Long-Term Outcomes of Pectoralis Major Transfer for the Treatment of Irreparable Subscapularis Tears: Results After a Mean Follow-up of 20 Years.

Abstract

One recognized salvage option in the treatment of an irreparable subscapularis tear is the pectoralis major tendon transfer (PMT). We aimed to analyze the long-term clinical and imaging outcome of PMT for irreparable subscapularis deficiency. Twenty-eight consecutive patients representing 30 shoulders underwent PMT at a mean age of 53.0 years (range, 35 to 67 years). At a mean of 19.7 years (range, 18 to 22 years) postoperatively, 24 shoulders (80%) were clinically examined and 21 were radiographically and sonographically assessed. The long-term results were compared with preoperative findings and previously published short-term results. The mean relative Constant score (percentage of age and sex-matched normal scores; CS%) and the Subjective Shoulder Value (SSV) both improved significantly from preoperatively (CS%, 47%, and SSV, 22%) to postoperatively (CS%, 77%, and SSV, 71%; p < 0.001 for both). All patients rated their results as good or excellent. Active anterior elevation was improved from preoperatively (120°) to postoperatively (131°), but the difference was not significant. Active internal and external rotation decreased significantly from the short-term (32-month) follow-up to the time of the latest follow-up (p = 0.005 and p = 0.002, respectively); however, internal rotation remained at 6 points compared with the 8 points recorded at short-term follow-up and external rotation decreased only from a mean of 51° to 39°. Loss of active range of motion was not observed subjectively and was not subjectively limiting, represented by the high ultimate SSV and overall satisfaction. Four shoulders (19%) showed evidence of glenohumeral arthropathy (Samilson and Prieto grade 3), but clinically were mildly symptomatic to asymptomatic at the time of the latest follow-up (CS% range, 67% to 88%; SSV range, 70% to 80%). Rupture of the PMT was sonographically identified in 2 patients (10%) and was associated with radiographic evidence of advanced cuff tear arthropathy (Hamada stages ≥4). Six (20%) of the initial 30 shoulders were revised, and 1 (4%) of the 24 shoulders that were clinically examined underwent reverse total shoulder arthroplasty. At long-term follow-up, PMT for isolated and combined subscapularis tears is associated with good to excellent clinical results. Although one-third of the shoulders developed mildly symptomatic or asymptomatic osteoarthritis, the need for salvage with use of reverse total shoulder arthroplasty was rare. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.