Effect of Intraoperative Three-Dimensional Imaging During the Reduction and Fixation of Displaced Calcaneal Fractures on Articular Congruence and Implant Fixation

Background: Operative treatment of displaced calcaneal fractures should restore joint congruence, but conventional fluoroscopy is unable to fully visualize the subtalar joint. We questioned whether intraoperative 3-dimensional (3D) imaging would aid in the reduction of calcaneal fractures, resulting in improved articular congruence and implant positioning. Method: Sixty-two displaced calcaneal fractures were operated on using standard fluoroscopic views. When the surgeon had achieved a satisfactory reduction, an intraoperative 3D scan was conducted, malreductions or implant imperfections were revised, the calcaneus was rescanned, and this sequence was repeated until the optimal operative result was achieved. Results: Five fractures underwent 1 intraoperative scan, 39 fractures underwent 2 scans, 13 fractures underwent 3 scans, and 5 fractures underwent 4 scans. The average number of scans was 2.3. Intraoperative scanning led to re-reduction and improvement of reduction in 13 fractures, change of plate position in 1 patient, optimizing of the screw directions in 5 fractures, and shortening of screws that were intra-articular or protruding medially in 6 fractures. The postoperative articular displacement was 0 mm in 69% of the Sanders type 2 fractures and 57% of the Sanders type 3 fractures. Operation duration averaged 118 minutes, and there were no reoperations due to misplaced screws or plates. The average absorbed radiation dose per patient was 288 mGy<bold>cm</bold>. Conclusion: Intraoperative 3D imaging improved the articular reduction of the posterior facet and secured optimal implant position in displaced calcaneal fractures. Radiation dose to the patient was less than that of a normal foot computed tomography scan. Level of Evidence: Level IV, case series.