Suture Technique Influences the Biomechanical Integrity of Pectoralis Major Repairs

Pectoralis major ruptures occur in large, muscular individuals, and repair constructs may experience significant tension. Four different suture techniques were evaluated biomechanically to determine the effect of suture technique on optimizing fixation strength. Forty fresh-frozen cadaveric shoulders were repaired using endosteal buttons. The control group was repaired with #2 polyblend suture in a modified Mason-Allen stitch configuration. The triple group was repaired using the same suture and configuration, but with the addition of triple-loaded buttons. The configuration group was repaired using the same suture in a Krackow/Bunnell configuration. The tape group was repaired using 2-mm polyethylene tape and #5 polyblend suture in the Krackow/Bunnell configuration. Under cyclic loading, there was no significant difference between groups. Under load-to-failure testing, the tape group withstood a significantly greater maximum load (726.0±90.0 N) than the control and triple groups (330.2±20.2 and 400.2±35.2 N, respectively; P<.005), and similar load to the configuration group (509.9±68.6 N; P=.16). The configuration group failed via suture breakage (9/10); the other groups failed via suture pullout, in which suture pulled through tendon (26/30). Pectoralis major repair in a running, locked configuration appears to improve biomechanical performance by preventing suture pullout. Use of a polyethylene tape construct demonstrates the potential for improved failure loads, but its role remains undefined.