet the rate of failure to heal after surgery is high. Repair site rupture is due to poor tendon-to-bone healing and lack of regeneration of the native fibrocartilaginous enthesis. During development, the enthesis is formed and mineralized by a pool of progenitors activated by hedgehog signaling. Furthermore, hedgehog signaling drives regenerative enthesis healing in young animals, in contrast to older animals, in which enthesis injuries heal via fibrovascular scar and without participation of hedgehog signaling. HYPOTHESIS Hedgehog activation improves tendon-to-bone healing in an animal model of rotator cuff repair. STUDY DESIGN Controlled laboratory study. METHODS A total of 78 adult Sprague-Dawley rats were used. Supraspinatus tendon injury and repair were completed bilaterally, with microsphere-encapsulated hedgehog agonist administered to right shoulders and control microspheres administered to left shoulders. Animals were sacrificed after 3, 14, 28, or 56 days. Gene expression and histological, biomechanical, and bone morphometric analyses were conducted. RESULTS At 3 days, hedgehog signaling pathway genes Gli1 (1.70; P = .029) and Smo (2.06; P = .0173), as well as Runx2 (1.69; P = .0386), a transcription factor of osteogenesis, were upregulated in treated relative to control repairs. At 14 days, transcription factors of tenogenesis, Scx (4.00; P = .041), and chondrogenesis, Sox9 (2.95; P = .010), and mineralized fibrocartilage genes Col2 (3.18; P = .031) and Colx (1.85; P = .006), were upregulated in treated relative to control repairs. Treatment promoted fibrocartilage formation at the healing interface by 28 days, with improvements in tendon-bone maturity, organization, and continuity. Treatment led to improved biomechanical properties. The material property strength (2.43 vs 1.89 N/m2; P = .046) and the structural property work to failure (29.01 vs 18.09 mJ; P = .030) were increased in treated relative to control repairs at 28 days and 56 days, respectively. Treatment had a marginal effect on bone morphometry underlying the repair. Trabecular thickness (0.08 vs 0.07 mm; P = .035) was increased at 28 days. CONCLUSION Hedgehog agonist treatment activated hedgehog signaling at the tendon-to-bone repair site and prompted increased mineralized fibrocartilage production. This extracellular matrix production and mineralization resulted in improved biomechanical properties, demonstrating the therapeutic potential of hedgehog agonism for improving tendon-to-bone healing after rotator cuff repair. CLINICAL RELEVANCE This study demonstrates the therapeutic potential of hedgehog agonist treatment for improving tendon-to-bone healing after rotator cuff injury and repair.
Collapse
Affiliation(s)
- Andrew J. Luzzi
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
| | - Xavier Ferrer
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
| | - Fei Fang
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
| | - Mikhail Golman
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Lee Song
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
| | - Brittany P. Marshall
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Andy J. Lee
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Jieon J. Kim
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
| | - Clark T. Hung
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Stavros Thomopoulos
- Department of Orthopaedic Surgery, Columbia University, New York, New York, USA
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| |
Collapse
|
3
|
Abraham AC, Fang F, Golman M, Oikonomou P, Thomopoulos S. The role of loading in murine models of rotator cuff disease. J Orthop Res 2022; 40:977-986. [PMID: 34081350 PMCID: PMC8639823 DOI: 10.1002/jor.25113] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/07/2021] [Accepted: 05/31/2021] [Indexed: 02/04/2023]
Abstract
Rotator cuff disease pathogenesis is associated with intrinsic (e.g., age, joint laxity, muscle weakness) and extrinsic (e.g., mechanical load, fatigue) factors that lead to chronic degeneration of the cuff tissues. However, etiological studies are difficult to perform in patients due to the long duration of disease onset and progression. Therefore, the purpose of this study was to determine the effects of altered joint loading on the rotator cuff. Mice were subjected to one of three load-dependent rotator cuff tendinopathy models: underuse loading, achieved by injecting botulinum toxin-A into the supraspinatus muscle; overuse loading, achieved using downhill treadmill running; destabilization loading, achieved by surgical excision of the infraspinatus tendon. All models were compared to cage activity animals. Whole joint function was assessed longitudinally using gait analysis. Tissue-scale structure and function were determined using microCT, tensile testing, and histology. The molecular response of the supraspinatus tendon and enthesis was determined by measuring the expression of 84 wound healing-associated genes. Underuse and destabilization altered forepaw weight-bearing, decreased tendon-to-bone attachment strength, decreased mineral density of the humeral epiphysis, and reduced tendon strength. Transcriptional activity of the underuse group returned to baseline levels by 4 weeks, while destabilization had significant upregulation of inflammation, growth factors, and extracellular matrix remodeling genes. Surprisingly, overuse activity caused changes in walking patterns, increased tendon stiffness, and primarily suppressed expression of wound healing-related genes. In summary, the tendinopathy models demonstrated how divergent muscle loading can result in clinically relevant alterations in rotator cuff structure, function, and gene expression.
Collapse
Affiliation(s)
- Adam C. Abraham
- University of Michigan, Department of Orthopaedic Surgery, Biomedical Science Research Building, 109 Zina Pitcher Pl, Ann Arbor, MI 48109, USA,Corresponding author Adam C. Abraham, Ph.D., Research Investigator, University of Michigan, Department of Orthopaedic Surgery, Ann Arbor, MI 48109, USA,
| | - Fei Fang
- Columbia University Irving Medical Center, Department of Orthopaedic Surgery, New York, NY 10032, USA
| | - Mikhail Golman
- Columbia University, Department of Biomedical Engineering, New York, NY 10027
| | | | - Stavros Thomopoulos
- Columbia University Irving Medical Center, Department of Orthopaedic Surgery, New York, NY 10032, USA,Columbia University, Department of Biomedical Engineering, New York, NY 10027
| |
Collapse
|
4
|
Golman M, Birman V, Thomopoulos S, Genin GM. Enthesis strength, toughness and stiffness: an image-based model comparing tendon insertions with varying bony attachment geometries. J R Soc Interface 2021; 18:20210421. [PMID: 34932930 PMCID: PMC8692040 DOI: 10.1098/rsif.2021.0421] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Tendons of the body differ dramatically in their function, mechanics and range of motion, but all connect to bone via an enthesis. Effective force transfer at the enthesis enables joint stability and mobility, with strength and stiffness arising from a fibrous architecture. However, how enthesis toughness arises across tendons with diverse loading orientations remains unclear. To study this, we performed simultaneous imaging of the bone and tendon in entheses that represent the range of tendon-to-bone insertions and extended a mathematical model to account for variations in insertion and bone geometry. We tested the hypothesis that toughness, across a range of tendon entheses, could be explained by differences observed in interactions between fibre architecture and bone architecture. In the model, toughness arose from fibre reorientation, recruitment and rupture, mediated by interactions between fibres at the enthesis and the bony ridge abutting it. When applied to tendons sometimes characterized as either energy-storing or positional, the model predicted that entheses of the former prioritize toughness over strength, while those of the latter prioritize consistent stiffness across loading directions. Results provide insight into techniques for surgical repair of tendon-to-bone attachments, and more broadly into mechanisms for the attachment of highly dissimilar materials.
Collapse
Affiliation(s)
- Mikhail Golman
- Columbia University, Black Building, Room 1408, 650 W 168 ST, New York, NY 10032-3702, USA
| | - Victor Birman
- Missouri University of Science and Technology, Rolla, MO 65409, USA
| | - Stavros Thomopoulos
- Columbia University, Black Building, Room 1408, 650 W 168 ST, New York, NY 10032-3702, USA
| | - Guy M. Genin
- Washington University, Jubel Hall, Room 103F, 1 Brookings Drive, St Louis, MO 63130, USA
| |
Collapse
|
5
|
Golman M, Abraham AC, Kurtaliaj I, Marshall BP, Hu YJ, Schwartz AG, Guo XE, Birman V, Thurner PJ, Genin GM, Thomopoulos S. Toughening mechanisms for the attachment of architectured materials: The mechanics of the tendon enthesis. Sci Adv 2021; 7:eabi5584. [PMID: 34826240 PMCID: PMC8626067 DOI: 10.1126/sciadv.abi5584] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/06/2021] [Indexed: 05/09/2023]
Abstract
Architectured materials offer tailored mechanical properties but are limited in engineering applications due to challenges in maintaining toughness across their attachments. The enthesis connects tendon and bone, two vastly different architectured materials, and exhibits toughness across a wide range of loadings. Understanding the mechanisms by which this is achieved could inform the development of engineered attachments. Integrating experiments, simulations, and previously unexplored imaging that enabled simultaneous observation of mineralized and unmineralized tissues, we identified putative mechanisms of enthesis toughening in a mouse model and then manipulated these mechanisms via in vivo control of mineralization and architecture. Imaging uncovered a fibrous architecture within the enthesis that controls trade-offs between strength and toughness. In vivo models of pathology revealed architectural adaptations that optimize these trade-offs through cross-scale mechanisms including nanoscale protein denaturation, milliscale load-sharing, and macroscale energy absorption. Results suggest strategies for optimizing architecture for tough bimaterial attachments in medicine and engineering.
Collapse
Affiliation(s)
- Mikhail Golman
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Adam C. Abraham
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032, USA
| | - Iden Kurtaliaj
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Brittany P. Marshall
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Yizhong Jenny Hu
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Andrea G. Schwartz
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University, St. Louis, MO 63130, USA
| | - X. Edward Guo
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Victor Birman
- Missouri University of Science and Technology, Rolla, MO 65409, USA
| | - Philipp J. Thurner
- Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, Vienna, Austria
| | - Guy M. Genin
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University, St. Louis, MO 63130, USA
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University, New York, NY 10032, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| |
Collapse
|
6
|
Abstract
BACKGROUND More than 450,000 rotator cuff repairs are performed annually, yet healing of tendon to bone often fails. This failure is rooted in the fibrovascular healing response, which does not regenerate the native attachment site. Better healing outcomes may be achieved by targeting inflammation during the early period after repair. Rather than broad inhibition of inflammation, which may impair healing, the current study utilized a molecularly targeted approach to suppress IKKβ, shutting down only the inflammatory arm of the nuclear factor κB (NF-κB) signaling pathway. PURPOSE To evaluate the therapeutic potential of IKKβ inhibition in a clinically relevant model of rat rotator cuff repair. STUDY DESIGN Controlled laboratory study. METHODS After validating the efficacy of the IKKβ inhibitor in vitro, it was administered orally once a day for 7 days after surgery in a rat rotator cuff repair model. The effect of treatment on reducing inflammation and improving repair quality was evaluated after 3 days and 2, 4, and 8 weeks of healing, using gene expression, biomechanics, bone morphometry, and histology. RESULTS Inhibition of IKKβ attenuated cytokine and chemokine production in vitro, demonstrating the potential for this inhibitor to reduce inflammation in vivo. Oral treatment with IKKβ inhibitor reduced NF-κB target gene expression by up to 80% compared with a nontreated group at day 3, with a subset of these genes suppressed through 14 days. Furthermore, the IKKβ inhibitor led to enhanced tenogenesis and extracellular matrix production, as demonstrated by gene expression and histological analyses. At 4 weeks, inhibitor treatment led to increased toughness, no effects on failure load and strength, and decreases in stiffness and modulus when compared with vehicle control. At 8 weeks, IKKβ inhibitor treatment led to increased toughness, failure load, and strength compared with control animals. IKKβ inhibitor treatment prevented the bone loss near the tendon attachment that occurred in repairs in control. CONCLUSION Pharmacological inhibition of IKKβ successfully suppressed excessive inflammation and enhanced tendon-to-bone healing after rotator cuff repair in a rat model. CLINICAL RELEVANCE The NF-κB pathway is a promising target for enhancing outcomes after rotator cuff repair.
Collapse
Affiliation(s)
- Mikhail Golman
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Xiaoning Li
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Dimitrios Skouteris
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Adam A. Abraham
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Lee Song
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Yousef Abu-Amer
- Department of Orthopaedic Surgery, Washington University, St Louis, Missouri, USA
| | - Stavros Thomopoulos
- Department of Biomedical Engineering, Columbia University, New York, New York, USA.,Department of Orthopedic Surgery, Columbia University, New York, New York, USA.,Address correspondence to Stavros Thomopoulos, PhD, Carroll Laboratories of Orthopedic Research, Columbia University, Black Building, Room 1408, 650 W 168 St, New York, NY 10032-3702, USA () (Twitter: @ThomopoulosLab)
| |
Collapse
|
7
|
Abraham AC, Shah SA, Golman M, Song L, Li X, Kurtaliaj I, Akbar M, Millar NL, Abu-Amer Y, Galatz LM, Thomopoulos S. Targeting the NF-κB signaling pathway in chronic tendon disease. Sci Transl Med 2020; 11:11/481/eaav4319. [PMID: 30814338 DOI: 10.1126/scitranslmed.aav4319] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/31/2019] [Indexed: 01/20/2023]
Abstract
Tendon disorders represent the most common musculoskeletal complaint for which patients seek medical attention; inflammation drives tendon degeneration before tearing and impairs healing after repair. Clinical evidence has implicated the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway as a correlate of pain-free return to function after surgical repair. However, it is currently unknown whether this response is a reaction to or a driver of pathology. Therefore, we aimed to understand the clinically relevant involvement of the NF-κB pathway in tendinopathy, to determine its potential causative roles in tendon degeneration, and to test its potential as a therapeutic candidate. Transcriptional profiling of early rotator cuff tendinopathy identified increases in NF-κB signaling, including increased expression of the regulatory serine kinase subunit IKKβ, which plays an essential role in inflammation. Using cre-mediated overexpression of IKKβ in tendon fibroblasts, we observed degeneration of mouse rotator cuff tendons and the adjacent humeral head. These changes were associated with increases in proinflammatory cytokines and innate immune cells within the joint. Conversely, genetic deletion of IKKβ in tendon fibroblasts partially protected mice from chronic overuse-induced tendinopathy. Furthermore, conditional knockout of IKKβ improved outcomes after surgical repair, whereas overexpression impaired tendon healing. Accordingly, targeting of the IKKβ/NF-κB pathway in tendon stromal cells may offer previously unidentified therapeutic approaches in the management of human tendon disorders.
Collapse
Affiliation(s)
- Adam C Abraham
- Department of Orthopedic Surgery, Columbia University, 650 W 168th St, New York, NY 10032, USA
| | - Shivam A Shah
- Department of Biomedical Engineering, Washington University in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Mikhail Golman
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Ave, New York, NY 10027, USA
| | - Lee Song
- Department of Orthopedic Surgery, Columbia University, 650 W 168th St, New York, NY 10032, USA
| | - Xiaoning Li
- Department of Orthopedic Surgery, Columbia University, 650 W 168th St, New York, NY 10032, USA
| | - Iden Kurtaliaj
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Ave, New York, NY 10027, USA
| | - Moeed Akbar
- Institute of Infection, Immunity and Inflammation, College of Medicine, Veterinary and Life Sciences, University of Glasgow, 120 University Ave., Glasgow, Scotland G12 8TA, UK
| | - Neal L Millar
- Institute of Infection, Immunity and Inflammation, College of Medicine, Veterinary and Life Sciences, University of Glasgow, 120 University Ave., Glasgow, Scotland G12 8TA, UK
| | - Yousef Abu-Amer
- Departments of Orthopedic Surgery and Cell Biology and Physiology, Washington University in St. Louis, 660 S. Euclid Ave., St. Louis, MO 63110, USA.,Shriners Hospital for Children, 4400 Clayton Ave, St. Louis, MO 63110, USA
| | - Leesa M Galatz
- Department of Orthopedic Surgery, Mount Sinai, 5 E 98th St., New York, NY 10029, USA
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University, 650 W 168th St, New York, NY 10032, USA. .,Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Ave, New York, NY 10027, USA
| |
Collapse
|
8
|
Golman M, Wright ML, Wong TT, Lynch TS, Ahmad CS, Thomopoulos S, Popkin CA. Rethinking Patellar Tendinopathy and Partial Patellar Tendon Tears: A Novel Classification System. Am J Sports Med 2020; 48:359-369. [PMID: 31913662 DOI: 10.1177/0363546519894333] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Patellar tendinopathy is an overuse injury of the patellar tendon frequently affecting athletes involved in jumping sports. The tendinopathy may progress to partial patellar tendon tears (PPTTs). Current classifications of patellar tendinopathy are based on symptoms and do not provide satisfactory evidence-based treatment guidelines. PURPOSE To define the relationship between PPTT characteristics and treatment guidelines, as well as to develop a magnetic resonance imaging (MRI)-based classification system for partial patellar tendon injuries. STUDY DESIGN Cohort study (prognosis); Level of evidence, 2. METHODS MRI characteristics and clinical treatment outcomes were retrospectively reviewed for 85 patients with patellar tendinopathy, as well as 86 physically active control participants who underwent MRI of the knee for other conditions. A total of 56 patients had a PPTT and underwent further evaluation for tear size and location. The relationship between tear characteristics and clinical outcome was defined with use of statistical comparisons and univariate and logistic regression models. RESULTS Of the 85 patients, 56 had partial-thickness patellar tendon tears. Of these tears, 91% involved the posterior and posteromedial regions of the proximal tendon. On axial MRI views, patients with a partial tear had a mean tendon thickness of 10 mm, as compared with 6.2 mm for those without (P < .001). Eleven patients underwent surgery for their partial-thickness tear. All of these patients had a tear >50% of tendon thickness (median thickness of tear, 10.3 mm) on axial views. Logistic regression showed that tendon thickness >8.8 mm correlated with the presence of a partial tear, while tendon thickness >11.45 mm and tear thickness >55.7% predicted surgical management. CONCLUSION Partial-thickness tears are located posterior or posteromedially in the proximal patellar tendon. The most sensitive predictor for detecting the presence of a partial tear was patellar tendon thickness, in which thickness >8.8 mm was strongly correlated with a tear of the tendon. Tracking thickness changes on axial MRI may predict the effectiveness of nonoperative therapy: athletes with patellar tendon thickness >11.5 mm and/or >50% tear thickness on axial MRI were less likely to improve with nonoperative treatment. A novel proposed classification system for partial tears, the Popkin-Golman classification, can be used to guide treatment decisions for these patients.
Collapse
Affiliation(s)
- Mikhail Golman
- Department of Orthopedic Surgery, Columbia University Medical Center, New York, New York, USA.,Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Margaret L Wright
- Center for Shoulder, Elbow and Sports Medicine, Columbia University, New York, New York, USA
| | - Tony T Wong
- Department of Musculoskeletal Radiology, Columbia University Medical Center, New York, New York, USA
| | - T Sean Lynch
- Center for Shoulder, Elbow and Sports Medicine, Columbia University, New York, New York, USA
| | - Christopher S Ahmad
- Center for Shoulder, Elbow and Sports Medicine, Columbia University, New York, New York, USA
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University Medical Center, New York, New York, USA.,Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Charles A Popkin
- Center for Shoulder, Elbow and Sports Medicine, Columbia University, New York, New York, USA
| |
Collapse
|
9
|
Abstract
Tendon disorders are common, affect people of all ages, and are often debilitating. Standard treatments, such as anti-inflammatory drugs, rehabilitation, and surgical repair, often fail. In order to define tendon function and demonstrate efficacy of new treatments, the mechanical properties of tendons from animal models must be accurately determined. Murine animal models are now widely used to study tendon disorders and evaluate novel treatments for tendinopathies; however, determining the mechanical properties of mouse tendons has been challenging. In this study, a new system was developed for tendon mechanical testing that includes 3D-printed fixtures that exactly match the anatomies of the humerus and calcaneus to mechanically test supraspinatus tendons and Achilles tendons, respectively. These fixtures were developed using 3D reconstructions of native bone anatomy, solid modeling, and additive manufacturing. The new approach eliminated artifactual gripping failures (e.g., failure at the growth plate failure rather than in the tendon), decreased overall testing time, and increased reproducibility. Furthermore, this new method is readily adaptable for testing other murine tendons and tendons from other animals.
Collapse
Affiliation(s)
- Iden Kurtaliaj
- Department of Orthopedic Surgery, Columbia University; Department of Biomedical Engineering, Columbia University
| | - Mikhail Golman
- Department of Orthopedic Surgery, Columbia University; Department of Biomedical Engineering, Columbia University
| | | | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University; Department of Biomedical Engineering, Columbia University;
| |
Collapse
|
10
|
Linderman SW, Golman M, Gardner TR, Birman V, Levine WN, Genin GM, Thomopoulos S. Enhanced tendon-to-bone repair through adhesive films. Acta Biomater 2018; 70:165-176. [PMID: 29427745 DOI: 10.1016/j.actbio.2018.01.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 01/04/2018] [Accepted: 01/23/2018] [Indexed: 12/16/2022]
Abstract
Tendon-to-bone surgical repairs have unacceptably high failure rates, possibly due to their inability to recreate the load transfer mechanisms of the native enthesis. Instead of distributing load across a wide attachment footprint area, surgical repairs concentrate shear stress on a small number of suture anchor points. This motivates development of technologies that distribute shear stresses away from suture anchors and across the enthesis footprint. Here, we present predictions and proof-of-concept experiments showing that mechanically-optimized adhesive films can mimic the natural load transfer mechanisms of the healthy attachment and increase the load tolerance of a repair. Mechanical optimization, based upon a shear lag model corroborated by a finite element analysis, revealed that adhesives with relatively high strength and low stiffness can, theoretically, strengthen tendon-to-bone repairs by over 10-fold. Lap shear testing using tendon and bone planks validated the mechanical models for a range of adhesive stiffnesses and strengths. Ex vivo human supraspinatus repairs of cadaveric tissues using multipartite adhesives showed substantial increase in strength. Results suggest that adhesive-enhanced repair can improve repair strength, and motivate a search for optimal adhesives. STATEMENT OF SIGNIFICANCE Current surgical techniques for tendon-to-bone repair have unacceptably high failure rates, indicating that the initial repair strength is insufficient to prevent gapping or rupture. In the rotator cuff, repair techniques apply compression over the repair interface to achieve contact healing between tendon and bone, but transfer almost all force in shear across only a few points where sutures puncture the tendon. Therefore, we evaluated the ability of an adhesive film, implanted between tendon and bone, to enhance repair strength and minimize the likelihood of rupture. Mechanical models demonstrated that optimally designed adhesives would improve repair strength by over 10-fold. Experiments using idealized and clinically-relevant repairs validated these models. This work demonstrates an opportunity to dramatically improve tendon-to-bone repair strength using adhesive films with appropriate material properties.
Collapse
|
11
|
Golman M, Padovano W, Shmuylovich L, Kovács SJ. Quantifying Diastolic Function: From E-Waves as Triangles to Physiologic Contours via the ‘Geometric Method’. Cardiovasc Eng Technol 2018; 9:105-119. [DOI: 10.1007/s13239-017-0339-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 12/23/2017] [Indexed: 10/18/2022]
|