Comparison of efficacies of posterior screw-rod fixation and fusion with or without bone graft in the treatment of unstable Hangman′s fracture

English Keywords:Hangman′s fracture  Posterior screw-rod fixation  Non-bone graft  Spontaneous fusion

English Abstract:

  【Abstract】 Objectives: To compare the efficacies of posterior screw-rod fixation and fusion without bone graft and with bone graft in the treatment of unstable Hangman′s fracture. Methods: The clinical and imaging data of 39 patients with unstable Hangman′s fracture who underwent posterior cervical screw-rod internal fixation in our hospital between January 2014 and December 2020 and were followed up for more than 2 years were analyzed retrospectively, and the follow-up period was 3.2±1.9 years(range from 2 to 9 years). There were 31 males and 8 females with an average age of 43.1±16.1 years(13-70 years). Among the patients, 22 cases received simple posterior screw-rod fixation(non-bone graft group: group A), and 17 cases received posterior screw-rod fixation and autogenous iliac bone graft fusion(bone graft group: group B). The operative time and intraoperative blood loss, postoperative complications, the visual analogue scale(VAS) preoperatively, at 1 week, 3 months and final follow-up after surgery, and neck disability index(NDI) preoperatively, at 3 months and final follow-up after surgery, and American Spinal Cord Injury Association(ASIA) grade preoperatively and at final follow-up, and Odom′s grade at final follow-up were recorded and compared between the two groups. The displacement, angulation of C2/3 and cervical lordosis angle were measured on lateral X-ray films before operation, at 1 week after operation and final follow-up. The fracture healing, and C2/3 posterior facet joint and interbody fusion were observed on anteroposterior and lateral X-ray films and three-dimensional CT images. Results: All the 39 patients completed the operation successfully. The operative time was 99.3±14.2min in group A and 137.9±19.5min in group B, the intraoperative blood loss was 94.6±12.6mL in group A and 140.6±17.8mL in group B, and group A was shorter in operative time and less in blood loss(P<0.05). Superficial incision infection occurred in 2 cases in group A and 1 case in group B, and 4 cases of pain in bone donor area occurred in group B, all of which were improved after symptomatic treatment. The VAS score at postoperative 1 week and 3 months, and final follow-up, and NDI at postoperative 3 months and final follow-up of both groups all significantly improved than those before operation(P<0.05), while there was no significant difference in the indexes mentioned above between the two groups at each follow-up time point(P>0.05). At final follow-up, there was no significant difference in ASIA classification and Odom′s grade between the two groups(P>0.05). The angulation, displacement of C2/3 and cervical lordosis angle in the two groups were significantly improved at 1 week after operation and final follow-up(P<0.05). There was no significant difference in the indexes mentioned above between the two groups at each follow-up time point(P>0.05). At final follow-up, all the patients achieved solid bony fusions of fracture lines. In group A, spontaneous fusion at bilateral C2/3 facet joints was found in all the patients, spontaneous fusion of the anterior edge of vertebral body occurred in 1 case, spontaneous fusion of the posterior edge of vertebral body occurred in 9 cases, and spontaneous fusion of both anterior and posterior edges of vertebral body occurred in 4 cases. In group B, bony fusion of bilateral C2/3 facet joints was achieved in all the patients, no spontaneous fusion of the anterior edge of vertebral body, spontaneous fusion of the posterior edge of vertebral body occurred in 10 cases, and spontaneous fusion of both anterior and posterior edges of vertebral body occurred in 3 cases. At final follow-up, there was no statistical difference in the results of C2/3 facet joints and interbody fusion between the two groups(all facet joints were fused in both groups, and the interbody fusion rates in groups A and B were 63% and 76%, respectively)(P>0.05). Conclusions: Posterior screw-rod fixation and fusion without or with bone graft can both achieve satisfactory clinical results in the treatment of unstable Hangman′s fracture, with similar postoperative C2/3 facet joint and interbody fusion rates. Non-bone graft fusion can shorten the operative time, reduce intraoperative blood loss and avoid iliac bone removal-related complications.