Generally, a glenoid bone loss greater than 20% to 25% is considered critical for poor surgical outcomes after a soft tissue repair. However, recent studies have suggested that the critical value should be lower. To determine the critical value of anterior glenoid bone loss that led to surgical failure in patients with anterior shoulder instability. Case-control study; Level of evidence, 3. The study included 169 patients with anterior glenoid erosion. The percentage of glenoid erosion was calculated as the ratio of the glenoid loss width and the glenoid width to the diameter of the outer-fitting circle based on the inferior portion of the glenoid contour. The critical value of the glenoid bone loss was analyzed by means of receiver operating characteristic (ROC) curve analysis. Patients were divided into 2 groups based on the amount of glenoid bone loss: group A (less than the critical value) and group B (more than the critical value). Patients evaluated their shoulder function as a percentage of their preinjury level using the Single Assessment Numeric Evaluation (SANE) score, and postoperative clinical outcomes were assessed with the American Shoulder and Elbow Surgeons (ASES) score and Rowe score. Surgical failure was defined as the need for revision surgery or the presence of subjective symptoms of instability. The optimal critical value of glenoid bone loss was 17.3% (area under the curve = 0.82; 95% confidence interval, 0.73-0.91; P < .001; sensitivity 75%; specificity 86.6%). Group A and B contained 134 and 35 patients, respectively. Shoulder functional scores were significantly lower in group B than in group A (P < .001). Five patients (3.7%) in group A and 15 (42.9%) in group B had surgical failure (P < .001). The SANE score was significantly lower in group B (83.8 ± 12.1) than in group A (92.9 ± 4.7, P = .001). An anterior glenoid bone loss of 17.3% or more with respect to the longest anteroposterior glenoid width should be considered as the critical amount of bone loss that may result in recurrent glenohumeral instability after arthroscopic Bankart repair.

Many studies have identified risk factors that cause retear after rotator cuff repair. However, it is still questionable whether retears can be predicted preoperatively. To determine the risk factors related to retear after arthroscopic rotator cuff repair and to evaluate whether it is possible to predict the occurrence of retear preoperatively. Case-control study; Level of evidence, 3. This study enrolled 112 patients who underwent arthroscopic rotator cuff repair with single-row technique for a large-sized tear, defined as a tear with a mediolateral length of 3 to 5 cm. All patients underwent routine magnetic resonance imaging (MRI) at 9 months postoperatively to assess tendon integrity. The sample included 61 patients (54.5%) in the healed group and 51 (45.5%) in the retear group. In multivariate analysis, the independent predictors of retears were supraspinatus muscle atrophy (P < .001) and fatty infiltration of the infraspinatus (P = .027), which could be preoperatively measured by MRI. A significant difference was found between the two groups in sex, the acromiohumeral interval, tendon tension, and preoperative or intraoperative mediolateral tear length and musculotendinous junction position in univariate analysis. However, these variables were not independent predictors in multivariate analysis. The cutoff values of occupation ratio of supraspinatus and fatty infiltration of the infraspinatus were 43% and grade 2, respectively. The occupation ratio of supraspinatus <43% and grade ≥2 fatty infiltration of the infraspinatus were the strongest predictors of retear, with an area under the curve of 0.908, sensitivity of 98.0%, and specificity of 83.6% (accuracy = 90.2%). In patients with large rotator cuff tears, it was possible to predict the retear before rotator cuff repair regardless of intraoperative factors. The retear could be predicted most effectively when the occupation ratio of supraspinatus was <43% or the fatty infiltration of infraspinatus was grade ≥2. Predicting retear preoperatively may help surgeons determine proper treatment and predict the postoperative prognosis.

The optimal procedure for anterior shoulder instability with a borderline (15%-20%) bone defect on the anterior rim of the glenoid is still controversial. To compare the clinical outcome and recurrence rate between the arthroscopic Bankart repair and Latarjet procedure among patients with recurrent anterior shoulder instability and a borderline glenoid bone defect. Cohort study; Level of evidence, 3. The authors retrospectively reviewed cases of arthroscopic Bankart repair and the Latarjet procedure for recurrent anterior shoulder instability with a borderline (15%-20%) glenoid bone defect. Enrollment comprised 149 patients (Bankart group, n = 118; Latarjet group, n = 31). The mean follow-up and age at operation were 28.9 ± 7.3 months (range, 24-73 months) and 26 ± 5 years (range, 16-46 years), respectively. Rowe and UCLA (University of California, Los Angeles) shoulder scores significantly improved from 42.0 ± 14.3 and 22.9 ± 3.2 preoperatively to 90.9 ± 15.4 and 32.5 ± 3.3 postoperatively in the Bankart group (P < .001) and from 41.0 ± 17.9 and 22.3 ± 3.4 to 91.1 ± 16.1 and 32.3 ± 3.4 in the Latarjet group (P < .001), respectively. There were no significant between-group differences in Rowe (P = .920) or UCLA (P = .715) scores at the final follow-up. Mean postoperative loss of motion during forward flexion, external rotation in abduction, and internal rotation to the posterior was 3.0° ± 6.2°, 11.6° ± 10.2°, and 0.6 spinal segment in the Bankart group and 3.7° ± 9.8°, 10.3° ± 12.8°, and 0.9 spinal segment in the Latarjet group, respectively. These differences were not significant. However, the loss of external rotation at the side was significantly greater in the Bankart group (13.3° ± 12.9°) than in the Latarjet group (7.3° ± 18.1°, P = .034). The overall recurrence rate was significantly higher in the Bankart group (22.9%) than in the Latarjet group (6.5%), (P = .040). The Latarjet procedure and arthroscopic Bankart repair both provided satisfactory clinical outcome scores and pain relief for anterior shoulder instability with a borderline glenoid bone defect. However, the Latarjet procedure resulted in significantly lower recurrences and less external rotation limitation than the arthroscopic Bankart repair. Therefore, the Latarjet procedure could be a more reliable surgical option in anterior recurrent instability with a borderline glenoid bone defect.

Osteoarthritis (OA) has generally been introduced as a degenerative disease; however, it has recently been understood as a low-grade chronic inflammatory process that could promote symptoms and accelerate the progression of OA. Current treatment strategies, including corticosteroid injections, have no impact on the OA disease progression. Mesenchymal stem cells (MSCs) based therapy seem to be in the spotlight as a disease-modifying treatment because this strategy provides enlarged anti-inflammatory and chondroprotective effects. Currently, bone marrow, adipose derived, synovium-derived, and Wharton’s jelly-derived MSCs are the most widely used types of MSCs in the cartilage engineering. MSCs exert immunomodulatory, immunosuppressive, antiapoptotic, and chondrogenic effects mainly by paracrine effect. Because MSCs disappear from the tissue quickly after administration, recently, MSCs-derived exosomes received the focus for the next-generation treatment strategy for OA. MSCs-derived exosomes contain a variety of miRNAs. Exosomal miRNAs have a critical role in cartilage regeneration by immunomodulatory function such as promoting chondrocyte proliferation, matrix secretion, and subsiding inflammation. In the future, a personalized exosome can be packaged with ideal miRNA and proteins for chondrogenesis by enriching techniques. In addition, the target specific exosomes could be a gamechanger for OA. However, we should consider the off-target side effects due to multiple gene targets of miRNA.