Common Peroneal Nerve Palsy at the Level of Proximal Fibula After Total Hip Arthroplasty: A Case Report.

Sciatic nerve injury is a well-known devastating complication and is the most commonly involved nerve after total hip arthroplasty (THA). Most of these injuries occur at the level of the hip and surgery site rather than a distal location. In this case report, a 62-year-old male presented with common peroneal nerve (CPN) palsy at the level of the knee immediately after undergoing left THA via posterior hip approach. This likely occurred due to direct compression during the surgical positioning or intraoperative leg manipulation. It was associated with excruciating uncontrolled neuropathic pain around the ipsilateral lateral leg and foot and absence of motor function. The patient's THA was performed elsewhere, seven weeks prior to his presentation to us. His clinical examination and electromyographic (EMG) findings confirmed focal peroneal nerve entrapment around the neck of the fibula. An urgent distal peroneal nerve decompression was performed followed by a dramatic improvement in the pain. Consequently, the patient discontinued all pain medications within three days after the decompression. On follow up, he demonstrated remarkable improvement in his motor and sensory functions. In conclusion, direct or indirect CPN injury at the level of the knee is extremely rare after THA. Early distal peroneal nerve decompression after THA can be beneficial in selected patients based on the clinical presentation and EMG findings.