Biomechanical Comparison of 3 Methods to Repair Pectoralis Major Ruptures

Abstract

Background: Pectoralis major ruptures are closely associated with weight lifting and participation in sports. The anatomy of the pectoralis major tendon is unique with an elongated thin footprint requiring multiple points of fixation to restore the native anatomy. Multiple options exist for tendon repairs, but the strongest construct has yet to be identified. Purpose: The intent of this study was to compare the load to failure of bone trough, cortical button, and suture anchor repairs of the pectoralis major tendon in the extended and abducted position. Study Design: Controlled laboratory study. Methods: Thirty fresh-frozen cadaveric shoulders were divided equally into 3 groups based on the repair technique to be performed. Bone mineral density of the surgical neck of the proximal humerus was assessed before each repair. Bone trough, suture anchor, and cortical button repairs were performed as dictated by computerized randomization. Each specimen was loaded to failure and mode of failure was noted. Results: The majority of failures occurred through the suture used for tendon repair. One specimen in the bone trough group failed via fracture of the proximal humerus. The suture anchor group failed at the implant in 5 of 9 specimens and through the suture in 4 of 9 specimens. Load to failure was greatest in bone trough repairs at 596 N, followed by cortical button at 494 N, and finally suture anchor repairs with 383 N. Load to failure was significantly greater in the bone trough group when compared with suture anchor repairs ( P = .007). No correlation was found between bone mineral density and load to failure. Conclusion: Bone trough repair of the pectoralis major tendon was stronger than suture anchor repair. Clinical Relevance: Identification of the strongest repair may help guide surgical repair.