The Intersection of Hypermobile Ehlers-Danlos Syndrome and Thoracic Outlet Syndrome.

OBJECTIVE: Hypermobile Ehlers-Danlos Syndrome (hEDS) is a rare disorder resulting in joint hypermobility. Thoracic Outlet Syndrome (TOS) is an uncommon compressive disorder affecting neurovascular structures of the upper limb. The coincidence of these syndromes may affect the prognosis of interventions for TOS. The aim of this study was to characterize the presentation, evaluation, and surgical outcomes in patients with hEDS and TOS. METHODS: A retrospective review of clinical encounters from January 2024 to January 2026 was conducted, identifying patients with hEDS and TOS. Medical records were reviewed for demographics, comorbid conditions, medications, allergies, clinical presentation testing, and surgical outcomes. Standardized outcome measures (Quick DASH, Derkash Score) were employed. RESULTS: Approximately 1400 encounters occurred for TOS during the study period. Of these, 28 subjects with hEDS were identified: 2 with venous TOS (VTOS) and 26 with neurogenic TOS (NTOS). The average age at presentation was 35.5 years (range 12-64). Patients were predominantly women, (n=22, 78.6%). TOS etiology included spontaneous onset in 12 (42.8%), repetitive motion injury in 8 (28.6%), accidents in 5 (17.9%), and sports-related in 3 (10.7%). The average number of medical problems listed was 15.8 (range 0-36), medical diagnoses 11.5 (range 0-43), medications 12.4 (range 0-41), allergies 3.5 (range 0-25), and prior surgeries 6.8 (range 0-35). Patients had undergone an average of 4.6 (range 1-18) upper extremity orthopedic procedures. Sixteen patients underwent TOS surgical decompression: 2 VTOS and 14 NTOS. A total of 19 operations were performed. Patients with VTOS underwent one operation each. Of 14 NTOS patients, all underwent first rib resection (FRR); 2 required bilateral FRR, 3 required scalene resections, and 12 underwent pectoralis minor tenotomies. Outcomes were rated as resolved (18.8%), improved (62.5%), unchanged (6.3%), worsened (6.3%), or complicated by venous restenosis (6.3%). The combined endpoint of resolved/improved accounted for 81.3% of surgical cases. Quick DASH scores improved from 69.3 to 44.3 (p=0.019) and Derkash scores improved from 2.0 to 3.06 (p<0.001). CONCLUSION: Patients with hEDS and TOS have a broad spectrum of presentation, this is reflected in the high incidence of significant comorbidities which may affect presentation of upper extremity symptoms, and adversely affect the outcomes of surgery for TOS. Despite the impact of comorbidities, surgical intervention for TOS showed statistically significant improvement in outcomes based on standardized metrics.