Sciatic Nerve Injury from Direct Transection by Femoral Cerclage Wire: Case Report and Management Nuances

UCSF, CA, USA

John K. Yue, MD; Jun Y. Oh, MD; Alexander A. Aabedi, MD; Vinil N. Shah, MD; Rosanna L. Wustrack, MD

BACKGROUND AND AIMS: Sciatic neuropathy after total hip arthroplasty (THA) confers significant disability. Mechanisms of injury are not well-understood. We reviewed the management of a rare case of sensorimotor impairment and neuropathic pain secondary to sciatic nerve transection by femoral cerclage wire placed during prior THA.

CASE REPORT: 65-year-old woman presented with medically-refractory right sciatic sensorimotor neuropathy beginning one-year ago after THA. Neurologic exam was notable for weakness in ankle dorsiflexion/plantarflexion and foot inversion/eversion (2-3/5), toe extension/flexion (1/5), and foot numbness and paresthesias, with electromyogram confirmation. Preoperative magnetic resonance neurogram (MRN) showed an abnormally thickened sciatic nerve abutting the femoral cerclage wire site. Computed tomography reconstruction showed the wire was contiguous with the sciatic nerve. Intraoperatively, the cerclage wire was found to have transected through the sciatic nerve, requiring orthopedic surgery consultation and wire cutdown at the transection site. The nerve was freed and repaired with allograft. Intraoperative neurophysiology monitoring (IONM) signals remained stable. Postoperative radiographs showed uncomplicated cerclage wire disconnection. The patient was discharged home postoperative day 1 and noted significant symptomatic relief from sciatic distribution pain and paresthesias at one-month follow-up.

INTERPRETATION: This is the first report of a through-and-through transection of the sciatic nerve by femoral cerclage wire. Surgical anatomy may be complex, underscoring the importance of operative planning in primary THA and revision neuroplasty. Strategies include preoperative MRN to evaluate the anatomical course of the affected nerve, judicious co-management by neurosurgery and orthopedic surgery, and multimodal IONM nerve mapping to reduce risks of neural injury and optimize outcomes.

KEY WORDS: bone wire; neuropathic pain; sciatic nerve palsy; surgical diagnostic technique; total hip arthroplasty