Temporary distal interlocking of the Prevision® stem with screws improves the stability of the implant in large bone defects. The defective zones are bridged and proximal bone areas can regenerate. Regeneration of the proximal bone can be assisted with allogeneous bone or through the transfemoral approach technique. Removal of the interlocking screws after successful bone regeneration results in a renewed proximal force transfer. The Prevision® reverse principle offers the possibility of influencing the effects of an exclusively distal force transfer on the proximal bone structures. Depending on the bone defect, the proximal section of the Prevision® revision prosthesis takes over a new load bearing function at an early stage. For low grade bone defects and intact proximal femurs, distal interlocking can be used for additional temporary implant stabilization.
Plasmapore® µ-CaP surface
The proximal component of the Prevision® revision prosthesis is coated with a rough Plasmapore® titanium micro-porous coating for cementless implantation. An additional 20 µm calcium phosphate layer is applied electrochemically. This thin layer has an osteoconductive effect and accelerates contact between the bone and the prosthesis stem.
Implant range for bone regeneration
The Prevision® revision prosthesis comprises a comprehensive range of straight and curved stems over 250 possible combinations. A selection of implants with distal diameters from 12-24 mm and implant lengths from 240-400 mm is available as standard. For optimum reconstruction of the hip joint and leg length, it is also possible to use the proximal components for finer adjustment since each proximal implant size is available in length increments of 0 mm, +10 mm and +20 mm. Because the implant components can be assembled in situ, the leg length can be adjusted easily and at the latest possible stage in the implantation.
Instruments for hip revision
The Prevision® instruments are designed for both transfemoral and proximal implantation of the prosthesis components. A free choice of assembly inside or outside the femur is possible, even for the connection of the distal and proximal components. In addition to reliable preparation of the implant site, the instruments offer early and repeated opportunities for trial reduction and secure fastening of the proximal and distal implant components. A brace applied to the distal component effectively cancels out the transfer of torque onto the distal implant site during in situ assembly.