The feasibility and efficacy of anterior interboby bone graft for thoracolumbar fracture

English Keywords:Thoracolumbar burst fracture  Anterior approach  Grafting around the cage

English Abstract:

  【Abstract】 Objectives: To evaluate the feasibility and efficacy of anterior interbody bone graft for the treatment of thoracolumbar burst fracture. Methods: From March 2005 to March 2011，167 patients with thoracolumbar burst fracture were treated with anterior approach. All patients were evaluated using X-ray and 3 dimensional CT scans prior to surgery, 3, 6, 12 months postoperatively and annually thereafter to observe the fusion status and the kyphotsis Cobb angle, the height of fractured vertebrae and spinal stenosis rate. The modified Brantigan grade was used to assess the fusion rate. Results: All patients underwent surgery successfully. 116 patients were followed up for an average of 2.2 years(range, 1-4.5 years). One week after surgery, X-ray revealed no bone graft shifting into the spinal canal. CT scans of 56 patients revealed no obvious hematoma around the cage. In 48 cases, CT scan showed a 1-2mm transparent line between cage and bone graft while no trace of bone fragments in the spinal canal 3 months at surgery. No heterotopic ossification was found by X-ray 6 months after surgery. CT scans revealed continuous trabeculae bone formation between cage and bone graft with no bone fragments in the spinal canal in 41 patients. One year into the follow-up, 48 patients scored 4 points on the modified Brantigan grade, 39 scored 3 points, and 29 scored 2 points. For the 12 cases with nano cages, the cages was partially fused with the surrounding bone graft, leaving a fissure of 1-2mm wide. Cages were found inclined(in the coronal or sagittal plane the inclination were less than 10°) in 7 cases with a Cobb angle between 13° to 16°(more than 9.5°). At last follow-up no obvious side convex or kyphosis was noted, the difference before and after the surgery is significant(P＜0.05). Conclusions: Anterior interbody bone graft for thoracolumbar fracture increases the mechanical strength of spine, improve stability and fusion ratewhile decreases the risk of implant failure.