Nomenclature and Classification of Lumbar Disc Pathology

INTRODUCTION

Physicians need reliable terms that describe normal and pathologic conditions of lumbar discs. Terms that can be interpreted accurately, consistently, and with reasonable precision are particularly important for communicating impressions gained from imaging for clinical diagnostic and therapeutic decision making. Although clear understanding of disc terminology between radiologists and clinicians is the focus of this work, such understanding can be critical, also, to patients, families, employers, insurers, jurists, social planners, and researchers.

In 1995, a multi-disciplinary task force from the North American Spine Society (NASS) addressed deficiencies in standardization and current practice of the language defining conditions of the lumbar disc. It cited several documentations of the problem ^{3,4,5,13,16,28} and made detailed recommendations for standardization. Its work was published in a co-publication of NASS and the American Academy of Orthopaedic Surgeons (AAOS).¹⁵ The work has not been otherwise endorsed by major organizations and has not been recognized as authoritative by radiology organizations. Many previous^{2,4,13,27,28,29,31,33,39,43,44,45,49}and some subsequent^{12,19,22,25,26}efforts have addressed the issues, but have been of more limited scope and none have gained widespread compliance or formal endorsement.

Though the NASS 1995 effort has been the most comprehensive to date, it remains deficient in clarifying some controversial topics, lacking in its treatment of some issues, and does not provide recommendations for standardization of classification and reporting. To address the remaining needs, and in hopes of securing endorsement sufficient to result in universal standardization, joint task forces were formed by NASS, the American Society of Neuroradiology (ASNR), and the American Society of Spine Radiology (ASSR). This work is the product of those task forces.

A few general principles guided the generation of this document. The definitions should be based upon the anatomy and pathology. Recognizing that some criteria, under some circumstances, may be unknowable to the observer, the definitions of diagnoses should not be dependent upon or imply value of specific tests. The definitions of diagnoses should not define or imply external etiologic events such as trauma. The definitions of diagnoses should not imply relationship to symptoms. Definitions of diagnoses should not define or imply need for specific treatment.

The task forces worked from a model that could be expanded from a primary purpose of providing understanding of reports of imaging studies. The result would provide a simple and relatively imprecise classification of diagnostic terms, based upon pathology, which could be expanded, without contradiction, into more precise sub-classifications. When reporting pathology, degrees of uncertainty would be labeled as such rather than compromising upon the definitions of the terms.

All terms used in the classifications and sub-classifications were to be defined and those definitions would be adhered to throughout the model. For practical purpose, some existing English terms were given meanings different from those found in some contemporary dictionaries. The task forces would provide a list and classification of recommended terms, but, recognizing the nature of language practices, would discuss, and include in a glossary, commonly used, and misused, non-recommended terms and non-standard definitions.

Although the principles and most of the definitions of this document could be easily extrapolated to the cervical and dorsal spine, the focus is on the lumbar spine. While clarification of terms related to posterior elements and disorders related to dimensions of the spinal canal are also needed, this work is limited to discussion of the disc. Though it is not always possible to fully discuss the definition of anatomical and pathological terms without some reference to symptoms and etiology, the definitions, themselves, stand the test of independence from etiology, symptoms, or treatment. Because of the focus on anatomy and pathology, this work does not define certain clinical syndromes that may be related to lumbar disc pathology.

Guided by those principles, this document provides a universally acceptable nomenclature that is workable for all forms of observation, that addresses contour, content, integrity, organization, and spatial relationships of the lumbar disc; and that serves a system of classification and reporting built upon that nomenclature.

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Introduction

Preface	Introduction	Recommendations	Discussion (part 1)
Discussion (part 2)	Glossary	References	Appendix