Midterm results in 500 titanium alloy straight femoral stem prostheses -cemented and cementless technique

Summary Mid- and long term stability is still the major challenge in total hip replacement (THR). A consecutive series of cemented 250 cases and of uncemented 250 cases was analyzed in a prospective follow-up study. The femoral component of the BiCONTACT hip stem system with the same design for cemented and uncemented implantation was used. While the cemented stems had a smooth surface, the cementless implants were proximally coated with a microporous titanium plasmaspray (Plasmapore^®). Follow-up time averaged 7 years for cemented and 6.5 years for uncemented THRs. Follow-up rate was 88.7% in cases treated with cemented stems and 93.1% in cases treated with an uncemented stem. The rate of aseptic loosening was 1.2% for the cemented version and 0.4% for the uncemented one. Radiological loosening could be observed in another 1.2% of the cemented stems but was not found in the uncemented cases. Our data suggest excellent midterm stability of both the cemented and the uncemented version of the BiCONTACT hip stem system. Early aseptic loosening especially of the cemented titanium alloy straight stem has not occurred in our series as reported recently. The prosthesis design and follow-up time may therefore play an important role. The long-term results for both cemented and uncemented BiCONTACT prostheses of our series are still to be evaluated.