Journal of Orthopaedic Research®最新文献

{"title":"Development of Artificial Intelligence-Assisted Lumbar and Femoral BMD Estimation System Using Anteroposterior Lumbar X-Ray Images.","authors":"Toru Moro, Noriko Yoshimura, Taku Saito, Hiroyuki Oka, Sigeyuki Muraki, Toshiko Iidaka, Takeyuki Tanaka, Kumiko Ono, Hisatoshi Ishikura, Naoya Wada, Kenichi Watanabe, Masayuki Kyomoto, Sakae Tanaka","doi":"10.1002/jor.70000","DOIUrl":"https://doi.org/10.1002/jor.70000","url":null,"abstract":"<p><p>The early detection and treatment of osteoporosis and prevention of fragility fractures are urgent societal issues. We developed an artificial intelligence-assisted diagnostic system that estimated not only lumbar bone mineral density but also femoral bone mineral density from anteroposterior lumbar X-ray images. We evaluated the performance of lumbar and femoral bone mineral density estimations and the osteoporosis classification accuracy of an artificial intelligence-assisted diagnostic system using lumbar X-ray images from a population-based cohort. The artificial neural network consisted of a deep neural network for estimating lumbar and femoral bone mineral density values and classifying lumbar X-ray images into osteoporosis categories. The deep neural network was built by training dual-energy X-ray absorptiometry-derived lumbar and femoral bone mineral density values as the ground truth of the training data and preprocessed X-ray images. Five-fold cross-validation was performed to evaluate the accuracy of the estimated BMD. A total of 1454 X-ray images from 1454 participants were analyzed using the artificial neural network. For the bone mineral density estimation performance, the mean absolute errors were 0.076 g/cm² for the lumbar and 0.071 g/cm² for the femur between dual-energy X-ray absorptiometry-derived and artificial intelligence-estimated bone mineral density values. The classification performances for the lumbar and femur of patients with osteopenia, in terms of sensitivity, were 86.4% and 80.4%, respectively, and the respective specificities were 84.1% and 76.3%. CLINICAL SIGNIFICANCE: The system was able to estimate the bone mineral density and classify the osteoporosis category of not only patients in clinics or hospitals but also of general inhabitants.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144591492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial Intelligence-Assisted Standard Plane Detection in Hip Ultrasound for Developmental Dysplasia of the Hip: A Novel Real-Time Deep Learning Approach.","authors":"Muhammed Furkan Darilmaz, Mehmet Demirel, Hüseyin Oktay Altun, Mevlüt Can Adiyaman, Fuat Bilgili, Hayati Durmaz, Yavuz Sağlam","doi":"10.1002/jor.70020","DOIUrl":"https://doi.org/10.1002/jor.70020","url":null,"abstract":"<p><p>Developmental dysplasia of the hip (DDH) includes a range of conditions caused by inadequate hip joint development. Early diagnosis is essential to prevent long-term complications. Ultrasound, particularly the Graf method, is commonly used for DDH screening, but its interpretation is highly operator-dependent and lacks standardization, especially in identifying the correct standard plane. This variability often leads to misdiagnosis, particularly among less experienced users. This study presents AI-SPS, an AI-based instant standard plane detection software for real-time hip ultrasound analysis. Using 2,737 annotated frames, including 1,737 standard and 1,000 non-standard examples extracted from 45 clinical ultrasound videos, we trained and evaluated two object detection models: SSD-MobileNet V2 and YOLOv11n. The software was further validated on an independent set of 934 additional frames (347 standard and 587 non-standard) from the same video sources. YOLOv11n achieved an accuracy of 86.3%, precision of 0.78, recall of 0.88, and F1-score of 0.83, outperforming SSD-MobileNet V2, which reached an accuracy of 75.2%. These results indicate that AI-SPS can detect the standard plane with expert-level performance and improve consistency in DDH screening. By reducing operator variability, the software supports more reliable ultrasound assessments. Integration with live systems and Graf typing may enable a fully automated DDH diagnostic workflow. Level of Evidence: Level III, diagnostic study.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144575700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estrogen and Progesterone Exhibit Distinct Yet Coordinated Roles in the Regulation of Tendon Extracellular Matrix Remodeling.","authors":"Allison M Sander, Brianne K Connizzo","doi":"10.1002/jor.70018","DOIUrl":"10.1002/jor.70018","url":null,"abstract":"<p><p>Remodeling of the extracellular matrix (ECM) is required for the proper healing, strengthening, and maintenance of tendon tissue. There are well-documented sex differences in tendon injury rates and healing outcomes, often attributed to either innate differences in tissue structure and resident cell signaling or the influence of sex hormones. However, these factors are rarely decoupled. Estrogen (17β-estradiol) and progesterone (P4) receptors are expressed in both male and female tendons and thus could participate in the remodeling process, but studies are extremely limited. Therefore, the objective of this study was to address whether biological sex differences are present in tendon remodeling and to determine the individual and combined roles of estrogen and progesterone in the remodeling process. We capitalized on a three-dimensional explant model to directly examine hormone-mediated ECM turnover without disruption to the native cell microenvironment. Flexor digitorum longus tendon explants harvested from mature male and female mice were stimulated continuously with chemically endogenous hormones for 1 week, after which we examined synthesis and degradation of matrix components as well as overall tissue composition. We found sex differences in the absence of hormonal stimulation, indicating a chromosomal influence to observed functional sex differences. We also demonstrate that the response to exogenous hormone delivery is sex-dependent, and that progesterone and estrogen serve complementary yet independent roles. Overall, this study demonstrates the importance of hormones in the regulation of tissue structure and function and underscores the critical need for additional research in this area.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12308506/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144567534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Dynamic Joint Space During Physiological Loading to Objectively Measure Hip Stability.","authors":"Edward Godbold, Connor Luck, Camille Johnson, Ashley Disantis, Craig Mauro, Michael McClincy, William Anderst","doi":"10.1002/jor.70011","DOIUrl":"https://doi.org/10.1002/jor.70011","url":null,"abstract":"<p><p>An objective measurement of hip stability during functional loading is needed to improve diagnosis, guide treatment decisions, and evaluate intervention success. This study aimed to develop a reference measurement for stable hips based upon dynamic minimum hip joint space (HJS) in healthy young adults. Synchronized biplane radiographs of the hips of 24 healthy young adults were collected (50 images/s) during treadmill walking and squatting. Subject-specific femur and pelvis models were created from CT scans, and bone motion was determined by a validated volumetric model-based tracking technique. The distance between femur and acetabulum subchondral bone surfaces was calculated during each movement. Range in minimum subchondral bone distance was measured in radial and sagittal regions of the acetabula. Regression analysis identified kinematics and morphologic predictors of range in minimum HJS. Range in minimum HJS during gait in the anterior-inferior (1.8 mm) and posterior-superior regions (1.7 mm) was 31%-38% larger than in the anterior-superior and superior regions (1.3 mm; p ≤ 0.001), and 13%-20% larger than in the posterior-inferior region (1.5 mm; p ≤ 0.001). No differences in minimum HJS were identified in radial regions during squat (range: 0.7-0.9 mm). No sex differences were identified. Femur head translation during gait was a stronger predictor of the range in minimum HJS than changes in femur head morphology. This suggests anterior-inferior to posterior-superior pistoning of the femur may be a mechanical mechanism for commonly observed pathology. These results suggest that gait is a better activity than squatting to assess dynamic hip stability when using this metric.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144553804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synovial Dysregulation in Ankle Osteoarthritis: Molecular Insights and Pathogenetic Pathways.","authors":"Julia Matthias, Sara Buckley, Michael David, Cheryl L Ackert-Bicknell, Joshua A Metzl, Daniel K Moon, Courtney Miller, Michael J Zuscik, Kenneth J Hunt","doi":"10.1002/jor.70016","DOIUrl":"https://doi.org/10.1002/jor.70016","url":null,"abstract":"<p><p>Osteoarthritis of the ankle is a debilitating condition affecting nearly 20% of adults in the United States. The tissue, cellular, and molecular basis of this disease remains poorly understood, particularly the role of the synovial membrane. This prospective case-control study examined the gene expression profile of synovial tissue in ankle osteoarthritis to uncover biological pathways altered in the disease. Synovial biopsies were obtained from twenty-six patients with ankle osteoarthritis undergoing joint replacement and eight patients with minimal or no evidence of osteoarthritis. Bulk RNA-sequencing and differential gene expression analysis were performed, followed by biological pathway enrichment, unsupervised cluster, and network-based analysis. Synovium from ankle osteoarthritis patients showed distinct gene expression patterns compared to controls, with enrichment in pathways related to extracellular matrix remodeling and tissue morphogenesis. Age and a prior history of ankle fracture were identified as significant factors influencing the transcriptomic profile of osteoarthritic synovium. After accounting for these variables, transcriptomic clustering perfectly distinguished osteoarthritic from non-osteoarthritic synovium and revealed upregulation of pathways involved in muscle development, neural signaling, immune response, and carbohydrate metabolism. Conversely, pathways related to ribosome production, protein synthesis, and cellular signaling were downregulated. Multiple WNT signaling pathways remained significantly enriched in osteoarthritic ankle synovium. This study identifies a distinct gene expression profile in the synovium of ankle osteoarthritis patients, highlighting key molecular pathways possibly involved in disease progression. These findings provide valuable insights into the molecular mechanisms driving ankle osteoarthritis and have the potential to inform the development of novel targeted therapeutic strategies.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144553803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chitosan/Platelet-Rich Plasma Implants in an Ovine Arthroscopic Model of Meniscus Repair.","authors":"Margaux Delvaux, Anik Chevrier, Sotcheadt Sim, Éric Quenneville, Mark B Hurtig, Gregory De Crescenzo, Marc Lavertu","doi":"10.1002/jor.70014","DOIUrl":"https://doi.org/10.1002/jor.70014","url":null,"abstract":"<p><p>Despite the availability of various repair techniques, many meniscal tears remain irreparable. A freeze-dried chitosan-based formulation reconstituted in autologous platelet-rich plasma has shown potential in preclinical studies for enhancing suture-based meniscus repair. This study aimed at developing a fully arthroscopic ovine model of meniscus repair and evaluating chitosan/platelet-rich plasma's efficacy and safety as an augmentation strategy for suture-based meniscus repair. Unilateral radial lesions were induced in the medial menisci mid-body of 22 skeletally mature ewes. Tears were sutured inside-out. Two groups received a chitosan/platelet-rich plasma injection into the sutured lesions (0.5 or 1 mL doses, n = 6/group), while one group received a 1 mL autologous platelet-rich plasma injection (n = 5). The control group was only sutured (n = 5). A multiaxial mechanical tester and a hand-held probe were used respectively for mechanical (menisci and articular cartilages) and electromechanical testing (articular cartilages). All surfaces were then histologically assessed. Chitosan/platelet-rich plasma was resident in tears at 1 day and induced polymorphonuclear cell recruitment (assessed in n = 2 sheep). All operated joints developed signs of osteoarthritis compared to contralateral unoperated joints, with some of them displaying severe structural and functional changes. Instantaneous modulus properties and structural appearance of menisci and articular surfaces from chitosan/platelet-rich plasma treated groups were better than those of the other groups at 6 months postsurgery. Clinical pathology data were similar at baseline and at terminal in all groups, which suggests high safety. Chitosan/platelet-rich plasma implants helped limit cartilaginous degradation in joints with radially incised and sutured medial menisci and show promise as a treatment for meniscal tears.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144553802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced Muscle Strength Can Alter the Impact of Gait Modifications on Knee Cartilage Mechanics.","authors":"Joose P J Peitola, Amir Esrafilian, Morten B Simonsen, Michael S Andersen, Rami K Korhonen","doi":"10.1002/jor.70007","DOIUrl":"https://doi.org/10.1002/jor.70007","url":null,"abstract":"<p><p>Muscle strength can substantially influence knee joint loading, stability, and cartilage biomechanics, all of which are important factors in the onset and progression of knee osteoarthritis (KOA). Noninvasive rehabilitation methods, such as gait modifications, are suggested to effectively alter knee joint loading, potentially helping to prevent or slow KOA progression. However, no studies to date have assessed if reduced lower limb muscle strength can influence the effects of rehabilitation exercises such as gait modifications. This study aimed to reveal how reducing the strength of three lower limb muscle groups (knee extensors, hip abductors, and ankle extensors) impacts the effects of gait modifications (Toe-out, Toe-in, and Wide gait) on knee cartilage stresses. We analyzed motion and ground reaction force data from seven healthy male participants using a musculoskeletal-finite element workflow, where we systematically reduced the isometric strength of the selected muscle groups in the musculoskeletal models. Our findings indicate that reductions in hip abductor and ankle extensor strength had the most pronounced impact on the effects of gait modifications on cartilage mechanics (maximum decrease of 6 percentage points (PP) in the changes of maximum principal stress). Overall, Toe-out gait was least affected by reduced muscle strength compared to other gait styles, although responses varied greatly between participants (0-14 percentage point differences). This study emphasizes the importance of considering participant-specific muscle strengths when designing personalized rehabilitation strategies such as gait modifications and provides theoretical insights into optimizing rehabilitation exercises for managing KOA based on a given motion and joint kinetics.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Analysis of Ultrasound Images of the Median Nerve Using Particle Image Velocimetry.","authors":"Issei Shinohara, Takahiro Furukawa, Atsuyuki Inui, Yutaka Mifune, Kohei Yamaura, Tomoyuki Matsumoto, Ryosuke Kuroda","doi":"10.1002/jor.70009","DOIUrl":"https://doi.org/10.1002/jor.70009","url":null,"abstract":"<p><p>Carpal tunnel syndrome (CTS) diagnosis is typically confirmed through electrophysiologic studies and ultrasound (US) imaging. Recent studies have suggested that median nerve gliding is reduced in patients with CTS. This study employed particle image velocimetry (PIV) to analyze median nerve dynamics. Ultrasound movies were captured during finger flexion and extension for 20 healthy volunteers (control group) and 20 CTS patients (CTS group). These movies were then analyzed using the PIV method. Within a 10 x 10 mm² region of interest (ROI) that included the median nerve and flexor tendon, the velocity magnitude and vector direction of movement were examined using PIV software. The maximum and mean velocity magnitudes were compared between the two groups using the Mann-Whitney U test. The maximum velocity in the ROI was significantly lower in the CTS group (9.3 ± 3.0 mm/s) than in the control group (11.5 ± 3.4 mm/s). The mean velocity was also significantly lower in the CTS group (1.7 ± 0.3 mm/s) than in the control group (2.5 ± 0.7 mm/s). Regarding motor properties, transverse motor velocity was significantly lower in CTS patients than in controls, while vertical movement showed no significant difference between the two groups. This study applied the PIV method to US images for dynamic analysis of the median nerve, revealing reduced gliding of the median nerve and flexor tendon in CTS patients, particularly in transverse movements. The application of dynamic analysis using the PIV method has potential for use in diagnosis and rehabilitation of CTS.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144528404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soft Tissue Injury and Immobilization Are Both Required for Persistent Elbow Contracture in a Rat Model.","authors":"Rebecca F Reals, Alex J Reiter, Ryan M Castile, Sophia D Miller, Paul C Cannon, Benjamin M Zmistowksi, Aaron M Chamberlain, Spencer P Lake","doi":"10.1002/jor.70010","DOIUrl":"https://doi.org/10.1002/jor.70010","url":null,"abstract":"<p><p>Post-traumatic joint contracture commonly occurs after elbow injury. Although known as a risk factor for poor outcomes, immobilization is necessary to prevent reinjury. The objective of this study was to isolate the contribution of immobilization to mechanical and functional disability using an animal model. Left elbows of Long-Evans rats were immobilized in the absence (IM) or presence of an elbow injury (INJ+IM). Animals were immobilized for 21 or 42 days or immobilized for 21 days followed by free mobilization (FM) for 21 days. Uninjured animals without immobilization (CTRL) were also evaluated. Forelimb strength and gait were measured during FM, and joints underwent post-mortem mechanical testing. Contracture in 21IM elbows was moderate compared to CTRL but not as severe as 21INJ+IM. 42IM elbows were severely contracted compared to CTRL and not different from 42INJ+IM. 21IM/21FM mechanics were no longer different from CTRL while 21INJ+IM/21FM were still contracted. Gait was less altered for IM compared to INJ+IM and nearly returned to CTRL levels over time. Forelimb strength was not different between IM and INJ+IM but both were decreased compared to CTRL. For immobilization without injury, contracture took longer to develop but eventually reached levels of INJ+IM. Following remobilization, IM groups recovered faster and to a greater extent than INJ+IM groups. Thus, immobilization alone is not sufficient to recapitulate characteristics of human elbow PTJC (e.g., long-term loss of motion) in an animal model. Clinically, immobilization may not contribute to irreversible contracture development if duration is limited and strategic, active mobilization is provided.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Murine Supraspinatus Tendons Demonstrate Aging-Related Changes in Multiscale Mechanics, Structure, and Gene Expression.","authors":"Michael S DiStefano, Jeremy D Eekhoff, Stephanie N Weiss, Courtney A Nuss, Rebecca L Betts, Andrew F Kuntz, Louis J Soslowsky","doi":"10.1002/jor.70013","DOIUrl":"https://doi.org/10.1002/jor.70013","url":null,"abstract":"<p><p>Rotator cuff disorders are common in the aging population, often leading to pain, disability, and reduced quality of life. Age-associated changes can occur disproportionately in regions of high mechanical stress, such as the insertion site of the supraspinatus tendon, leading to increased injury rates and tendinopathies. We previously demonstrated site-specific differences in structure, function, and gene expression between the insertion and midsubstance regions of supraspinatus tendons in mature, Day 150 mice. However, a comprehensive study examining the role of aging on site-specific supraspinatus tendon multiscale structure, function, and gene expression is needed. Therefore, our objective was to elucidate the role of aging on supraspinatus tendon multiscale structure, function, and gene expression. Whole-tissue and regional mechanics, as well as regional fibril response to load, cellularity and cell shape, collagen fibril morphology, and gene expression were evaluated in supraspinatus tendons of Day 300 and Day 570 mice. Aging resulted in decreased stiffness, dynamic modulus, and decreased midsubstance modulus. Collagen fibril morphology analysis revealed a more noticeable shift toward smaller fibril diameters with aging in the midsubstance region. Histological evaluation demonstrated reduced cellularity and a transition to more elongated cell morphology in aged tendons. Gene expression profiling highlighted upregulation of pro-inflammatory and catabolic markers and downregulation of major collagens in Day 570 tendons relative to Day 300 tendons. Understanding the effects of aging on tendon structure, function and gene expression provides critical insights into the mechanisms underlying aging-related injury and tendinopathy.</p>","PeriodicalId":16650,"journal":{"name":"Journal of Orthopaedic Research®","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}