Purpose: To review the results of periprosthetic femoral fractures treated using cortical strut allograft and plate internal fixation.

Material & Methods: Between November 1996 and July 2006, 17 patients with periprosthetic fractures of the femur after hip arthroplasty were treated using deep-frozen cortical strut allografts as an adjunct support after internal fixation. The average age was 79 years (range 56 to 96 years) with 13 woman and 4 men. According to the Vancouver classification system, there were 6 type B1, 5 type B2, 1 type B3 and 5 type C fractures. All fractures were closed except for one type I of Gustilo. Twelve patients had internal fixation of the fracture using a Dall-Miles cable and plate system, 5 using a AO/ASIF 4.5 dynamic compression plate, and 2 had an associated revision arthroplasty of the stem. Cortical strut allograft was used from the femur in 6 cases and from the tibia in 11 cases. Mean follow-up was of 97.5 weeks.

Results: One patient presented a rupture of a screw and varus displacement of the fracture, but healed without symptomatic complaints. A superficial infection occurred in the patient with open fracture. All the patients, except for two, required allogenic blood transfusion. Mean inhospital stay was of 18.6 days and walk with weigh was allowed at a mean of 50.9 days. Two patients died few weeks after the treatment due to complications of their previous pathological disorders. Aseptic loosening of a hip arthroplasty occurred at two years follow-up requiring revision surgery. Three patients referred mild pain at the last follow-up visit.

Conclusions: Cortical strut allograft associated with internal fixation has provided satisfactory results in the present serie. We consider this procedure safe and effective, specially for type B1 and C periprosthetic femoral fractures.

Aims: The study we present compares quantitatively the bone regeneration in experimental animals obtained with autologus and homologus grafts against a calcium phosphate cement. Methods: We performed cavitary defects o 6 mm of diameter in the metaphiseal region of the distal femur of 48 rabbits of albine race. They were divided in 4 groups, and received respectively autologous grafts, homologous freezed graft, calcium phosphate cement or the absence of any implant (control group). Results: The results are valued by radiological, histological and histomorphometrical studies (with digitalysed images). Histological study shows a correct integration of the calcium phosphate cement, without þbrous interphase, and a bone regeneration which is progressive and centripetal. Statistical analysis of the histomorphometrical data shows that bone regeneration obtained with the calcium phosphate cement its similar to the one obtained with the grafts. Conclusions: Calcium phosphate cement is a biocompatible material, biodegradable and conductor.