Objective. To assess inter-expert agreement among spine surgeons having different levels of clinical experience when working with the AOSpine classification (TLCS, 2013). Materials and Methods. The study involved nine surgeons divided into three equal groups depending on work experience. All respondents were asked to classify the MSCT data of 50 patients with acute injuries to the thoracic and lumbar spine pursuant to TLCS (2013) classification. To evaluate inter-expert agreement, a Kappa coefficient interpreted according to Landis-Koch criteria was used. Results. The overall coefficient of inter-expert agreement for all observations among all groups of respondents was 0.43, which reflects a moderate level of agreement. Moderate inter-expert agreement was revealed for injury types A (0.45) and C (0.56), and satisfactory-for type B (0.34). The highest levels of agreement were obtained for subtypes A1 (0.67) and A4 (0.80) in the group of advanced specialists and for type C (0.70) in the group of specialists with a basic level of experience. Conclusion. The study demonstrated predominantly moderate level of inter-expert agreement when working with the AOSpine classification (TLCS, 2013). The accuracy of its use increases with a gain in practical experience of a surgeon.

Introduction. Every year, there is an increase in the number of operations performed using personalized cranioplasts, which are made with additive 3D printing technologies. They allow surgical intervention, taking into account the characteristics of the shape of the patient's skull. This is especially important when closing large and complex defects extending from the cranial vault to the bones of the facial skeleton. One of the innovative applications of additive technologies in cranioplasty is the creation of implants, preformed based on individual 3D-printed models. However, no preliminary estimates of the results of treatment of patients using the traditional methods of cranial implants and individualized modeling methods were found in the available literary sources.The study objective is to compare the results of treatment using cranioplasts, preformed based on individual 3D-printed skull models and using traditional intraoperative modeling.Materials and methods. A study of 50 patients with post-craniotomy defects of the skull. All patients have undergone cranioplasty. Depending on the technique of individualization of the cranial implants, patients were divided into 2 groups: 1st - using individual 3D-printed models (n = 32), 2nd - traditional intraoperative modeling (n = 18).Results. Statistically, the groups differed significantly in terms of the duration of the intraoperative stage of cranioplasty, postoperative and total hospital stay, indicators of symmetry and financial costs. No differences were found in the duration of the preoperative hospital stay, the number of implant fixation points, the volume of intraoperative blood loss and the quality of life according to the SF-36. The first group (6.25 %) in comparison with the second (16.7 %) had a smaller number of postoperative complications.Conclusion. Modern 3D printing technologies recreate bone models based on patients' individual characteristics, thereby providing time for careful planning of the operation, even at the outpatient stage. The results of the study showed that the usage of cranioplasts preformed with 3D-printed models provides precise closure of post-craniotomy defects, better restoration of the skull contours, and a significant reduction in the duration of the cranioplasty stage. The use of the technology does not lead to a significant increase in the cost of treatment using traditional intraoperative modeling.