Evaluation of the cavus foot for orthopedic treatment.

Each case of cavus and equinovarus foot must be thoroughly assessed prior to operation. Assessment includes diagnosis; electrodiagnostic and muscle testing; and evaluation of the type, location, and severity of the deformities and whether they are flexible or fixed. The vascular status must also be ascertained. The sites of plantar callus are noted, as well as the amount of correction that will be necessary. The integrity of the metatarsal fat pads must be noted. Muscle power is charted, and any sensory loss is mapped. Joints are evaluated clinically to determine the amount of fixed deformity and pain and roentgenographically to determine mainly the effect of prior surgical procedures, the presence of nonunion, and secondary osteoarthritic changes in noninvolved joints. Bone wedges are obtained proximal to any painful callus and should be taken from joints that are painful, stiff, arthritic, unstable, or functionless. Flexible and functional joints, e.g., the subtalar complex, should not be sacrificed for arthrodesis unless the cavus deformity is very severe or fusion is necessary to obtain necessary motors. Appropriate tendon transfers are usually done only after bony correction of fixed deformities but may also be used (along with soft tissue releases) to balance muscle power before deformities become fixed.