Surgical treatment of kyphosis due to avascular osteonecrosis of the vertebral bodies

Abstract

Objective. To analyze the results of surgical treatment of patients with fixed spinal deformity due to osteonecrosis of the vertebral bodies of the thoracic and lumbar spine.Material and Methods. The data obtained from the case histories of 40 patients operated on for kyphosis due to osteonecrosis of the vertebral bodies were studied. The patients underwent staged surgical interventions in one surgical session. Demographic data and radiological results of surgical treatment before surgery, after surgery and up to 1 year after surgery were assessed.Results. As a result of surgical interventions, local kyphosis was corrected on average from 30° to -0.25°. After correction of kyphosis, statistically significant changes in the sagittal curves of the spine were revealed: an increase in thoracic kyphosis and a decrease in lumbar lordosis. There was an improvement in sagittal balance indicators in the form of a regression in the number of imbalanced patients – 17 (42.5 %) patients improved balance indicators. During the follow-up period, a statistically significant improvement in VAS and ODI scores was noted. Intra- and postoperative complications accounted for 35 %, and 8 (20 %) mechanical complications were identified during dynamic observation. Predictors of mechanical complications were the presence of imbalance: 2 and 3 points according to the balance modifier of the Formica classification and the GT index (global angle) > 7°, and insufficient correction of kyphosis (LK postOp > 4°), T-score index < -3.35.Conclusion. Simultaneous staged surgical interventions allow for complete correction of the deformity, restoration of the sagittal profile, thereby improvement of the patient’s quality of life. To reduce mechanical complications when planning and performing surgical intervention, it is necessary to take into account the identified predictors.