A modular system for cemented and cementless implantation of femoral stem prostheses

A femoral stem [BiContact, Aesculap, Germany) has been developed which is suitable for both cemented and uncemented implantation. Thus a highly standardized procedure and a standard implant for any iritraoperative finding is available. While the cemented stems have a smooth surface, the cementless implants are proximally coated with a microporous titanium plasmaspray [Plasmapore]. The strategy based on the intraoperative choice of the surgeon to use either cemented or cementless implants after bone preparation turned out to be very successful in our institution. A consecutive series of 250 cases with cemented implantation and 250 cases with uncemented implantation was analyzed in a prospective follow-up study, Pollow-up time averaged 7 years for cemented and 6.5 years for uncemented THRs. The follow-up rate was 88.7% in cases treated with cemented stems and 93.1% in cases treated with uncemented stems. The rate of aseptic loosening was 1.2% for the cemented version and 0.4-% for the uncemented stem. Radiological loosening could be observed in another 1.2% of the cemented stems and was not to be found in the uncemented cases. Our data suggest an excellent midterm stability of both the cemented and the uncemented version of the BiContact hip system. The long-term results for both the cemented and uncemented prostheses of our series are still to be evaluated.