Analysis of subscapularis integrity and function after lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty using ultrasound and validated clinical outcome measures.

BACKGROUND

The optimal method-subscapularis peel (SP) or lesser tuberosity osteotomy (LTO)-for takedown of the subscapularis during total shoulder arthroplasty (TSA) is controversial. This study compares the functional outcomes in a 2-surgeon cohort using the 2 techniques.

METHODS

Patients who underwent TSA with a minimum 1 year of follow-up were evaluated. Physical and ultrasound examinations of the operative shoulder were performed. Radiographs were evaluated for osteotomy healing. Patients completed the Western Ontario Osteoarthritis of the Shoulder (WOOS) index, Disability of the Arm, Shoulder, and Hand (DASH), and Constant Scores.

RESULTS

Subscapularis tenotomy (n = 32) and LTO (n = 28) patients were similar in age, hand dominance, and sex. Follow-up duration for subscapularis tenotomy and LTO patients differed (31.7 vs 22.1 months, P = .003). SP patients demonstrated increased external rotation (69° ± 12° vs 60° ± 11°). Belly press and bear hug resistance were not significantly different. WOOS (P = .13), DASH (P = .71), and Constant Scores (P = .80) were not significantly different. After controlling for follow-up imbalance, the WOOS score difference was statistically significant (91.5 ± 10.2 for LTO vs 82.1 ± 18.9 for SP, P = .05) but not clinically significant. By ultrasonography assessment, 4 subscapularis tendons were abnormal in the SP group (3 attenuated, 1 ruptured), and all tendons were normal in the LTO group. Patients with an abnormal ultrasound result had significantly inferior WOOS (88 ± 15 vs 65 ± 18) and DASH (11.5 ± 11.4 vs 25.9 ± 11.2) scores. Belly press resistance was significantly decreased, bear hug resistance trended lower, and external rotation was increased in the abnormal ultrasound group.

CONCLUSIONS

Abnormal subscapularis tendons identified by ultrasonography only in the SP group correlate with clinically significant inferior functional outcome scores.