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

• Published in: Journal of bone and joint surgery. American volume 2019-12, Vol.101 (23), p.2091-2100
• Main Authors: Ernstbrunner, Lukas, Wieser, Karl, Catanzaro, Sabrina, Agten, Christoph A., Fornaciari, Paolo, Bauer, David E., Gerber, Christian
• Format: Article
• Language: English
• Subjects: Adult; Aged; Female; Follow-Up Studies; Humans; Injury Severity Score; Male; Middle Aged; Observer Variation; Pectoralis Muscles - surgery; Range of Motion, Articular - physiology; Risk Assessment; Rotator Cuff Injuries - diagnostic imaging; Rotator Cuff Injuries - surgery; Shoulder Injuries - diagnostic imaging; Shoulder Injuries - surgery; Statistics, Nonparametric; Tendon Transfer - methods; Time Factors; Treatment Outcome; Ultrasonography, Doppler
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/JBJS.19.00172

BACKGROUND: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. METHODS: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. 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. CONCLUSIONS: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 art