A PREOPERATIVE PLANNING METHOD FOR LONG TUBULAR BONE OSTEOSYNTHESIS

Abstract

Objective. To compare the shape and size of human contralateral humerus bones based on the «Autoplan» program to justify the possibility of using healthy bone in a preoperative planning for bone osteosynthesis (on the example of the humerus). Methods. 20 patients underwent computed tomography of the chest, shoulder girdleand upper extremities. Two-dimensional medical imaging of separate layers were converted into three-dimensional models of the humerus bone STL format, which is used for 3D printing in all 3D printers. Preliminary registration to superimpose the mirrored left humerus bone on the right one was carried out for at least 4 key points; their matching in shape and size was analyzed. A comparison was made of the contralateral humerus bones of one patient according to computed tomograms of 20 people. The main anatomical landmarks of the humerus bones and the distance between adjacent points were selected for comparison when the bones were superimposed on each other. Superimposed humeral bones were compared using the Hausdorff distance calculation algorithm, which is used to measure the difference between scanned models and the ground-truth model separately. To visualize the result of calculating of Hausdorff distance, that is, the difference between the bones, color mapping of the latter was performed, where the proximity to red color means the difference tends to zero, the proximity to blue - to 1 cm (the maximal obtained difference). Results. The greatest difference was recorded in humeral heads - up to 6.8 mm, and in the epicondyle: the medial epicondyle - up to 4.5 mm, the lateral epicondyle - up to 4.4 mm. Color mapping allowed to see that the difference between the heads of the humerus increases from the center of the articular surface to the attachment points of the capsule. At the level of the diaphysis, from the anatomical neck to the condyles, the size differencesamong allbones in 20 patients was no more than 1.5 mm. Conclusion. Thereby, the comparison of the shape and size of the contralateral bones of the human humerus based on the «Autoplan» program will allow applying a three-dimensional model of healthy contralateral bone in the preoperative planning for bone osteosynthesis: thus reducing the surgical risks and injury for the patient. What this paper adds For the first time, the use of a 3-dimensional model for a preoperative planning method for long tubular bone osteosynthesis using the contralateral healthy bone for affected bone has been proposed. It has been found that in the preoperative period during osteosynthesis of the diaphysis of long tubular bones, it is possible to use a healthy contralateral bone for plate of the damaged bone (on the example of the humerus fracture). The identity of the shape and size of the humerus diaphyses with an accuracy of 1.5 mm has been proved, and the possibility of using a 3-dimensional model of a healthy bone for preoperative planning for long tubular bone osteosynthesis is justified.