Concurrent Long Thoracic and Lateral Cutaneous Intercostal Nerve Entrapment After Chest Tube Thoracostomy Causing Scapular Winging and Chest Wall Pain: Diagnosis With Ultrasound and Treatment With Hydrodissection

BACKGROUND: Chest tube thoracostomy may cause iatrogenic nerve injury, resulting in persistent pain and functional impairment. Long thoracic nerve (LTN) palsy after chest tube placement has been described, but concurrent involvement of the LTN and the lateral cutaneous branch of an intercostal nerve (LCIN) appears to be rarely reported. We describe a patient with persistent post-thoracostomy chest wall pain and scapular winging in whom musculoskeletal ultrasonography identified entrapment of both nerves. CASE PRESENTATION: A 43-year-old man presented with severe left shoulder and chest wall pain 6 months after chest tube placement for traumatic hemopneumothorax. Examination demonstrated focal tenderness, dysesthesia, and mechanical allodynia at the chest tube scar, along with medial/inferior scapular winging during serratus anterior provocative testing. Shoulder range of motion was full on examination; however, forward flexion beyond 15° markedly aggravated pain, resulting in pain-related reluctance to move the shoulder. Manual muscle testing was 4+/5 before treatment because pain limited force generation. Musculoskeletal ultrasound demonstrated focal abnormality of the LTN where it pierced the axillary fascia over the sixth rib, with loss of fascicular definition and reduced glide, and tethering/thickening of the LCIN within scar tissue at the prior tube insertion site. Symptom reproduction with sonopalpation supported the clinical relevance of both findings. INTERVENTION AND RESULTS: Ultrasound-guided hydrodissection using 5% dextrose in water was performed around both nerves. A total of approximately 40 mL of 5% dextrose in water was used, with 20 mL administered per nerve. Immediately after the first procedure, pain improved from NRS 9/10 to 2/10, with marked reduction in pain during shoulder movement, including forward flexion. The patient subsequently underwent 5 treatment sessions at 2-week intervals over 10 weeks. During follow-up, manual muscle testing improved to 5/5 without pain, scapular winging was no longer evident on provocative testing, and the Shoulder Pain and Disability Index improved from pain/disability scores of 25/15 to 6/4. At the sixth follow-up visit, pain and function were satisfactory, and the patient elected continued monitoring without further intervention. At 1-year follow-up, treatment efficacy remained sustained without recurrence. CONCLUSION: In patients with persistent shoulder or chest wall pain after chest tube thoracostomy, iatrogenic peripheral nerve entrapment should be considered. This case highlights the value of a focused neuromuscular examination and musculoskeletal ultrasound for identifying concurrent motor and sensory nerve involvement and suggests that ultrasound-guided hydrodissection may be a useful minimally invasive treatment. Because electrodiagnostic studies were not performed, the findings are most consistent with entrapment/neurapraxia with dynamic tethering rather than electrodiagnostically proven axonal palsy.