Study Design. A systematic review and single-arm meta-analysis of randomized clinical trials.Objective. The aim of this study was to evaluate whether the load-sharing classification (LSC) is reliable to predict the best surgical approach for thoracolumbar burst fracture (TBF). Summary of Background Data. There is no previous review evaluating the efficacy of the use of LSC as a guide in the surgical treatment of burst fractures. Methods. On April 19 th , 2019, a broad search was performed in the following databases: EMBASE, PubMed, Cochrane, SCO-PUS, Web of Science, LILACS, and gray literature. This study was registered on the International Prospective Register of Systematic Reviews. We included clinical trials involving patients with TBF undergoing posterior surgical treatment, classified by load-sharing score, and that enabled the analysis of the outcomes loss of segmental kyphosis and implant failure (IF). We performed random-or fixed-effects models meta-analyses depending on the data homogeneity. Heterogeneity between studies was estimated by I 2 and t 2 statistics. Results. The search identified 189 references, out of which nine studies were eligible for this review. All articles presenting LSC up to 6 proved to be reliable in indicating that only posterior instrumentation is necessary, without screw failures or loss of kyphosis correction. For cases where the LSC was >6, only 2.5% of the individuals presented IF upon posterior approach alone. For loss of kyphosis correction, only 5% of patients had this outcome where LSC >6. For both outcomes together, we had 6% of postoperative problems (I 2 ¼ 77%, t 2 < 0.0015, P < 0.01). Conclusion. Load-sharing scores up to 6 are 100% reliable, only requiring posterior instrumentation for stabilization. For scores >6, the risk of implant breakage and loss of kyphosis correction in posterior fixation alone is low. Thus, other factors should be considered to define the best surgical approach to be adopted.

Objective: To define whether the electroneurophysiological stimulation would be a safe method for reducing injuries in nerve roots during surgery of lumbar spine arthrodesis, as well as verify whether there is a direct correlation between the intraoperative impedance values and the distance from the medial cortical pedicle screw. Methods: Randomized retrospective multicenter study of 10 patients who underwent arthrodesis of lumbar spine after conservative treatment failure, with a total of 50 pedicle screws instrumented. Reliable and safe impedance values were measured in order to reduce the risk of injury to nerve roots in the perioperative period, and these values were compared with the distance between the screw and the medial cortical of the pedicle by CT scan, measured in the immediate post-operative period. Results: There is no direct correlation between the intraoperative impedance values and the distance from the screw to the medial cortical of the pedicle. Conclusion: The electroneurostimulation proved to be a reliable quantitative method to reduce the risk of injury to nerve roots during surgery of lumbar spine arthrodesis when the measured values are greater than 10mA.

Objective:To evaluate a method to reduce high degree spondylolisthesis in adults with monosegmental fixing preserving the adjacent level and the improvement of sagittal balance.Methods:A prospective study, with 12 adult patients with high degree spondylolisthesis (III and IV) in adults who underwent surgery by the same team. We included 7 women and 5 men with a mean age of 37 years and lombosciatalgy that had no improvement with conservative treatment. The surgical technique used was total or partial reduction by Spondylolisthesis Reduction Instrument (SRI) system, with instrumentation only in the affected level, thus sparing the adjacent level, associated with 360ofusion.Results:The L5-S1 level was involved in nine patients, L4-L5 in two, and VT-S1 in one patient. The isthmic type predominated in nine patients, followed by dysplastic type in two, and one iatrogenic spondylolisthesis. These patients were assessed by the Oswestry scale, which showed a preoperative average of 59% and postoperative average of 12.4% (P<0.05). A significant improvement in the average slip angle from 54.66% to 9.5% (35% to 0%) was found. No major complications such as infection, neurological damage or material breaks were observed.Conclusion:The reduction of high degree listhesis instrumenting only the affected level produces good results, with good control of pain and functional improvement of patients. However, a larger follow-up is required to better evaluation.