No abstract

Patients with severe adolescent idiopathic scoliosis (AIS) require instrumented spinal fusion surgery. The range of instrumented vertebra is still questioned, especially the selection of the lowest instrumented vertebra (LIV). This single institution retrospective consecutive study is to provide real-world data on outcomes. The study aims to assess whether bending films can determine the LIV. The method of determination of the lower tilted vertebra (LTV) is presented. The selection of the LTV was identified on standing PA (LTVs) and on bending X-rays (LTVb). Group A is a reference group, with less flexible curves. Groups B and C contained patients with more flexible curves. Group B covered patients with instrumentation ending at the LTVs and group C with shorter instrumentation ending at LTVb. The disc angle below the LIV was monitored for postoperative decompensation. Sixty-eight subjects with AIS Lenke 1A and 1B types underwent selective fusion. The decompensation criteria of the unfused disc below the fusion were determined as a wedging disk of >5° of the Cobb angle. The patients were monitored during the postoperative period with 5.8 years average followup (minimum of 2 years). The rate of decompensation was comparable in groups A and B (31% and 33%, respectively). In contrast, the rate of decompensation was doubled in group C (60%). Caudal fusion shortening in more flexible curves according to bending films is associated with the first free disc asymmetry, which leads to decompensation below the fusion. This method should be considered in addition to other LIV selection criteria.

Dysplastic spondylolisthesis is a severe pathological condition, based on dysplastic changes in the lumbosacral part of the spine, that causes the asymmetry of the lumbosacral junction. The appropriate therapeutic algorithm remains controversial. As the gold standard, the surgical reposition of the slipped vertebra and 360° fusion of the affected spinal segment is preferred. Thirty-two patients were operated on between the years 2005 and 2018. Different techniques of 360° fusion, based on the severity of the displacement of the affected vertebral segment, were used. Herein, the advantages and disadvantages of different techniques of interbody fusion are discussed. The slippage and retention after reduction in the vertebrae are evaluated prior to the operation, postoperatively, one year after the surgery, and during follow-up, which was 7 years on average (minimum 2 years for a follow-up). Complications associated with the surgery are evaluated, in addition to the operation time, blood loss, spinopelvic parameters, and patient satisfaction with the surgery. All surgical techniques improved the slippage compared to preoperative conditions. The retention of the reposition was not changed significantly in postoperative controls. The incidence of neurological complications reached 12.5%. Surgical treatment is the only treatment option that successfully addressed the pathological principle of dysplastic spondylolisthesis. All of the surgical methods used led to restoring the symmetry of the lumbar spine, and to the improvement in both radiological parameters and the alleviation of subjective difficulties. The aim of this article is to summarize surgical methods in patients having dysplastic spondylolisthesis with a slip of more than 25%, who were operated on, and to determine the optimal treatment algorithm according to the severity of the slip.