Traumatic injury of left femoral nerve causing unilateral hindlimb lameness in a cat

Abstract

A 1‐year‐old, female, domestic shorthair cat was referred for orthopaedic evaluation of acute‐onset, non‐progressive left pelvic limb lameness of 2.5‐week duration. Orthopaedic examination revealed an abnormal gait with impaired ability to support weight on the left pelvic limb. There was marked atrophy of the quadriceps muscles. Neurological examination revealed an absent patellar reflex and decreased sensation in the cutaneous zone of the saphenous nerve of the left pelvic limb. Magnetic resonance imaging showed T2‐weighted/short‐tau inversion recovery hyperintensity and contrast enhancement in the area of the femoral nerve and within muscles innervated by this nerve. Findings were deemed consistent with traumatic nerve injury and denervation/traumatic myopathy or myositis/neuritis. Electromyography of the quadriceps muscles revealed fibrillation potentials and positive sharp waves. Follow‐up over the next 9 months revealed no changes in the neurological deficits. This was deemed to be consistent with either partial axonotmesis or partial neurotmesis of the left femoral nerve.