Keywords: توموگرافی انتشار تک فوتون; Diagnostics; Imaging; Tarsal fusion; Hindfoot; AOFAS; American Orthopaedic Foot and Ankle Score; AP; antero-posterior; CAOS; computer-assisted orthopaedic surgery; CT; computed tomography; FAOS; Foot and Ankle Outcome Score: FFI, Foot Function Index; Lat;