- PreOp Planning: - knee deformities should be corrected prior to any forefoot fusions; - stability of talus in mortise is necessary for successful arthrodesis; - determine if flexibility of forefoot and hindfoot; - if foot can be reduced to a satisfactory position then an in situ type of arthrodesis may be considered; - if hindfoot deformity is fixed & cannot be brought back to good position, corrective type of triple arthrodesis will be necessary; - varus hindfoot will usually have a compensatory forefoot valgus w/ plantarflexed first ray; - look for cavus type deformity -
hammer toes may also be present; - dynamic hammer toe formation in cavus type of foot; - valgus hindfoot will usually be assoc w/ varus forefoot deformity to compensate, along with an abducted forefoot via hindfoot joint; - look for Achilles contracture w/ pronation deformity of the foot; - achilles tendon contracture is difficult to asses w/ fixed valgus deformity; - in the acquired flatfoot there may be an accentuation of midfoot collapse at midstance just prior to heel raise;
- PreOp Xrays: - standing AP radiograph of both ankles - look for calcaneovalgus impingement in acquire flatfoot as well as any valgus or varus deformities of ankle joint; - anatomic axis of tibia w/ ankle & hindfoot is evaluate; - standing lateral: - look for divergences of lateral talocalcaneal angle, & note "sag" sign of the foot at the talonavicular joint; - look for a stress frx of the fibula as a result of prolonged lateral impingment;
