Long-term follow-up of a cemented titanium stem

Abstract

We present the outcome of 270 cemented titanium alloy femoral stems. These patients were followed up annually both clinically and radiologically, and were included up until their last follow-up. 120 patients completed a 10-year follow-up. The 10-year survival of the Ultima Straight Stem cemented femoral component (defined by revision of the femoral stem) was 90.1% (95% CI=84.0-94.0%), with aseptic loosening being the major reason for failure. The preoperative Harris Hip Score improved from 35.3 to 79.3 at 10 years. There were 17 cases of stem subsidence, radiolucent lines in 11 hips, 5 cases of cement fracture and 18 hips had osteolysis in 2 adjacent Gruen zones. This is the largest study in the English literature of this implant, and reflects UK district general hospital practice with surgery performed by a variety of surgical grades and via different surgical approaches. Although the outcome of this implant was within the previous standard set by the National Institute for Health and Clinical Excellence and is comparable to other series of titanium stems, it is inferior to that of more modern cemented and uncemented implants, and falls outside the new NICE recommendation of <5% revision rate at ten year. As a result this implant is no longer used in our institution, and it has also now been withdrawn from the market. We suggest that patients with this implant should be followed up radiologically due to the relatively high rate of stem subsidence and lucency between the cement and prosthesis, to identify those who may be at risk of failure.