Factors affecting postural reduction in posterior surgery for thoracolumbar burst fracture.

STUDY DESIGN Retrospective analysis of a prospectively collected patient database. OBJECTIVE To investigate the significance and relevant factors of postural kyphosis reduction during posterior surgical treatment of thoracolumbar burst fracture. SUMMARY OF BACKGROUND DATA Optimal reduction of kyphosis is a goal in the surgical treatment of thoracolumbar burst fracture. Several factors are known to limit the amount of posterior surgical reduction. However, few comprehensive assessments of intraoperative postural reduction have been reported. METHODS Seventy-two consecutive patients who underwent posterior surgical treatment for thoracolumbar (T11-L2) burst fracture were included. Postural reduction was evaluated using C-arm fluoroscopic images and regarded as insufficient when the lateral Cobb angle was ≥20 degrees or AP Cobb angle ≥10 degrees. Clinical characteristics including sex, age, body mass index, time to operation, injury level, and neurological injury, as well as radiologic characteristics including fracture morphology, fracture deformity, canal stenosis, and ligament injuries were investigated to determine the relevant factors. RESULTS The mean lateral Cobb angle was 22.2±11.0 degrees preoperatively, 16.4±7.7 degrees after postural reduction (P<0.001), and 13.4±6.9 degrees after instrumental reduction (P<0.001). Insufficient postural reduction was found in 25 (34.7%) patients, all of which were lateral. The relevant factors for insufficient reduction, as identified by multivariate analysis, were time to operation >72 hours (OR, 6.453; 95% CI, 1.283-32.553), burst-split type injury (OR, 4.689; 95% CI, 1.314-25.225), and anterior compression ratio >0.5 (OR, 2.284; 95% CI, 1.151-19.811). CONCLUSIONS Postural reduction plays an important role in the reduction of kyphosis and compression deformity after thoracolumbar burst fracture. However, it was affected by delayed operation time, burst-split type injury, and severe anterior vertebral compression.