Radiological Evaluation of Treatment of Periprosthetic Femoral Fractures.

Background: Periprosthetic fracture of the femur is a common complication of total hip replacement surgery. There are several risk factors, including the female gender, an uncemented implant, the use of a straight or revision stem and secondary osteoarthritis. The aim of the study was a radiological evaluation of treatment of periprosthetic femoral fractures Material and methods. The study group consisted of patients who underwent hip replacement surgery at the Department of Orthopaedics and Traumatology, Medical University of Silesia, between 2002 and 2006. Radiologic evaluation of outcomes was based on the scheme developed by HIP Society, SICOT, AAOS and, additionally, on Beals and Tower's classification.

Results: The incidence of pathological findings, such as lucent zones along the stem-bone interface, crack of the cement and focal osteolysis of the greater trochanter and around the cement, did not exceed 10%. Lucent zones were most frequently seen in radiographs of cemented prostheses in Gruen's zones 2, 3 , 4 and 5. Cortical hypertrophy was seen medially in Gruen's zones 4, 5 and 6. Adams' arc osteolysis was found in 15.5% of patients with intraoperative fractures and almost 40% of patients with late fractures. Heterotopic ossification was noted only in 7 patients.

Conclusions: 1. Radiological evaluation of treatment of periprosthetic femoral fractures after hip replacement surgery is one of the most difficult parts of patient status assessment in post-surgical patients. 2. The most common pathological radiographic findings were stem subsidence and the presence of osteolytic foci around Adams` arc. 3. The occurrence of a periprosthetic fracture did not significantly affect Beals and Tower scores.