The unstable painful shoulder (UPS) as a cause of pain from unrecognized anteroinferior instability in the young athlete

Hypothesis The etiology of shoulder pain in the overhead athlete is often difficult to determine. This study hypothesized that (1) instability can present in a purely painful form, without any apparent history of instability, but with anatomic lesions indicative of instability, termed unstable painful shoulder (UPS), and that (2) arthroscopic shoulder stabilization is effective. Materials and methods The study evaluated 20 patients (mean age, 22 ± 8 years) at a mean of 38 months postoperatively (range, 24-69 months). Inclusion criteria were painful shoulder with lesions indicative of instability on imaging or at surgery, minimum 2-year follow-up. Exclusion criteria were recognized instability, other associated pathologies, and previous shoulder surgery. Results Patients were young, hyperlax athletes who complained of deep, anterior shoulder pain and denied any instability. Pain was reproduced with the arm in an anterior apprehension position and relieved by a relocation test; however, no actual apprehension was experienced. Patients often had glenohumeral laxity and hyperlaxity. Lesions indicative of instability confirmed that at least 1 unapparent shoulder subluxation occurred. The Rowe, Walch-Duplay, and University of California, Los Angeles scores improved significantly ( P < .05); 19 patients (95%) were satisfied, and 15 (75%) returned to their previous level of sports. Discussion The diagnosis of UPS is often missed but is important to consider in the young hyperlax athlete. Soft tissue and/or bony lesions consistent with instability are necessary to confirm the diagnosis. Arthroscopy certainly deserves a significant place in this form of anteroinferior instability because it allows both the assessment of lesions (ie, diagnosis) and a satisfactory functional result and return to sport.