Pectoralis major ruptures.

Although previously considered rare, ruptures of the pectoralis major muscle and tendon have become more common over the past 20 years with increasing participation in competitive sports and weight lifting. These injuries result from maximal eccentric contraction of the muscle with the arm held in an abducted, extended position. Most often, they occur near the tendon insertion. Complete ruptures are more common than partial tears, though many mild strains and partial tears likely go unreported or undiagnosed. Magnetic resonance imaging is the diagnostic study of choice when the diagnosis or extent of the injury is unclear. Partial tears and neglected complete tears with near complete restoration muscle strength after rehabilitation may be treated nonoperatively, with good results. Excellent results can be obtained with early anatomic repair for complete ruptures, though good results have also been reported with delayed repair of complete injuries. Early diagnosis and, when appropriate, anatomic surgical repair are the factors critical to optimizing patient outcomes after pectoralis major rupture.