OBJECTIVETo investigate the clinical results of pedicle-screw placement and reduction on the level of injured vertebrae in treating thoracolumbar fractures.

METHODSFrom March 2006 to May 2009, 27 patients with thoracolumbar fractures were treated with short-segment fixation system and pedicle-screw placement on injured vertebrae through posterior approach. There were 19 males and 8 females with an average age of 36 years old ranging from 24 to 68 years. Eleven patients were injuried by traffic accident, 9 patients were injuried by falling from high, 5 patients were injuried by crush from weighty object, 2 patients were others injuries. Thoracolumbar fractures were classified according to Gertibein classification: 2 cases were of type A1, 3 cases A2, 12 cases A3, 5 cases B1, 5 cases B2. Among them, 14 cases were accompanied with spinal cord injuries,functional assessment of nerves was assessed according to Frankel criteria: 5 cases were of grade B, 3 cases C, 6 cases D. Lumbago according to Denis standard, grade P5 was in all cases. The injured level of 5 cases was in T11, 11 cases in T12, 8 cases in L1, 3 cases in L2. From injury to operation it was 2-15 days with an average of 4 days. The ratio of vertebral height between anterior and posterior border, anteroposterior Cobb angle were compared before and after operation. Function of nerves and index of lumbago were evaluated by Frankel and Denis classification.

RESULTSAll patients were followed up from 14 to 17 months with the mean of 15.5 months. At final follow-up,according to Frankel score system to evaluate function of nerve,2 cases were of grade B, 4 case grade C, 3 cases grade D, 5 cases grade E; according to Denis score system to evaluate index of lumbago, there was P1 (without pain) in 17 cases, P2 (between whiles minute pain, need not treatment) in 8 cases, P3 (moderate pain, between whiles need medication) in 2 cases. The ratio of vertebral height between anterior and posterior border from preoperatively 0.32 +/- 0.14 to postoperatively 0.85 +/- 0.03 (P<0.01); anteroposterior Cobb angle from preoperatively (25.3 +/- 7.8) degrees to postoperatively (11.1 +/- 1.5) degrees (P<0.01). At final follow-up, the ratio of vertebral height between anterior and posterior border, anteroposterior Cobb angle were respectively 0.81 +/- 0.06 and (11.8 +/- 1.9) degrees, there was no significant difference between postoperative and at final follow-up (P>0.05). No complications such as infection, internal fixation failure,nerve injuries were found during follow-up.

CONCLUSIONPosterior short-segment fixation system and pedicle-screw placement on level of injured vertebrae is one kind of effective method in treating thoracolumbar fracture, which can maintain corrective effect and obtain better clinical outcomes.