Functional and radiological outcome of periprosthetic femoral fractures after hip arthroplasty.

BACKGROUND

The aim of this study was to determine the functional and radiological results of the treatment of periprosthetic femoral fractures.

MATERIALS AND METHODS

A review was performed of all periprosthetic femur fractures after a total hip arthroplasty (THA) or hemiarthroplasty (HA) treated at our institution from 1995 to 2011. Functional outcome was assessed in terms of the Harris Hip Score and ambulatory status. Radiological findings were classified using Beals and Tower's criteria.

RESULTS

A total of 59 periprosthetic fractures were identified in 58 patients. The mean age of patients was 79 years old and the mean follow-up time was 33.6 months. Local risk factors were identified in 71% of the patients, principally osteoporosis (59%), followed by osteolysis (24%) and loosening of the stem (19%). In the multivariable analysis, the presence of local risk factors was associated with worsening of patients' ambulatory status. According to the Vancouver classification, there were 8 type A, 46 type B and 5 type C fractures. Of the type B fractures 24 were B1, 14 were B2 and 8 were B3. Fracture union was achieved in 54 fractures, with a mean union time of 6 months. Applying Beals and Tower's criteria, radiological results were excellent in 20 patients (34%), good in 22 (37%), and poor in 17 (29%). None of the patients improved their ability to walk after these fractures and 31 patients (52%) did not regain their prefracture walking status. The mean Harris Hip Score postoperatively was 67.9. There were major or minor complications in 33 patients (56%) and 11 patients (19%) required further operations.

CONCLUSION

Although this study shows good radiological results following methods of treatment in accordance with the Vancouver classification, there was marked functional deterioration in many patients and a high rate of complications. Local risk factors were associated with poorer ambulatory status.