[Total ankle arthroplasty with simultaneous subtalar fusion]. / Endoprothese des oberen Sprunggelenks mit simultaner Subtalararthrodese.

OBJECTIVE: Pain free weight bearing ability with orthograde hindfoot position and preserved tibiotalar motion. INDICATIONS: Symptomatic arthritis of the ankle and subtalar joint, additional subtalar hindfoot malalignment. CONTRAINDICATIONS: Absolute: acute infection, noncorrectable ligamentous instability or bony defects, restricted perfusion, diabetic foot syndrome. Relative: inability to comply with postoperative partial weight bearing, only moderate symptoms of subtalar arthritis, smoking, intricate soft tissue situation. SURGICAL TECHNIQUE: Lateral approach to the subtalar joint. Removal of residual cartilage. The joint surfaces are deeply feathered while preserving anatomic congruency. Now tibia and talus are prepared for implantation of a total ankle arthroplasty via an anterior approach. With trial implants in the ankle joint, hindfoot position is evaluated and, if necessary, corrected. Definite fixation of the subtalar joint with 5-10° valgus by one or more compression screws. Final check of ligamentous balance of the ankle and implantation of the definite components. POSTOPERATIVE MANAGEMENT: Immobilization in a cast for 1 week, then removable walker boot for another 5 weeks with partial weight bearing (15 kg) and mobilization in the sagittal plane under physiotherapeutic instruction. With radiologic proof of consolidation weight bearing can be allowed after 6 weeks, with cortical iliac crest bone graft after 8 weeks. RESULTS: From 1998-2016, 41 total ankle replacements with simultaneous isolated subtalar fusion were performed. The consolidation rate was 92.6%. The mean AOFAS Ankle-Hindfoot Score rose from 51.6 preoperatively to 79.7 one year postoperatively. The mean total range of motion (ROM) was 32.3° (range 14-50°) one year after surgery.