BACKGROUND: The currently available reverse shoulder arthroplasty (RSA) designs can be classified into medial glenoid/medial humerus (MGMH), lateral glenoid/medial humerus (LGMH), and medial glenoid/lateral humerus (MGLH) prosthesis designs. The purpose of this study was to radiologically analyze the effect of different RSA designs on humeral position following RSA.METHODS: A total of 50 patients who underwent primary RSA were retrospectively analyzed. Among 50 patients, 33 patients (group A: MGMH) underwent RSA with Aequalis system (Wright, Inc, Bloomington, MN, USA), 6 (group B: LGMH) with Aequalis system using bony increased offset, and 11 (group C: MGLH) with Aequalis Ascend Flex system. The acromiohumeral distance, acromioepiphyseal distance (AED), lateral humeral offset (LHO), LHO from the center of rotation (LHO(COR)), and deltoid length were radiologically measured to quantify the distalization and lateralization of the humerus.RESULTS: The increment in postoperative AED was 19.92 ± 3.93 mm in group A, 24.52 ± 5.25 mm in group B, and 25.97 ± 5.29 mm in group C, respectively (p=0.001). The increment in postoperative LHO was 0.13 ± 6.30 mm, 8.00 ± 12.14 mm, and 7.42 ± 6.88 mm, respectively (p=0.005). The increment in postoperative LHOCOR was 20.76 ± 6.06 mm, 22.04 ± 5.15 mm, and 28.11 ± 4.14 mm, respectively (p=0.002).CONCLUSIONS: The radiologic analysis of the effect of different RSA designs on humeral position following RSA showed significant differences in the increment in postoperative AED, LHO, and LHO(COR) between the 3 groups. Therefore, MGLH design seems to be more effective for humeral distalization and lateralization compared to original Grammont design.

Background: A novel technique for the repair of tears of the upper subscapularis tendon-intraarticular knotless fixation-has been introduced recently. The purpose of this study was to evaluate the clinical and structural outcomes of arthroscopic intraarticular knotless fixation for the treatment of upper subscapularis tendon tears. Methods: We retrospectively analyzed the clinical and radiological outcomes of 27 patients who underwent arthroscopic intraarticular knotless fixation for upper subscapularis tendon tears. Finally, a total of 10 patients who could participate in at least a 6 month follow-up of magnetic resonance imaging evaluation and in a least 1-year follow-up on an outpatient basis were enrolled in our study. The mean age at the time of operation was 60.7 years, and the mean duration of follow-up was 14.7 months. Two patients had concomitant tears of the supraspinatus tendon and 8 patients had concomitant tears of the supraspinatus and the infraspinatus tendons. Results: The clinical and radiological outcomes improved after the patients had undertaken arthroscopic intraarticular knotless fixation. The mean visual analogue scale score for pain during motion improved from 6.7 preoperatively to 1.4 at the final follow-up (p<0.001). The mean Constant score improved from 59.3 preoperatively to 79.6 at the final follow-up, and the mean the University of California at Los Angeles score, from 21.7 to 30.2, respectively (p<0.001 and p<0.001). The upper subscapularis tendon tear was healed in every patient except one (90%), for the patient had suffered from a postoperative trauma that resulted in a retear. Conclusions: We found that arthroscopic intraarticular knotless fixation gives good clinical and structural outcomes for the repair of upper subscapularis tendon tears. Arthroscopic intraarticular knotless fixation provided such a reliable and efficient restoration of the subscapularis tendon footprint that we anticipate it will become a widely-used procedure for upper subscapularis tendon tears. (Clin Shoulder Elbow 2016;19(3):130-136)