Femoral nerve paralysis complicating a post-traumatic iliopsoas haematoma

Paralysis of the femoral nerve secondary to iliopsoas haematoma is a rare post-traumatic complication. Because of the large differential diagnosis, a high level of suspicion is required for its early recognition. Treatment modalities are controversial due to the rarity of this entity. An 18-year-old student presented with complete paralysis of the knee extensors and a sensory deficit on the anterior side of the thigh 5 weeks after a sport accident. MRI of the lesser pelvis showed an iliopsoas haematoma. Surgical decompression was performed and recovery was complete at 6 months of follow-up.