Upper tibial coronal plane - oblique osteotomy for deformity correction in Blount's disease

ABSTRACT

Correction of tibia vara deformity entails correction of varus and internal rotation deformities. In small children, the use of internal fixation is not desirable to avoid physeal violation; also, external fixator may not be applicable. Then, the osteotomy should be inherently stable, corrects all elements of deformity and allows post-operative adjustments of position. Oblique osteotomy has been described to perform varus derotation of the proximal femur and to correct varus internal rotation of the tibia in Blount's disease. The present study included 16 children. In ten patients the deformity was bilateral and it was unilateral in the other six patients, with a total of 26 tibiae. The youngest child was three years old and the oldest was 12 years old. The procedure included coronal plane oblique osteotomy starting distal to the tibial tubercle and runs up to the posterior tibial metaphysis just distal to the epiphyseal plate. A single fixation screw was used for limited internal fixation in the sagittal plane to allow post-operative position correction by cast wedging. All osteotomies healed within 12 weeks. The deformities were corrected with ten degrees of over-correction of varus deformity. In two patients post-operative weakness of extensor hallucis longus occurred which resolved within one week. Upper tibial oblique osteotomy in the coronal plane has the advantages of correction of all deformity elements with minimal internal fixation, at the same time allows post-operative adjustments which are desirable in small children