The results of thirty-one consecutive primary total hip arthroplasties using the anatomic locking hip system were reviewed after a minimum of five years. Their pre-operative JOA score of 41 points improved to 88 points post-operatively. One performed revision surgery. The survival rate at five years from the operation was 0.97. Proximal femoral bone atrophy appeared in twenty-five hips (83%), but the revision case showed no bone atrophy. It is not clear whether the proximal femoral bone atrophy correlated with the stability of the femoral component. The cementing technique in the revised case was grade C. We considered this was the most important cause for loosening. The width of the clear zone of another two hips showed more than 2mm. These two cases finally showed stem loosening, but did not undergo surgery.
