Surgical Results of Common Peroneal Nerve Neuroplasty at Lateral Fibular Neck

Abstract

Background: Common peroneal nerve (CPN) compressive neuropathy is the most common lower-extremity entrapment neuropathy.

Materials and methods: A retrospective review of a prospectively maintained single-institution database of all patients with CPN palsy who underwent decompression and neuroplasty over a 5-year period was performed.

Results: Thirty patients underwent a neuroplasty of the CPN over a 5-year period (2010-2015) at our institution. The median age was 45 years, and there was a male preponderance. The average time between first onset of symptoms to surgery was 122.9 weeks and between first clinic visit and surgery was 21 weeks. The etiology of the CPN neuropathy was as follows: in 12 patients, it followed a surgical procedure and in 14 patients, it occurred after a trauma to the lower extremity. In 2 patients, it occurred as a result of a mass lesion compromising the nerve and in 1 patient, a local infection predisposed to CPN palsy. Right and left lower extremities were equally involved. The median body mass index was 28.6. The most common presentation was weakness of the tibialis anterior (TA) and extensor hallucis longus (EHL) and loss of sensation in the distribution of the CPN or one of its major branches. Pain was a presenting symptom in 16 patients. Only 12 of the 30 patients had a positive Tinel's sign at the site of compression over the lateral fibular neck. Preoperative electrophysiologic confirmation of CPN neuropathy was available in all patients. Mean follow-up was 52 weeks. Prone positioning and selective use of the operating microscope provided excellent visualization and surgical exposure of the CPN from the lower popliteal region to the peroneal tunnel. Average operating room time was 170 minutes and average skin-to-skin time 91 minutes. Clinical improvement after surgery in terms of motor function was noted in 24 of the 26 patients who presented with a motor deficit. The most consistent improvement was noted in the TA and EHL; a trend toward greater improvement with shorter time to surgery was noted. No complications related to the surgical site or CPN were encountered, and no patient had a decline in their neurologic examination as a consequence of the surgery. One patient developed a positioning-related right upper-extremity brachial plexus neuropraxic injury after surgery that recovered completely.

Conclusions: Common peroneal neuropathy usually presents with weakness of the TA and EHL and decreased sensation or pain in the distribution of the CPN. Microscope-assisted surgical neuroplasty of the CPN at the lateral fibular neck with the patient in a prone position allows decompression of the nerve from the lower popliteal region to the peroneal tunnel. Significant improvement in motor strength after surgery, particularly of the TA and EHL, was observed in this series.

Keywords: Common peroneal nerve; Common peroneal neuroplasty; Foot drop.