Posterior Surgically Treated Thoracolumbar Burst Fracture: A Retrospective Study

Objectives:1) To conduct a retrospectively clinical trial, the demographic data were collected.2) To compare the results of H-Graft versus Vertebra-Graft versus No-Graft for surgically treated thoracolumbar fracture.Methods:1) The inclusion criteria were as follows:①Single of the thoracolumbar burst fracture, no dislocation;②fresh fracture within one week;③No significant organ dysfunction;④Aged 18 to 65, no pathological fracture and severe osteoporosis;⑤The follow-up period was more than 18 months.2) The demographic data of age, gender, cause of injury, level of fracture and Frankle classification were collected.3) Preoperative radiographic parameters of the sagittal curve and loss of vertebral body height were measured in plain roentgenograms.4) All patients were sent to the operating room on a priority rather than an emergency basis. The operation was carried out by one senior surgeon. A standard posterior midline approach with AF screw fixation with one level above and one level below the injured segment was undertaken on all patients. All screws were connected with 2 rods, which were bent into a lordotic configuration. Distraction force was applied, based on the injured endplate, before tightening the setscrews, and one cross-link was used. In the graft groups, H-Graft group carried out autogenous bone graft from the left iliac, incision along the ridge, exposed bone, with wide-iliac bone knife split along the central of iliac ridge, dislodge 4 x 6cm bone (one side is bone cortex, the other side is bone medulla), pruning of the "H" type. Cortical side of bone plate towards the canal to prevent developing hyperosteogeny to oppress bone marrow; medullary side of bone plate embedded close to processus spinosus of vertebral body, and restored hinder margin height of vertebral body in the greatest extent (picture 2).Vertebra-Graft surgery was put autogenous bone which were harvested from bone chips that were taken from the laminae and spinous processes of the fixed segments between transverse process. No graft material was used in the No-Graft group. Finally, the wound was closed in the usual manner with a suction drainage tube left in.5) All patients were allowed to ambulate in a brace on postoperative day 7 to 14. A brace was used for 3 months after the operation.6) Intraoperative estimated blood loss and operative time were observed.7) Every patient was followed-up at the outpatient department, which was taken after surgery at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and then annually. Preoperative radiographic parameters of the sagittal curve and loss of vertebral body height were measured in plain roentgenograms. The follow-up radiographic parameters measured the differences in the sagittal curves and the loss of vertebral body height. Sagittal curves were measured by measuring the angle between the endplates one body above and one body below. The percentage of vertebral body height loss was calculated by special formula. Neurologic status was recorded at the time of injury, immediately after operation, and at the final follow-up by using the Frankel grading system. Results:1) Eighty-two patients were included in this study, posterior fixation with autogenous bone graft was performed for the H-Graft group and Vertebra-Graft (n = 36, n = 30, respectively), and no bone graft procedure was done for the No-Graft group (n = 16)2) The intraoperative estimated blood loss was (250±53) ml for H-Graft group, and (275±62) ml for Vertebra-Graft, there was not different between them. The operative time was (120±34) minutes and (135±39) minutes for H-Graft group and Vertebra-Graft, respectively, P <0.05. Both the intraoperative estimated blood loss (180±27) ml and the operative time (90±36) minutes of No-Graft group were significantly less than bone-Graft groups, P <0.01. The length of stay of the 3 groups had no significant difference.3) The lost correction of decreased vertebral body height of bone-graft groups was obviously lower than that of No-graft group. The radiographic parameters including the average loss of sagittal angulation and the lost correction of decreased vertebral body height of H-Graft group were significantly better than those of other groups.4) At the final follow-up, all the patients of H-Graft group had improved, except 5 patients with Grade A; In the Vertebra-Graft group, all patients were improved, except the 4 patients with Grade A, and 2 Grade B. In the No-Graft group, all patients were improved, except the 2 patients with Grade A, and 2 patients with Grade B. The average improvement of neurologic status was 1.06grade for the patients in the H-Graft group, 0.84grade for the Vertebra-Graft group, and 0.86grade for the No-Graft group.5) Complications were encountered during follow-up: 12 patients experienced donor site pain or discomfort that could be well tolerated without any medication, at an incidence of 17.9%; crew breakage occurred in 6 patients, of which 2 in the Vertebra-Graft group, 4 in the No-Graft group, and no people in the H-Graft group.6) Neither nonunion nor postoperative infection was encountered. Conclusions:Although there are many bone graft fusion methods at present. However, this study shows that H -Graft can effectively restore transmission of line of force in vertebral fracture and greatly reduce vertebral height loss and implant failure probability compare to Vertebra-Graft. Meanwhile, H-Graft is easy to operate, less bleeding, shorter operative time, less loss reduction, and there is small probability of kyphosis. So H-Graft is a stable and reliable posterior bone grafting method.