What should an ideal spinal injury classification system consist of? A methodological review and conceptual proposal for future classifications

Abstract

Since Böhler published the first categorization of spinal injuries based on plain radiographic examinations in 1929, numerous classifications have been proposed. Despite all these efforts, however, only a few have been tested for reliability and validity. This methodological, conceptual review summarizes that a spinal injury classification system should be clinically relevant, reliable and accurate. The clinical relevance of a classification is directly related to its content validity. The ideal content of a spinal injury classification should only include injury characteristics of the vertebral column, is primarily based on the increasingly routinely performed CT imaging, and is clearly distinctive from severity scales and treatment algorithms. Clearly defined observation and conversion criteria are crucial determinants of classification systems’ reliability and accuracy. Ideally, two principle spinal injury characteristics should be easy to discern on diagnostic images: the specific location and morphology of the injured spinal structure. Given the current evidence and diagnostic imaging technology, descriptions of the mechanisms of injury and ligamentous injury should not be included in a spinal injury classification. The presence of concomitant neurologic deficits can be integrated in a spinal injury severity scale, which in turn can be considered in a spinal injury treatment algorithm. Ideally, a validation pathway of a spinal injury classification system should be completed prior to its clinical and scientific implementation. This review provides a methodological concept which might be considered prior to the synthesis of new or modified spinal injury classifications.

AO spine injury classification system: a revision proposal for the thoracic and lumbar spine

“…At present, there are no guidelines published for the development of spinal injury classifications [11]. In line with the AO philosophy and other successfully validated long-bone injury classifications [12], we believe that the characterization and categorization of TL injuries should primarily be based on morphological characteristics that can be reliably identified on diagnostic images.…”

“…A clear distinction has to be made between severity measures, treatment algorithms, and classification systems as recently outlined by van Middendorp et al [11]. Other medical prognostic factors, co-morbidities, and neurological deficits also have an impact on treatment decisions, but need to be classified separately and thus are not integrated into the present classification system.…”

The precision, accuracy and validity of detecting posterior ligamentous complex injuries of the thoracic and lumbar spine: a critical appraisal of the literature

“…Content validity of a measurement is often established through subjective judgments, i.e. face validity, about whether the relevance and applicability of a diagnostic item seems reasonable [2,12].…”

“…In order to be useful, a spinal injury classification system should be reliable, accurate and clinically relevant [2]. As such, a classification should facilitate a surgeon in determining the 'stability' of the injured spine and its potential consequences.…”

The Michel Benoist and Robert Mulholland yearly European Spine Journal Review: a survey of the “surgical and research” articles in the European Spine Journal, 2010

“…The paper concerning spinal injury classification by van Middendorp et al [54] is not an easy read. However, it repays study.…”