Sural Nerve Entrapment in Postoperative Scar Tissue: A Case of Successful Management With Hydrodissection After Calcaneal Fracture Repair

Sural nerve entrapment is a recognized yet frequently overlooked etiology of persistent lateral ankle and heel pain following lower extremity trauma or surgery. This report describes a case of refractory sural nerve entrapment within scar tissue that persisted after calcaneal fracture repair and subsequent hardware removal, which was successfully managed with ultrasound-guided hydrodissection. A 31-year-old male presented with refractory right heel pain following open reduction and internal fixation (ORIF) for a calcaneal fracture and subsequent elective hardware removal. Physical examination revealed allodynia and hyperesthesia along the surgical scar, accompanied by a positive jump sign. Diagnostic ultrasonography confirmed entrapment of the sural nerve within adjacent hypoechoic scar tissue. The diagnosis was dynamically confirmed using sonoguided digital palpation (SDP), which precisely reproduced the patient's characteristic pain at the site of nerve-scar adhesion. The patient subsequently underwent two sessions of ultrasound-guided hydrodissection with 5% dextrose in water (D5W). He experienced significant and immediate pain relief after the first procedure, reporting over 90% symptom resolution following the second session, which was sustained at follow-up. This case highlights that sural nerve entrapment should be considered in the differential diagnosis of persistent lateral heel pain following calcaneal surgery, even after hardware removal. A comprehensive diagnostic workup incorporating dynamic ultrasound with SDP can reliably identify and confirm the symptomatic site of entrapment. Ultrasound-guided hydrodissection represents a safe, effective, and minimally invasive therapeutic option that can facilitate substantial symptom relief and functional improvement, potentially obviating the need for more extensive surgical interventions.