The major challenges in an increasing number of periprosthetic femoral fractures are pre-existent aseptic loosening and femoral bone loss. The successful concept of interlocked intra medullarynailing of multi fragmentary femoral fractures has been applicated onperiprosthetic fractures. A specially designed revision stem combines the features of an intramedullary nail in its distal part and of an uncemented coated prosthesis in the proximal part. This prosthesis has been used successfully in elective revision surgery for aseptic loosening.

Thirty-nine patients with periprosthetic fractures have been operated between 1994 and 2000. Eleven patients were male, the mean age was 70,3 years. The series includes three intra operative fractures of the femoral shaft, in which a revision stem was applied, in the other cases the primary intervention was 10.9 years before the periprosthetic fracture. In 16 cases the shaft was loose prior to the fractures, and in 13 cases the cup was loose as well.> A modified transfemoral approach was done in any case, and long revision stem with distal interlocking was applied. The fragments were adapted to the shaft by cerclage wires, and bone grafting was done in 14 selected cases.

All patients could be followed up. In all but 4 cases the fracture was healed and the revision stem was well osteointegrated. Radiologically, the bone stock of the proximal femur was restored by means of bone grafting and fracture healing in this cases. A recurrent revisionhad to be undertaken in four cases due to lack of osteointegration and subsidence of the stem. In 5 cases the cerclage wires had to be removed due to local irritation. 3 patients had a recurrent trauma and a new periprosthetic fracture distal to the tip of the revision stem; plating had to be performed in this cases.

We conclude that interlocked intramedullary stabilisation of periprosthetic fractures with a revision stem can be a option especially in those challenging cases with pre-existent shaft loosening and bone loss.

The treatment of fractures of the proximal tibia is complex and makes great demands on the implants used. Our study aimed to identify what levels of primary stability could be achieved with various forms of osteosynthesis in the treatment of diaphyseal fractures of the proximal tibia. Pairs of human tibiae were investigated. An unstable fracture was simulated by creating a defect at the metaphyseal-diaphyseal junction. Six implants were tested in a uniaxial testing device (Instron) using the quasi-static and displacement-controlled modes and the force-displacement curve was recorded. The movements of each fragment and of the implant were recorded video-optically (MacReflex, Qualysis). Axial deviations were evaluated at 300 N.

The results show that the nailing systems tolerated the highest forces. The lowest axial deviations in varus and valgus were also found for the nailing systems; the highest axial deviations were recorded for the buttress plate and the less invasive stabilising system (LISS). In terms of rotational displacement the LISS was better than the buttress plate.

In summary, it was found that higher loads were better tolerated by centrally placed load carriers than by eccentrically placed ones. In the case of the latter, it appears advantageous to use additive procedures for medial buttressing in the early phase.

Aims: A femoral stem design (BiCONTACT¨) for cementless þxation is being used without any technical modiþcation since 14 years. The long term results should be evaluated in this study. Methods: A consecutive series was continuously monitored in a prospective follow-up study. A survival analysis was performed, clinical results were rated according to the HARRIS Score. Results: There were 236 patients with 250 hips, mean age at time of implantation was 58.2 years. Indications for THR included osteoarthritis (62.4%), dysplasia (16.8%), trauma (8.4%) and femoral head necrosis (16.8%). Average time of follow-up evaluation was 11.8 years (range 10.6 Ð 13.7 years). At follow-up, 44 patients have died and three could not be located. Eight patients have been revised, 2 for infection, 1 for recurrent dislocation, 2 for component undersizing with rapid subsidence and 1 for aseptic loosening of a varus-malaligned stem. Two stems have been revised during acetabular revision. Survival estimate showed an overall survival of 96.6% after 14 years (conþdence limits: 98.4% (upper) and 92.8% (lower)). The average HARRIS hip score at time of follow-up was 78.3 points. Radiologically, tiny reactive lines (< 2mm) were present in the distal zones of the femoral shaft in 39%, but no radiolucencies could be found in the proximal anchoring zone. Conclusions: The long-term follow-up results with the BiCONTACT¨ femoral component are encouraging and are comparable to those of modern techniques of cementing in primary total hip arthroplasty.