Transpedicular grafting after short-segment pedicle instrumentation for thoracolumbar burst fracture: Calcium sulfate cement versus autogenous iliac bone graft

Abstract

Study Design. A retrospective clinical and radiographic study was performed. Objective. To compare 2 grafting materials of anterior augmentation for thoracolumbar burst fractures: transpedicular cancellous bone (TPCB) grafting and transpedicular calcium sulfate grafting and to decide whether calcium sulfate cement can replace autogenous cancellous bone applied in anterior vertebral body augmentation after posterior short-segment instrumentation. Summary of Background Data. Additional TPCB grafting was developed as an alternative to prevent early implant failure. However, the results are inconsistent and donor-site complications are a major concern. Calcium sulfate has been offered as a bone substitute for treating patients with metaphysis fractures or bone defect, but the results of application in spinal surgeries are uncertain. Methods. Fifty-one patients with a single-level thoracolumbar burst fracture for treatment with short-segment pedicle screw fixation were enrolled in the study. Fractures in group 1 patients were reinforced with TPCB (n = 31), and fractures in group 2 patients were augmented with transpedicular calcium sulfate cement (TPCSC; n = 20). All patients were followed-up at least 2 years after surgery. Radiographic parameters and clinical outcomes were compared between the 2 groups. Results. The 2 groups were similar in age, sex, fracture levels, preoperative neurologic status distribution, and the associated injuries. The TPCB group had a longer period of follow-up (52.7 ± 4.9 vs. 28.6 ± 3.5 months, P < 0.001). Blood loss and operation time were less in the TPCSC group (247.5 ± 164.2 vs. 600.0 ± 403.1 mL, P = 0.001 and 161.7 ± 28.5 vs. 227.2 ± 43.6 minutes, P < 0.001). Radiographic parameters and clinical outcomes were similar in both groups. The TPCSC group had no surgical complication, but the TPCB group revealed 2 cases with wound infection after surgery. The failure rate, defined as an increase of 10° or more in loss of correction or implant failure, was also not significantly different (TPCB = 9.6% and TPCSC = 15%; P = 0.565). All patients with partial neurologic deficits initially improved at the final follow-up. Conclusion. Additional TPCB grafting after posterior short-segment instrumentation remains a reliable surgical method for correcting and maintaining sagittal alignment and vertebral body height in thoracolumbar burst fractures. Calcium sulfate cement also proved to be an effective bone substitute used in spinal surgeries for patients with thoracolumbar burst fractures. © 2010, Lippincott Williams & Wilkins.