[Comparative study on indirect decompression versus open decompression to vertebral canal in treating thoracolumbar burst fractures without neurologic deficit].

OBJECTIVE: To compare the clinical effects of indirect decompression versus open decompression to vertebral canal in treatment of thoracolumbar burst fractures without neurologic deficit.

METHODS: From April 2004 to June 2008, 52 cases of thoracolumbar burst fracture without neurologic deficit underwent posterior exposition, reduction and fixation with Atlas Fixator (AF) instrumentation. There were 34 males and 18 females with an average age of 43.1 years (range, 31-63 years). The affected locations were T11 in 5 cases, T12 in 24 cases, L1 in 16 cases, and L2 in 7 cases. The time from injury to operation was 3-8 days (4.4 days on average). All cases were divided into indirect decompression group (group A) and open decompression group (group B). There were no statistically significant differences (P > 0.05) in sex, age, affect site, and disease course between two groups. The operative time, blood loss were recorded. Preoperatively, immediately postoperatively and at last follow-up, the height of the fracture vertebra and the Cobb angle were obtained from X-ray pictures and were statistically analysed. Radiographic parameters on computed tomography (CT) pictures were used to get the encroachment rate of vertebral canal.

RESULTS: The operative time was (87.3 +/-7.9) minutes and (125.3 +/- 13.6) minutes, and the blood loss was (273.7 +/- 23.4) mL and (512.6 +/- 37.7) mL in groups A and B, respectively; showing statistically significant differences (P < 0.05). The average follow-up time was 17.4 months (range, 11-31 months) in group A and 19.9 months (range, 12-33 months) in group B. All wounds achieved primary healing postoperatively without deaths and spinal cord injuries. Postoperative complications in group B included 3 cases of screws loosening, 1 case of screw breakage, and 3 cases of low back pain, and were given symptomatic management. There were no statistically significant differences (P > 0.05) in the height of the fracture vertebra, the Cobb angle and the encroachment rate of vertebral canal preoperatively or postoperatively between two groups. There were statistically significant differences (P < 0.05) in the above three parameters between preoperation and postoperation in two groups, but there were no statistically significant differences (P > 0.05) in the spinal correction between two groups. The losing-rate of spinal correction of the height of the fracture vertebra and the Cobb angle of group A was lower than group B, showing statistically significant differences (P < 0.05).

CONCLUSION: The short-term results of two decompression styles in treatment of thoracolumbar burst fractures without neurologic deficit were satisfactory, but indirect decompression has more merits than open decompression: shorter operative time, less blood loss, lower losing-rate of spinal correction, and better stabilization of vertebral column.