Fibrous lesion of the distal femur associated with angular deformity

Unilateral femoral angulation is uncommon. We describe two children with un ilateral progressive distal femoral varus and limb-length discrepancy. Thes e deformities were associated with a fibrous lesion involving the medial as pect of the distal femoral metaphysis. Both patients were 15 to 16 months o ld. In both, the deformity was progressive, resulting in excisional biopsy and osteotomy. The gross and microscopic appearance of both lesions was sim ilar, and the histology was dense fibrous connective tissue. The patients' femoral alignment was maintained at follow-up of a minimum of 16-36 months. The etiology of these lesions is unknown; they are associated with progres sive deformity and appear to respond well to surgical intervention.