Comparative study on treatment of thoracolumbar burst fractures with bone grafting by transpedicular approach and by interlaminal small fenestration

Abstract

To investigate the effectiveness and long-term stability of small fenestration vertebral bone grafting and transpedicular bone grafting in the treatment of Denis types A and B thoracolumbar burst fractures. Between January 2012 and February 2014, 50 patients with Denis type A or B thoracolumbar burst fractures were treated with vertebroplasty and pedicle screw rod fixation system, and the clinical data were retrospectively analyzed. Small fenestration vertebral bone grafting by trans-interlaminar approach was used in 30 cases (group A), and bone grafting by unilateral transpedicular approach was used in 20 cases (group B). X-ray and CT examinations of the thoracolumbar vertebrae were performed routinely before and after operation. There was no significant difference in sex, age, cause of injury, time from injury to operation, fracture type, injury segment, and preoperative Frankel classification, the percentage of the anterior body height of the injured vertebra, and visual analogue scale (VAS) score between two groups ( P>0.05). There was significant difference in preoperative Cobb angle of kyphosis between two groups ( P<0.05). The Cobb angle of kyphosis, the percentage of the anterior body height of the injured vertebra, and the recovery of neurological function were recorded and compared between two groups. The patients were followed up for 16-31 months (mean, 19.1 months) in group A and for 17-25 months (mean, 20.2 months) in group B. Primary healing of incisions was obtained in the two groups; no nerve injury and other operative complications occurred. The neurological function was improved in varying degrees in the other patients with neurological impairment before operation except patients at grade A of Frankel classification. The lumbar back pain was relieved in two groups. There was significant difference in VAS score between before operation and at 3 months after operation or last follow-up in two groups ( P<0.05), but no significant difference was found between at 3 months and last follow-up in two groups and between two groups at each time point after operation ( P>0.05). X-ray examination showed that there was no breakage of nail and bar, or dislocation and loosening of internal fixation during follow-up period. The bone grafts filled well and fused in the fractured vertebra. The vertebral height recovered well after operation. The percentage of the anterior body height of the in-jured vertebra and Cobb angle of kyphosis at 1 week, 3 months, and last follow-up were significantly better than preope-rative ones in two groups ( P<0.05), but there was no significant difference between different time points after operation ( P>0.05), and between two groups at each time point after operation ( P>0.05). For Denis types A and B thoracolumbar burst fractures, vertebral bone grafting and pedicle screw internal fixation through interlaminal small fene-stration or transpedicular approach can restore the vertebral height, correct kyphosis, and maintain the vertebral stability, which reduce the risk of complications of loosening and breakage of internal fixators. The appropriate bone grafting approach can be chosen based on the degree of spinal canal space occupying, collapse of vertebral and spinal cord injury.