Chiari pelvic osteotomy

Chiari pelvic osteotomy

1. Chiari Pelvic O steotomy Khalid Bakarman, MD KKUH 20 th sept 2014

2. Chiari osteotomy It was described in 1955 . It is a stable ( shelf ) procedure It produces a bony platform above the femoral head ,with capsular fibro cartilage metaplasia interpostion,by displacing the distal pelvic fragment after osteotomy of the pelvic isthmus

3. indication Incongruous hip & femoral head coverage cannot be achieved by other methods of reconstruction. Femoral head is irregular or cannot be centered in the acetabulum by Abduction/IR. Painful subluxated hip CEA is less than -10 degress Age >8 years

4. Contraindication Late OA hip joint Sufficient proximal migration of femoral head ,which would preclude an appropriate level of osteotomy. Inability to cover 80%of the femoral head

5. Preoperative planning An oblique osteotomy in a proximal &medial direction start at the lateral margin of the dysplastic acetabulum . Avoid starting either too proximal or too distal osteotomy level. Avoid posterior displacement of the distal osteotomy fragment by curve other than horizontal osteotomy cut. Avoid medial displacement > 50% of iliac bone b.c that will reduces the contact area of osteotomy

6. Operative Technique An image –translucent operated table,free leg. Fluoroscopic imaging Smith –Peterson approach. 2.5 mm S P at sup –lateral acetabular edage.and direct 10degree to the transverse plane of the pelvis. After osteotomy push the distal fragment medially manually or by abduction ,50% displacement is adequate ,to obtain 80% FHC.

7. Large cannulated screw or large threaded SP. Skin traction of few days ,TWB for 6 weeks PT after 6 weeks

8. Complications Sciatic nerve injury . Superior Gluteal nerve and artery . High level osteotomy . Low level osteotomy .