Results of transfer of the pectoralis major tendon to treat paralysis of the serratus anterior muscle.

BACKGROUND: Paralysis of the serratus anterior muscle can be functionally disabling. As a result of the scapular winging associated with such paralysis, the scapula does not remain apposed to the thorax when the upper extremity is elevated forward at the shoulder. This produces functional disability associated with pain and loss of a stable base for movement of the upper extremity.
METHODS: We reviewed the results of transfer of the pectoralis major tendon with the addition of a fascial graft in sixteen patients who had paralysis of the serratus anterior. The average age of the patients at the time of the operation was thirty-three years (range, twenty to fifty-five years). Electrodiagnostic studies confirmed the presence of an isolated injury of the long thoracic nerve. The index operation was performed sixteen months to eleven years after the onset of pain and weakness. The etiology of the paralysis was idiopathic in two patients, traumatic in seven, and secondary to operative intervention in seven. All patients had pain in the shoulder on the side of the paralysis.
RESULTS: The result was excellent for eight patients, good for five, and fair for one at an average of four years and three months (range, two years and one month to nine years) postoperatively. There were two failures, both of which occurred after a traumatic event. Of the fourteen patients in whom the procedure did not fail, eight were asymptomatic and had normal function, five had intermittent mild discomfort, and one had frequent mild pain without any winging of the scapula. The average Constant and Murley score for the fourteen patients in whom the procedure did not fail increased from 36 points preoperatively to 92 points postoperatively.
CONCLUSIONS: The index procedure successfully alleviated the functional disability caused by paralysis of the serratus anterior muscle.