Abstract
Clubfoot is medically defined as luxatio pedis sub talo. The process of dislocation mostly caused by muscular imbalance results in bony deformities and soft tissue contractures, which in the majority of cases – even after meticulous conservative treatment – have to be corrected by surgery. In children before school age, surgical corrections should always address the main pathology. To achieve normal alignment of the fore and hindfoot, a complete reduction of the talus within the acetabulum pedis has to be done by soft tissue release.
Analysing the pathomorphology, a clubfoot is characterised by equinus, varus, forefoot adduction, and horizontal subtalar medial rotation. Regarding bony deformation, the medial side of the talus is narrowed by the navicular, the medial malleolus, and the fibrocartilage between. Growth expansion is limited on the medial side and there is more growth expansion on the lateral convex side, leading to external rotation of its body (~ 10-25°) and internal inclination of the neck (~30-50°). The calcaneus is internally rotated 20-30°.
Regarding joint dislocation, there is a displacement of the navicular medially and plantarward towards the medial malleolus. The cuboid bone usually follows the position of the navicular and dislocates gradually to the medial side.
Soft tissue contractures are located medially (Lacinate Lig., M. Add. hallucis, Spring Lig., talo navicular Lig., Master knot of Henry) and posterior (lat. fibulo calc. Lig, post. capsule of the ankle joint). There is also a shortening of muscles e.g. short plantar flexors, M. tib. post., M. flex. hall. longus., M. flex. digit. comm., M. tib. ant.
The method of treatment depends on the severity of a clubfoot, the preoperatively achieved results of conservative treatment, and how extensive a subtalar release has to be performed. If the navicular can be reduced conservatively, a posterolateral surgical approach is indicated.
A transversal incision is performed starting laterally at the calcaneal cuboid joint and ending medially below the medial malleolus. A dorso lateral release of the subtalar joint, Tendo Achilles lengthening, and dorsal release of the ankle joint is performed.
At the age of three to six months, it is possible to correct subtalar malalignment to move the calcaneus away from the fib. Malleolus by external rotation in relation to the talus (Mini Cincinnati technique). If the talonavicular and the calcaneo-cuboid joint are dislocated, a complete subtalar release has to be done in order to reduce the talo-navicular, calcaneo-cuboid and talo-calcaneal joint. To avoid overcorrection, the talo calcaneal interosseous lig. should be kept intact whenever possible (Mc Kay-Simons procedure). This type of surgery should not be performed before the age of six months.
The subtalar release technique described by McKay was introduced in our hospital in 1983. Since then, 362 clubfeet have been treated by the above-mentioned techniques: 249 by the Mini Cincinnati (Group 1) and 113 by the McKay-Simons procedure (Group 2). Age at the time of surgery ranged from 2 to 12 months in Group 1 and 5 to 52 months in Group 2.
In Group 1, the results were excellent in 42%, and good (residual forefoot adduction) in 49%. A second surgical intervention had to be done in only 9%. Regarding shape and appearance of the foot in Group 2, results were excellent in 46%, good in 38% and insufficient in 16% (overcorrection 3%, relapse 13 %). Concerning functional outcome, the feet of Group 2 presented much more stiffness than those of Group 1, which was also found pre-operatively.
The treatment of clubfoot is still a matter of controversy because of different severity of deformity and different treatment philosophies.
According to our experience, the McKay-Simons procedure has proved to be ideal for simultaneous correction of various components of the deformity from one single approach. In particular, correction of subtalar horizontal rotational deformity in the subtalar joint can be easily performed.
Based on the survey, the danger of damaging nerves, blood vessels, tendons and joint cartilages can be kept to a minimum by using the Cincinnati approach. In the majority of cases, the foot appears normal, moves without pain, and is flexible enough to enable the child to walk on his toes or heels and to participate in sportactivities.
Limitation of mobility is nevertheless the main problem of all extensive soft tissue procedures in clubfoot surgery, and it is not known at this time if this will cause subtalar osteoarthritis in early adulthood.
Complete subtalar release develops less osteonecrosis, fewer changes in the navicular, and less cavus and adductus than the use of other surgical techniques.
Overcorrection and poor functional results were seen in patients less than six months old at the time of surgery. We recommend that a complete subtalar release be delayed until the child is aged 6 to 12 months. Treatment should ideally be completed by the time the child is ready to walk.
The abstracts were prepared by David P. Davlin. Correspondence should be addressed to him at the Orthopedic Clinic Bulovka, Budínova 2, 18081 Prague 8, Czech Republic.
