Pectoralis Major Transfer for Scapular Winging

Scapular dysfunction is a relatively common orthopaedic problem, resulting from a variety of conditions that includes deconditioning and primary shoulder pathology. In most patients, rehabilitation leads to a resolution of symptoms. Occasionally, scapular winging (Figure 1) is refractory to nonsurgical treatment. In most of these patients, scapular winging results from serratus anterior dysfunction and may be a source of considerable functional limitations and pain, especially with overhead activities or when the arm is positioned away from the body. The serratus anterior stabilizes the scapula to the chest wall during elevation and is the most powerful protractor of the upper limb. Themost frequently reported complaints are weakness of elevation, fatigue with overhead activities, and posterior periscapular pain. Because these symptoms are frequently vague and nonspecific, delayed or incorrect diagnoses such as glenohumeral instability or subacromial impingement are common. The long thoracic nerve supplies the serratus anterior muscle and is formed from the anterior rami of C5 to C7; its injury causes weakness or complete paralysis. The roots of C5 andC6 run through the middle scalene muscle, then merge with fibers from C7, before traveling along the lateral aspect of the thorax. The superficial location makes it susceptible to blunt trauma, but other etiologies exist such as traction injuries, brachial plexus neuritis (Parsonage-Turner syndrome), and iatrogenic injuries. Most traumatic insults to the long thoracic nerve are blunt injuries from sports participation or accidents that result in a neurapraxia, but repetitive strenuous activities also have been implicated. Long thoracic nerve palsy usually resolves within 8 to 12 months but can last up to 2 years in infectious etiologies. However, up to 25% of patients experience persistent scapular winging and fatigue. Initial treatment should consist of gentle range-of-motion exercises to avoid shoulder stiffness. Electrodiagnostic studies can be obtained at 3-month intervals to evaluate recovery of the nerve. If physical examination or electrodiagnostic studies do not demonstrate signs of recovery after a year, surgical treatmentmay be indicated. The procedure of choice for persistent scapular injury secondary to long thoracic nerve palsy/serratus anterior weakness is transfer of the pectoralis major tendon to the scapula.