ABSTRACT
Objective To investigate the guidance value of TOI classification in treating traumatic T-type atlantoaxial dislocation (ADD).Methods A retrospective case series study was made on 32 cases of traumatic TOI T-type ADD treated between January 2012 and December 2015.There were 19 males and 13 females,aged (38.4 ± 14.7) years.Fifteen cases of T1-type underwent external fixation or internal fixation without fusion,while 17 cases of T2-type underwent internal fixation with fusion.Symon-Lavender clinical standard,Japanese orthopedic association score (JOA),visual analogue scale (VAS),atlas-dens interval (ADI) and space available for the cord (SAC) were used to evaluate the therapeutic effect.Results Patients were followed up for 6-54 months (mean,32.4 months).At final follow-up,ADI was decreased to (2.3 ± 1.4) mm from preoperative (5.6 ± 1.6) mm,but SAC was increased to (15.4 ± 1.9) mm from preoperative (12.0 ± 2.9) mm(P ＜ 0.01).At final follow-up,cervical axial rotation range of motion was 102°-154° in T1-type cases and 57°-93° in T2-type cases.Range of motion for atlantoaxial joint was preserved in T1-type cases,but lost in T2-type cases.According to the Symon-Lavender clinical standard,there were 14 cases of mild disability,nine moderate disability,eight severe disability and one extremely severe disability before operation;there were 21 cases of mild disability,nine moderate disability and two severe disability at last follow-up.Significant difference was observed in the grades according to the Symon-Lavender clinical standard before operation and at last follow-up (P ＜0.05).At last follow-up,JOA score was increased to (14.6 ± 2.9) points from preoperative (9.9± 3.2) points,and VAS was decreased to (2.7 ± 1.3)points from preoperative (6.0 ± 1.6)points (P ＜ 0.01).Conclusions By using TOI classification,reconstruction of stability and improved neurological function can be achieved in treatment of traumatic T-type atlantoaxial dislocation.Non-fusion treatment of T1-type atlantoaxial dislocation can preserve range of motion for atlantoaxial joint.