Bursal Acromial Reconstruction (BAR) Using an Acellular Dermal Allograft for Massive, Irreparable Posterosuperior Rotator Cuff Tears: A Dynamic Biomechanical Investigation.

PURPOSE: To investigate the effect of bursal acromial reconstruction (BAR) using an acellular dermal allograft on glenohumeral joint kinematics including maximum abduction angle, glenohumeral superior translation, cumulative deltoid force, and subacromial contact pressure. METHODS: In this dynamic biomechanical cadaveric shoulder study, 8 fresh-frozen cadaveric shoulders (age 53.4 ± 14.2 years, mean ± standard deviation) were tested using a dynamic shoulder testing system. Maximum abduction angle (MAA), glenohumeral superior translation (ghST), maximum cumulative deltoid force (cDF), and subacromial peak contact pressure (sCP) were compared across 3 conditions: (1) intact shoulder; (2) massive retracted irreparable posterosuperior rotator cuff tear (psRCT) according to Patte III; and (3) BAR. Additionally, humeral head containment was measured using contact pressure. RESULTS: Compared with the simulated psRCT, BAR significantly increased mean MAA and significantly decreased ghST (P < .001, respectively) and cDF (P = .017) Additionally, BAR was found to significantly decrease sCP compared with psRCT (P = .024). CONCLUSION: In a dynamic biomechanical cadaveric shoulder simulator, resurfacing the undersurface of the acromion using the BAR technique leads to significantly improved ghST, MAA, cDF, and sCP compared with the irreparable rotator cuff tear. CLINICAL RELEVANCE: With the BAR technique, native humeral containment may be restored, which can potentially delay progressive subacromial and glenoidal abrasive wear and improve overall shoulder function. As such, the proposed BAR technique can be considered as a technically feasible and potentially cost- and timesaving procedure, as no bone anchors are needed, glenoidal or humeral side graft ruptures can be avoided, and postoperative rehabilitation can be started immediately. However, future clinical studies are needed.

Arthroscopic Superior Capsular Reconstruction of the Shoulder Using Dermal Allograft.

Irreparable massive cuff tears in young patients pose a difficult problem for shoulder surgeons. Arthroscopic superior capsular reconstruction has shown promise in recent years in the treatment of this challenging patient population. The majority of the literature is limited to surgical techniques. The authors present the 2-year clinical outcomes of 25 patients undergoing arthroscopic superior capsular reconstruction with dermal allograft from a single center. The Oxford Shoulder Score and range of motion were assessed preoperatively and then at 3 to 6 months, 1 year, and 2 years following surgery. Patient satisfaction was recorded at final follow-up. Magnetic resonance imaging was performed at 3 months postoperatively to assess graft integrity. All patients were available at 1-year follow-up, and 23 were available at 2 years. The mean Oxford Shoulder Score improved by a minimum of 10 points at all time points compared with preoperatively. The mean forward flexion and abduction improved by 20° and external rotation by 7°. Revision to reverse shoulder arthroplasty was seen in 3 patients (12%). Graft failure was seen in 4 patients (16%). Overall, 20 patients had successful outcomes at 1 year (80%) and 18 patients had successful outcomes at 2 years (72%). Superior capsular reconstruction offers a safe and effective short-term bridging option for young patients with irreparable supraspinatus tears in the absence of glenohumeral arthritis. However, long-term outcome studies are required to evaluate the true clinical effectiveness and failure rates. [Orthopedics. 2020;43(4):215-220.].

Clinical Outcome of Transtendon Repair of Partial Articular Supraspinatus Tendon Avulsion Tear.

Partial articular supraspinatus tendon avulsion (PASTA) tears are common. However, there is no consensus on the optimal surgical technique for the management of grade 3 tears (>50%). The authors report a retrospective consecutive case series of 64 patients with grade 3 PASTA lesions. The patients were treated by 2 surgeons from 2 centers with the same transtendon repair technique and implant system. The preoperative Oxford Shoulder Score (OSS) was compared with the postoperative OSS at final follow-up (mean, 28 months). Significant improvement in mean OSS occurred from 19.2 (SD, 7.5) preoperatively to 39.8 (SD, 7.8) postoperatively (P=.0001), and patient satisfaction rates were high (88%). The authors believe that transtendon repair of PASTA lesions of 50% or more is beneficial. High-quality randomized controlled trials are required to compare the benefit of repair vs debridement alone. [Orthopedics. 2020;43(6):e533-e537.].

Histological incorporation of acellular dermal matrix in the failed superior capsule reconstruction of the shoulder.

BACKGROUND: Superior capsule reconstruction addresses massive rotator cuff tears using allografts and aims to restore the natural superior constraint of the shoulder and therefore shoulder biomechanics and function. There is no evidence relating to the histological incorporation of these grafts. METHODS: 27 superior capsule reconstructions were performed between June 2016 and November 2017. Follow-up was with clinical assessment and Magnetic Resonance Imaging, to identify graft failure. Reverse total shoulder replacement was offered for ruptured grafts and the graft was sent for histological analysis along with the footprint of graft attachment where possible. RESULTS: Five patients (18.5%) had evidence of graft failure, three of whom (11.1%) underwent revision procedures. Of the five ruptures, four failed at the glenoid insertion, and one was an intra-substance tear. Histological analysis showed extensive fibroblastic infiltration. The intra-substance tear showed some vascularity at the medial and lateral ends, and one of the glenoid pull-outs demonstrated micro-calcification and osteoid formation. There was no evidence of in-growth into the bone. DISCUSSION: An inflammatory response to the grafts was seen, with neo-vascularisation, and micro-calcification observed. These findings are from ruptured grafts, so may not represent the characteristics of those which have not ruptured. Further evidence from explanted intact grafts could be gained to improve our understanding of its incorporation. LEVEL OF EVIDENCE: Level IV evidence.