A critical look at cementless stems. Taper designs and when to use alternatives.

The clinical and radiographic efficacy of cementless taper design femoral components in total hip arthroplasty was determined. Cementless, taper design, femoral components have been shown to offer comparable clinical results to cemented femoral implants in a double blind, randomized, clinical trial. No differences were observed in terms of disease specific, patient specific, global health, functional capacity, or cost to utility outcome measures. The prevalence of pain in the thigh was the same in each group. Fixation of cementless, taper design, femoral stems depended on three-point fixation as shown on lateral radiographs. A clinical algorithm for femoral stem selection, based on more than 10 years experience with more than 1000 cementless, taper design femoral stems has been developed. Cementless, taper design, femoral implants currently are used in 75% of the authors' patients, provided they are younger than 75 years of age and have funnel shaped proximal femoral medullary canals. Cemented femoral stems are used in older patients, those who have cylindric medullary canals, and those who have inflammatory or unusual bone diseases (Paget's disease, previously irradiated bone).