LAUSR

BACKGROUND Serratus anterior (SA) palsy following mechanical injury to the long thoracic nerve (LTN) is the most common cause of scapular winging. This study aimed to identify the factors influencing the outcome of neurolysis of the distal segment of the LTN. We hypothesized that poor results are due to duration before surgery and to persistent scapulothoracic dysfunction. METHODS A retrospective study was conducted. The inclusion criteria were partial or complete isolated non-iatrogenic SA paralysis of at least 4 months duration with preoperative electrophysiologic assessment confirming the neurogenic origin without signs of reinnervation. RESULTS Seventy-three patients were assessed at 45 days, 6 months and 24 months after neurolysis of the distal segment of the LTN. At last follow-up, improvement was excellent in 38 (52%) or good in 22 cases (30%), moderate in 6 (8%) and poor in 7 (10%). No patient showed deterioration in outcome since the beginning of follow-up. Scapular winging was no longer present in 46 cases (63%), while it was minimal in 23 (31.5%). In 4 cases (5.5%), winging was similar to the preoperative condition. DISCUSSION The best outcomes occurred in patients who presented without compensatory muscle pain and who were treated within 12 months of paralysis. Beyond this time frame, neurolysis can still provide useful functional improvement and avoid palliative surgery. CONCLUSION Neurolysis of the distal segment of the LTN is a safe and reliable procedure. This technique allows treatment of SA muscle palsy and corrects scapular winging with excellent or good outcomes in 82% of cases.