Rupture of the pectoralis major muscle (PMM) is a rare but incapacitating sports injury. This report introduced a novel technique for the repair of this injury using the Endobutton. 5 male patients (3 judo players, 1 martial arts player and 1 body-builder) underwent the primary repair of complete rupture of PMM at its humeral insertion within 2 weeks after injury. The average age at surgery was 28.4 years old (range 23-33), and the average follow-up was 26.8 months (range 18-36). A rectangular bone trough (4 x 1cm) was made at the PMM insertion and the tendon stump was introduced into this trough to be transfixed over the other side of the cortex using Endobuttons (Smith & Nephew Inc.) and fiber wires (Arthlex Inc.). The clinical assessment included rate of rerupture by MRI, range of motion (ROM) of the shoulder, JSS sports score and isometric power at final follow-up. No rerupture was detected clinically, and MRI findings also showed continuity of the PMM tendon in all cases at the final follow-up. Significant differences were present between average pre- (9.4, range 5-13) and postoperative (82.6, range 73-95) JSS sports scores (p<0.01) but not in ROM between affected and unaffected shoulders. Postoperative isometric power in horizontal flexion and extension of affected shoulders was as equal as that of unaffected shoulders. Satisfactory outcomes were obtained by early repair of complete rupture of the PMM within 2 weeks after injury using the Endobutton technique.
