Chiari osteotomy of the pelvis: a long-term study.

We evaluated 104 osteotomies of the pelvis after an average of 18 years: 48% of patients had hip joint pain, 15% had low back pain, 41% had restricted movement, 74% had a positive Trendelenburg sign, and 77% had limb length discrepancy greater than 1 cm. We also followed the anti-Chiari effect, the influence of the osteotomy on narrowing the birth canal, and deterioration of the opposite acetabulum. We showed that the optimum indications for Chiari osteotomy are severe instability of the hip joint and an irregular femoral head.