Abstract
The assortment of primary operative techniques starts with posterior release and ends with the most sophisticated ones such as complete subtalar release. The proper selection of one of them is a key to success and has to be done on the basis of clinical and radiographic parameters.
Posterior release: The indication for this procedure is determined by persistent equinus. On AP and lateral radiographs the normal talocalcaneal angle is visible AP greater than 20; lateral greater than 35 degrees). On the lateral radiograph in corrected equinus or standing, the angle between the calcaneus and tibia should be smaller than 80 degrees. A physical examination con- firms equinus position more precisely. Attention should be paid to the possibility of iatrogenic rocker bottom deformity. In such cases posterior release should be combined with dorsal release of the calcaneocuboid and talonavicular joint.
Posteromedial release: Clinical indications for this procedure are hindfoot equinus and varus and passively corrected medial spin measured with a bimalleolar angle less than 85 degrees. This angle should be checked during surgery when the posteromedial release is completed. If overcorrection is not achieved, the procedure has to be extended in sequence to lateral release or complete subtalar release. Radiographic indications are as follows: diminished talocalcaneal angle on AP (less than 20 degrees) and/or on lateral radiographs (less than 35 degrees), as well as partial overlap of the talus and calcaneus on AP radiographs.
Posteromedial-lateral, posterolateral-medial and partial subtalar release: Indications for these techniques are the same as for posteromedial release. The difference concerns the not corrigible medial spin. The decision about which technique should be used is made before surgery, but its conversion during surgery to another one is possible and depends on obstacles appearing during release. Intraoperative radiographs may help in making the decision.
Complete subtalar release: The clinical indication for this technique is primarily stiff varus and medial spin. The selection of this procedure may be the result of the primary decision or incomplete correction after less extensive procedures. To overcome the obstacles, the talocalcaneal interosseous ligament must be completely cut. Radiographic indications are the same as for posteromedial- lateral or partial subtalar release. Complete overlapping of the talus and calcaneus on AP radiograph inclines the surgeon to choose this method.
All techniques mentioned can be extended to the correction of forefoot adduction. A metatarsal first ray angle lower than 70 degrees is indicated for correction. For small children, the opening of the cuneonavicular and first cuneometatarsal joint with a slight transposition of the tibialis anterior is preferred. In older children, open wedge osteotomy of the medial cuneiform is done. For correction of calcaneocuboid displacement, no open reduction is performed even if a +2 displacement of the cuboid is seen on AP radiograph, because self-existent reduction occurred. However, closed stabilisation of this joint by K-wire is performed. A stable subtalar complex can be rotated as a block during partial or complete subtalar release.
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.
