Periprosthetic Femur Fracture on Alkaptonuric Patient: A Rare Case Report in Indonesia

Abstract

A 74-year-old male with alkaptonuria (AKU) was admitted to the emergency department with left distal femur pain and Rorabeck type 2 periprosthetic femur fracture following total knee arthroplasty (TKA). AKU is an autosomal recessive disorder characterized by homogentisic acid buildup in connective tissues and joints, leading to ochronosis and arthritis. Multiple joint replacements are common in AKU patients, and periprosthetic fractures may occur due to osteopenia. Rorabeck type 2 fracture is treated with intramedullary nailing or locked plating. The patient underwent internal fixation with locking plate and bone grafts using minimally invasive plate osteosynthesis (MIPO) procedure, resulting in good fracture healing. The case highlights the importance of considering AKU as a differential diagnosis in arthritis patients and managing periprosthetic fractures with care in AKU patients.