TO THE EDITOR
Intraoperative Monitoring for ACDF
We read with interest the study of Ajiboye et al on the use of intraoperative monitoring (IOM) during anterior cervical decompression and fusion surgery.1
The authors do indeed admit several limitations linked to the retrospective nature of their study and the usage of an administrative database as a data source. One of the main limitations, not explicitly mentioned, is the inclusion of a variety of different diagnostic codes without any analysis of their frequency in the two studied groups. Severity of neurological involvement can therefore differ between the two groups. It is quite possible that the more severe neurological cases are operated with IOM, while the so-called routine cases or those considered low risk might not have been thought suitable for IOM.
Resolving the issue of the utility of IOM is not a straightforward task. False positives are quite common as we also found out during spinal osteotomy procedures.2 Nevertheless, a complete loss of signal does usually demand some action, which in itself could perhaps be determinant for the neurological outcome. Even if the cost of IOM could be as high as 1 million USD/yr as mentioned in the Discussion section, such a cost might be warranted by the high societal and human cost of severe neurological damage. We feel that the conclusions of the paper namely that IOM does not prevent neurological injury is not necessarily supported by data presented. The risk of such a statement would be to see a further decline in IOM on the basis that there is no direct benefit.