1445 - Ultrasound-Guided Hydrodissection of the Lateral Femoral Cutaneous Nerve in Meralgia Paresthetica: A Case Report

Case Diagnosis: Lateral Femoral Cutaneous Neuropathy

Case Description: A 39-year old female patient presented with proximal, burning right thigh pain with numbness in the LFCN distribution. On exam, Tinel’s test of the right hip was noted to be positive. The LFCN was investigated on ultrasound and noted to have an abrupt caliber change at the anterior superior iliac spine (ASIS). Under ultrasound guidance, a 3.5 inch 22-gauge spinal needle was introduced into the space surrounding the LFCN. Hydrodissection was performed with 4 cc of lidocaine. Subsequently, 1cc of Kenalog 40 mg/ml and 4 cc of Xylocaine 1% were cc injected. The patient reported 0 out of 10 on the pain and resolution of numbness.

Discussions: There is a wide breadth of treatment modalities to address LCFN with varying degrees of invasiveness. The first step in management involves the mitigation of a mechanical cause of nerve compression at the inguinal ligament. Up to 90% patients respond positively to lifestyle modification and weight loss. Patients with severe intractable symptoms poorly responsive to medications may consider operative management. Meanwhile, ultrasound-guided injections have a favorable side effect profile relative to chronic use of analgesic medications as well as a reduced degree of invasiveness compared to surgery. This case supports the role of hydrodissection in the conservative management of MP.

Conclusions: This case indicates that hydrodissection to address peripheral nerve entrapment is a viable treatment modality for cases of lateral femoral cutaneous neuropathy. This offers an alternative to avoid the escalation to further invasive measures such as surgical decompression, which can be complicated by anatomical variants, present in a quarter of patients. Hydrodissection serves as an additional clinical intervention when other options such as anesthetics, corticosteroids, or pulsed radiofrequency have been considered, offering a diversity of treatment options to appropriately tailor to specific patient presentations and needs.