While reverse shoulder arthroplasty has shown satisfactory outcomes in rotator cuff deficient shoulders, its performance in shoulders with an intact rotator cuff has not been fully elucidated. Shoulder osteoarthritis can present with alterations in glenoid morphology which have contributed to inconsistent outcomes in anatomic shoulder replacement. A predominance of these arthroplasty complications is due to the glenoid component. Given these glenoid related difficulties, RSA may provide a more favorable option. We aimed to summarize the current literature for rotator cuff intact osteoarthritis treated with primary reverse shoulder arthroplasty and to determine whether morphological changes in the glenoid led to inferior outcomes.
A literature search was performed which utilized an inclusion criteria of primary reverse shoulder arthroplasty for osteoarthritis with intact rotator cuff. Modified Coleman Methodology Score was calculated to analyze reporting quality. Following appropriate exclusions, 13 studies were selected of the 1002 which were identified by the databases.
Postoperative improvement in weighted means for Constant scores reached statistical significance (p=0.02). Mean rate of major complication was 3.8%. A subset of 7 studies was created which detailed the following descriptions for altered glenoid morphology: “static posterior instability”, “severe posterior subluxation”, “posterior glenoid wear >20º”, “significant posterior glenoid bone loss”, “biconcave glenoid”, “B2 glenoid”, “B/C glenoid”. Within this subset, the mean complication rate was 4.7% with 4 of the 7 studies having a rate of 3% or lower and improvements in Constant (p=0.002) and external rotation (p=0.02) reached statistical significance.
Reverse shoulder arthroplasty as treatment for intact rotator cuff osteoarthritis provides optimal outcomes with low rates of complication. Preoperative considerations for using reverse arthroplasty in osteoarthritis with intact rotator cuff include glenoid retroversion, posterior humeral subluxation and glenoid bone loss. The attributes of reverse arthroplasty which contribute to favorable outcomes in arthritic shoulders include its semi constrained design and its robust glenoid fixation. Soft tissue imbalances as a consequence of pathologic glenoid morphology and chronic humeral subluxation can be mitigated with the RSA semi constrained design. Glenoid bone loss can be effectively managed with reverse’s robust glenoid fixation, with and without the use of bone graft. The capability to lateralize the joint center of rotation may be valuable when faced with a medialized glenoid wear pattern. The current findings suggest that reverse arthroplasty can achieve highly favorable outcomes for glenohumeral osteoarthritis with intact rotator cuff.

Copyright © 2021. Published by Elsevier Inc.

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