Comparison of long-term efficacy of posterior atlantoaxial fixation without fusion and posterior atlantoaxial fixation and fusion in the treatment of fresh odontoid fractures

English Keywords:Odontoid fracture  Posterior atlantoaxial fixation  Single fixation  Fixation and fusion

English Abstract:

  【Abstract】 Objectives: To compare the long-term clinical efficacy of non-fusion posterior atlantoaxial fixation and posterior atlantoaxial fixation and fusion in the treatment of fresh odontoid fractures. Methods: The clinical data of 63 patients(49 males and 14 females, mean age 42.9±13.7 years) with fresh odontoid fractures who underwent posterior surgery and were followed up more than 5 years in our hospital from 2006 to 2015 were retrospectively analyzed. The patients were divided into group A and group B: 33 cases in group A were treated with posterior atlantoaxial fixation without fusion; 30 cases in group B were treated with posterior atlantoaxial fixation and fusion. Gender, age, cause of injury, time from trauma to surgery, fracture displacement, preoperative score of visual analogue scale(VAS), neck disability index(NDI) and American Spinal Injury Association(ASIA) were recorded and compared between the two groups, which showed no significant difference(P>0.05). The operation time, blood loss, clinical efficacy evaluation indexes(VAS score, NDI, ASIA) and complications (donor site pain, postoperative infection, cerebrospinal fluid leakage, etc.) were recorded and compared between the two groups. At the final follow-up, atlantoaxial stability was evaluated using dynamic X-ray; degeneration of atlantoodontoid joint and lateral atlantoaxial joints, spontaneous atlantoaxial fusion, and bone graft fusion in group B were observed by using multiplanar reconstruction CT. We further compared the age, gender, cause of injury, time from trauma to surgery, fracture type, fracture displacement, fixation method, VAS score, and NDI between the patients with atlantoaxial spontaneous bone fusion and patients without bone fusion in group A and analyzed the influencing factors of spontaneous bone fusion in group A. Results: At the final follow-up, all patients had fracture healing. The VAS scores were 6.5±1.2 in group A and 6.8±1.3 in group B before operation. And the NDI were 31.1±3.8 and 32.5±4.3 in group A and group B. At the final follow-up, the VAS score and NDI of groups A and B were 1.3±0.8 and 1.5±0.9, 4.2±1.3 and 4.5±1.9, respectively, which were significantly lower than those before operation(P<0.05). Preoperative ASIA grade: 1 case of grade C, 2 cases of grade D and 30 cases of grade E in group A, 2 cases of grade C, 3 cases of grade D and 25 cases of grade E in group B; At the final follow-up, there were 1 case of grade D and 32 cases of grade E in group A, 2 cases of grade D and 28 cases of grade E in group B. In both groups, there was no significant difference in ASIA grade between the final follow-up and before operation(P>0.05). There was no significant difference in VAS score, NDI and ASIA grade between the two groups at the final follow-up(P>0.05). The operation time and blood loss in group A were significantly less than those in group B(P<0.05). The incidence of operation related complications was 9.1%(3/33) in group A and 30%(9/30) in group B(P<0.05). At the final follow-up, there was no atlantoaxial instability in both groups; there was no significant difference in the degeneration grade of atlantoodontoid and atlantoaxial joints between the two groups(P>0.05). There were 7 cases(21.2%) of atlantoaxial spontaneous fibre fusion and 23 cases(69.7%) of atlantoaxial spontaneous bone fusion in group A, and 30 cases(100.0%) of atlantoaxial bone fusion in group B; there was a significant difference in the rate of atlantoaxial bone fusion between the two groups(P<0.05). In group A, the follow-up time of patients with spontaneous bone fusion was longer than that of patients without spontaneous bone fusion(P<0.05). Although the patients with spontaneous bone fusion had a higher rate of apparent displacement of fracture(>2mm) than that without spontaneous fusion, there was no significant difference(47.8% vs 10%, P>0.05). Conclusions: Both posterior atlantoaxial fixation without fusion and posterior atlantoaxial fixation and fusion are effective in managing fresh odontoid fractures. However, posterior atlantoaxial fixation without fusion can further shorten the operation time, reduce intraoperative blood loss. Spontaneous atlantoaxial fusion after posterior fixation without fusion is the crucial factor to maintain atlantoaxial stability and long-term curative effect. The fracture displacement is the influencing factor of postoperative spontaneous bone fusion.