Lesser tuberosity osteotomy in total shoulder arthroplasty: impact of radiographic healing on outcomes

Abstract

Lesser tuberosity osteotomy (LTO) has gained popularity in anatomic total shoulder arthroplasty (TSA); however, healing rates have not been universally high. This study examined differences in outcomes based on variations in LTO healing. A retrospective review identified primary TSA patients with 2-year minimum follow-up treated with a LTO. Postoperative radiographs classified LTO healing as "bony union," "nondisplaced nonunion," "displaced nonunion," and "not seen," creating 4 cohorts. Comparisons were made among patient-reported outcome measures (PROMs), motion, and radiographic evidence of component loosening. The study cohort consisted of 189 patients who met inclusion criteria, with an average age of 69.5 years (range, 32-89 years) and follow-up of 50 months (range, 24-95 months). There were 143 patients with union, 16 with nondisplaced nonunion, 14 with displaced nonunion, and 16 not seen. There were no differences in preoperative comparisons. All cohorts demonstrated significant improvements in PROMs and ranges of motion; however, the displaced nonunion cohort had no improvement in Single Assessment Numeric Evaluation (0.114) or internal rotation (P = .279). Patients with displaced nonunion had lower postoperative functional scores (Simple Shoulder Test and American Shoulder and Elbow Surgeons scores; P < .01), and higher pain scores (visual analog scale for pain; P < .01). However, 85.7% of patients reported they would have the same procedure again. Simple Shoulder Test (2.5) and American Shoulder and Elbow Surgeons score (37.5) improvements exceeded minimal clinically important difference thresholds for TSA. A higher rate of glenoid gross loosening was present in the displaced nonunion cohort (3 patients [21.4%]; P < .01). There were no cases of loose humeral stems. Patients with a displaced nonunion LTO site have lower functional scores and higher pain scores but still achieve substantial clinical improvement and high satisfaction rates.