Abstract
Aims: Bone stock preservation is thought to be essential when performing THR in young patients. For this purpose we developed a new CAD-CAM titanium cementless femoral stem to be implanted with minimal femoral resection. This implant is constructed to þll completely the proximal metaphysis transferring loads on both the lateral ßare and the calcar. This allows the elimination of the diaphyseal portion of the stem which is prolonged only till approximately 1 centimetre below the lesser tro-canter. Methods: Since 1995, we implanted 76 stems in 71 patients. Average age was 51 yrs (30–63), 34 females and 37 males. Mean follow-up is 45 months (min.12, max 84 months). In all cases we employed an hemispherical pressþt cup. Metal to polyethylene interface was used in the þrst 30 implants whilst metal to metal coupling was chosen for the latter 46 hips. Clinically patients were evaluated with Harris Hip Score. All patients ware evaluated by X-ray 1, 3, 6 and every year postoperative. Results: Average preoperative value of HHS was 42,4, postoperative 98. Tight pain was never recorded. All the stems appear stable radiograþcally, we had no subsidence, no radiolucent lines, no stress shielding, no osteolisis. In 26,4% of cases we had mild proximal calcar resorption. Conclusions: Clinical and radiographic results conþrm that axial and torsional loads can be properly controlled even without the distal portion of the stem. We believe that maximal bone stock preservation in young patients undergoing THR is mandatory in view of the high possibility for these patients to require multiple revisions in the future.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
