CASE 120

By: Dr. Nizar Al-Nakshabandi MD, FRCPC

HISTORY: 55-year-old bodybuilder using steroids, has extreme pain during bench press. On examination, there is a dimple in his anterior chest wall.

What are your findings?

What is the differential diagnosis?

What are the causes?

FINDINGS:

Axial T1-weighted image [A] through the right chest wall demonstrates discontinuity of the right pectoralis major muscle with disruption of the musculotendinous junction from the sternal and clavicular heads [not shown] and retraction by more than 10 cm.

Axial STIR sequence [B] confirms the findings on the T1-weighted sequences and demonstrates extensive edematous changes present that have replaced most of the fibers of the right pectoralis major muscle.

Coronal T2 fat sat sequences [C] demonstrate retraction of the musculotendinous junction from the proximal shaft of the right humerus.

DIAGNOSIS:

Pectoralis major muscle rupture.

PEARLS AND DISCUSSION:

Pectoralis major muscle rupture is being increasingly seen in bodybuilders, particularly those using anabolic steroids.

MRI plays a remarkable role in diagnosing these cases.

The sternal and clavicular heads are torn in full tears. The sternal head is torn in partial tear. Fibrosis and scarring is seen in chronic tears.

Pectoralis muscle is a large muscle in front of the upper chest. Two parts are present: the pectoralis muscle major and the pectoralis muscle minor. The pectoralis muscle major tendon attaches to the arm bone [humerus] which can rupture from forceful activities such as weightlifting particularly in bench pressing exercise. Other sports such as football and wrestling can occur

Close association between anabolic steroids is thought to be a contributing factor in many major pectoralis muscle ruptures.

Surgery is the most common recommendation for complete tears of the pectoralis muscle tendon. However, in partial tears or in the elderly surgery may be avoided.

FURTHER READING:

1.      David A. Connell, MD1, Hollis G. Potter, MD1, Mark F. Sherman, MD2, and Thomas L. Wickiewicz, Injuries of the Pectoralis Major Muscle: Evaluation with MR Imaging. Radiology, March 1999 Volume 210, Issue 3

2.      J F Quinlan, M Molloy, B J Hurson. Pectoralis major tendon ruptures: when to operate. Br J Sports Med 2002; 36:226-228 doi:10.1136/bjsm.36.3.226

3.