A seventy-five-year-old female patient, operated on three years previously for a left hip fracture using a proximal femoral nail (PFN, Synthes), started to feel left groin pain with no traumatic antecedent; she was otherwise healthy. She was not using any drug interfering with bone metabolism. Clinical examination revealed that the pain was exacerbated by internal and external rotation of her hip. X-ray examination of the left hip revealed a consolidated hip fracture with lateral migration of the screw. There were no signs of acetabular fracture on this AP projection (Fig. 1).
Since the pain continued, two months later further x-rays were obtained, revealing a transverse acetabular fracture according to Letournel's classification with the femoral head medially protruding onto the anterior acetabular wall; probably because of this, the femoral head had an anteriorsuperior notch, and was collapsed (Fig. 2).
A cemented total hip replacement was performed, with no osteosynthesis or bone graft of the acetabular fracture (Fig. 3); bone and soft tissue samples obtained intraopera-tively were negative for bacteriological cultures. The pathology biopsy presented no noteworthy findings, apart from acute inflammation cellularity. A chest X-ray revealed no sign of a former pulmonary tuberculosis. The patient improved clinically after the operation. Six year follow-up X-rays showed proximal migration and medialization of the acetabular component (Figs. 4, 5).
The pain eased and the patient continued to be clinically well at the 7 year follow-up. Although she walked with a slight limp and needed the help of a crutch, daily activities such as short-distance walking and climbing stairs were well tolerated. Painkillers were needed occasionally.