The effect of subscapularis management technique on outcomes and complication rates following reverse total shoulder arthroplasty

BackgroundRepair of the subscapularis tendon following rTSA has been shown to decrease postoperative dislocations in some studies, but the effect of repair on other outcomes has not been defined. We proposed to assess differences in postoperative pain, function, range of motion, strength, complications, and reoperations after three types of management of the subscapularis tendon—primary repair (tendon-to-tendon), transosseous repair, and no repair—at a minimum of two years of follow-up after rTSA.MethodsReview of an institutional database identified patients with primary rTSA treated by a single surgeon using the same operative technique and implant (medial glenoid with lateral humeral implant) except for subscapularis repair (tendon-to-tendon repair, transosseous repair, no repair). Patients with revision rTSA, anatomic TSA, hemiarthroplasty, or surgery for proximal humeral fracture, nonunion, or malunion were excluded.ResultsOf 210 patients meeting inclusion criteria, 82 (39%) had primary tendon repair of the subscapularis (PTR), 88 (41.9%) had transosseous repair (TOR), and 40 (19%) did not have the subscapularis repaired (NR). Of all demographics and comorbidities measured, the only significant differences among treatments groups were in gender (54.9% female in PTR, 43.2% in TOR, and 72.5% in NR, p = 0.008) and subscapularis status before surgery (89% intact in PTR, 80.7% in TOR, and 38.5% in NR, p < 0.001). There were significantly more patients in the NR group whose operative indication was massive rotator cuff tear compared to the TO and PR groups. Similarly, there were significantly more patients whose operative indication was primary osteoarthritis in the TR group over the PR group, and the PR group over the NR group. There were no significant differences in complication rates (11% PTR, 13.6% TOR, 15% NR, p = 0.79) or reoperation rates (PTR 2.4%, TOR 2.3%, NR 5.0%, p = 0.66) or associations between subscapularis management technique and reoperation or complication rates.ConclusionSubscapularis management technique in rTSA did not affect complication or reoperation rates, and the procedure led to improvements in pain, function, range of motion, and strength in all three treatment groups. Repair of the subscapularis, regardless of technique, led to greater improvements in pain compared to no repair, although this may be partially attributable to better preoperative subscapularis status in the repair groups. Both repair techniques led to equal improvements in all measured outcomes, with the exception of primary tendon repair producing more improvement in ER strength compared to transosseous repair.Level of evidenceLevel III; Case Control Study