[Sagittal Profi le of the Spine in Patients after Lumbar Stabilisation Surgeries]. / Sagitální profi l pátere u pacientu po stabilizacních operacích bederní pátere.

PURPOSE OF THE STUDY: Spine stabilization surgery is nowadays one of the most common spinal surgical procedures. Spinopelvic alignment is considered to be an important factor impacting the patients' preoperative diffi culties as well as the outcome of surgery. In our study, the outcomes of stabilization surgeries in patients with lumbar spine disorders were evaluated - especially in those with stenosis and spondylolisthesis, in whom the importance of sagittal parameters were assessed with respect to the patients' clinical outcomes and diffi culties. MATERIAL AND METHODS: The study included 50 patients with lumbar spine disorders who had undergone a spine stabilization surgery for a degenerative disease - lumbar spinal stenosis, spondylolisthesis between 2015 and 2017. Spino-pelvic radiological parameters and clinical parameters were evaluated using the nonparametric Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests. RESULTS: In 38 of 50 patients, who at the end of the follow-up period did not have the PI-LL (pelvic incidence-lumbar lordosis) mismatch, i.e. PI-LL was ≤10°, a statistically signifi cant difference in pelvic tilt (p=0.049) and sagittal vertical axis (p<0.001) was reported, which was not the case in the remaining patients of the study population. Claudication and OSWESTRY (ODI) showed no statistically signifi cant difference. We have also compared the differences in the number of fused vertebrae and type of stabilization. A signifi cant change was seen in the claudication parameter at 12 and 24 months after surgery (p=0.007, p=0.005), with better outcomes achieved by 360° lumbar fusion compared to posterior lumbar fusion. The improvement of VAS and ODI scores in both the groups over time (from 6.1 to 3.6 or from 6.3 to 3.5 in VAS and from 62 to 32, or from 62 to 30 in ODI) was also statistically signifi cant (p<0.001 in both groups), while when comparing the groups against each other it was statistically insignifi cant. DISCUSSION: The authors confi rmed signifi cant improvement in the studied clinical parameters in all groups of patients (VAS, ODI, claudication), which is consistent with the results of recently published papers. The authors also established the correlation between different radiological parameters in the studied groups. The results do not confi rm the importance of the length or type of instrumentation for the clinical outcomes. This is consistent with the fi ndings of other published manuscripts. The authors failed to confi rm a signifi cant change in clinical parameters in dependence on the matching relationship between the pelvic incidence and lumbar lordosis. CONCLUSIONS: Proper spinopelvic balance in patients after spinal surgery is a very important indicator of postoperative development and condition, but our cohort showed no statistically signifi cant difference in the clinical outcomes of patients whose postoperative sagittal parameters were unsatisfactory. KEY WORDS: sagittal profi le, spine stabilization, pelvic tilt, pelvic incidence, sagittal vertical axis, SVA.

[Pedicle screw fixation of thoracic spine fractures]. / Transpedikulárna stabilizácia zlomenín hrudnej chrbtice.

PURPOSE OF THE STUDY: Fractures of the thoracic spine involve injury at the levels of Th2 to Th10. Because of pedicle morphology, pedicle screw fixation is a demanding procedure. However, evidence on the reliability and efficiency of this technique has recently been provided by several studies. The aim of this study was to analyse a group of patients with thoracic spine fractures treated by pedicle screw fixation and to evaluate treatment outcomes. MATERIAL AND METHODS: A total number of 33 patients treated by pedicle screw fixation for thoracic spine fractures between January 2007 and December 2011 were enrolled in this retrospective study. The mean age was 39.7 ± 16.7 years. The evaluation included demographic data, mechanism of injury, associated injuries, neurological status, fracture type (AO classification), levels of the fractured vertebrae, injury-surgery interval, type and duration of surgery, type and length of pedicle screw fixation and complications. The position of pedicular screws in relation to the pedicle walls and correction of kyphotic deformity were assessed on post-operative CT scans. RESULT: Of the 33 patients, 24 had associated injuries (72.7%), 22 had thorax injury (66.7%) and 17 had neurological deficit (51.5%). The most frequent spinal fracture type was type B2, 15 (45.5%); followed by type C, nine (33.3%); and type B1, five (15.1%). The mean injury-to-surgery interval was 5.2 ± 4.3 days. The mean operative time was 210 ± 56 min. The most frequently used configuration of pedicle screw fixation involving two segments above and two below the fracture level was used in 20 cases (58.8%). The position of 149 out of 282 pedicle screws (52.8%) was evaluated on post-operative CT scans as follows: 98 % of the pedicle screws were placed in acceptable positions, 76% were placed completely within pedicle borders. The mean pre-operative Cobb angle was 18.7° ± 8.2°, the mean post-operative Cobb angle was 9.3 ± 3.4°. Six intraoperative and three post-operative complications occurred. During follow-up no instrumentation failure or apparent loss of correction was recorded. DISCUSSION: Early stabilisation of thoracic spine fractures reduces the risk of complications, shortens the hospital stay and allows for faster recovery of patients. Early thoracic spine stabilisation is most beneficial in patients with a high ISS (Injury Severity Score). In the case of small-sized pedicles there is the possibility of pedicle screw insertion via an extrapedicular or parapedicular trajectory. Recommended pedicle screw fixation is two levels above and two levels below the fracture level. CONCLUSIONS: Pedicle screw fixation of thoracic spine fractures is a safe therapeutic method with a low risk of complications. It facilitates effective reduction and stable fixation with a low risk of secondary displacement and implant failure. Key words:transpedicular stabilisation, thoracic spine, fracture, pedicle screws.