Pectoralis Major Rupture - Shoulder & Elbow

Introduction
Epidemiology demographics exclusively seen in males often occurs in weightlifters location most commonly occurs as a tendinous avulsion Pathophysiology mechanism excessive tension on a maximally eccentrically contracted muscle may be an iatrogenic injury caused during open rotator cuff repair
Anatomy
Pectoralis major innervation lateral (C5-C7) and medial (C8-T1) pectoral nerves origin (two heads) clavicular head: medial clavicle and proximal sternum sternocostal head: distal sternum, costal cartilage ribs 1-6, external oblique aponeurosis insertion humeral shaft just lateral to the bicipital groove one of four muscles connecting the upper limb to the thoracic wall other muscles include pectoralis minor subclavius serratus anterior Biomechanics inferior fibers of sternal head at maximal stretch during final 30 degrees of humeral extension position at which pectoralis major is most vulnerable to rupture (as with bench pressing)
Presentation
History patient may report a sharp tearing sensation with resisted adduction and internal rotation Symptoms pain and weakness of shoulder Physical exam swelling and ecchymosis if localized to the anterior arm, then humeral attachment rupture is more likely than a musculotendinous junction rupture palpable defect and deformity of the anterior axillary fold weakness with adduction and internal rotation
Imaging
Radiographs recommended views standard shoulder trauma series (true AP, scapular Y, and axillary lateral) findings often normal MRI useful in identifying the site and extent of the rupture may show avulsion of the pectoralis major tendon from the humerus
Treatment
Nonoperative initial sling immobilization, rest, ice, NSAIDs indications may be indicated for partial ruptures tears in the muscle or musculotendinous junction low-demand patients Operative open exploration and repair of tendon avulsion indications tendon avulsion from the bone (will see ecchymosis down arm) treatment of choice for high level athletes outcomes may show improvement regardless of location of tear