Classification of screw malpositions in instrumental fixation of spinal deformities

Objective. To perform a non-systematic review of classifications of screw malpositions in transpedicular fixation of thoracic and lumbar spine deformities and to develop a tactical classification of screw malpositions in instrumental fixation of scoliotic deformities of the spine with a consensus assessment (kappa coefficient). Material and Methods. A search of studies was conducted in the Pubmed, eLibrary, and Google databases that evaluated the location of screws using or justifying the classification. Given the narrow specificity of the topic, publications of any design were included in the sample. Based on the data obtained, the authors proposed a tactical classification of screw malpositions in instrumental fixation of scoliotic deformities of the spine with an assessment of expert agreement using the Cohen’s kappa coefficient. Results. A total of 139 articles were found in the databases, including 21 articles from references. Of them, 66 articles did not correspond to the topic of the study, 12 – did not have the open-text access, and 85 – had open-text access. Twenty articles met the inclusion criteria. The analysis showed that classifications used mainly determine the displacement of screws into the lumen of the spinal canal without taking into account clinical manifestations and treatment tactics. Five classifications have been proposed to assess the position of screws in scoliosis, while only one determines the tactics of patient management based on a score assessment. Conclusion. An objectified method for assessing the accuracy of screw position is needed to provide additional evidence of the safety of malpositions and to determine the clinical significance of malpositions, risk factors associated with incorrect installation, and further actions of the surgeon.