Prevalence and risk factors associated with anterior shoulder pain following reverse total shoulder arthroplasty.

BACKGROUND: The annual incidence of reverse total shoulder arthroplasty (rTSA) indications has surpassed that of anatomic total shoulder arthroplasty. Its unique complications include prosthetic dislocation, acromial and scapular stress fractures, and scapular notching. Anterior shoulder pain is a less recognized, poorly understood complication, with little literature describing its existence, risk factors, and causes. The purpose of this work was to describe its prevalence in our patient population undergoing rTSA and its potential associations.

METHODS: A retrospective chart review of a prospectively maintained database was performed for all patients undergoing rTSA from 2010 to 2023 by 2 fellowship-trained shoulder and elbow surgeons with minimum 12-month clinical and radiographic follow-up. All patients were evaluated for the development of anterior shoulder pain after surgery. It was defined as pain located within the borders of the midclavicular region medially to lateral aspect of the acromion and from the coracoid process superiorly to the mid portion of the arm. Postoperative clinical notes were reviewed for the development of "anterior shoulder pain" which included pain over the conjoint tendon, biceps tenodesis site, subscapularis repair site, and anterior deltoid. Patient height and weight, surgical indications, bicep management, version of the humeral component, inlay vs. onlay humeral design, subscapularis management, glenosphere size, total glenoid lateralization according to manufacturer specifications, use of glenoid augmentation, and use of a humeral metallic spacer were evaluated for association in the development of anterior shoulder pain.

RESULTS: One thousand four-hundred one patients undergoing rTSA were analyzed. Of them, 174 (12.4%) had documented anterior shoulder pain during postoperative follow-up. Variables that were found to be associated with anterior shoulder pain: rotator cuff deficiency (P = .0075), lower weight, 84.3 to 87.5 kg; (P = .041), inlay humeral component in 20 degrees of retroversion vs. onlay component in 30 degrees of retroversion (15.8% vs. 11%, P = .014), and greater total glenoid lateralization (2.5 vs. 1.84 mm; P = .0075).

DISCUSSION: To our knowledge, this is the first work describing the prevalence as well as analyzing variables associated with the development of anterior shoulder pain following rTSA. With a prevalence of 12.4%, this is a common complication that is underreported in literature. Our data show that at our institution the use of inlay prostheses, 20 degrees of humeral retroversion, rotator cuff deficient patients, patients with lower weight, and increased glenoid-sided lateralization are associated with statistically significantly higher rates of the development of anterior shoulder pain postoperatively. No association was noted for bicep management, subscapularis repair, or glenosphere size.