Varus and valgus foot in cerebral palsy and its management.

Varus and valgus foot, often associated with equinus, are common problems in cerebral palsy. These deformities can interfere with standing or walking, aggravate shoe wear, and lead to painful calluses on pressure areas of the foot. The deformities are caused by a basic muscle imbalance. If the posterior or anterior tibial muscles are overactive, the foot will swing into varus. If the peroneal muscles predominate, the foot assumes a valgus position. However, the alignment of the hip and knee play an important role in the production of deformity. Correction of the deformity must be preceded by assessment of the deforming forces. In the younger child, simple muscle releases weaken the overpowering muscles and help restore muscle balance. In some instances, muscle transfers, either whole or split, not only alleviate the deforming force but also may provide needed support for the weaker muscles. Once bone deformities are established, they must be corrected either prior to or simultaneously with muscle procedures. The purposes of this article is to outline the evaluation of the deformity and the various soft tissue and bone operations which can be performed to correct them in order to obtain a satisfactory plantigrade foot.