抄録
While satisfactory results with Chiari pelvic osteotomy for dysplastic hips with subluxation have been reported, those for coxathrosis in advanced and terminal stage is sometimes reported to be unpredictable. To check the results of Chiari osteotomy in these stages, 31 hips in advanced and terminal stage of coxarthrosis were assessed at 2 to 7 years (a mean of 3 years, 1 month) after operation.
The JOA score was 60.6±17.0 before operation and 77.3±15.0 at the time of follow-up (p<0.01) . Satisfactory results were provided with uni-late ral Chiari osteotomy (60.0±18.6 to 82.6±8.7: p<0.01), however, there was no improvement in cases with bilateral Chiari osteotomy within two years (62.0±18.6 to 62.0±19.4) .
Radiographs taken before operation, immediately after operation, and at the time of follow-up were evaluated. Remodeling of the hip joint after Chiari osteotomy was found in every case and sometimes resulted in the phenomenon of proximal migration (pm) of the femoral head into the newly formed acetabulum. A pm of over 5 mm (pm (+) ) was found in 45.1% of the joints in our study. The results with pm (+) joints (71.3±14.5) were worse than those with other joints (82.9±14.3: p<0.01) . The bilateral coxarthrosis cases had more incidences of pm (+) than the unilateral ones. Moreover, 75% of the cases of bilateral Chiari osteotomy showed pm (+) .
Unilateral Chiari osteotomy for coxarthrosis in the advanced or terminal stage showed relatively good results. With pm (-) joints there were also good results, whereas with pm (+) joints there were worse ones. The factors which cause pm (+) through remodeling after asteotomy are still obscure except in cases of bilateral coxarthrosis and when the patient is over 60 years old.
