Perioperative and early complications of extended instrumental fixation for spinal deformity in children: what does the application of the Clavien – Dindo classification reveal and what questions does it raise?

Objective. To analyze complications of extended posterior instrumental fixation for spinal deformity in children in accordance with the Clavien – Dindo classification and to assess its information content and limitations. Material and Methods. A retrospective single-center cohort study included 136 patients aged from 1 year to 17 years 11 months consecutively operated in 2020–2023 for thoracic and lumbar spine deformities associated with congenital, neuromuscular, syndromic, idiopathic scoliosis and Scheuermann’s kyphosis. At least four spinal motion segments were included in the zone of posterior instrumental fixation. All perioperative events and postoperative complications noted in the medical records were registered in accordance with the Clavien – Dindo classification. An analysis of factors influencing the development of complications of grade IIIB and higher was carried out. Results. With a total apparent high number of complications/events (55 or 40.4 % of the number of operations), the vast majority of them correspond to grade I–II (41; 30.1 %) and do not affect the tactics and outcome of treatment. Complications of grade III and IV were noted in 13 (9.6 %) cases, and of grade V – in 1 (0.7 %) case. The influence of deformity etiology, gender, age or underweight on the risk of grade IIIB and IVA complications was not revealed, which may be due to the limited number of observations. The installation of more than 18 transpedicular screws, which correlated with surgery duration and blood loss volume, was significant for the development of such complications. The results obtained were compared with those presented in the literature, the information content and limitations of the use of the Clavien – Dindo classification in spine surgery were discussed. Conclusion. A significant part of the complications of spinal deformity correction in children is conventionally not taken into account in domestic practice and, accordingly, cannot be prevented. The use of the Clavien – Dindo classification allows estimating the frequency of complications that potentially do not affect (grade I–II) and affect (grade III–IV) the tactics of postoperative treatment and outcomes. The installation of 18 or more supporting elements of instrumentation is directly related to surgery duration, intraoperative blood loss volume and the risk of developing grade IIIB and IVA complications. Larger data sets are needed for a more objective analysis of the risk of severe complications for each nosology.