抄録
We investigated clinical and roentgenological results on 24 THR performed at our clinic in 22 cases whose progress we were able to follow up for at least 5 years and a maximum of 12 years and 10 months. The clinical results were evaluated according to the JOA hip score and were found to be: for the Müller type, 45.5 (preoperatively), 89.3 after 5 years, and 76.5 after 10 years; for the T-28 type, 53.9 (preoperatively), and 92.0 after 5 years. In regards to ROM, the degree of improvement in adduction, abduction and rotation tended to be greater than the degree of improvement in flexion.
During the postoperative roentgenographic evaluation of 5 cases with the Muller type for more than 10 years, a radiolucent line of less than 2 mm at zones I, II and N on the cup side was seen in all 5 and a radiolucent line wider than 2 mm was seen in 2 out of the 5 indicating cup migration. A revision was performed on one of these cases. On the stem side, sinking of less than 5 mm was observed in 2 cases at 5 years after the operation using the Müller type, and at an average of 10 years afterwards, sinking of more than 5 mm was seen in 2 cases, one of which was judged to be varus migration. Since we have only had experience in using T-28 for a relatively short period (5 years and 2 months), it is difficult to compare it to the Müller type, but thus far it is considered to have produced satisfactory clinical and roentgenological results.
