Computed Tomography Image Analysis of the Fusion Site of Subtalar Arthrodesis for Traumatic Arthritis after a Displaced Intraarticular Calcaneal Fracture

Financial support: None. Conflict of interests: None. Purpose: The study examined the fusion site and characteristics of the subtalar arthrodesis after intraarticular calcaneal fractures using computed tomography. Materials and Methods: The clinical results and computed tomographic analysis of the fusion site were reviewed in 18 patients who were followed-up for a minimum of six months after undergoing subtalar arthrodesis due to traumatic arthritis caused by an intra-articular calcaneal fracture from December 2012 to April 2017. Results: An evaluation of clinical results after subtalar arthrodesis revealed statistically significant improvements. In all cases, arthritis was found in the injured articular surface, which was displaced superolaterally from the initial primary fracture line of the calcaneus. Six months after arthrodesis, the subtalar fusion rate was 80.0% (16/20). Of these, 14 cases had a cannulated screw inserted in the uninjured site that is medial to the primary fracture line. Joint fusion was observed on the uninjured articular surface in 17 cases (85.0%). Conclusion: Joint fusion was initially achieved at the uninjured posterior facet after subtalar arthrodesis due to traumatic arthritis caused by a displaced intra-articular calcaneal fracture. This suggests that meticulous surgical techniques and cannulated screw positioning at the uninjured site will promote joint fusion.