Acellular porcine Achilles tendon patch encapsulating tendon-derived stem cells for rotator cuff repair in a rabbit model.

Currently, the predominant method for repairing rotator cuff involves surgical suture techniques, but the failure rate remains notably high. Failure of the rotator cuff insertion to provide adequate biomechanics during early healing is considered a major cause of failure. Addressing this problem, biological augmentation emerges as a promising strategy for enhancing the biomechanical properties during early stages. Tendon-derived stem cells (TDSCs), which facilitate the differentiation of repair-supportive cells, hold the potential to improve the efficacy of patch application. The study aims to assess the behavior of TDSCs in acellular porcine Achilles tendon (APAT) patches and to explore the capacity of the APAT patch encapsulating TDSCs in promoting both tendon-to-bone healing and biomechanical enhancements in a rabbit rotator cuff repair model. Transmission electron microscopy (TEM) analyses validated the complete cellular clearance of native cells from APAT patches, with uniform distribution of TDSCs. Immunofluorescence staining confirmed successful TDSCs attachment, while population doubling time (PDT) underscored increased TDSCs proliferation on APAT patches. Quantitative polymerase chain reaction (qPCR) demonstrated upregulation of tenocyte and osteocyte related genes in TDSCS cultured within the patches. In the subsequent in vivo experiment, fifty-four rabbits were used to create rotator cuff injury models and randomly assigned to a control group, an APAT patch group, and an APAT patch with TDSCs group. Histological analysis showed that the APAT patch with TDSCs group had significantly enhanced tendon-to-bone healing and a distinctly organized tendon-fibrocartilage-bone structure, as compared to the APAT patch group. In addition, the biomechanical properties of the APAT patch with TDSCs group were significantly improved. In conclusion, APAT patches promote TDSC proliferation and stimulate tenogenic and osteogenic differentiation. APAT patches encapsulating TDSCs have shown considerable potential in promoting tendon-to-bone healing of rotator cuff injuries, indicating that their use in rotator cuff repair surgery is clinically meaningful.

A Modified Arthroscopic Triple-row Repair Technique for L-shaped Delaminated Rotator Cuff Tears.

OBJECTIVE: To compare the clinical outcomes of a modified arthroscopic triple-row (TR) repair technique with the suture bridge (SB) repair technique in treating L-shaped delaminated rotator cuff tears. Various surgical techniques for L-shaped delaminated rotator cuff tears have been reported, many of which aid in increasing the contact area and pressure of the rotator cuff. However, there is still debate over which technique yields superior results. METHODS: From January 2017 to March 2020, 61 cases of L-shaped delaminated rotator cuff tears were included in this study. Of these, 34 cases underwent the modified arthroscopic triple-row repair technique, while 27 cases were addressed with the suture bridge repair technique. Functional assessment was conducted using the American Shoulder and Elbow Surgeons (ASES) score, the University of California Los Angeles (UCLA) shoulder score, the Constant score (CS), and the visual analogue scale (VAS) score. Magnetic Resonance Imaging (MRI) assessments for rotator cuff healing were performed at the 24-month postoperative mark. Statistical evaluations were conducted using SPSS for Windows (Version 25.0, IBM, Armonk, NY, USA), employing the Wilcoxon signed-rank test to compare preoperative and postoperative data and ROM differences, and the Mann-Whitney U test for statistical differences in clinical outcome scores between the two groups. A p-value of less than 0.05 was considered statistically significant. RESULTS: Comparative analysis of the preoperative and final follow-up scores revealed a substantial enhancement in shoulder function, as indicated by the ASES, UCLA, CS, and VAS scores, with statistical significance (p < 0.001). At both the preoperative stage and final follow-up, no notable differences were observed in ASES, UCLA, CS, and VAS scores between the two groups. However, the TR repair group exhibited lower VAS scores than the SB group at 1 and 3 months postoperatively. Active range of motion (ROM) showed significant improvement in both groups. No significant differences in ROM were noted between the two groups either before the surgery or at the final follow-up. CONCLUSION: The study demonstrates that both the modified arthroscopic TR and SB techniques for L-shaped delaminated cuff tears yield satisfactory outcomes, with no significant differences in overall clinical performance. Notably, early postoperative pain management appears more effective with the modified TR technique, suggesting its potential for enhanced early recovery experiences. This technique's design, promoting securer fixation and optimal contact conditions, is implied to facilitate superior long-term healing, warranting further investigation into its long-term benefits.

[Study on injectable chitosan hydrogel with tendon-derived stem cells for enhancing rotator cuff tendon-to-bone healing].

Objective: To explore the effect of chitosan (CS) hydrogel loaded with tendon-derived stem cells (TDSCs; hereinafter referred to as TDSCs/CS hydrogel) on tendon-to-bone healing after rotator cuff repair in rabbits. Methods: TDSCs were isolated from the rotator cuff tissue of 3 adult New Zealand white rabbits by Henderson step-by-step enzymatic digestion method and identified by multidirectional differentiation and flow cytometry. The 3rd generation TDSCs were encapsulated in CS to construct TDSCs/CS hydrogel. The cell counting kit 8 (CCK-8) assay was used to detect the proliferation of TDSCs in the hydrogel after 1-5 days of culture in vitro, and cell compatibility of TDSCs/CS hydrogel was evaluated by using TDSCs alone as control. Another 36 adult New Zealand white rabbits were randomly divided into 3 groups ( n=12): rotator cuff repair group (control group), rotator cuff repair+CS hydrogel injection group (CS group), and rotator cuff repair+TDSCs/CS hydrogel injection group (TDSCs/CS group). After establishing the rotator cuff repair models, the corresponding hydrogel was injected into the tendon-to-bone interface in the CS group and TDSCs/CS group, and no other treatment was performed in the control group. The general condition of the animals was observed after operation. At 4 and 8 weeks, real-time quantitative PCR (qPCR) was used to detect the relative expressions of tendon forming related genes (tenomodulin, scleraxis), chondrogenesis related genes (aggrecan, sex determining region Y-related high mobility group-box gene 9), and osteogenesis related genes (alkaline phosphatase, Runt-related transcription factor 2) at the tendon-to-bone interface. At 8 weeks, HE and Masson staining were used to observe the histological changes, and the biomechanical test was used to evaluate the ultimate load and the failure site of the repaired rotator cuff to evaluate the tendon-to-bone healing and biomechanical properties. Results: CCK-8 assay showed that the CS hydrogel could promote the proliferation of TDSCs ( P<0.05). qPCR results showed that the expressions of tendon-to-bone interface related genes were significantly higher in the TDSCs/CS group than in the CS group and control group at 4 and 8 weeks after operation ( P<0.05). Moreover, the expressions of tendon-to-bone interface related genes at 8 weeks after operation were significantly higher than those at 4 weeks after operation in the TDSCs/CS group ( P<0.05). Histological staining showed the clear cartilage tissue and dense and orderly collagen formation at the tendon-to-bone interface in the TDSCs/CS group. The results of semi-quantitative analysis showed that compared with the control group, the number of cells, the proportion of collagen fiber orientation, and the histological score in the TDSCs/CS group increased, the vascularity decreased, showing significant differences ( P<0.05); compared with the CS group, the proportion of collagen fiber orientation and the histological score in the TDSCs/CS group significantly increased ( P<0.05), while there was no significant difference in the number of cells and vascularity ( P>0.05). All samples in biomechanical testing failed at the repair site during the testing process. The ultimate load of the TDSCs/CS group was significantly higher than that of the control group ( P<0.05), but there was no significant difference compared to the CS group ( P>0.05). Conclusion: TDSCs/CS hydrogel can induce cartilage regeneration to promote rotator cuff tendon-to-bone healing.

Outcomes after rotator cuff repair in the elderly as assessed by the American Shoulder and Elbow Surgeons shoulder score.

Rotator cuff tears are common among the elderly, and studies on the outcomes after rotator cuff repair in the elderly are limited. We carried out this meta-analysis with systematic literature search, aiming to clarify the outcomes after rotator cuff repair in the elderly as assessed by the American Shoulder and Elbow Surgeons (ASES) shoulder score. We conducted a literature search through October 2019 in PubMed and EMBASE databases and performed meta-analysis to calculate the summary mean difference comparing the post- and pre-operation ASES scores under both fixed-effect and random-effect models. Among 4978 studies identified through literature search, four studies (two in the United States, one in France, and one in Republic of Korea) were eligible for the meta-analysis, including 282 patients who were aged over 70 years. These studies had low heterogeneity as measured by Cochran's Q test (p=0.88) and I2 statistic (0%). The ASES scores on average increased by 39.7 (95% confidence interval 28.3-51.1, p<0.001) after rotator cuff repair, in both fixed-effect and random-effect models. No substantial publication bias was indicated. Our findings suggest improved outcomes after rotator cuff repair in the elderly population as measured by the ASES score, and such improvements have been consistent in previous studies.

Recurrence of pigmented villonodular synovitis of the knee: A case report with review of literature on the risk factors causing recurrence.

RATIONALE: Pigmented villonodular synovitis is a rare disease which may involve any joints. It has localized and diffuse forms, and the latter is more aggressive with a higher recurrence rate. Different treatments are applied to each form of the disease, but there is no standard surgical procedure or any consensus on whether adjuvant therapy should be used. Many factors may lead to recurrence of the disease; however, there is no reliable way to predict the recurrence. PATIENT CONCERNS: A 21-year-old female patient presented with a one-year history of progressive pain of the right knee. DIAGNOSES: Pigmented villonodular synovitis. INTERVENTIONS: We performed an anterior approach arthroscopic synovectomy and a posterior approach open synovectomy in the popliteal fossa, but the patient declined to take radiotherapy as a post-surgical adjuvant therapy. Then, she received a repeat arthroscopic synovectomy 20 months later because of the recurrent lesions, and a radiotherapy was performed 6 weeks after the second surgery. OUTCOMES: There were no abnormal signs in the right knee on magnetic resonance imaging scanning 6 months after the second surgery. The range of motion of her right knee was normal. LESSONS: Pigmented villonodular synovitis is a rare disease which may involve any joints. Surgical resection plus adjuvant therapy is recommended for patients with risk factors of recurrence.

Outcomes after rotator cuff repair in the elderly as assessed by the American Shoulder and Elbow Surgeons shoulder score

Rotator cuff tears are common among the elderly, and studies on the outcomes after rotator cuff repair in the elderly are limited. We carried out this meta-analysis with systematic literature search, aiming to clarify the outcomes after rotator cuff repair in the elderly as assessed by the American Shoulder and Elbow Surgeons (ASES) shoulder score. We conducted a literature search through October 2019 in PubMed and EMBASE databases and performed meta-analysis to calculate the summary mean difference comparing the post- and pre-operation ASES scores under both fixed-effect and random-effect models. Among 4978 studies identified through literature search, four studies (two in the United States, one in France, and one in Republic of Korea) were eligible for the meta-analysis, including 282 patients who were aged over 70 years. These studies had low heterogeneity as measured by Cochran's Q test (p=0.88) and I2 statistic (0%). The ASES scores on average increased by 39.7 (95% confidence interval 28.3-51.1, p<0.001) after rotator cuff repair, in both fixed-effect and random-effect models. No substantial publication bias was indicated. Our findings suggest improved outcomes after rotator cuff repair in the elderly population as measured by the ASES score, and such improvements have been consistent in previous studies.