Comparison of Short Segment and Long Segment Posterior Instrumentation of Thoracolumbar and Lumbar Bursting Fractures at Load Sharing Score 7 or Above

ABSTRACT

STUDY DESIGN: A retrospective comparative analysis of the short-segment and long-segment posterior fixation in thoracolumbar burst fractures that are 7 points or above in load-sharing score was performed. OBJECTIVES: The purpose of this study is to demonstrate the appropriate level of fixation by comparing the results of short-segment and long-segment posterior fixation. SUMMARY OF LITERATURE REVIEW There is general consensus that short-segment fixation should be done in thoracolumbar burst fractures that are 6 points or less in load-sharing classification. There is some controversy regarding whether short-segment or long-segment fixation should be done in thoracolumbar burst fractures that are 7 points or above in load-sharing classification. MATERIALS AND METHODS: From 1998 through 2008, 32 patients with thoracolumbar burst fractures above 7 points in load-sharing classification had been operated with short-segment (1 segment above and 1 segment below 23 patients) or long-segment (2 segments above and 1 segment below 9 patients) transpedicular screw fixation at the author's institution. They were divided by two groups (group I short-segment fixation, group II long-segment fixation). The mean age of patients was 49.2 years old and the mean follow-up period was 2.4 years (1-7 years). In preoperative and postoperative simple radiographs, the bony unions, breakages or loosening of implants were assessed, and the losses of correction angle and anterior vertebral body height were measured. RESULTS: In all cases, non-union or loosening of implants were not observed. There was 1 screw breakage in short-segment fixation group during the follow up period, but bony union was obtained at final follow-up. The mean score of load sharing classification was 7.3 in Group I and 7.1 in Group II, and there was no significant difference between two groups. (p>0.05) The mean anterior vertebral body height loss was 5.3% in Group I and 3.6% in Group II and the mean loss of correction angle were 4.72 in Group I and 3.38 in Group II. There was no significant difference between the two groups for both. (p>0.05) CONCLUSIONS: There was no significant difference in radiologic parameters between two groups. Short-segment fixation could be used successfully in selected cases of thoracolumbar burst fractures that are 7 points or above in load-sharing classification.