Incidence, recovery, and management of serratus anterior muscle palsy after axillary node dissection

The purposes of this study were to determine the occurrence of serratus anterior muscle weakness after axillary node dissection, to monitor the recovery of serratus anterior muscle strength, and to compare shoulder range of motion in palsied and nonpalsied groups. Thirty-six patients were studied who had 40 axillary node dissections for breast carcinoma or malignant melanoma. Range of motion and manual muscle tests were done preoperatively and at specific postoperative intervals by two observers. To regain range of motion, all subjects were treated daily while hospitalized and as needed when outpatients. Twelve of the 40 dissections (30%) resulted in serratus anterior muscle palsy after surgery. Strength was normal in all the palsied shoulders by the sixth month after surgery. Both the palsied and nonpalsied groups had comparable range of motion at each assessment. The mechanism of long thoracic nerve injury and the clinical significance of serratus anterior muscle palsy are discussed as well as the rationale for early detection and proper physical therapy management. This study suggests that serratus anterior muscle palsy is a frequent but reversible event after axillary node dissection.