The Chiari pelvic sliding osteotomy.

The Chiari pelvic osteotomy deserves better than the rather damning description of "salvage procedure." Although it cannot be regarded as a physiologic reconstructive procedure because hyaline articular cartilage is not brought over the femoral head, it nvertheless has unique advantages and specific indications. The procedure is entirely extra-articular, and the tissue (largely new bone) that forms between the displaced ilium above and the capsule of the joint below has the capability of adapting to irregularities in the femoral head. This provides the operation with flexibility of application and it may be used when acetabular rotation procedures are contraindicated. It is most effective in containing coxa magna and the moderately distorted, exposed femoral head. Because it success does not depend upon the shape of the acetabulum, it finds a further important role in containing the femoral head in conditions of acetabular dysplasia. The Chiari pelvic osteotomy must be performed accurately and with due care. When applied correctly, it has specific and important roles in the management of many difficult conditions of the hip joint.