Introduction
It is inappropriate to divorce one portion of the anatomy from the total organism afflicted with Cerebral Palsy. Locomotion, the primary function of the lower extremity is never independent from the rest of the patient either from mechanical or physiological point of view. For our purposes, however, we shall confine ourselves primarily to this area for the discussion and then an attempt will be made to relate between principal articulations of the lower extremity.
(1) Pat ho kinetics
(1) Characteristic deformity of the lower extremities in Cerebral palsy are adducted, internally located and flexed hips, the flexed knees, the equinus varus and calcaneal valgus feet. The eqinus varus is associated with the genu valgum flexum. According to Lowman deformities of the different joints are linked
together in the function and form kinetic, chain. That is a system in which a number of articulations cooperate and mutually influence each other under the effect of gravity or under stress.
(2) The foot and ankle in relation to the knee.
The spastic equinus throws the line of gravity forward and thereby increases the tension of the calf muscles.
The line of gravity shifts until it falls into the ball of the foot. This position greatly increase the tension in the quadriceps muscle group and the knee joint is firmly held in extension. As long as the line of gravity falls in front of the knee joint axis the tension of the quadriceps is relaxed because of gravity acts as an extensor of the knee. At the same time we see that the trunk bent forward, so that the hip is in flexion. This again puts more tension on the extensors of the hip consequently This situation results Innervational overload of, the triceps and the gluteus maximus. This position is a laborious one and both lateral and the anterior posterior
balance is jeopardized. Spastic calcaneal valgus, however, contrarily heel-cord is lengthened the
line of gravity is now moved backward and the caif group is relieved of tension. Quadriceps on the other hand improves its intention. Likewise, since the body is thrown backward in the hip joint the tension, gluteals would be found diminished, while the flexors of the hip is increased.
(3) Varus and valgus in relation to internal
and external rotation of tibia Equinus with varus deformity causes and external rotation of
that will respond to the abnormal Babinsk
reflex and a triple flexor response as an active dorsiflexor and will also counteract the equinus of these patients resulting in an improved gait. The Grice subtalar extra-articular arthrodesis has been the past procedure recommended for permanent correction of the valgus deformity in the mobile foot. Grice himself used his technique in cerebral palsy. Baker in 1967 introduced his posterior calcaneal osteotomy as an anternative procedure of the subtalar arthrodesis. Duyer has been the leading surgeon of calcaneal osteotomy during the past ten years. He first used it in treatment of pes cavus and then for correction of valgus and varus deformity of the foot. Baker also reported horizontal osteotomy to the base of the posterior articular process of the calcaneus with lateral wedge graft performed in 72 children, mostly in spastic feet and obtained a satisfactory
correction of the undesirable widening of the lateral part of the subtalar joint. Another form of subtalar stabilization operation was reported by Austin Brown in Brighton, England in 1968. They. gave the credit to Batchlor who first suggested the operation in 1933. According to Brown this procedure was indicated in young age group proferably under the age of 11 years. It was, however, noted two cases out of twenty were complicated by fracture of the fibular graft. For a fixed foot deformity in adults or older children there is no substitute for triple arthrodesis. With early attention to the foot inbalance this major surgery may well be escaped.
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