Delayed Recovery of Idiopathic Common Peroneal Nerve Palsy After Total Knee Arthroplasty: A Rare Case Report

INTRODUCTION: Common peroneal nerve palsy (CPNP) is a rare complication post total knee arthroplasty (TKA). Even though it is diagnosed acutely, the recovery potential is just over 50%. The average period for complete recovery in such cases is 5 months; however, the management remains controversial. Through this report, we present one such case of left sided complete CPNP after bilateral TKA who was conserved with various modalities. Even though the recovery was delayed, the patient made full recovery. CASE REPORT: A 70-year-old female patient was diagnosed to have bilateral tricompartmental knee osteoarthritis with varus deformity, both clinically and radiologically (Kellgren–Lawrence grade 4). She underwent bilateral TKA in a single sitting as per the standard protocols practiced by the primary author. On post-operative day 1, she had left-sided foot drop with a complete sensory deficit. The patient underwent routine rehabilitation with an ankle foot orthosis splint in the immediate post-operative period, with simultaneous faradic current stimulation for the left lower limb. Periodic electromyography and nerve conduction study was done at the end of 4-week and 3-month post-TKA. At 6.5-month post-surgery, she made a full clinical recovery. CONCLUSION: The surgical maneuvers and full neurovascular examination before and after every TKA surgery should be carefully performed. Despite this, if a patient presents with CPNP, the surgeon need not take an aggressive approach, unlike fracture fixation cases. These patients can be managed conservatively using appropriate orthosis, physical therapy, and faradic current stimulation. Through this case, we attempt to report that CPNP patient can recover even after 6 months of surgery when there is no tangible cause for the palsy.