# A Rare Case of Transepiphyseal Distal Femur Fracture Dislocation With Delayed Recovery of a Common Peroneal Nerve Injury

## TL;DR

This paper presents a rare case of a 11-year-old boy with a distal femur fracture and delayed recovery of a common peroneal nerve injury.

## Contribution

The study highlights an unusual delayed recovery of common peroneal nerve palsy following a distal femur fracture in a pediatric patient.

## Key findings

- The patient showed no improvement in dorsiflexion for 12 weeks after treatment.
- EMG/NCV tests confirmed CPN injury with early denervation.
- Full recovery of dorsiflexion occurred after 15 weeks with minor residual effects.

## Abstract

The aim of this study is to bring attention to a unique case and our approach to treatment in this context. We describe a case of an 11-year-old male who presented to us with an injury to his left knee following trauma with pain, swelling, shortening and deformity for one day. An X-ray revealed a transepiphyseal fracture dislocation of the left distal femur (Salter-Harris type 1 injury) and neurovascular examination was conclusive of foot drop which pointed towards injury to common peroneal nerve (CPN).

The patient was taken up for closed reduction with percutaneous pinning under mobile C-arm guidance. The fracture was reduced and fixed with two cross K-wires and immobilized with the above knee anterior-posterior slab for six weeks. The wires were removed after six weeks but there was no improvement in the dorsiflexion of the left ankle. An electromyography (EMG) and nerve conduction velocity (NCV) study test was performed after 12 weeks which showed decreased amplitude and prolonged latency in the left CPN with early denervation of the muscles supplied by the left CPN. Fifteen weeks of follow-up showed complete recovery in the dorsiflexion of the left ankle with a slight lag in the extension of the left great toe making this an unusually delayed recovery of CPN palsy following a distal femur transepiphyseal fracture.