Press-fit hip arthroplasty: a European alternative

The Cement-Less Stem (CLS; Sulzer Medica, Baar, Switzerland) was borne out of the proximal fixation and mechanical stability through press-fit and secondary osseointegration theories. The biomechanical concept is characterized by the three-dimensional wedge-shaped taper, ribs in the proximal region, and the undersized tip of the stem. Histologic studies showed that the coarse-grained titanium alloy of the CLS provides primary stability. In a series of 300 consecutive CLS prostheses with a minimum follow-up of 10 years (range, 10-16 years), femoral survivorship was 95% at 10 years and 90% at 14 years. Stem-bone fixation was stable, with bone ongrowth in 97% of patients, stable fibrous fixation in 1%, and unstable fibrous fixation in 2%. The CLS grit-blast, press-fit, collarless, tapered femoral component continues to perform well. Although continued surveillance is warranted, the good long-term results justify the continued use of the CLS for primary total hip arthroplasty.