[Surgical treatment strategies of odontoid fractures]

To explore the characteristics of both odontoid fractures and adjacent section instability so as to devise proper surgical strategies and achieve better curative effect.

A total of 37 patients (including 26 males and 11 females) with odontoid fractures treated from January 2005 to June 2012 with a mean age of (21-65) 36 years were analyzed retrospectively. Among 25 cases of simple odontoid fractures, there were type II (n = 20) and low type III (n = 5). There were 12 cases of odontoid fractures with adjacent section instability with C1/2 instability (n = 6), C2/3 instability (n = 4) and C1/2 and C2/3 instability (n = 2). The Frankel scale was used to assess nerve function. There were Grade A (n = 1), Grade B (n = 2), Grade C (n = 3) and Grade D (n = 6) at preoperation. Treatment included anterior and/or posterior pedicle screw fixation for reducing fracture and stabilizing upper cervical vertebrae. The Japanese Orthopedic Association (JOA) standards were used to evaluate the therapeutic effect. According to Frankel grade, nerve functional restoration of spinal cord injury was gauged. Fracture healing, bone graft fusion and spinal stability were monitored by radiology or computed tomography.

All patients underwent surgery safely without severe complications. The average follow-up period was 18 (12-48) months. There was significant difference (t = 13.464, P = 0.000) in JOA score between pre-operation (12.11 ± 2.09) and post-operation (15.36 ± 3.17). And the rate of improvement was 90.8% ± 11.6% and that of "excellent" or "good" 98%. Degree 1-2 recovery of neural function was achieved in all except for 1 case of Frankel B. All patients were immobilized in a hard collar for 3 months postoperatively. Fusion occurred in all cases within a mean time of (3-6) 4.5 months. Radiology confirmed a proper screw position at postoperation. There were no occurrences of such complications as loosening, displacement or breakage of internal fixations.

Proper surgical approaches may be selected according to the characteristics of both odontoid fractures and adjacent section instability.