Efficacy Of Short-Segment USS Fixation In The Treatment Of Severe Lumbar Burst Fracture Without Spinal Decompression

Objective: To investigate the safety,availability and clinical efficacy of short-segment Universal spinal system(USS)posterior fixation without canal decompression in the treatment of severe lumbar burst fractures with incomplete nerve paralysis.Methods: Twenty patients with severe lumbar burst fractures(lumbar 1-lumbar 3)and incomplete nerve paralysis were instumentationed short-segment USS without decompression in Affiliated Zhongshan Hospital of Dalian University from January2013 to October 2016 were selected.All patients did not undergo spinal decompression through incising the spinal canal and all treated with the 4-nail short segment USS fixation one level above and one level below(The numbor of certificate of sci-tech novelty search:2017-DJ-0661-LB).Around14±3months after operation,when the fratures union the internal fixations were removed.Surgical time,surgical bleeding,postoperative complications,the injury recovery,the clinic effiacy Denis rating,ASIA(American Spinal Cord Injury Association of Spinal Nerve Injury and Functional Classification Criteria)and vertebral imaging indicators were measured at different points in time.In statistical analysis,analysis of variance was run through software SPSS19.0 and found P <0.05 which is statistically significant.Results: All patients were operated in an average of 100 ± 20 minutes with an average amount of surgical bleeding of 200 ± 50 ml.There was no infection,severe broken nail,broken rod or serious complications after nails were removed and no Kyphosis recurrences were found in patients.The Denis ratings of lower back pain were significantly relieved compared with that before the surgery in all patients(p<0.05).The ASIA score was improved by one grade or more at the time of nails removal compared with that before operation(p <0.05).No delayed neurological injury occurred.The segment Cobb angle after surgery and nail removal was significantly reduced compared with that in preoperative phase(P <0.05).There wasno significant difference in the Cobb angle from when operation was done to when nail was removed(p> 0.05).No significant change occurred in segment Cobb angle correction rate from the completion of operation to the removal of nails(p> 0.05).Spinal canal stenosis in injured vertebrae after operation and before nailing was significantly improved compared with that before operation(p <0.05).There is no significant change in Spinal canal stenosis in injured vertebrae before nailing and after surgery.(p>0.05).The anterior height of injured vertebral body 1-week postoperative and before nailing and after the nail removal was significantly higher than that before the operation(p <0.05).There is no significant change in the anterior height of injured vertebral body after surgery and nail removal before and after(p>0.05).There is no significant change in the anterior height of injured vertebral body before and after nailing(p>0.05).The posterior edge height of injured vertebral body 1-week postoperative and before nailing and after was significantly higher than that before the operation(p <0.05).There is no significant change in the posterior edge height of injured vertebral body after surgery and nail removal before and after(p > 0.05).There is no significant change in the posterior edge height of injured vertebral body before and after nailing(p>0.05).Conclusion: Short-segment USS instumentation without decompression is an effective,simple and safe method for the treatment of severe lumbar burst fractures,and the correction of the injuried vertebral has not lose.