Ipsilateral Lower Limb Neuropathies Following Hip Surgery Can Be Due to Inflammation (P06.129)

Abstract

Objective: To assess for an inflammatory etiology of new lower limb neuropathies occurring ipsilateral to hip surgery. Background New neuropathic pain, numbness or weakness after hip surgery is often attributed to mechanical factors (stretch, compression or transection). Recently we described inflammatory neuropathy as a treatable cause of post-surgical neuropathy. Here, we focus on patients who presented with ipsilateral lower limb neuropathy after hip surgery with progressive symptoms (suggesting a non-mechanical cause). Design/Methods: We characterized the clinical, electrophysiological and pathological features of new ipsilateral neuropathy in post-hip surgery patients who had nerve biopsy. Results: We identified 7 patients (8 surgeries) who developed ipsilateral leg weakness within 4 weeks of surgery. Three were men with median age 63 years (range 18-75). All patients developed focal neuropathies (5 lumbosacral plexopathies, 2 sciatic) presenting as acute pain and weakness that was progressive. Electrophysiology showed severe axonal damage. All biopsies were abnormal showing 1) ischemic injury: perineurial thickening (3/7), multifocal fiber loss (5/7), neovascularization (4/7) and 2) increased inflammation: epineurial perivascular inflammatory infiltrates (7/7), vessel wall infiltration (6/7) that was diagnostic (2/7) or suggestive (4/7) of microvasculitis. All patients were treated with intravenous methylprednisolone. In 6 patients with longitudinal follow-up (median 5 months), all showed improvement of neuropathy impairment score [median: 25 (first evaluation) to 16.5 (second) (p=0.003)]. Conclusions: Herein, we show that in a subset of patients with progressive neuropathic symptoms ipsilateral to the side of hip surgery, inflammatory (not mechanical) factors played the prominent etiological role. Identification of these patients through nerve biopsy may lead to improved outcome with use of immunotherapy. A major question remains about the role of inflammatory mechanisms in post-hip surgery patients who present with new, non-progressive, ipsilateral neuropathies previously assumed to be due to mechanical factors and what benefit more intensive evaluation and immunotherapy might play. Supported by: In part by NIH grant NS36797. Disclosure: Dr. Laughlin has nothing to disclose. Dr. Staff has nothing to disclose. Dr. Watson has received personal compensation for activities with Nevro as a consultant. Dr. Dyck has nothing to disclose.