Introduction: The incidence of postoperative periprosthetic femoral fractures ranges from 0.1% in primary arthroplasty to 2.1% in revision surgery, and is often a challenge for the surgeon.

Materials and methods: We carried out a retrospective clinical study of periprosthetic femoral fractures found among the primary arthroplasties and revision hip replacements performed at San Carlos University Hospital between 1991 and 2003. We found 82 patients with postoperative periprosthetic femoral fractures. The fractures were classified according to the Vancouver classification, and we analysed the associated risk factors, treatments used, complications and results.

Results: The mean age of the patients was 72 (SD 12). There were 57 women (69.5%) and 25 men (30.5%). Of the 82 cases, 22 (26.8%) were type B1 fractures, 33 type B2 (40.2%), 20 type B3 (24.4%) and 7 type C (8.5%). The most common surgical treatment was the combination of a long stem held in place with cerclage wires in 27 cases (33%), followed by treatments using allografts in different combinations in 22 cases (26.8%).

Conclusions: Femoral bone stock is a factor that influences the occurrence of periprosthetic fractures.

The use of allografts has little effect on the fracture consolidation time, although it involves an increase of femoral bone stock, which makes allografts advisable even in Vancouver type B2 fractures.