Abstract
To the Editor,
We read with great interest the retrospective comparative study by Niu et al (2025) titled Monoaxial Screws vs Polyaxial Screws Osteosynthesis for Unstable Atlas Fractures: A Retrospective, Comparative Study With a Minimum Follow-Up of 3 years” by Niu et al. 1 Posterior atlantoaxial-fusion is indicated in unstable atlas burst fractures with intraligamentous lesion of the transverse ligament (type Dickman I), dislocated bony avulsion fragments of the TAL (major dislocated Dickman type II), translatory atlantoaxial instability. 2 Fusion techniques include transarticular C1-2 screw fixation according to Grob and Magerl or posterior screw and rod fixation according to Harms and Melcher.3,4
We commend the authors for their dedication in evaluating long-term outcomes in this challenging patient population. It puts an end to old age dilemma to the efficacy of Monoaxial vs polyaxial screws. I would like to appreciate the authors work and paving for decision making in unstable atlas fractures very clear, From this article, we can easily conclude that we should prefer polyaxial screws in the novice phase and shift to monoaxial once we gain more expertise. However, we would like to offer some perspectives to further contextualise these findings and guide future research.
Study Design Considerations
Given the retrospective nature of the study and the relatively small sample size (Group A: 12, Group B: 21), we recognise that statistical power and generalisability may be limited. While the authors ensured balance in demographic variables, unmeasured confounders such as surgeon preference and fracture complexity, could have influenced the outcomes. A prospective, multicenter study with a larger cohort would enhance the robustness of these findings.
Clinical Versus Radiographic Outcomes
The study highlights a higher anterior arch reduction rate with polyaxial screws (100% vs 67%, P = 0.002). However, long-term clinical outcomes, including the Neck Disability Index (NDI), Range of Motion (ROM), and Anterior Atlantodental Interval (AADI), showed no significant differences between groups. This raises the question: does superior radiographic alignment translate into meaningful clinical benefits?. Future research emphasising patient-reported outcomes, such as pain relief and functional recovery could provide more practical insights for surgical decision-making.
Surgical Considerations and Complications
The findings suggest that monoaxial screws are associated with shorter operative times and reduced blood loss but a higher complication rate (33% chronic bursitis). Conversely, polyaxial screws led to fewer complications but required longer hospital stays. A cost-benefit analysis comparing perioperative efficiency with long-term morbidity would be invaluable for guiding treatment selection. Gus et al fixed the lateral mass is fixed with a towel clamp while inserting the posterior transpedicular screw and found it to be safe and reliable during treatment of unstable atlas fracture. No such reduction technique has been mentioned in this article. 5
Technical and Reproducibility Factors
Since all procedures were performed by a single senior surgeon, the study benefits from consistency but may lack generalisability. Would outcomes differ with variations in screw placement techniques or surgeon expertise? Future studies involving multiple surgeons or institutions could help clarify this aspect and improve external validity. Also, there has been no mention of the deficit status of the patient and how imperative it is to reduce the fracture or decompress if there is a spinal cord injury. The role of clinical biomarkers playing a pivotal role in evaluating the injury pre operatively as well as intra operatively while reducing the fracture may add more strength to this study. 6
Long-Term Considerations
A three-year follow-up provides valuable mid-term data, but long-term outcomes remain uncertain. Late complications, such as implant failure or degenerative changes, could influence the preferred fixation method. Additionally, the role of Transverse Atlantoaxial Ligament (TAL) integrity in post-surgical stability warrants further investigation, as TAL injury is a known predictor of instability.
In conclusion, this study offers important insights into the benefits and trade-offs of monoaxial and polyaxial screws. While polyaxial screws appear advantageous for anatomical reduction, monoaxial screws provide perioperative efficiencies. However, the similar clinical outcomes suggest that both techniques remain viable, with the choice ultimately depending on fracture characteristics and surgeon expertise. We appreciate the authors’ contributions to this important discussion and encourage further research to refine surgical strategies for unstable atlas fractures.
