INTRAMEDULLARY FIXATION FOLLOWING DIAPHYSEAL DEROTATIONAL OSTEOTOMY IN CHILDREN – A PRELIMINARY REPORT.

Abstract

Aim: To report the clinical and radiological outcome of intramedullary fixation following corrective femoral diaphyseal derotational osteotomy, particularly in children with cerebral palsy.

Methods: We conducted a retrospective study of all femoral diaphyseal derotational osteotomies with Trigen antegrade intramedullary fixation (TAN system, Smith & Nephew) from April 2005 to June 2006. There were 9 patients with 14 affected limbs. The diagnosis was spastic diplegia in 8 of the 9 children, of whom 5 underwent the osteotomy as part of multilevel surgery.

Results: The mean age at surgery was 13.7 years (Range 11.2 – 17.3 years). The mean preoperative femoral anteversion was 43.6 degrees (Range 30 – 50 degrees) with the mean internal & external rotation being 61.6 (Range 50 – 70) & 8.3 (Range 0 – 20) degrees respectively. The average follow-up period was 9.5 months (Range 1.5 – 15 months). All patients mobilised with crutches in an average of 5 days (Range 3 – 12 days) and full weight bearing was achieved by 65 days (Range 45 – 150 days). Marked improvement in gait was noted in all children with postoperative mean internal & external rotation being 42.9 & 52.6 degrees respectively. There have been no instances of avascular necrosis or postoperative complications to date. Correction was maintained at the final follow up in all children with good bony union by 8 – 12 weeks.

Conclusion: The key to the success of femoral derotational osteotomy for correction of excessive femoral anteversion in children lies in achieving correction and early mobilisation. Intramedullary fixation following diaphyseal derotational osteotomy in children is a safe, effective, cosmetic and reliable procedure with rapid bony union, attributable to biological fixation and early mobilisation. Good early results have been obtained in children with cerebral palsy undergoing this procedure as a part of multilevel corrective surgery.