I recently saw a 32 year old male patient in the office who said he was weight lifting when he felt a tearing sensation and had immediate pain and later bruising and swelling in his chest wall and arm pit area. Furthermore, when he flexed his chest musculature, there was an obvious deformity. He had sustained a pectoralis major rupture. In this injury, the tendon of the pectoralis major muscle is torn away from its normal attachment on the upper arm or humerus bone. An MRI was performed, and it clearly showed that he tore away both portions of the pectoralis, namely the sternal and clavicular heads.

Pectoralis major muscle tears are not very common. They almost exclusively occur in males and usually result from weight lifting (62%), trauma (22%), and martial arts (8%). As for weight lifting, bench pressing is the main exercise that people report doing when they sustain this injury. Pectoralis muscle tears are often misdiagnosed and unfortunately, these injuries are much harder to repair when there has been a delay in diagnosis as the tendon can further retract into the chest wall.

In competitive body builders, steroid use and vigorous training may increase muscle strength at a rate to which the tendon cannot adapt, leaving it vulnerable to injury. A study of the effects of steroids on rat tendons, showed that the tendons became stiffer, could not absorb as much energy, and tore more easily. Fortunately, these negative effects seemed to be reversible when the steroids were discontinued in this rat study.

Partial tendon tears can be treated nonsurgically. Initially the patient is placed in a sling, and instructed to rest and ice the area. Early shoulder range of motion can be started. When shoulder mobility is regained and the pain has resolved at approximately 6 to 8 weeks, some gentle strengthening exercises can be started. When first returning to bench press, a more narrow grip is recommended.

If there is a full thickness pectoralis tendon tear, surgery is recommended as the results are superior with better return of strength, cosmesis and return to sports. A study showed that patients repaired surgically had excellent or good results in 88% compared to only 27% in patients treated nonsurgically.  Furthermore, in another study, peak torque returned to 99% of that of the uninjured side in the surgically treated group compared to only 56% in the nonsurgically treated group. Furthermore, these studies were done over 10 years ago, and today the surgical techniques and implants used to fix these are even better today.

Today, orthopedic sports medicine surgeons have very strong but small diameter suture material available to use. This suture material is passed through the torn tendons in a locking fashion. These sutures are then loaded onto several small titanium buttons that are inserted through small drill holes into the canal of the humerus. The sutures are tensioned which brings the tendon down the bone attachment site, which has been prepared. The sutures are then tied so that the tendon is held securely to the bone. The tendon fibers will slowly regrow into its native bony attachement site in 6-8 weeks. By 6 weeks from surgery, the patient’s sling can be discontinued and more aggressive shoulder range of motion is started. Strengthening exercises can begin at 8 weeks from surgery. Most patients can be back to sports by 12-14 weeks.