Surgical treatment of posttraumatic kyphosis of the lumbar spine: compensatory changes and dynamics of sagittal balance

Objective. To analyze clinical and radiological results of staged surgical interventions in the treatment of patients with posttraumatic kyphosis of the lumbar spine and to identify a mechanism of deformity compensation. Material and Methods. The data obtained from the case histories of 42 patients operated on for clinically significant posttraumatic kyphosis at the L3 and L4 vertebral levels were studied. Patients underwent staged surgical interventions in one surgical session. Demographic data and radiological results of surgical treatment were evaluated. Results . As a result of surgical interventions, local kyphosis was corrected on average by 29.66° ± 13.83° from 15.48° ± 13.04° to-14.19° ± 8.85°. After correction of posttraumatic kyphosis, statistically significant changes in the parameters of sagittal curvatures of the spine were revealed: an increase in thoracic kyphosis (TK) and lumbar lordosis (LL), changes in the parameters of the spinopelvic balance PT and SS with a p-level < 0.05, as well as in the global angle (p < 0.001) were noted. According to the GAP scale, 26 (61.9 %) patientsmoved to a more balanced category. A correlation (r = 0.45; p < 0.05) was found between the indices of local kyphosis and the GAP scores before surgery. The total duration of all surgical stages was 318 [150; 600] minutes, and blood loss was 677 [150; 1800] ml. In 9 (21.4 %) patients, 12 intra- and postoperative complications were noted. Conclusion. The main compensatory mechanisms of posttraumatic deformities with the apex at L3 and L4 vertebrae are a decrease in thoracic kyphosis, the thoracolumbar lordosis and pelvic retroversion. Staged surgical treatment for posttraumatic spinal deformities significantly improves the parameters of the spinopelvic and global sagittal balance. It ameliorated the sagittal profile of patients in 61.9 % of cases and was accompanied by moderate duration of surgery and intraoperative blood loss and an acceptable number of complications.