Poster 180: Diagnostic Algorithm and Outcomes of Treatment for Neurogenic Pectoralis Minor Syndrome

OBJECTIVES: Neurogenic pectoralis minor syndrome can generate chronic anterior shoulder pain and a variety of non – specific neurologic symptoms in an affected upper extremity. This study presents a diagnostic algorithm used to identify neurogenic pectoralis minor syndrome and reports short-term outcomes for a series of patients who underwent either open or arthroscopic, coracoid – based, pectoralis minor tenotomy to treat the condition. METHODS: Following IRB approval, the senior investigator’s operative records were queried for pectoralis minor release performed between January 2012 and July 2021. Demographic, surgical, and outcomes data was extracted from each subject’s medical record. Only subjects with a minimum of 30-day follow-up were considered in data analysis. Generalized descriptive statistical analysis, along with ANOVAs and post-hoc t-tests were performed to compare outcomes of pectoralis minor release. RESULTS: Twenty-one subjects were identified meeting enrollment criteria. Mean age at time of diagnosis was 44.3years (range 17-70 years). Subjects had undergone prior shoulder surgery in 16/21 (76.2%) of cases and 18 (85.7%) were Worker’s Compensation related injuries. All patients had undergone a minimum of 3 months of a structured physical therapy program preoperatively. All patients underwent a diagnostic, ultrasound – guided pectoralis minor block with temporary resolution of self – reported symptoms. Symptoms prior to treatment included anterior shoulder pain and neurologic symptoms in 20/21 (95.2%) cases, with a mean duration of 15.7 months (range 3-40 months). Pretreatment ASES score was mean 41.5 (range 13.3-73.3) with mean pain of 4.9/10 (range 1-9/10). At mean 6.8 months post-release, patients reported mean 9.5 point increase in ASES score versus index score (p<0.05) and 85.0% (17/20 with pre-operative neurologic symptoms) reported complete resolution or improvement of neurologic symptoms related to neurogenic pectoralis minor syndrome. CONCLUSIONS: Findings of insertional pectoralis minor tenderness to palpation with or without reproduction of neurologic symptoms, a positive diagnostic, ultrasound – guided pectoralis minor block and anterior shoulder pain can be useful findings to establish the difficult diagnosis of neurogenic pectoralis minor syndrome. In select patients either open or arthroscopic release of the pectoralis minor insertion on the medial aspect of the coracoid process can alleviate symptoms.