The short stem titanium prothesis preserves the femoral neck. No reamer and no rasp is used for the implantation. Two times compression of the bone with a compressor and with the prothesis it self continues the principle of bone retention. Preserving the femoral neck and compression of the bone lead to an high anchorage and the best primary stability. This is mandatory for safe osseo integration. Except metal on metal all combinations are suitable. Deltaceramic-Deltaceramic is the most modern possibility. The high anchored short-stemp leaves enough virgin-bone for any standard prothesis in case of later revision. In 1999 implantation of CFP Prothesis was started in the Endoklinik-Hamburg. Until 2005 2500 prothesis were implanted. A five year follow up of the first hundert cases does not show system corellated failures. An overview of 2400 implants shows a revision rate of 1%. Total exchange procedure was necessary in 8 cases because of deep infection (0,33%). Only very few none fixed stems and cups had to be reviced. Minimal invasive surgery is well suitable. In our clinic we prefer the posterior aproach. With six sizes left and right nearly all tipe of bone shape is covered. Extreme varus or valgus hips are not indicated as well as severe deformaties. The CFP Prothesis is an good alternative to the CUP Prothesis especially for the young patients with femoral head necrosis which we see in about 10%. A five year follow up is only really interessting if it has bad results, with goog results it gives us confidence to wait for the ten year results.
Glass ionomer cement (Ionocem) was developed for use in bone surgery and is reported to be notably biocompatible. Between 1991 and 1994 we performed revision operations for aseptic loosening of arthroplasties of the hip on 45 patients using this material in its granulate form (Ionogran) mixed with homologous bone as a bone substitute. Of these 45 patients, 42 were followed up for a mean of 42 months. Early reloosening of the acetabular component has occurred in ten after a mean of 30 months. Histological examination showed large deposits of aluminium in the adjacent connective tissue and bone. Osteoblastic function and bone mineralisation were clearly inhibited. The serum levels of aluminium were also increased. The toxic damage at the bone interface caused by high local levels of aluminium must be seen as an important factor in the high rate of early reloosening. Our findings cast doubt on the biocompatibility of this material and we do not recommend continuation of its further use in orthopaedic surgery.
Eleven patients underwent disarticulation for infected arthroplasty of the hip. Exchange total hip arthroplasty or conversion to a Girdlestone excision arthroplasty had been undertaken previously an average of 2.9 times. The indications for disarticulation were as a life-saving measure, or as a result of severe infection of soft tissue and bone, loss of bone stock, or vascular injury. While the indications for this drastic operation were highly individual, there were instances where disarticulation could have been avoided if repeated exchange operations had been eschewed in deference to a Girdlestone procedure.
