Iatrogenic Femoral Neuropathy Mimicking Meralgia Paresthetica Following Groin Flap Surgery: A Case Report.

BACKGROUND: Groin flap surgery carries a risk of iatrogenic nerve injury, most commonly involving the lateral femoral cutaneous nerve and presenting as meralgia paresthetica. In contrast, femoral nerve injury is rare and typically associated with motor deficits. Pure sensory femoral neuropathy is exceptionally uncommon and may closely mimic meralgia paresthetica, creating a diagnostic challenge. CASE REPORT: We report a 24-year-old man who developed severe neuropathic pain over the anterolateral thigh following groin flap donor-site closure. Initial clinical suspicion was meralgia paresthetica. However, motor examination and electrodiagnostic studies were normal. High-resolution ultrasound revealed femoral nerve displacement and edema, and ultrasound-guided transcutaneous nerve stimulation reproduced the patient's symptoms, confirming a diagnosis of pure sensory iatrogenic femoral neuropathy. The patient was successfully treated with ultrasound-guided femoral nerve hydrodissection, resulting in sustained pain relief at the 6-month follow-up visit. CONCLUSIONS: Pure sensory femoral neuropathy can mimic meralgia paresthetica after groin surgery. High-resolution ultrasound is critical for accurate diagnosis, and ultrasound-guided hydrodissection may be an effective therapeutic option when conservative management fails, though further studies are needed.