Risk Factors of Arthropathy Change of the Lateral Side of Subtalar Joint After Calcaneal Fracture Surgery

CATEGORY: Hindfoot, Trauma INTRODUCTION/PURPOSE: As a result of arthropathy change on the lateral side of subtalar joint after intra-articular calcaneal fracture, the secondary disorders such as pain or restricted range of motion occasionally occur. The purpose of this study is to examine factors that cause such arthropathy change. METHODS: We divided 23 joints into two groups according to arthropathy change of the lateral side of subtalar joint: the existence of such arthropathy (O) group included 8 joints, the absence of arthropathy (N) group included 15 joints. The patients’ mean age at the time of surgery were 49.1 years and 54.9 years respectively, and the mean follow-up period were 16.1 months and 12.4 months respectively. The anterolateral approach or the sinus tarsi approach was used for both groups, and the medial approach was combined as needed. The fixing materials were a plate or screws, and in some cases, staples and Kirschner wires were used in combination. We assessed Sanders classification, postoperative clinical evaluation using Creighton-Nebraska scale, and the width, height and dislocation of subtalar joint surface of calcaneus. RESULTS: The breakdown of the Sanders classification is as follows: N group consists of 3 joints of type 2A, 7 of type 2B, 3 of type 2C, 1 of type 3BC, 1 of type 4. O group consists of 5 joints of type 2A, 2 of type 2B, 1 of type 2C. The proportion occupied by Sanders classification type 2A in O group was larger than in N group. The average of the postoperative clinical evaluation was 94.9points in N group, 86.9points in O group. In postoperative image evaluation, the mean width in the was 106.2% in N group, 117.1% in O group, the mean dislocation of the subtalar joint surface was 0.4 mm in N group and 1.1 mm in O group. CONCLUSION: It was suggested that Sanders type 2A and the residual dislocation of the subtalar joint surface may be a cause of arthropathy change on the lateral side of subtalar joint.