2010 年 29 巻 2 号 p. 189-200
Background: Chiari pelvic osteotomy (Chiari osteotomy) and rotational acetabular osteotomy (RAO) have been commonly performed for osteoarthritis of the hip secondary to acetabular dysplasia. However, the articular morphology obtained immediately after surgery cannot necessarily be maintained: various types of remodeling are considered to contribute to a stable clinical result in the long term. The authors examined such remodeling 10 years postoperatively based on radiographic changes in patients who had undergone these surgeries.
Methods: Between 1976 and 1996, Chiari osteotomy or RAO alone was performed at our institution (Chiari osteotomy: 75 joints, RAO; 124 joints). Patients were divided into two groups based on the presence or absence of joint space narrowing at 10 years postoperatively, and comparative assessment was made between the group with joint space narrowing and the group without narrowing.
Results: Osteophyte formation after Chiari osteotomy and RAO tended to be found in the subgroup with joint space narrowing. Extension of the osteosclerotic area in the acetabular load-bearing area after Chiari osteotomy and RAO was found more frequently in the subgroup without joint space narrowing. After RAO, the postoperative acetabular cartilage angle (AC angle) tended to be smaller in cases without medial extension of the osteosclerotic area of the acetabular fragment.
Conclusion: Both Chiari osteotomy and RAO for the treatment of prearthritis and early type osteoarthritis of the hip achieved favorable results. Due to differences in the surgical techniques involved, postoperative remodeling was also different. It seems that important findings for favorable postoperative joint remodeling are lateral extension of the osteosclerotic area for Chiari osteotomy and medial extension of the osteosclerotic area for RAO. Among the radiological parameters, the postoperative AC angle is likely to be an important index for the progression of arthritis and joint remodeling.
