Nerve Injuries in Total HIP Arthroplasty with a Mini Invasive Anterior Approach

Purpose Minimal invasive techniques in total hip arthroplasty (THA) have become increasingly popular during recent years. Despite much debate over the outcome of several minimal invasive techniques, complications arising from the use of anterior minimally invasive surgery (AMIS) for THA on a traction table are not well documented. Our study aims to focus on nerve damage during the AMIS procedure and the possible explanations of these injuries. Methods We reviewed all primary THAs performed with the AMIS technique using a traction table, over 5 years and recorded all intraoperative and postoperative complications up to the latest follow-up. We focused on nerve injuries and nerve function impairment following the aforementioned technique. Results Our study included 1,512 THAs performed with the AMIS technique in 2 major hip reconstruction centres (KAT General Hospital, Athens, Greece and University Hospital of Geneva, Switzerland), on 1,238 patients (985 women, 253 men; mean age 65.24 years). Mean follow-up was 29.4 months. We observed 51 cases of transient lateral femoral cutaneous nerve neuropraxia (3.37%), 4 cases of femoral nerve paralysis (3 permanent, 1 transient [0.26%]) and 1 case of permanent sciatic nerve paralysis (0.06%). No case of obturator or pudendal nerve injury was noticed. Mean age of these cases was 68.97 years. Sciatic and femoral nerve injuries were confirmed by electromyography, showing axonotmesis of the damaged nerve. Conclusions Neurological injuries are a rare but distinct complication of THAs using the AMIS technique. Possible explanations for such referred nerve injuries are direct nerve injury, extreme traction, hyperextension, extreme external rotation of the leg, use of retractors and coexisting spinal deformities. Controlled use of traction in hip extension, cautious use of retractors and potential use of dynamometers may be useful, so that neurological damage can be avoided. Further studies are needed to fully elucidate the role of the above factors in AMIS neurological complications.