A Comparison of different posterior arthrodesis techniques versus anterior dens screw for odontoid fractures: A systematic review and meta-analysis.

Abstract

Background and objectives: Odontoid fractures are often managed surgically. The most common approaches are anterior dens screw (ADS) and posterior arthrodesis (PA), with the latter being associated with significantly higher fusion rates. PA techniques can include wiring, C1-C2 transarticular (TA) screws, and C1 lateral mass (LM)-C2 pars/pedicle screws. Most comparative studies group multiple PA techniques together when comparing PA versus ADS. Our objective was to systematically review the literature and identify studies that separately provide fusion rates of each different posterior C1-C2 arthrodesis (PA) technique utilized compared to ADS.

Methods: A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A random effects meta-analysis was performed, and the I² statistic was used to assess heterogeneity.

Results: In total, 15 studies comprising 685 patients (ADS: 377; wiring: 58; TA: 150; C1 LM-C2 pars/pedicle screws: 100). The average age of the patients ranged across the included studies between 22 and 82.4 years old. The mean last follow-up was >12 months in eight studies. Only two studies reported a follow-up period of <6 months. Most of the odontoid fractures were type II based on the Anderson-D'Alonzo classification. Use of C1 LM-C2 pars/pedicle screws was associated with significantly higher odds of fusion compared to ADS (C1 LM-C2 pars/pedicle: 97%; ADS: 87.2%; odds ratio [OR]: 3.89; 95% confidence interval [CI]: 1.34-11.29; I^2: 0%). TA screws were associated with significantly higher odds of fusion compared to ADS (TA: 98%; ADS: 87%; OR: 4.19; 95% CI: 1.67-10.47; I^2: 0%). There was no difference in the rate of fusion between wiring and ADS (wiring: 84.4%; ADS: 92.6%; OR: 0.34; 95% CI: 0.08-1.40; I^2: 48.8%).

Conclusions: C1-C2 TA screws and C1 LM-C2 pars/pedicle screws are both associated with statistically significant higher rates of fusion compared to ADS for odontoid fractures. ADS showed higher rates of fusion compared to wiring, although this did not reach statistical significance.