Response to Letter to the Editor for “The AO Spine TL Classification System Drives Clinical Decision Making in Acute Thoracolumbar Fractures: A Retrospective Evaluation of Clinical Implementation”

Dear Editor,

We thank the authors for their interest in our work and appreciate the valuable remarks raised in response to our recent publication, which (1) examined the association between AO Spine Thoracolumbar Injury Classification System and treatment choice in patients with acute traumatic thoracolumbar fractures, and (2) evaluated the extent to which clinical decision-making adhered to the classification system’s recommendations. ¹

The first comment addresses the concerns about the conclusion that the AO Spine TL Injury Classification System “drives” clinical decision-making and highlights the multifactorial decision-making process to operate on patients with thoracolumbar fractures. This includes not only fracture morphology, but also neurologic compromise, spinal canal encroachment, mechanical instability, patient comorbidity burden, surgeon judgment, and patient preference within a shared decision-making framework. We fully concur with the authors’ perspective that real-world decision-making is multifactorial. Our intention in using the term “drive” was not to imply that the treatment decision is solely based on the classification system. Rather, the classification system offers treatment recommendations, and these recommendations (especially those based on the morphological components) align well with clinical practice in our hospital, as described in our discussion section. ¹ The AO Spine TL Injury Classification System should be considered as a valuable tool to guide the decision-making process, but is not the sole determining factor in clinical practice as the decision is multifactorial.

The second comment addresses the possibility of presence of confounding by indication. In our study we adjusted for multiple potential confounders, including sex, age, comorbidities, trauma mechanism, Injury Severity Score (ISS), and the number of fractures. While we initially intended to analyse neurological injury and Glasgow Coma Score (GCS) as potential confounders, this was not possible due to the relatively small number of patients. As described in our article, we found that all patients with A4 fractures who underwent surgery had neurological injury identified during physical examination and/or fragment dislocation into the spinal canal detected in imaging. This observation suggests that the neurological component of the classification system is an essential component in treatment decision-making for A4 fractures. ¹

The third comment emphasizes the study’s secondary findings and points toward an important opportunity for future research. We appreciate this insight and fully agree that future prospective, multicentre studies with standardized recording of morphology, neurologic status, (clinical) modifiers, and longitudinal clinical outcomes may help clarify not only whether the AO Spine TL Injury Classification System correlates with current treatment decisions, but also whether its full application improves prognostic discrimination and patient-centred outcomes. In this context, we also recommend that future studies include a larger number of patients with A4 fractures to validate our study findings.

We sincerely appreciate the authors sharing their thoughtful insights and are grateful for the opportunity to clarify several aspects. We hope that our study findings and considerations will contribute to the discussions and the body of evidence regarding the clinical utility, and practical implementation of the AO Spine TL Injury Classification System.