Influence of patient-, design-, and surgery-related factors on rate of dislocation after primary cementless total hip arthroplasty.

We performed clinical, radiographic, and computed tomography examinations on a consecutive series of 1268 patients (1648 hips) to determine the prevalence of and factors contributing to dislocation after using a primary cementless total hip system. The prevalence of posterior dislocation was 3.6% (60 hips). Significant risk factors (Fisher exact test or chi(2) test, P < .05) were female sex, advanced age, high American Society of Anesthesiologists score (3 or 4), fracture of the femoral neck, nonrepair of the posterior soft-tissue sleeve, low or high cup anteversion, low or high stem anteversion, and low height of hip rotation center.