We reviewed 44 patients who had a bipolar prosthetic replacement from July 1982 to July 1989. There were 5 men and 39 women, whose ages ranged from 33 to 82 years (average, 58.0). They were re-evaluated one year to seven years postoperatively by questionnaire and roentgenograms. According to JOA Hip Score, preoperative score (mean, 45.0 points) was improved postoperatively (mean, 80.9 points). Roentgenographically central migration was observed in 5 hips 10.4%) and proximal migration in 3 hips (6.3%). Distal migration was observed in 11 hips (22.9%) and the sclerotic change at the tip of the stem in 23 hips (47.9%).
