OSTEOPLASTY BLOCK FOR PRIMARY HIP OSTEOCHONDRITIS

Abstract

Purpose: The purpose of this work was to demonstrate the usefulness of osteoplasty block for the treatment of primary hip osteochondritis.

Material and methods: Eighteen children underwent surgery between 1992 and 2001. Mean age at diagnosis was eight years five months (5–13 years). Preoperatively, mean motion limitation was −25 in abduction and internal rotation. Radiologically the series included: Catterall II Herring B with signs of high-risk head (n=2), III B (n=7), III C (n=1), IV B (n=1), IV C (n=2), and sequelar stage (n=2). Mean excentration was 6.5 mm and mean lateral overhang was 10.2 mm. Surgery was indicated because of an aggravation of the excentration with revascularisation. An iliac graft was encrusted in a limbic rail and covered with rectus femoris tendon left continuous to provide elastic support. A bermuda cast was used for 17 children with immediate weight bearing for eleven. Hospital stay was 36 hours for all children.

Results: Sixteen children were reviewed at mean follow-up of three years two months. There were no complications. Clinically, there all patients were pain free, but three developed persistent limping. Ten had a moderate limitation of hip movement and three had severe joint stiffness. Radiologically, there was good head coverage in fifteen hips and joint congruency in fifteen, including eleven with concentric congruency. The intervention was considered useful for twelve children, and not useful for one who developed complete lysis of a poorly positioned graft. Usefulness was uncertain for three children, including the two with a sequelar-stage hip at diagnosis.

Discussion: Femoral osteotomy to correct the valgus and pelvic osteotomy to reorient or widen the acetabulum are effective treatments but have many disadvantages (limited abduction movement, leg length discrepancy, re-intervention to remove material). The excellent integration of the plasty block at mid term is a sign of effective head-acetabulum adaptation. Clinical and radiological results have been similar to those obtained with other methods. Joint stiffness and postoperative limping are observed in very severe cases. Joint prognosis depends on the severity of the disease.

Conclusion: This series of paediatric patients who have not yet reached bone maturity shows that the plasty block meets expectations for the treatment of early-stage primary hip osteochondritis. Treatment time is short and there are no complications.