Abstract Details

Traumatic isolated femoral nerve palsy in the absence of bleeding disorders or use of anticoagulants is rare, and is scarcely documented in the literature. Iliacus muscle hematoma can result from direct trauma to the hip or pelvis, which can compress the femoral nerve.

To recognize pediatric isolated femoral nerve palsy secondary to a traumatic iliacus muscle hematoma.

We report a 16-year-old male who presented with left leg pain and weakness after slipping while performing handstands on parallel bars, and hit his lower back on the bar. On the same day, the x-ray of the spine and hip performed in the ER were unremarkable and he was discharged home with crutches. The leg pain worsened after one week, and bed rest was recommended. One month later, his left thigh was markedly smaller than his right. MRI of the lumbar spine and left knee without contrast were reported normal. Two months after the initial insult he had significant atrophy of left thigh muscles, with left hip flexor and knee extensor weakness, absent left patellar reflex, and diminished sensation to pinprick in the left saphenous nerve distribution, suggestive of a left femoral nerve palsy. EMG revealed ongoing denervation in all muscles innervated by the femoral nerve. MRI of the pelvis with contrast revealed a hematoma underlying the left iliacus muscle with an enlarged and edematous left femoral nerve.

The patient underwent CT guided drainage of the left iliacus hematoma. One week later, there was minimal improvement in the muscle strength of the left knee extensors muscles.

Femoral nerve palsy resulting from traumatic iliacus hematoma should be considered in the pediatric population. It can mimic less serious conditions such as muscular strain, which can lead to delays in diagnosis and proper treatment.