The study is to evaluate incorporation of a bone-anterior cruciate ligament-bone (B-ACL-B) allograft in anterior cruciate ligament (ACL) reconstruction in a rabbit model. A total of 61 New Zealand white rabbits were used, with 23 donor rabbits for harvesting B-ACL-B allografts and 38 recipient rabbits undergoing unilateral ACL reconstruction with B-ACL-B allograft. Animals were euthanized for biomechanical testing, micro-computed tomography examination, histological analysis, multi-photon microscopy and transmission electron microscopy testing at 2, 4 and 8 weeks after surgery.
View Article and Find Full Text PDFHedgehog (Hh) signaling plays a fundamental role in the enthesis formation process and GLI-Kruppel family member GLI1 () is a key downstream mediator. However, the role of in tendon-bone healing after anterior cruciate ligament reconstruction (ACLR) is unknown. To evaluate the tendon-bone healing after ACLR in (GLI1-NULL) mice, and compare (GLI1-HET) and wild type (WT) mice, a total of 45 mice, 15 mice each of GLI1-NULL, GLI1-HET and WT were used in this study.
View Article and Find Full Text PDFThe standard grafts used for anterior cruciate ligament (ACL) reconstruction are tendon, either patellar tendon, hamstring, or quadriceps. However, the microstructure and composition of tendon differs from ligament. Ideally, the ACL would be replaced with the same tissue.
View Article and Find Full Text PDFPurpose: Schenck IV knee dislocation patients have dissatisfactory knee function and return-to-sport rate with the existing treatment methods. The purpose of this study was to illustrate a one-stage arthroscopic multiple ligament reconstruction method for treating Schenck IV knee dislocations.
Methods: A retrospective case series study was performed.
Ethnopharmacological Relevance: Xianglian pill (XLP), a traditional Chinese formula, is widely used as treatment for ulcerative colitis (UC) in China. However, the mechanism of its therapeutic effect is still unclear.
Aim Of The Study: Our previous studies showed a low oral bioavailability and a predominant distribution of major XLP ingredients in the gut.
Background: Previous studies have examined the transcriptomes and mechanical properties of whole tendons in different regions of the body. However, less is known about these characteristics within a single tendon.
Purpose: To develop a regional transcriptomic atlas and evaluate the region-specific mechanical properties of Achilles tendons.
Background: Prior studies have demonstrated mitochondrial dysfunction in tendinopathy. The objective of this investigation was to explore the potential of SS-31 (elamipretide), a mitochondrial protectant, to improve mitochondrial function and promote tendon healing in a murine supraspinatus tendinopathy model.
Methods: One hundred and twenty-six mice (252 limbs) were divided into 6 groups (42 limbs/group) that received (I) 4 weeks of impingement; (II) 8 weeks of impingement; (III) 8 weeks of impingement including 4 weeks of SS-31 treatment (5 mg/kg/d) starting after 4 weeks of impingement; (IV) 4 weeks of impingement ending with clip removal, followed by harvesting 4 weeks later; and (V) 4 weeks of impingement ending with clip removal, followed by 4 weeks of SS-31 treatment and harvesting; and a control group.
Macrophages are important for repair of injured tissues, but their role in healing after surgical repair of musculoskeletal tissues is not well understood. We used single-cell RNA sequencing (RNA-seq), flow cytometry, and transcriptomics to characterize functional phenotypes of macrophages in a mouse anterior cruciate ligament reconstruction (ACLR) model that involves bone injury followed by a healing phase of bone and fibrovascular interface tissue formation that results in bone-to-tendon attachment. We identified a novel "surgery-induced" highly inflammatory CD9+ IL1+ macrophage population that expresses neutrophil-related genes, peaks 1 day after surgery, and slowly resolves while transitioning to a more homeostatic phenotype.
View Article and Find Full Text PDFBackground: Studies in our laboratory have demonstrated mitochondrial dysfunction in human and animal models of supraspinatus tendinopathy. SS-31 (elamipretide) has been reported to improve mitochondrial function and to be effective in clinical trials for several diseases. The potential of SS-31 in treating tendinopathy has not been explored.
View Article and Find Full Text PDFThe relative contributions of sex differences in anatomy, biomechanics, and hormones to the increased risk of anterior cruciate ligament (ACL) injury in female athletes remains unknown. The purpose of this study is to investigate sex differences in anatomy and biomechanics of the native and reconstructed ACL using our established murine model. A total of 140 12-week-old wild-type C57Bl/6 (70 male vs.
View Article and Find Full Text PDFBackground: Subacromial impingement of the rotator cuff caused by variations in acromial anatomy or altered glenohumeral kinematics leads to inflammation and degeneration of the rotator cuff, ultimately contributing to the development of tendinopathy. However, the underlying cellular and molecular changes in the impinged tendon remain poorly understood. Because the rat is an accepted model for rotator cuff studies, we have developed a rat model to study rotator cuff tendinopathy.
View Article and Find Full Text PDFJ Orthop Surg (Hong Kong)
March 2022
Background: The availability of non-invasive means to evaluate and monitor tendon-bone healing processes is limited. Micro Positron-Emission-Tomography (µPET) using F-Fluoride is a minimally invasive imaging modality, with which osteoblast activity and bone turnover can be assessed. The aim of this study was to investigate the use of serial µPET/CT scans to evaluate bone turnover along the graft-tunnel interface in a rat ACL (anterior cruciate ligament) reconstruction model.
View Article and Find Full Text PDFThis study investigated whether transforming growth factor-β receptor I (TGF-βRI) and TGF-βRII mediate matrix degradation and abnormal hypertrophy in T-2 toxin-induced hypertrophic chondrocytes. Hypertrophic chondrocytes were exposed to TGF-βRI and TGF-βRII binding inhibitor (GW788388) for 24 h prior to exposure to different concentrations of T-2 toxin (0, 10, 25, and 50 ng/mL for 48 h). Hypertrophic chondrocytes were assessed based on the expression of matrix-degrading and terminal differentiation-related genes and cell viability.
View Article and Find Full Text PDFBMC Musculoskelet Disord
December 2021
Background: Kashin-Beck disease (KBD) is a chronic, deforming, endemic osteochondropathy that begins in patients as young as 2-3 years of age. The pathogenesis of KBD remains unclear, although selenium (Se) deficiency and T-2 toxin food contamination are both linked to the disease. In the present study, we evaluated transforming growth factor-β receptor (TGF-βR I and II) levels in clinical samples of KBD and in pre-clinical disease models.
View Article and Find Full Text PDFBackground: The underlying cellular and molecular mechanisms involved in the development of tendinopathy due to subacromial supraspinatus tendon (SST) impingement and the response to subsequent removal of impingement remain unknown.
Purpose: To investigate the involvement of Indian hedgehog (IHH) signaling in the development of SST tendinopathy and the subsequent healing process after the relief of subacromial impingement in a novel mouse shoulder impingement model.
Study Design: Controlled laboratory study.
Background: Rotator cuff repair site failure is a well-established clinical concern. Tendon-to-bone healing is initiated by inflammatory mediators followed by matrix synthesis by fibroblasts. The kinetics of fibroblast accumulation and activity are currently poorly understood.
View Article and Find Full Text PDFMuscle atrophy and fatty infiltration have been directly correlated with higher rates of incomplete or failed healing following surgical repair of the rotator cuff. The purpose of this study was to evaluate clinically relevant functional and morphological changes in the supraspinatus muscle at various time points in this model of rotator cuff tendinopathy. Subacromial impingement was induced in 47, male C57BL/6 mice (total 94 limbs) by implantation of a metal clip in the subacromial space.
View Article and Find Full Text PDFBackground: Curcumin (CUR) is a natural diarylheptanoid with marked anti-tumor activities. Recent investigations demonstrate that CUR combines with some other phytochemicals exerts advantages over its single application manifested as lower toxicity, higher efficacy or more significant reversal of multidrug resistance.
Purpose: This study aimed to elucidate a new biflavonoid (wikstroflavone B, WFB) isolated from Wikstroemia indica and to assess the synergistic inhibition of combined CUR and WFB (CUR/WFB) on human nasopharyngeal carcinoma (NPC) cell lines proliferation and metastasis.
J Bone Joint Surg Am
January 2021
Background: The purpose of this study was to assess mitochondrial dysfunction in a murine model of supraspinatus tendinopathy.
Methods: Eighty-four mice (168 limbs) were included in the study. Supraspinatus tendinopathy was induced by inserting a microsurgical clip in the subacromial space of 63 mice bilaterally (126 limbs).
The aim of this study was to investigate the presence of alarmins in a novel murine rotator cuff tendinopathy model. Alarmins have been described as essential early activators of an immune response to tissue damage. Subacromial impingement was induced in both shoulders of 37 male C57Bl/6 mice by placement of a small metal clip in the subacromial space.
View Article and Find Full Text PDFBackground: Lubricin, a mucinous glycoprotein, plays a chondroprotective role as a constituent of synovial fluid. Structural analogs have been synthesized to mimic the structure and function of native lubricin in an effort to recapitulate this effect with the goal of delaying progression of osteoarthritis (OA).
Purpose: To investigate the efficacy of intra-articular injections of lubricin mimetics in slowing or preventing the progression of posttraumatic OA by using a rat anterior cruciate ligament transection model.
Background: Doxycycline has broad-spectrum activity as a matrix metalloproteinase (MMP) inhibitor and thus could reduce the progression of posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament (ACL) rupture.
Hypothesis: Doxycycline would inhibit progression of PTOA in a murine ACL rupture model.
Study Design: Controlled laboratory study.
Subacromial impingement is associated with a spectrum of disorders-including rotator cuff disease-but their relationship is complex. We have established a novel murine model of subacromial impingement to study supraspinatus tendinopathy. The purpose of this study was to evaluate changes in gene expression in this murine shoulder impingement model to further elucidate the mechanisms underlying the development of tendinopathy.
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