The human foot is a highly complex structure. It has two major functions. To support the body in standing and progression; to lever it forwards in walking, running and jumping.
The human foot, alone among primates, is normally arched in its skeletal basis. Its medial margin arches up between the heel and the ball of the big toe, forming a visible and obvious medial longitudinal arch. Bony factors do not play a significant role in maintaining the stability of this arch. Ligaments are important, but are unable to maintain the arch entirely on their own.
Loss of the medial longitudinal arch of the foot; results in pes planus or flat foot deformity. The term is used to describe a mixture of anatomical variations and pathological conditions. In children and adolescents the most common disorders seen include flexible flatfoot, tarsal coalition, calcaneovalgus foot, accessory navicular bone and congenital vertical talus.
Flexible flatfoot in most cases is a physiological variant rather than a pathological condition. It occurs in all infants and is common in children and adolescent. Actually the medial longitudinal arch develops during the first decade of life. Many etiological factors contribute to flexible flatfoot, including familial tendency, generalized ligamentous laxity, obesity as will as shoe-wearing in early childhood. While the definit aetiology is unknown.
Diagnosis of flexible flatfoot should be based on careful clinical examination. The clinical examination includes assessment of the height of the medial longitudinal arch, tightnesss of heel cord, integrity of muscles, subtalar joint motion and the degree of flexibility. The x-ray is helpful for diagnosis of flexible flatfoot, various angles have been described for the measurement of flatfoot. The talo-meatarsal "Meary angle" must be measured in lateral weight-bearing plain radiograph.
Treatment should be reserved for patients who have problems as a
result of flatfoot. Shoe inserts have been proved to be ineffective in correction of the deformity but may relieve symptoms in some cases. Surgery is indicated when non-operative treatment fails to relieve symptoms. Surgical options include soft tissue reconstruction, that includes the following procedures. Tibialis anterior transfer into talus It has been utilized in selected symptomatic patients with severe talar declination and subluxation.. The tibialis anterior is transferred through the talus from dorsal lateral to planter medial for direct talar control, Flexor digitorum longus transfere through which a medial curved incision used for flexor digitorum longus transfere to the navicular through a tunnel and sutured to itself, Tendo Achilis lengthening that is used in patient with a tight heel cord despite a vigorous stretching program. Z plasty of the tight tendo achillis is always needed to bring the ankle to at least 10 to 15 degree of dorsiflexion, Spring ligament reconstruction When rupture is present repair with advancement may not be possible but reconstruction options are available. The peroneus longus tendon is rerouted to the medial aspect of the foot. The tendon is detached at the musculotendinous junction that remain attached distally. Once rerouted, it is secured to the planter medial aspect of the sustentaculum tali under tension, thus reconstructing the planter calcaneonavicular ligament.
Osteotomy which may be either, Evan's calcaneal osteotomy for treatment of calcaneovalgus deformity with lateral column lengthening using autogenous tibial cortical bone graft. Although autograft remains the standard choice of biomaterial, allogenic bone has also been used with success, Medial Displacement calcaneal osteotomy in which the osteotomy is done through the body of the os calcis, moving the proximal calcaneus medially and derotating it out of valgus and positions the contact portion of the heel more in line with the weight-bearing axis. The osteotomy elevates the medial arch, and centralizes the motion of the subtalar joint. This procedure is . indicated in patients who have excessive heel aversion without excessive abduction or varus of the forefoot. Arthrodesis, used in marked deformity associated with arthritis and/or fixed osseous deformity is best managed by arthrodesis. Talonavicular arthrodesis as an isolated procedure can-be used for an unstable talonavicular joint when the remainder of the foot is supple. It is best used in an older patient with low physical demands. It is important to place the subtalar joint in 5 degrees of valgus angulation at the time of fusion to preserve maximum motion in the hindfoot. A double arthrodesis involving the talonavicular joint and the calcaneocuboid joint is indicated in the younger patient with an unstable talonavicular joint but a stable subtalar joint. There is less morbidity than is associated with a triple arthrodesis, but the procedure offers the same stability. Isolated subtalar arthrodesis are indicated in the presence of a rigid or incompetent subtalar joint accompanied by a flexible forefoot and a stable talonavicular joint. It is an excellent alternative to a double arthrodesis, and when the heel is left in 5 degrees of valgus angulation, excellent motion of the foot is preserved. Calcaneocuboid distraction arthrodesis, this procedure fuses the calcaneus and the cuboid by excising the articular cartilage from the joint and inserting a bone graft into the prepared joint. This lengthens the lateral column and creates a solid fusion between the calcaneus and the cuboid. Arthroereisis is the name for stabilization of the subtalar joint by an implant. The implant can be constructed by a variety of materials, and its purpose is to hold the talus in proper alignment with the calcaneus so this corrects the planter-flexed posture the talus assumed in flexible pes planus. The procedure usually is done in young children. Complications of arthroereisis include peroneal spastic flatfoot, stiffness of the subtalar joint, and foreign body reaction. |
