[Calcaneal Z osteotomy for correction of subtalar hindfoot varus deformity].

OBJECTIVE: Joint-preserving correction of mild and moderate hindfoot varus deformities by Z-shaped calcaneal osteotomy. INDICATIONS: Mild and moderate subtalar varus deformities in conditions like cavovarus or equinovarus foot deformity, peroneal tendon rupture, malpositioned tarsal fusion, after ankle arthroplasty. CONTRAINDICATIONS: Supramalleolar varus deformities, ankle instability with talar tilting, varus arthritis of the ankle joint, severe subtalar arthritis, and complete loss of peroneal muscle function that should be treated by fusions. SURGICAL TECHNIQUE: Lateral curved incision at the tuber calcanei with exposure of the lateral calcaneal wall. Z-shaped osteotomy of the calcaneal bone with lateral displacement and rotation in the transversal plane of the tuber fragment combined with lateral wedge resection for frontal plane correction. Fixation of the osteotomy with K-wires or screws. In case of extended correction, prophylactic tarsal tunnel release is advisable. POSTOPERATIVE MANAGEMENT: Cast without weight-bearing for 4 weeks. After removal of K-wires, 4 weeks with partial weight-bearing in a walker. In case of screw fixation, time of immobilization and nonweight-bearing can be shortened.
RESULTS: Since 2009, 20 cases have been performed in the described technique by the author. In addition, all patients had simultaneous bony and soft tissue surgery. Residual deformity or overcorrection, delayed bony healing or tibial nerve damage were not observed. No patient has undergone revision surgery.