Alkaptonuria with Fracture Neck of Femur - A Case Report

Alkaptonuria is a rare autosomal recessive genetic disorder found in 2-5/million live births. It results in dark brown pigmentation of connective tissues including cartilage and joint capsule that can often lead to arthropathy of large joints. However, bone fractures are unusual. This article describes a fracture neck of the femur in a patient with undiagnosed alkaptonuria managed at a rural center.

A 60-year-old daily wage laborer with previously pain-free hips presented with sudden onset pain in the left hip while walking with no prior history of trauma. Radiographs showed a displaced fracture of the neck of the left femur. She underwent Left hip hemiarthroplasty. Intraoperatively, her soft-tissue including the joint capsule and the femoral head had dark brown pigmentation. Postoperatively, her urine was tested and the same turned black supporting the clinical diagnosis of alkaptonuria. At her 1-year follow-up, she had a painless, stable, and mobile hip.

We report a rare and unique case of neck of femur fracture in a patient with alkaptonuria treated with hemiarthroplasty in a resource-limited hospital in rural India. It is essential to consider the possibility of this condition when we come across a patient with an atypical fracture presentation. This article also presents an overview of alkaptonuria with a discussion on etiopathogenesis, clinical presentation, diagnosis, and management.