We reviewed 30 patients who had had a dual bearing type prosthesis between January 1987 and July 1990. The cases consisted of 4 males and 26 females.
The age range from 55 to 77 years old with an average of 66 years old.
They were evaluated over a pevicd of between one and three years and six months postoperatively by questionnaire and roentgenograms.
According to the J. O. A. hip score, the preoperative score had improved postoperatively by a mean, of 49.8 points to a mean, of 83.8 points.
Roentgenographically, central migration was observed in 10 hips (27.7%) and sinking of the stem in 10 hips (27.7%).
