A Motorcycle Ride In The Canal: Hydrodissection For Peripheral Nerve Entrapment, A Case Report

Case Diagnosis: Superficial peroneal and adductor canal nerve entrapment.

Case Description or Program Description: 50-year-old male with chronic low back pain presented with acute bilateral medial thigh and lateral shin pain with associated numbness, after a 3,000-mile motorcycle ride.
Initially, his symptoms were attributed to lumbar radiculopathy, therefore underwent multiple diagnostic and therapeutic lumbar injections, and surgical interventions without benefit. Ultrasound demonstrated neuro-fibular swelling along the adductor canal and superficial peroneal nerve bilaterally.
Attempting to avoid a lumbar fusion, bilateral hydrodissections were performed twice through the adductor canal and superficial peroneal nerve under ultrasound-guidance using lidocaine and dexamethasone.

Setting: Outpatient interventional pain clinic.

Assessment/Results: Two months post-treatment, the patient returned to work after requiring disability for two years with complete symptom resolution. He remains symptom free without physical therapy unless he rides his motorcycle for prolonged periods.

Discussion (relevance): The adductor canal is a fascial tunnel in the middle thigh that transmits neurovascular structures between the femoral triangle and the popliteal fossa, including the sensory saphenous nerve. Adductor canal blocks are common in lower extremity surgeries but not typically used in the treatment of medial thigh neuropathic pain. The superficial peroneal nerve, originating from the common peroneal nerve, provides motor function to the peroneus muscles and sensory innervation to the lateral leg and dorsum of the foot. Compression in the distal leg can mimic lumbar radiculopathy. While hydrodissection has been studied in carpal tunnel syndrome, research on other peripheral nerve entrapments is limited. This case supports hydrodissection in peripheral nerve entrapment as an effective yet unconventional treatment requiring keen clinical assessment.

Conclusions: Peripheral nerve entrapment should be considered in cases of radicular lower extremity pain, especially in the context of postural or mechanical compression. Ultrasound-guided hydrodissection may be a viable, minimally invasive treatment for peripheral neuropathy. This is the first reported case of adductor canal hydrodissection for peripheral nerve entrapment.