The effect of a lateral flare feature on implant stability.

We reviewed the X-rays of 109 patients with 115 primary total hip replacements utilizing a lateral flare cementless stem to assess axial migration and stability. The average follow-up was 48.6 (24-104) months. The average subsidence at 2 years was 0.32 mm, remaining at a level below 1 mm for the duration of the follow-up. Even though there were ten reoperations involving either the change of a polyethylene liner and the acetabular component, or both, none of the patients required a femoral stem revision. It was concluded that the proximal geometry of the stem provides significant initial stability, which seems to be preserved throughout a long follow-up period.