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Camy C, Brioche T, Senni K, Bertaud A, Genovesio C, Lamy E, Fovet T, Chopard A, Pithioux M, Roffino S. Effects of hindlimb unloading and subsequent reloading on the structure and mechanical properties of Achilles tendon-to-bone attachment. FASEB J 2022; 36:e22548. [PMID: 36121701 DOI: 10.1096/fj.202200713r] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 08/10/2022] [Accepted: 09/02/2022] [Indexed: 11/11/2022]
Abstract
While muscle and bone adaptations to deconditioning have been widely described, few studies have focused on the tendon enthesis. Our study examined the effects of mechanical loading on the structure and mechanical properties of the Achilles tendon enthesis. We assessed the fibrocartilage surface area, the organization of collagen, the expression of collagen II, the presence of osteoclasts, and the tensile properties of the mouse enthesis both after 14 days of hindlimb suspension (HU) and after a subsequent 6 days of reloading. Although soleus atrophy was severe after HU, calcified fibrocartilage (CFc) was a little affected. In contrast, we observed a decrease in non-calcified fibrocartilage (UFc) surface area, collagen fiber disorganization, modification of morphological characteristics of the fibrocartilage cells, and altered collagen II distribution. Compared to the control group, restoring normal loads increased both UFc surface area and expression of collagen II, and led to a crimp pattern in collagen. Reloading induced an increase in CFc surface area, probably due to the mineralization front advancing toward the tendon. Functionally, unloading resulted in decreased enthesis stiffness and a shift in site of failure from the osteochondral interface to the bone, whereas 6 days of reloading restored the original elastic properties and site of failure. In the context of spaceflight, our results suggest that care must be taken when performing countermeasure exercises both during missions and during the return to Earth.
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Affiliation(s)
- Claire Camy
- Aix Marseille University, CNRS, ISM, Institute of Movement Sciences, Marseille, France
| | - Thomas Brioche
- DMEM, Montpellier University, INRAE, UMR 866, Montpellier, France
| | - Karim Senni
- Laboratoire EBInnov, Ecole de Biologie Industrielle-EBI, Cergy, France
| | - Alexandrine Bertaud
- Aix Marseille Univ, INSERM, INRAE, C2VN, Marseille, France.,Laboratoire de Biochimie, Faculté de Pharmacie, Marseille, France
| | - Cécile Genovesio
- Laboratoire de Biochimie, Faculté de Pharmacie, Marseille, France
| | - Edouard Lamy
- Aix Marseille University, CNRS, ISM, Institute of Movement Sciences, Marseille, France.,Laboratoire de Biochimie, Faculté de Pharmacie, Marseille, France
| | - Théo Fovet
- DMEM, Montpellier University, INRAE, UMR 866, Montpellier, France
| | - Angèle Chopard
- DMEM, Montpellier University, INRAE, UMR 866, Montpellier, France
| | - Martine Pithioux
- Aix Marseille University, CNRS, ISM, Institute of Movement Sciences, Marseille, France.,Department of Orthopaedics and Traumatology, Aix Marseille Univ, APHM, CNRS, ISM, Sainte-Marguerite Hospital, Institute for Locomotion, Marseille, France.,Aix Marseille Univ, APHM, CNRS, Centrale Marseille, ISM, Mecabio Platform, Anatomy Laboratory, Timone, Marseille, France
| | - Sandrine Roffino
- Aix Marseille University, CNRS, ISM, Institute of Movement Sciences, Marseille, France.,Aix Marseille Univ, APHM, CNRS, Centrale Marseille, ISM, Mecabio Platform, Anatomy Laboratory, Timone, Marseille, France
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2
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Forrester LA, Fang F, Jacobsen T, Hu Y, Kurtaliaj I, Roye BD, Guo XE, Chahine NO, Thomopoulos S. Transient neonatal shoulder paralysis causes early osteoarthritis in a mouse model. J Orthop Res 2022; 40:1981-1992. [PMID: 34812543 PMCID: PMC9124737 DOI: 10.1002/jor.25225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/08/2021] [Accepted: 11/20/2021] [Indexed: 02/04/2023]
Abstract
Neonatal brachial plexus palsy (NBPP) occurs in approximately 1.5 of every 1,000 live births. The majority of children with NBPP recover function of the shoulder. However, the long-term risk of osteoarthritis (OA) in this population is unknown. The purpose of this study was to investigate the development of OA in a mouse model of transient neonatal shoulder paralysis. Neonatal mice were injected twice per week for 4 weeks with saline in the right supraspinatus muscle (Saline, control) and botulinum toxin A (BtxA, transient paralysis) in the left supraspinatus muscle, and then allowed to recover for 20 or 36 weeks. Control mice received no injections, and all mice were sacrificed at 24 or 40 weeks. BtxA mice exhibited abnormalities in gait compared to controls through 10 weeks of age, but these differences did not persist into adulthood. BtxA shoulders had decreased bone volume (-9%) and abnormal trabecular microstructure compared to controls. Histomorphometry analysis demonstrated that BtxA shoulders had higher murine shoulder arthritis scale scores (+30%), and therefore more shoulder OA compared to controls. Articular cartilage of BtxA shoulders demonstrated stiffening of the tissue. Compared with controls, articular cartilage from BtxA shoulders had 2-fold and 10-fold decreases in Dkk1 and BMP2 expression, respectively, and 3-fold and 14-fold increases in Col10A1 and BGLAP expression, respectively, consistent with established models of OA. In summary, a brief period of paralysis of the neonatal mouse shoulder was sufficient to generate early signs of OA in adult cartilage and bone.
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Affiliation(s)
- Lynn Ann Forrester
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Fei Fang
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Timothy Jacobsen
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Yizhong Hu
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Iden Kurtaliaj
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Benjamin D. Roye
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - X. Edward Guo
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Nadeen O. Chahine
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
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3
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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: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [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.
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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
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Wang Z, Liu X, Liu M, Jiang K, Kajimura S, Kim H, Feeley BT. β 3-Adrenergic receptor agonist treats rotator cuff fatty infiltration by activating beige fat in mice. J Shoulder Elbow Surg 2021; 30:373-386. [PMID: 32599287 PMCID: PMC7765745 DOI: 10.1016/j.jse.2020.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 02/01/2023]
Abstract
BACKGROUND Rotator cuff (RC) muscle atrophy and fatty infiltration (FI) are independent factors correlated with failure of attempted tendon repair in larger RC tears. However, there is no effective treatment for RC muscle atrophy and FI at this time. The recent discovery of beige adipose tissue (BAT) in adults shed light on a new avenue in treating obesity and excessive fat deposition by promoting BAT activity. The goal of this study was to define the role of intramuscular BAT in RC muscle FI and the effect of β3-adrenergic receptor agonists in treating RC muscle FI by promoting BAT activity. MATERIALS AND METHODS Three-month-old wild-type C57BL/6J, platelet derived growth factor receptor-alpha (PDGFRα) green fluorescent protein (GFP) reporter and uncoupling protein 1 (UCP-1) knockout mice underwent a unilateral RC injury procedure, which included supraspinatus (SS) and infraspinatus tendon resection and suprascapular nerve transection. To stimulate BAT activity, amibegron, a selective β3-adrenergic receptor agonist, was administered to C57BL/6J mice either on the same day as surgery or 6 weeks after surgery through daily intraperitoneal injections. Gait analysis was conducted to measure forelimb function at 6 weeks or 12 weeks (in groups receiving delayed amibegron treatment) after surgery. Animals were killed humanely at 6 weeks (or 12 weeks for delayed amibegron groups) after surgery. SS muscles were harvested and analyzed histologically and biochemically. RESULTS Histologic analysis of SS muscles from PDGFRα-GFP reporter mice showed that PDGFRα-positive fibroadipogenic progenitors in RC muscle expressed UCP-1, a hallmark of BAT during the development of FI after RC tears. Impairing BAT activity by knocking out UCP-1 resulted in more severe muscle atrophy and FI with inferior forelimb function in UCP-1 knockout mice compared with wild-type mice. Promoting BAT activity with amibegron significantly reduced muscle atrophy and FI after RC tears and improved forelimb function. Delayed treatment with amibegron reversed muscle atrophy and FI in muscle. CONCLUSIONS Fat accumulated in muscle after RC tears possesses BAT characteristics. Impairing BAT activity results in worse RC muscle atrophy and FI. Amibegron reduces and reverses RC atrophy and FI by promoting BAT activity.
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Affiliation(s)
- Zili Wang
- Department of Orthopaedic Surgery, The Third Xiangya Hospital of Central South University, Changsha, China; San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA, USA; Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Xuhui Liu
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA, USA; Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Mengyao Liu
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA, USA; Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Kunqi Jiang
- Department of Orthopaedic Surgery, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Shingo Kajimura
- Diabetes Center, Department of Cell and Tissue Biology, The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA
| | - Hubert Kim
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA, USA; Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA, USA
| | - Brian T Feeley
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA, USA; Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA, USA.
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5
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Smith BW, Chang KWC, Koduri S, Yang LJS. Nerve graft versus nerve transfer for neonatal brachial plexus: shoulder outcomes. J Neurosurg Pediatr 2021; 27:87-92. [PMID: 33096523 DOI: 10.3171/2020.6.peds2027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/29/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The decision-making in neonatal brachial plexus palsy (NBPP) treatment continues to have many areas in need of clarification. Graft repair was the gold standard until the introduction of nerve transfer strategies. Currently, there is conflicting evidence regarding outcomes in patients with nerve grafts versus nerve transfers in relation to shoulder function. The objective of this study was to further define the outcomes for reconstruction strategies in NBPP with a specific focus on the shoulder. METHODS A cohort of patients with NBPP and surgical repairs from a single center were reviewed. Demographic and standard clinical data, including imaging and electrodiagnostics, were gathered from a clinical database. Clinical data from physical therapy evaluations, including active and passive range of motion, were examined. Statistical analysis was performed on the available data. RESULTS Forty-five patients met the inclusion criteria for this study, 19 with graft repair and 26 with nerve transfers. There were no significant differences in demographics between the two groups. Understandably, there were no patients in the nerve grafting group with preganglionic lesions, resulting in a difference in lesion type between the cohorts. There were no differences in preoperative shoulder function between the cohorts. Both groups reached statistically significant improvements in shoulder flexion and shoulder abduction. The nerve transfer group experienced a significant improvement in shoulder external rotation, from -78° to -28° (p = 0.0001), whereas a significant difference was not reached in the graft group. When compared between groups, there appeared to be a trend favoring nerve transfer in shoulder external rotation, with the graft patients improving by 17° and the transfer patients improving by 49° (p = 0.07). CONCLUSIONS In NBPP, patients with shoulder weakness experience statistically significant improvements in shoulder flexion and abduction after graft repair or nerve transfer, and patients with nerve transfers additionally experience significant improvement in external rotation. With regard to shoulder external rotation, there appear to be some data supporting the use of nerve transfers.
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6
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Mid-Term Outcome after Selective Neurotization of the Infraspinatus Muscle in Patients with Brachial Plexus Birth Injury. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2020; 8:e2605. [PMID: 32095409 PMCID: PMC7015608 DOI: 10.1097/gox.0000000000002605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/04/2019] [Indexed: 01/25/2023]
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7
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Kurtaliaj I, Golman M, Abraham AC, Thomopoulos S. Biomechanical Testing of Murine Tendons. J Vis Exp 2019:10.3791/60280. [PMID: 31680671 PMCID: PMC7217614 DOI: 10.3791/60280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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.
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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;
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8
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Olofsson PN, Chu A, McGrath AM. The Pathogenesis of Glenohumeral Deformity and Contracture Formation in Obstetric Brachial Plexus Palsy-A Review. J Brachial Plex Peripher Nerve Inj 2019; 14:e24-e34. [PMID: 31308856 PMCID: PMC6625958 DOI: 10.1055/s-0039-1692420] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 11/05/2018] [Indexed: 01/25/2023] Open
Abstract
Contractures of the shoulder joint and glenohumeral joint dysplasia are well known complications to obstetrical brachial plexus palsy. Despite extensive description of these sequelae, the exact pathogenesis remains unknown. The prevailing theory to explain the contractures and glenohumeral joint dysplasia states that upper trunk injury leads to nonuniform muscle recovery and thus imbalance between internal and external rotators of the shoulder. More recently, another explanation has been proposed, hypothesizing that denervation leads to reduced growth of developing muscles and that reinnervation might suppress contracture formation. An understanding of the pathogenesis is desirable for development of effective prophylactic treatment. This article aims to describe the current state of knowledge regarding these important complications.
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Affiliation(s)
- Pontus N Olofsson
- Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden.,Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden
| | - Alice Chu
- Department of Orthopedic Surgery, NYU Langone Orthopedic Hospital, New York, New York, United States
| | - Aleksandra M McGrath
- Department of Hand and Plastic Surgery, Norrland's University Hospital, Umeå, Sweden.,Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden.,Department of Clinical Science, Umeå University, Umeå, Sweden
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9
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Deymier AC, Schwartz AG, Cai Z, Daulton TL, Pasteris JD, Genin GM, Thomopoulos S. The multiscale structural and mechanical effects of mouse supraspinatus muscle unloading on the mature enthesis. Acta Biomater 2019; 83:302-313. [PMID: 30342287 DOI: 10.1016/j.actbio.2018.10.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 10/04/2018] [Accepted: 10/15/2018] [Indexed: 12/17/2022]
Abstract
The musculoskeletal system is sensitive to its loading environment; this is of particular concern under conditions such as disuse, paralysis, and extended-duration space flight. Although structural and mechanical changes to tendon and bone following paralysis and disuse are well understood, there is a pressing need to understand how this unloading affects the bone-tendon interface (enthesis); the location most prone to tears and injury. We therefore elucidated these effects of unloading in the entheses of adult mice shoulders that were paralyzed for 21 days by treatment with botulinum toxin A. Unloading significantly increased the extent of mechanical failure and was associated with structural changes across hierarchical scales. At the millimeter scale, unloading caused bone loss. At the micrometer scale, unloading decreased bioapatite crystal size and crystallographic alignment in the enthesis. At the nanometer scale, unloading induced compositional changes that stiffened the bioapatite/collagen composite tissue. Mathematical modeling and mechanical testing indicated that these factors combined to increase local elevations of stress while decreasing the ability of the tissue to absorb energy prior to failure, thereby increasing injury risk. These first observations of the multiscale effects of unloading on the adult enthesis provide new insight into the hierarchical features of structure and composition that endow the enthesis with increased resistance to failure. STATEMENT OF SIGNIFICANCE: The musculoskeletal system is sensitive to its loading environment; this is of particular concern under conditions such as disuse, paralysis, and extended-duration space flight. Although changes to tendon and bone following paralysis are understood, there is a pressing need to clarify how unloading affects the bone-tendon interface (enthesis), which is the location most prone to tears and injury. We elucidated the effects of enthesis unloading in adult mice shoulders showing, for the first time, that unloading significantly increased the risk and extent of mechanical failure and was associated with structural changes across hierarchical scales. These observations provide new insight into the hierarchical features of structure and composition that endow the enthesis with resilience. This knowledge can be used to develop more targeted treatments to improve mobility and function.
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Affiliation(s)
- Alix C Deymier
- Department of Biomedical Engineering, University of Connecticut, Farmington, CT, USA.
| | - Andrea G Schwartz
- Department of Orthopaedic Surgery, Washington University, St. Louis, MO, USA.
| | - Zhounghou Cai
- Advanced Photon Source, Argonne National Lab, Argonne, IL, USA.
| | - Tyrone L Daulton
- Department of Physics, Washington University, St. Louis, MO, USA; Institute of Materials Science and Engineering, Washington University, St. Louis, MO, USA.
| | - Jill D Pasteris
- Department of Earth and Planetary Science, Washington University, St. Louis, MO, USA.
| | - Guy M Genin
- Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO, USA.
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Columbia University, New York, NY, USA; Department of Biomedical Engineering, Columbia University, New York, NY, USA.
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10
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Wang Z, Liu X, Davies MR, Horne D, Kim H, Feeley BT. A Mouse Model of Delayed Rotator Cuff Repair Results in Persistent Muscle Atrophy and Fatty Infiltration. Am J Sports Med 2018; 46:2981-2989. [PMID: 30198747 PMCID: PMC6730552 DOI: 10.1177/0363546518793403] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Rotator cuff (RC) tears are common tendon injuries seen in orthopaedic patients. Successful repair of large and massive RC tears remains a challenge due to our limited understanding of the pathophysiological features of this injury. Clinically relevant small animal models that can be used to study the pathophysiological response to repair are limited by the lack of chronic repair models. PURPOSE To develop a highly clinically relevant mouse model of delayed RC repair. STUDY DESIGN Controlled laboratory study. METHODS Three-month-old C57BL/6J mice underwent unilateral supraspinatus (SS) and infraspinatus (IS) tendon tear with immediate, 2-week delayed, or 6-week delayed tendon repair. Animals with no repair or sham surgery served as controls. Gait analysis was conducted to measure shoulder function at 2 weeks and 6 weeks after surgery. Animals were sacrificed 6 weeks after the last surgery. Shoulder joint, SS, and IS muscles were harvested and analyzed histologically. Ex vivo mechanical testing of intact and repaired SS and IS tendons was conducted. Reverse-transcriptase polymerase chain reaction was performed on SS and IS muscles to quantify atrophy, fibrosis, and fatty infiltration-related gene expression. RESULTS Histological and tendon mechanical testing showed that torn tendons could be successfully repaired as late as 6 weeks after transection. However, significant atrophy and fatty infiltration of muscle, with impaired shoulder function, were persistent in the 6-week delayed repair group. Shoulder function correlated with the severity of RC muscle weight loss and fatty infiltration. CONCLUSION We successfully developed a clinically relevant mouse model of delayed RC repair. Six-week delayed RC repair resulted in persistent muscle atrophy and fatty infiltration with inferior shoulder function compared with acute repair. CLINICAL RELEVANCE Our novel mouse model could serve as a powerful tool to understand the pathophysiological and cellular/molecular mechanisms of RC muscle and tendon degeneration, eventually improving our strategies for treating and repairing RC tears.
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Affiliation(s)
- Zili Wang
- Department of Orthopaedic Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan Province, China.,San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA. USA.,Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA. USA
| | - Xuhui Liu
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA. USA.,Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA. USA
| | - Michael R. Davies
- Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA. USA
| | - Devante Horne
- Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA. USA
| | - Hubert Kim
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA. USA.,Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA. USA
| | - Brian T. Feeley
- San Francisco Veterans Affairs Medical Center, Department of Veterans Affairs, San Francisco, CA. USA.,Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA. USA
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11
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Ford CA, Nowlan NC, Thomopoulos S, Killian ML. Effects of imbalanced muscle loading on hip joint development and maturation. J Orthop Res 2017; 35:1128-1136. [PMID: 27391299 PMCID: PMC5575772 DOI: 10.1002/jor.23361] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 07/02/2016] [Indexed: 02/04/2023]
Abstract
The mechanical loading environment influences the development and maturation of joints. In this study, the influence of imbalanced muscular loading on joint development was studied using localized chemical denervation of hip stabilizing muscle groups in neonatal mice. It was hypothesized that imbalanced muscle loading, targeting either gluteal muscles or quadriceps muscles, would lead to bilateral hip joint asymmetry, as measured by acetabular coverage, femoral head volume and bone morphometry, and femoral-acetabular shape. The contralateral hip joints as well as age-matched, uninjected mice were used as controls. Altered bone development was analyzed using micro-computed tomography, histology, and image registration techniques at postnatal days (P) 28, 56, and 120. This study found that unilateral muscle unloading led to reduced acetabular coverage of the femoral head, lower total volume, lower bone volume ratio, and lower mineral density, at all three time points. Histologically, the femoral head was smaller in unloaded hips, with thinner triradiate cartilage at P28 and thinner cortical bone at P120 compared to contralateral hips. Morphological shape changes were evident in unloaded hips at P56. Unloaded hips had lower trabecular thickness and increased trabecular spacing of the femoral head compared to contralateral hips. The present study suggests that decreased muscle loading of the hip leads to altered bone and joint shape and growth during postnatal maturation. Statement of Clinical Significance: Adaptations from altered muscle loading during postnatal growth investigated in this study have implications on developmental hip disorders that result from asymmetric loading, such as patients with limb-length inequality or dysplasia. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1128-1136, 2017.
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Affiliation(s)
- Caleb A. Ford
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Niamh C. Nowlan
- Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Stavros Thomopoulos
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110,Department of Orthopedic Surgery, Columbia University, New York, New York 10027
| | - Megan L. Killian
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110,Department of Biomedical Engineering, University of Delaware, Newark, Delaware 19716
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