Explore the vast range of titles available.

Successful rotator cuff repair requires biological anchoring of the repaired tendon to the bone. However, the histological structure of the repaired tendon-bone interface differs from that of a normal tendon insertion. We analysed differences between the normal tendon insertion and the repaired tendon-bone interface after surgery in the mechanical properties, histomorphometric analysis and 3-dimensional ultrastructure of the cells using a rat rotator cuff repair model. Twenty-four adult Sprague-Dawley (SD) rats underwent complete cuff tear and subsequent repair of the supraspinatus tendon. The repaired tendon-bone interface was evaluated at 4, 8 and 12 weeks after surgery. At each time point, shoulders underwent micro-computed tomography scanning and biomechanical testing (N = 6), conventional histology and histomorphometric analysis (N = 6) and ultrastructural analysis with focused ion beam/scanning electron microscope (FIB/SEM) tomography (N = 4). We demonstrated that the cellular distribution between the repaired tendon and bone at 12 weeks after surgery bore similarities to the normal tendon insertion. However, the ultrastructure of the cells at any time point had a different morphology than those of the normal tendon insertion. These morphological differences affect the healing process, partly contributing to re-tearing at the repair site. These results may facilitate future studies of the regeneration of a normal tendon insertion.

Background: Most studies have shown acceptable clinical results in patients with large or massive tears treated by arthroscopic rotator cuff repair (ARCR); however, the effects of retears after surgery in these patients remain unknown. Purpose: To evaluate functional and structural outcomes after retears of large and massive rotator cuff tears treated by ARCR. Study Design: Case series; Level of evidence, 4. Methods: A total of 196 consecutive patients with large to massive rotator cuff tears underwent physical examination and magnetic resonance imaging before and after ARCR at 6, 12, and 24 months. Of these, 9 patients were lost at 6 months after surgery. Therefore, 187 patients were followed up for 24 months after surgery; 148 patients showed no postsurgical ruptures. Consequently, the remaining 39 patients with postsurgical ruptures were included in this study (mean age at surgery, 64.2 ± 8.7 years). Functional outcome measures comprised the University of California, Los Angeles (UCLA) and Japanese Orthopaedic Association (JOA) scores. Structural outcome measures consisted of the global fatty degeneration index (GFDI), mediolateral tear size, and residual tendon attachment area as evaluated by our own scoring system. Results: The mean UCLA and JOA scores significantly improved from 16.3 ± 3.9 and 63.2 ± 10.7 preoperatively to 27.9 ± 5.5 (P < .0001) and 84.5 ± 9.4 (P < .0001) at final follow-up, respectively. The mean mediolateral tear size (P = .03, .02, and .02, respectively) and residual tendon attachment area (P = .04, .03, and .04, respectively) significantly improved from preoperatively to 6, 12, and 24 months postoperatively. The correlation analysis between the functional and structural variables confirmed significant associations between the residual tendon attachment area, the JOA and UCLA scores at 24 months postoperatively, and the preoperative GFDI (r = –0.81 to 0.78). Conclusion: The residual tendon attachment area after a retear was significantly larger at 24 months after surgery than before surgery. In addition, significant associations were confirmed between preoperative fatty degeneration, the residual tendon attachment area, and functional outcomes after a retear. These results may explain why functional outcomes significantly improved even after retears in this series.

Objective To investigate the effect of adipose-derived cells (ADCs) on tendon-bone healing in a rat model of chronic rotator cuff tear (RCT) with suprascapular nerve (SN) injury. Methods Adult rats underwent right shoulder surgery whereby the supraspinatus was detached, and SN injury was induced. ADCs were cultured from the animals’ abdominal fat. At 6 weeks post-surgery, the animals underwent surgical tendon repair; the ADC (+ve) group (n = 18) received an ADC injection, and the ADC (−ve) group (n = 18) received a saline injection. Shoulders were harvested at 10, 14, and 18 weeks and underwent histological, fluorescent, and biomechanical analyses. Results In the ADC (+ve) group, a firm enthesis, including dense mature fibrocartilage and well-aligned cells, were observed in the bone-tendon junction and fatty infiltration was less than in the ADC (−ve) group. Mean maximum stress and linear stiffness was greater in the ADC (+ve) compared with the ADC (−ve) group at 18 weeks. Conclusion ADC supplementation showed a positive effect on tendon-bone healing in a rat model of chronic RCT with accompanying SN injury. Therefore, ADC injection may possibly accelerate recovery in massive RCT injuries.

Background: Previous studies have shown good clinical outcomes in patients with irreparable large or massive rotator cuff tears treated using arthroscopic partial repair (APR); however, few studies have evaluated both functional and structural outcomes in these patients. Purpose: To evaluate both functional and structural outcomes in patients with large or massive rotator cuff tears treated using APR. Study Design: Case series; Level of evidence, 4. Methods: Between March 2009 and November 2016, a total of 30 patients underwent APR because of the irreparability of their large or massive rotator cuff tears during surgery. Of these patients, 24 completed the minimum 24-month follow-up (mean, 61.8 ± 27.1 months; range, 24-112 months) and were included in this study. Functional outcome measures included the Japanese Orthopaedic Association (JOA) and University of California Los Angeles (UCLA) scores and the visual analog scale for pain. Structural outcome measures comprised preoperative fatty degeneration, mediolateral tear size, residual tendon attachment area, and glenohumeral (GH) arthritic changes evaluated on magnetic resonance imaging scans or plain radiographs before and after surgery. Functional and structural outcomes were evaluated preoperatively, at 3 months postoperatively, and at the final follow-up. Results: The JOA scores for all patients significantly improved from 67.9 ± 11.3 preoperatively to 85.4 ± 15.6 postoperatively (P < .0001). Similarly, the UCLA scores significantly improved from 15.8 ± 4.20 preoperatively to 29 ± 6.69 at final follow-up postoperatively (P < .0001). The mediolateral tear size were significantly decreased at 3 months postoperatively (P < .001) and at the final follow-up (P < .001). Compared with preoperative scores, the novel score evaluating the residual tendon attachment area improved from 3.08 ± 0.46 to 3.54 ± 0.41 (P < .001) after surgery overall, although it significantly deteriorated from 3 months postoperatively to the final follow-up. GH osteoarthritis progressed in 6 patients (25%). Patients who developed osteoarthritis had lower JOA and UCLA scores than did those who did not (JOA, P = .010; UCLA, P = .037). Conclusion: In irreparable large or massive rotator cuff tears treated using APR, functional outcome improved after surgery. Although the residual tendon attachment area improved, functional outcome after APR corresponded to the GH alterations at the midterm follow-up. Longer-term follow-up is needed to further elucidate the effect of APR on clinical outcomes in these patients.

Purpose To compare arthroscopic suture bridge (SB) techniques with medial tying to those without tying, considering clinical and structural outcomes. Methods We included 124 patients with rotator cuff tears after arthroscopic rotator cuff repair (ARCR). Fifty-three patients with clinical and structural evaluations 3, 12, and 24 months postoperatively were included and divided into 29 patients with medial tying (WMT group) and 24 without tying (WOMT group). Clinical outcomes comprised the University of California Los Angeles (UCLA) and Japanese Orthopaedic Association (JOA) scores. Structural outcomes were evaluated with magnetic resonance images (MRI) using Sugaya classifications. Results JOA and UCLA scores in the WMT and WOMT groups improved significantly from before surgery to 24 months after surgery ( P  < 0.01, respectively). No significant difference was noted between groups. No significant postoperative retears (Sugaya types 4 and 5) between WMT and WOMT groups were noted at 3 months (5 vs 3 cases), 12 months (6 vs 5 cases), and 24 months (7 vs 6 cases) postoperatively. Complete healing (Sugaya type 1) was noted at 3 months (8 vs 11 cases), 12 months (10 vs 10 cases), and 24 months (8 vs 13 cases, P  = 0.024) postoperatively. Incomplete healing (Sugaya types 2 and 3) were noted at 3 months (16 vs 10 cases), 12 months (13 vs 9 cases), and 24 months (14 vs 5 cases, P  = 0.024) postoperatively. Conclusion Clinical outcomes for both techniques were comparable, but the number of incompletely healed tendons in SB with medial tying was significantly larger at 24 months after surgery. Level of evidence This study is a level III, case-control study. Clinical relevance This study revealed the influence of medial tying in rotator cuff repair.

Background Previous studies have evaluated the risk factors for retear of large/massive rotator cuff tears (RCTs) that were treated arthroscopically; however, most studies did not evaluate tear patterns. The present study hypothesized that postoperative risk factors are affected by the tearing patterns in large/massive cuff tears in patients undergoing arthroscopic rotator cuff repair (ARCR). Methods One hundred fifty patients with large/massive cuff tears underwent ARCR at our institution. Of these, 102 patients were enrolled in this study, with an average symptom duration of 36.3 ± 43.9 months and average age of 63.9 ± 9.4 years. According to the arthroscopic findings and magnetic resonance imaging (MRI), the 102 patients were divided into three groups based on the tendon location: anterosuperior tears ( N  = 59, group AS), posteosuperior tears ( N  = 21, group PS), and anteroposterior-extending tears ( N  = 22, group APE). Functional outcome was evaluated preoperatively and postoperatively using the Japanese Orthopedic Association (JOA) score and the University of California, Los Angeles (UCLA) score. Retear was evaluated with MRI at a minimum of 1 year after surgery, using Sugaya’s classification; Types IV and V were considered postoperative retears. Factors affecting postoperative retear were examined with univariate and multivariate analyses. Results JOA/UCLA scores significantly improved postoperatively in the three groups ( P  < 0.01 for all). Postoperative retear was noted in 26 of 102 patients (25.5%) in this series: 10 patients in group AS (16.9%), 9 in group PS (42.9%), and 7 in group APE (31.8%). The retear rate was significantly higher in group PS than in the other two groups ( P  = 0.02). Multivariate analysis showed that decreased preoperative active external rotation range was a unique risk factor for postoperative retear in the PS and APE groups (95% confidence interval: 0.02–0.18, cut-off value: 25°, with an area under the curve of 0.90, P  = 0.0025). Conclusions Although multivariate analysis failed to detect significant risk factor for retear in patients with anterosuperior large/massive cuff tears who undergo ARCR, it demonstrated that active external rotation less than 25° before surgery is a significant risk factor in those with posterosuperior large/massive tears. This study may help surgeons understand the results of arthroscopic surgery in patients with large/massive tears.

This report presents a case of rapidly progressive collapse of the humeral head following arthroscopic rotator cuff repair. We performed humeral head replacement 8 months after the index surgery; histological examination of the collapsed area revealed necrosis, degeneration, fibrillation, and granulation in the cartilage and trabeculae. Osteonecrosis due to the use of metal anchors was considered the primary cause of the post-operative humeral head collapse. As the demand for arthroscopic cuff repair is expected to increase in the future, we recommend that surgeons become aware of the potential for complications, as seen in the present case. Level of evidence IV.

Background To examine important factors that affect clinical outcomes following arthroscopic rotator cuff repair (ARCR). Methods Among 163 patients who underwent ARCR, we included 71 shoulders in 71 patients whose progress was monitored for > 2 years, postoperatively. We divided the patients into groups A (scores ≥ 83 points, 59 patients) and B (scores < 83 points, 12 patients) using the Japanese Orthopedic Association (JOA) score at 24 months. We then conducted univariate and multivariate analyses of pre- and postoperative (2 and 3 months, respectively) factors. Results The mean JOA score for all patients significantly improved from 63.7 ± 11.5 points preoperatively to 90.3 ± 9.6 points at 24 months postoperatively ( P  < 0.05). However, there were no significant between-group differences in the preoperative scores. In addition, there were no significant differences in the postoperative re-tear rate. Univariate analysis revealed that the range of motion (preoperative abduction and postoperative elevation, abduction, internal rotation, and external rotation), muscle strength (external rotation 3 months postoperatively), postoperative pain level [visual analog scale (VAS) maximum score, 10 points], partial repair, Cofield classification, and preoperative width were significant factors ( P  < 0.05 for all factors). Multivariate and receiver operating characteristic curve analyses showed that VAS at 2 months postoperatively and elevation at 3 months postoperatively were significant factors. Conclusions To obtain a JOA score of ≥ 83 points at 24 months postoperatively, following ARCR, a postoperative VAS of < 5 points at 2 months and postoperative elevation of ≥ 110° at 3 months should be achieved.

Background Recent studies have shown effective clinical results after arthroscopic Bankart repair (ABR) but have shown several risk factors for re-dislocation after surgery. We evaluated whether patients are at a risk for re-dislocation during the first year after ABR, examined the recurrence rate after ABR, and sought to identify new risk factors. Methods We performed ABR using bioabsorbable suture anchors in 102 consecutive shoulders (100 patients) with traumatic anterior shoulder instability. Average patient age and follow-up period was 25.7 (range, 14–40) years and 67.5 (range, 24.5–120) months, respectively. We evaluated re-dislocation after ABR using patient telephone interviews (follow-up rate, 100%) and correlated re-dislocation with several risk factors. Results Re-dislocation after ABR occurred in nine shoulders (8.8%), of which seven sustained re-injuries within the first year with the arm elevated at 90° and externally rotated at 90°. Of the remaining 93 shoulders without re-dislocation, 8 had re-injury under the same conditions within the first year. Thus, re-injury within the first year was a risk for re-dislocation after ABR ( P < 0.001, chi-squared test). Using multivariate analysis, large Hill-Sachs lesions (odds ratio, 6.77, 95% CI, 1.24–53.6) and <4 suture anchors (odds ratio, 9.86, 95% CI, 2.00–76.4) were significant risk factors for re-dislocation after ABR. Conclusions The recurrence rate after ABR is not associated with the time elapsed and that repair strategies should augment the large humeral bone defect and use >3 anchors during ABR.

Background Arthroscopic rotator cuff repair (ARCR) generally yields acceptable clinical results. Hyaluronic acid (HA), a high-molecular-weight polysaccharide, is present in the extracellular matrix of soft connective tissue and synovial fluid, and its injection is known to significantly improve pain and clinical outcomes after rotator cuff injury. Some studies have described the role of HA injections as conservative therapy for rotator cuff tears. Since the subacromial bursa is believed to be the main source of shoulder pain in rotator cuff tears, subacromial injection is frequently used before surgery; however, its relationship with the clinical outcome after surgery remains unclarified. Therefore, we aimed to examine effects of preoperative subacromial HA injection on postoperative clinical outcome in patients with ARCR. Methods Ninety-eight patients were divided into a HA injection group and a non-injection group. The functional outcome measured was the University of California, Los Angeles (UCLA) score. Univariate analysis was performed to obtain variables with p values less than 0.1; we then used propensity score analysis, adjusting for pre- and post-operative confounding factors. Results The UCLA scores of all patients significantly improved 1 year postoperatively (PO) ( p < 0.05). Subacromial HA injections were performed in patients with worse preoperative function. Univariate analysis showed significantly greater improvements in the injection group than in the non-injection group in terms of preoperative UCLA score, trauma, diabetes mellitus, UCLA score 3 months PO, abduction strength 4 months PO, and internal rotation (IR) strength 6 and 12 months PO. Propensity score analysis demonstrated that UCLA scores 3 months PO and IR strength 12 months PO in the injection group were significantly greater than those in the non-injection group. There were no significant differences in postoperative re-tear rates between the groups. In sub-analysis of the injection group, propensity scores showed that concurrent use of local anesthetics did not affect the data, suggesting that HA was effective. Conclusion Subacromial injection was administered to patients with worse function before ARCR. Propensity score analysis successfully demonstrated that functional outcome after surgery was improved in patients who were administered this injection compared with patients who were not administered this injection before surgery.