Pooled Analysis of Non-Union, Re-Operation, Infection, and Approach Related Complications after Anterior Odontoid Screw Fixation

Abstract

BackgroundAnterior odontoid screw fixation (AOSF) has been one of the most popular treatments for odontoid fractures. However, the true efficacy of AOSF remains unclear. In this study, we aimed to provide the pooled rates of non-union, reoperation, infection, and approach related complications after AOSF for odontoid fractures.MethodsWe searched studies that discussed complications after AOSF for type II or type III odontoid fractures. A proportion meta-analysis was done and potential sources of heterogeneity were explored by meta-regression analysis.ResultsOf 972 references initially identified, 63 were eligible for inclusion. 54 studies provided data regarding non-union. The pooled non-union rate was 10% (95% CI: 7%–3%). 48 citations provided re-operation information with a pooled proportion of 5% (95% CI: 3%–7%). Infection was described in 20 studies with an overall rate of 0.2% (95% CI: 0%–1.2%). The main approach related complication is postoperative dysphagia with a pooled rate of 10% (95% CI: 4%–17%). Proportions for the other approach related complications such as postoperative hoarseness (1.2%, 95% CI: 0%–3.7%), esophageal/retropharyngeal injury (0%, 95% CI: 0%–1.1%), wound hematomas (0.2%, 95% CI: 0%–1.8%), and spinal cord injury (0%, 95% CI: 0%–0.2%) were very low. Significant heterogeneities were detected when we combined the rates of non-union, re-operation, and dysphagia. Multivariate meta-regression analysis showed that old age was significantly predictive of non-union. Subgroup comparisons showed significant higher non-union rates in age ≥70 than that in age ≤40 and in age 40 to <50. Meta-regression analysis did not reveal any examined variables influencing the re-operation rate. Meta-regression analysis showed age had a significant effect on the dysphagia rate.Conclusions/SignificancesThis study summarized the rates of non-union, reoperation, infection, and approach related complications after AOSF for odontoid factures. Elderly patients were more likely to experience non-union and dysphagia.

Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients

“…In developing countries like ours, despite these intra-operative aids, the procedure can still be performed using pre-operative images and pertaining to our basic anatomical knowledge. Our results are comparable to previously published studies 10 .…”

“…Moreover, anterior approach is not justified in scenarios such as associated transverse ligament disruption, comminuted and significantly displaced fracture segments as well as posterior element injuries 19 . There is also high incidence of non-union in age groups of above 70 years with concomitant osteoporosis 20 . Posterior fusion is rather a more valid approach in such cases 19 .…”

Anterior transarticular atlantoaxial screw fixation in combination with dens screw fixation for type II odontoid fractures with associated atlanto-odontoid osteoarthritis

“…A CT was performed only in cases of clinical or radiological suspicion of non-union. Tian et al [26] observed that the pooled non-union rate based on CT scan was higher than that based on only X-rays. However, this difference was not statistically significant.…”

“…Generally, it is important to note that many studies or reviews in the literature consist of rather small samples or small original study populations [8,26,30,31]. To the best of our knowledge, this series represents the largest study investigating mortality in patients aged 70 years and older with type II odontoid fractures treated with TAFOF.…”

“…Tian et al [26] performed a pooled analysis and reported a 2.5 times higher non-union rate in a comparable patient group with respect to age. An even higher fusion rate might be possible by exposing the atlantoodontoid capsule, scraping the articular surface and adding bone graft to promote fusion.…”