We are truly grateful for the opportunity to respond to this Letter to the Editor concerning our recently published study entitled “Is anterior-only fixation adequate for three-column injuries of the cervical spine? [1].”

(1) The three-column concept is one of the first and broader classification systems used. The AO classification system is much fine-tuned and is still under development. Moreover, it does not use the three-column concept that is used traditionally. The initial AO classification was developed for thoracolumbar injuries [2] and was later adapted for the sub-axial cervical spine [3]. In the present study, the primary inclusion criteria were traumatic injury to the sub-axial cervical spine (anterior, middle, and posterior), and after that available data were sub classified according to the AO classification. We do accept the fact of not mentioning new additional modifiers. But we have certain limitations as this was a retrospective study (as mentioned in manuscript).

(2) The authors agree with the fact that the ideal treatment for three-column injury is combined anterior and posterior instrumentation (as mentioned in the manuscript). But with the lack of any clear guidelines in the literature and less patient morbidity associated, the anterior fixation also provides acceptable stabilization with the added advantage of the availability of large graft surface area and less fused segment [4,5]. In our case series, one patient did require additional posterior instrumentation given the persistent instability after anterior instrumentation. However, our case series did not discuss the treatment failure rate of the present study as that in the followup period was low (as mentioned under the limitations of the manuscript).

(3) The classification used in the manuscript was in accordance with the initial AO classification and its adaption in the sub-axial cervical spine [2,3,5]. Our retrospective study conducted in 2016 did not include the current AO classification modifiers.

(4) The authors accept the shortcoming fact of not mentioning the associated conditions and injuries. But as explained earlier, this is one of the limitations of a retrospective study.

(5) In one patient, we required the additional posterior instrumentation as mentioned in the manuscript (this could be due to the associated rotational component and poor patient compliance with the American Spinal Injury Association impairment scale D neurology). As mentioned earlier, this was a retrospective analysis of prospectively collected data. Furthermore, the authors agree to the need for a further extensive study to decide the clear guidelines and define a firmer treatment protocol.