Peroneal Nerve Palsy After Total Knee Arthroplasty.

Background: Common peroneal nerve palsy (CPNP) is a rare complication of total knee arthroplasty (TKA). It may lead to impaired function and pain. The purpose of this study was to determine the frequency and outcome of CPNP in a single orthopedic unit and to identify potential risk factors.

Methods: This is a single-center study using the hospital's prospectively collected quality registry. All TKAs from 2002 to 2022 were included and followed up from 3 to 24 months with a follow-up rate of 98.4%. The local joint register was reviewed to identify patients with CPNP and used to extract data regarding the operation and the patients with and without CPNP. The groups were compared to identify possible risk factors for nerve injury. The medical records of the patients with CPNP were reviewed to determine the CPNPs' severity and outcome, and their preoperative radiographs were analyzed and compared to a control group with no nerve injury.

Results: A total of 7704 TKAs were included, and 25 CPNPs were identified (0.32%). Complete palsies occurred in 18 cases, and partial palsies in 7. Postoperative epidural anesthesia, preoperative excessive valgus, and female sex were significant risk factors. Body mass index and age were not associated with CPNP. Two-thirds of the complete palsies had complete recovery, and four-fifths of the partial palsies recovered.

Conclusions: The incidence of CPNP was 0.32%, and risk factors were epidural anesthesia, excessive valgus, and female sex. Most patients with CPNP recovered completely. Partial palsies had better outcomes than complete palsies in our cohort.