(See also: Acetabular Osteotomies)
- a acetabular osteotomy salvage procedure which is indicated in patients without a concentrically reducible hip;
- modified shelf osteotomy above acetabulum w/ medial displacement of acetabulum;
- distal fragment is displaced medially and upward as osteotomy hinges on the symphysis pubis;
- hip capsule is interposed between newly formed acetabular roof & femoral head;
- relies on periarticular soft tissue metaplasia for coverage;
- femoral head is placed beneath surface of bone & joint capsule & corrects pathologic lateral displacement of the femur;
- medialization will reduce the lever arm and will reduce joint loading;
- because the biomechanics of the hip are improved by displacing hip nearer the midline, a Trendelenburg limp is often elminated;
- clinical results are mixed & are affected by patient age & degree of DJD;
- for patients over 4 years of age;
- recommended in cases w/ inadequate femoral head coverage, w/ moderate dysplasia and moderate subluxation
- generally considered when other reconstructions are impossible;
- when femoral head cannot be centered adequately in acetabulum by abduction and internal rotation;
- symptomatic subluxated hips w/ early signs of OA;
- for dislocations that have been reduced but have later become subluxations;
- preoperative center-edge angle of at least minus 10 degrees are desirable selection criteria.
- complete obliteration of the joint space;
- labral tear:
- tear usually leads to a poor result;
- if torn labrum is found, it should be repaired or resected;
- arthrogram will rule out labral tear;
- bilateral Chiari osteotomies may be contraindicated in women because it may interfere with child rearing;
- labral tear:
- iliac osteotomy is angled from the sciatic notch to the ASIS (anterolateral distally to posteromedial proximally);
- avoid placing iliac buttress into a horizontal position since this will cause a persistently unstable joint laterally;
- following osteotomy, a triangular osseous defect anteriorly which is stabilized w/ curved plate of bone graft from iliac wing;
- inadequate stabilization of anterior defect will result in anterior instability;
- acetabulum is displaced medially;
- acetabulum is abducted into a more vertical & medial position and replaces it w/ joint capsule supported by osseous buttress of the iliac wing;
- distal (acetabular) fragment is displaced medially and adducted;
- proximal (iliac) fragment is not allowed to move laterally;
- inferior surface of proximal fragment forms roof over femoral head;
- partial weight-bearing for at least three months to allow for capsule metaplasia;
- this procedure will shorten the affected leg
- Extra-articular augmentation for residual hip dysplasia. Radiological assessment after Chiari osteotomies and shelf procedures.
- Modified Chiari pelvic osteotomy: a long-term follow-up study.
- Chiari osteotomy in the treatment of congenital dislocation and subluxation of the hip.
- Chiari osteotomy for congenital dislocation and subluxation of the hip. Results after 20 to 34 years follow-up.
- Preoperative and postoperative evaluations by means of three-dimensional computed tomography in cases of Chiari osteotomy.
- Biomechanical analysis of the Chiari pelvic osteotomy. Preserving hip abductor strength.
- Chiari pelvic osteotomy in children and young adults.
- Chiari pelvic osteotomy for osteoarthritis secondary to hip dysplasia: Indications and long term results.
- Chiari Pelvic Osteotomy for Advanced Osteoarthritis in Patients with Hip Dysplasia.