The treatment of femoral neuropathy due to pseudotumour caused by metal-on-metal resurfacing arthroplasty

• Published in: Hip international 2008-10, Vol.18 (4), p.313-320
• Main Authors: Harvie, P, Giele, H, Fang, C, Ansorge, O, Ostlere, S, Gibbons, M, Whitwell, D
• Format: Article
• Language: English
• Subjects: Adult; Aged; Female; Femoral Nerve - pathology; Femoral Nerve - surgery; Femoral Neuropathy - etiology; Femoral Neuropathy - pathology; Femoral Neuropathy - surgery; Granuloma, Plasma Cell - etiology; Granuloma, Plasma Cell - pathology; Granuloma, Plasma Cell - surgery; Hip Joint - pathology; Hip Joint - surgery; Hip Prosthesis - adverse effects; Humans; Metals - adverse effects; Middle Aged; Pain, Postoperative - etiology; Pain, Postoperative - pathology; Reoperation
• ISSN: 1120-7000; 1724-6067
• DOI: 10.1177/112070000801800408

Concerns now exist about the long-term biological effects of exposure to orthopaedic metal alloys, particularly serum cobalt and chromium ions derived from metal-on-metal wear debris in these patients. A pseudotumour mass complicating metal-on-metal resurfacing arthroplasty has been recognized by orthopaedic oncologists and specialist hip units. Pseudotumours may also present with a major nerve palsy. Two cases of femoral neuropathy due to pseudotumour masses caused by metal-on-metal resurfacing arthroplasty are presented. Preoperative neurophysiological studies showed severe and irreversible pathological changes to nerve function with neurohistopathological evidence of complete nerve destruction with a previously unreported pathological appearance. This may represent a previously unrecognized pathological process, possibly 'toxic' in nature, resulting from metal-on-metal wear debris. Prolonged follow-up and detailed clinical assessment of patients after hip resurfacing arthroplasty is advocated with planned and expeditious revision of any patient in whom evidence of femoral neuropathy develops.