Case-control study comparing the efficacy of surgical techniques for C1-C2 arthrodesis

Atlantoaxial fusion rates between 85% and 98% using C1-C2 transarticular screw (TAS) fixation have been reported; however, all of these studies are class III data. As such, these studies carry little or no statistical significance. The authors thus designed a case-control study (class II data) to evaluate the efficacy of C1-C2 TAS fixation as compared with posterior wiring techniques (PWTs). Records of adult subjects were reviewed for fusions isolated to C1-C2. Immobilization requirements were a collar for patients treated with TAS fixation and a halo for those treated by PWT. The minimum acceptable interval of radiographic follow-up was 12 months, and the outcome (fusion or nonunion) was determined through independent interpretation by a radiologist. Twenty-seven of 72 patients undergoing a posterior atlantoaxial arthrodesis met enrollment criteria. Sixteen males and 11 females combined for an average age of 54.1 years and mean follow-up of 31 months. Successful fusions (n = 18) were defined as controls, and cases represented nonunions (n = 9). Successful fusion was achieved in 13 of 14 patients treated with the TAS technique as compared with 5 of 13 subjects who underwent a PWT. Patients with a radiographically solid fusion were 21 more times likely to have undergone TAS than PWT (P = 0.004). This study demonstrated a statistically increased rate of arthrodesis as determined by specific radiographic criteria with the use of TAS fixation as compared with PWT.