Effects of recombinant human bone morphogenetic protein-2 combined with pedicle screw fixation via dorsal-approach and vertebral body bone graft in treating type A thoracolumbar vertebral fractures

Abstract

Objective To observe the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) on patients with type A thoracolumbar fractures treated by pedicle screw fixation via dorsal-approach and vertebral body bone graft. Methods A retrospective case-control study was conducted to analyze the clinical data of 64 patients with type A thoracolumbar fractures treated from June 2012 to July 2015. The patients were divided into control group (32 cases) and research group (32 cases) according to the random number table. There were 22 males and 10 females aged (48.2±11.2)years old in control group. The injury was located at T11 in 2 cases, T12 in 4, L1 in 9, L2 in 7, L3 in 7 and L4 in 3 in control group. There were 24 males and 8 females aged (50.7±11.4) years old in research group. The injury was located at T11in 2 cases, T12in 4, L1in 8, L2 in 8, L3 in 7 and L4 in 3.The control group was treated with posterior pedicle screw reduction, internal fixation and allograft cancellous bone grafting through pedicle of vertebral arch. The research group was treated with rhBMP-2 (mixed with cancellous bone implants) on the basis of the control group. The time of operation, the amount of bleeding during operation, the volume of postoperative bleeding, the amount of postoperative drainage, the recovery of the injured vertebra, the Lane-Sandhu score, the time of fracture healing, and the postoperative complications were compared. Results There was no difference between two groups on operation time, amount of bleeding during operation or amount of postoperative drainage (P>0.05). No difference existed in two groups about Cobb angle and injured vertebral leading edge height at one week after operation (P>0.05). At the time of last follow-up (12 months), in research group, Cobb angle was lower while injured vertebral leading edge height was much higher than that of control group (P 0.05). Conclusion Compared with simple vertebral bone graft, posterior thoracolumbar vertebrae pedicle screw fixation with vertebral bone graft and hBMP-2 treatment for type A thoracolumbar fractures can restore vertebral stability, shorten the time of fracture healing and reduce the incidence of complications. Key words: Spinal fractures; Thoracic vertebrae; Lumbar vertebrae; Bone morphogenetic proteins; Bone transplantation