OBJECTIVE: To investigate the effect of preventing the loss of correction and vertebral defects after thoracolumbar burst fractures treated with recombinant human bone morphogenetic protein 2 (rhBMP-2) and allogeneic bone grafting in injured vertebra uniting short-segment pedicle instrumentation.
METHODS: A prospective randomized controlled study was performed in 48 patients with thoracolumbar fracture who were assigned into 2 groups between June 2013 and June 2015. Control group (=24) received treatment with short-segment pedicle screw instrumentation with allogeneic bone implanting in injured vertebra; intervention group (=24) received treatment with short-segment pedicle screw instrumentation combining with rhBMP-2 and allogeneic bone grafting in injured vertebra. There was no significant difference in gender, age, injury cause, affected segment, vertebral compression degree, the thoracolumbar injury severity score (TLICS), Frankel grading for neurological symptoms, Cobb angle, compression rate of anterior verterbral height between 2 groups before operation (>0.05). The Cobb angle, compression rate of anterior vertebral height, intervertebral height changes, and defects in injured vertebra at last follow-up were compared between 2 groups. n n P
RESULTS: All the patients were followed up 21-45 months (mean, 31.3 months). Bone healing was achieved in 2 groups, and there was no significant difference in healing time of fracture between intervention group [(7.6±0.8) months] and control group [(7.5±0.8) months] (=0.336,=0.740). The Frankel grading of all patients were reached grade E at last follow-up. The Cobb angle and compression rate of anterior verterbral height at 1 week after operation and last follow-up were significantly improved when compared with preoperative ones in 2 groups (<0.05). There was no significant difference in Cobb angle and compression rate of anterior verterbral height between 2 groups at 1 week after operation (>0.05), but the above indexes in intervention group were better than those in control group at last follow-up (<0.05). At last follow-up, there was no significant difference of intervertebral height changes of internal fixation adjacent upper position, injured vertebra adjacent upper position, injured vertebra adjacent lower position, and internal fixation adjacent lower position between 2 groups (>0.05). Defects in injured vertebra happened in 18 cases (75.0%) in control group and 5 cases (20.8%) in intervention group, showing significant difference (=14.108,=0.000); and in patients with defects in injured vertebra, bone defect degree was 7.50%±3.61% in control group, and was 2.70%±0.66% in intervention group, showing significant difference (=6.026,=0.000). t P P P P P χ P t P2
CONCLUSION: Treating thoracolumbar fractures with short-segment pedicle screw instrumentation with rhBMP-2 and allogeneic bone grafting in injured vertebra can prevent the loss of correction and vertebral defects.
