Introduction: This study evaluated the clinical and radiological outcomes of Chiari osteotomy for severe coxa irregularis and subluxation of the femoral head.

Materials and Methods: The study group included patients with late Legg-Calvé-Perthes disease (6 patients), posttraumatic avascular necrosis (1 patient), and multiple epiphyseal dysplasia (1 patient). The mean age at surgery was 11.4 years (range, 6.8 to 14.7). The clinical parameters evaluated included changes in pain, limp, and range of motion of the hip. Radiographic measurements were made to determine the width of the medial and superior joint spaces, acetabular coverage, lateral epiphyseal extrusion, and the Stulberg classification.

Results: At a mean follow-up of 5 years (range, 1.1 to 11.0 years), pain disappeared completely in 5 patients or markedly decreased, enough to complete normal daily physical activities, in the remaining 3 patients. Limping gait disappeared completely in 2 patients, but the remaining 6 patients had minimal limps. All the components of the range of hip motion increased significantly. Acetabular coverage averaged 55% (range, 33 to 87%) before operation and 88% (range, 79 to 97%) at the final follow-up. Lateral epiphyseal extrusion was 49% (range, 39 to 83%) before operation, and 18% (range, 8 to 40%) at the final follow-up. Joint spaces were not changed significantly after surgery.

Discussion: In conclusion, Chiari osteotomy has its own indications, as a salvage procedure, for older children and adolescents with subluxated, severe coxa irregularis. The current study confirms the efficacy of the operation in terms of the functional and radiological improvements.

Introduction: The authors introduce a modified technique of iliac splitting and expanding shelf (ISES) arthroplasty for severe LCPD, and report on the intermediate outcomes.

Materials and Methods: This new procedure is a modification of the previously reported tectoplasty of Saito (1986) and the shelf arthroplasty of Catterall (1992). Only the sartorius muscle and the indirect head of the rectus femoris muscle are detached, leaving the abductors intact. A superiorly hinged bony flap was raised from the lateral iliac wall just above the hip joint capsule. A corticocancellous bone plate was harvested from the inner table of the iliac wing, and was placed between the lateral hip joint capsule and the bony flap. The triangular space between the split iliac wall and the bone plate was packed with autogenous cancellous bone chips and Osteoset® (Wright-Medical, Arlington, Tennessee, USA). The repaired indirect head of the rectus femoris muscle gave stability to the shelf. After 4 weeks in a Petrie cast, the hip was mobilized, and partial weight bearing was started postoperative at 6 weeks. Twenty one hips in 21 children older than 8 years presenting with early (18 hips) and late (reossification) (3 hips) LCPD were treated by ISES arthroplasty. All patients were followed up for more than 2 years (range, 2 to 8.5 years).

Results: There were significant functional and radiological improvements after operation. One patient needed a secondary varus osteotomy to solve persistent subluxation. The poorest result occurred in a very obese child, presenting with early stage of Catterall IV involvement at age 11.5 years.

Discussion: Our modified technique of the shelf arthroplasty, sparing the abductor mechanism, appears to be a reliable and effective method to augment the superolateral coverage of the femoral head in severe LCPD.

Introduction: In severe Legg-Calve-Perthes (LCPD) disease with subluxated femoral head, the acetabulum sometimes takes a bicompartmental appearance. This study analyzed acetabular pathoanatomy using a 3-D CT program.

Materials and Methods: A 3-D CT software program that affords the section of 2-D image in any plane was used to analyze the acetabular pathoanatomy, with specific reference to the morphology of the inner surface of the acetabulum. Thirteen children with the bicompartmental acetabulae (12 LCPD and 1 AVN subsequent to septic hip arthritis) were evaluated.

Results: The anterior half of the acetabulum was concentric. The contour of the acetabular margin in the posterior half of the acetabulum consisted of two different arcs – an arc of the iliac acetabulum (superior) and the other arc of the acetabular fossa of the ischium (medial). The junction of these two arcs was located at the triradiate cartilage, which was increased in mediolateral thickness at this point. The osteochondral articular margin of the ischium posterior to the non-articular acetabular fossa was thickened forming a ridge. The mediolateral thickness of the non-articular acetabular fossa was thinner than that of the normal contralateral side. The combination of these focal morphologic changes of the acetabular fossa rendered the bicompartmental appearance on plain AP radiograph of the pelvis.

Discussion: The authors conclude that bicompartmentalization of the acetabulum apparently reflects the altered biomechanics of the hip joint due to the subluxated femoral head. The abnormal osteocartilaginous hypertrophy appears to be caused by synovial irritation and an eccentric molding effect of the subluxated femoral head.