Split tibialis posterior tendon transfer with concomitant distal tibial derotational osteotomy in children with cerebral palsy.

Fifteen lower extremities with a spastic equinovarus foot deformity associated with internal tibial torsion were identified. Each lower extremity underwent a split tibialis posterior tendon transfer combined with a distal tibial derotational osteotomy. The medical record of each patient was reviewed retrospectively. We paid particular attention to clinic visits, gait analyses, and surgical procedures performed. These patients were followed up for an average of 4 years and 5 months after surgery. Twenty-seven percent had an excellent result, 13% developed a rigid equinovarus deformity, and 40% developed a severe planovalgus deformity. Eight of the 15 lower extremities required further corrective surgery because their resultant deformities limited their ambulation, was painful, or both. The combination of a split tibialis posterior tendon transfer with a distal tibial derotational osteotomy increases the difficulty of balancing the muscle forces across the spastic equinovarus foot, increasing the likelihood that overcorrection and a planovalgus deformity will develop.