Comparison Of The Grafting Technique In Treatment Of Thoracolumbar Fractures: Posterolateral Fusion Versus Injectable Calcium Transpedicle Sulfate Vertebroplasty

Objective To retrospectively investigate the outcome of short-segment transpedicle fixation combined with posterolateral fusion and injectable calcium sulfate vertebroplasty.Method From December 2006 to December 2008,439 cases of thoracolumbar fracture patients were treated in our hospital. The clinical imaging data of 173 cases were evaluated retrospectively, and 120 of which were cured by short-segment transpedicle fixation combined with posterolateral fusion (posterolateral fusion group), and the others underwent injectable calcium sulfate vertebroplasty (vertebroplasty group). Radiographic measurements include Cobb angle(CA), vertebral wedge angle (VWA), lower inter-vertebral angle(LIVA), upper inter-vertebral angle(UIVA), ratio between anterior and posterior vertebral height (APHR) on X-ray, and then, the outcome was compared and analysed. Through that, we found the impact on kyphosis correction loss by observing bone fusion, inter-vertebral disc collapse by CT and MRI.Results The preoperative CA, VWA, LIVA, UIVA, and APHR had no statistical significance between the two groups(P>0.05). The mean correction rate of CA, VWA, and APHR of the posterolateral fusion group were 70.85%,68.70%,75.06%, the other group were 78.66%,89.07%,81.96%. Two groups had significantly statistical difference on the postoperative CA, VWA, and APHR (P<0.05). The average fracture healing time is about 6 months. During the 32 months' follow-up,2 cases of pedicle screw breakage occurred in the posterolateral fusion group, without severe neurological injury; 1 cases who fractured adjacent vertebrae after the removal surgery in the vertebroplasty group. In the final follow-up, the average loss rate of CA, VWA, and APHR were 32.89%,30.00%,9.93% in the posterolateral fusion group while they were 34.17%,15.98% and 6.15% in the other group. The upper and lower inter-vertebral correction lost occupied most important proportion in the correction lost of kyphosis deformity, the posterolateral fusion group was 71.62%, the another was 82.35%. The CA, LIVA, UIVA had no statistical significance, but VWA, APHR had statistical significance between the two groups(P<0.05). There are 10 cases, the preoperative inter-vertebral disc injury of which, at the final follow-up, turned out to be degeneration; and for the remaining 14cases, at the last follow-up,4cases of posterolateral fusion group and 1 case of vertebralplasty group, also presented the degeneration of inter-vertebral disc, some of which along with the nucleus breaking into the end plate.Conclusion The short-segment fixation combined with transpedicle calcium sulfate vertebralplasty can restore the shape of vertebral body and spinal sequence better than the posterolateral group in the early period; It also can prevent the lost of vertebral height to preserve the kyphosis angle, and to some extent prevent inter-vertebral disc collapse and disc nucleus breaking into the vertebrae, but can't prevent inter-vertebral disc degeneration occurred after removal surgery.