Periprosthetic femoral fractures--a comparison between cemented and uncemented hemiarthroplasties.

Over a 2-year period, 244 patients underwent hemiarthroplasty for a displaced intracapsular femoral neck fracture. Seventy patients had a cementless Austin-Moore prosthesis (AMP) inserted and 174 patients were treated using a cemented Thompson hemiarthroplasty. All the AMPs were inserted by or under the supervision of an orthopaedic consultant. Five patients (7%) from the AMP group sustained a periprosthetic femoral fracture. Two were iatrogenic and three occurred postoperatively after a simple fall. The fractures occurred proximally around the prosthesis (Johansson type I). Four required revision surgery. There were no periprosthetic femoral fractures in the Thompson group. When compared to the cemented Thompson hemiarthroplasties, the number of periprosthetic femoral fractures was significantly greater with the AMP. Patients in the AMP group were significantly older, although there was no significant difference in ASA grade between the two groups. There was no significant difference in age or gender between those who sustained a periprosthetic fracture and those who did not. These findings suggest that due to the increased risk of periprosthetic femoral fracture, cemented hemiarthroplasty is preferable. Furthermore, with modern cementing techniques, elderly frail patients appear to tolerate bone cement, which may serve to reinforce an osteoporotic proximal femur.