Anatomic, Image-based Classification of Diseased Lumbar Spinal Motion-Segment-Preliminary Clinical Report
Authors:   MD, FAAOS, FRCS Ed (Ortho), Advanced Spine Endoscopy and Pain Institute, Frederick, Maryland, USA, Osman Said G , Sura Sukumar ,   MCh, FRCS Ed, Asian Spine Hospital, Hyderabad, Telangana, India, anthila Mahesha ,   MS (Ortho), DNB (Ortho), Maithri Specialty Clinics Bendoorwell, Mangalore, India
Published: March 2024

Background: Multiple minimally invasive spine approaches and techniques have been developed in recent years. While the disease processes affecting the spinal motion-segment (SMS) have remained largely the same, surgical treatment options have changed radically and not necessarily in an organized fashion. This is inevitable given the rapid evolution of the technology. The current image-based diagnostic techniques, also evolving, have helped us appreciate the disease Patho anatomy in minute detail. A comprehensive classification method accounting for all anatomical participants in the spinal motion-segment pathology, tailored to treatment options, is necessary. Out of the many valid options, a spine surgeon should be able to choose a single surgical approach that is most appropriate for the Patho anatomy of his/her patient’s disease. We feel that our classification system will help the spine surgeon make that important decision consistently, with minimal risk of leaving behind a significant lesion, or disrupting a structure which is not a participant in the disease process. Furthermore, universal acceptance of this classification system will make it easier for spine surgeons to communicate with each other and meaningfully compare the results of the various surgical approaches. Purpose of the Study: To develop a comprehensive, treatment-orientated classification of lumbar spinal motion-segment disease. Materials and Methods: Contributors to spinal motion-segment disease - intervertebral disc, facet joint, ligamentum flavum and mal-alignment were identified. The degrees of abnormalities in each of these entities were coded, and the codes were entered in a table from which the possible combinations of pathologic processes were generated. Study of 57 lumbar MRI images (217 spinal motion-segments) was carried out to determine the prevalence of various combinations of the motion-segment disease. Pre- and post-operative MRI-based spinal motion-segment classifications were performed to evaluate the clinical application of this classification system in 15 patients. Results: This classification presents 494 possible combinations of the spinal motion-segment disease. Many of the combinations are only theoretical possibilities without clinical significance. Normal motion-segments, D0 A0 L0 F0 , represented 33.3% of the total motion-segments; D1 A0 L0 F0 was 8.8%, representing bulging disc, normal alignment, ligamentum flavum and facet joint. D2 A0 L0 F2 was 6.9% representing intraannular disc herniation, normal alignment, mildly thickened ligamentum flavum, and hypertrophied superior articular process of the facet joint. 6.4% was D1 A0 L1 F3 representing bulging disc, mildly hypertrophic ligamentum and hypertrophied facet joint. Clinical application of the classification revealed: Accurate anatomic classification; immediate post-operative classification changes which correlate with patient’s symptoms; pre-operative, immediate post-operative and late post-operative classifications which correlate with patient’s symptoms and accurately demonstrate post-operative remodeling of the motion-segment, especially after disc surgery, and accurate; and anatomic documentation of pre- and post op classifications of interlaminar endoscopic decompression. Conclusion: A treatment-orientated, standardized classification of spinal motion-segment disease is necessary considering current multiple treatment options and availability of sophisticated pre-operative imaging techniques. Such a classification will allow standardization of treatment options for various combinations of the pathological processes. With the emergence of new technologies surgical options can be upgraded based on a standardized classification. This in turn will help minimize confusion for those who want to learn and facilitate growth in the minimally invasive technology. The preliminary results of clinical application of the classification showed it to be a very accurate patho-anatomic representation; immediate post-operative classification change reflected clinical improvement post-operatively; and precise representation of post-operative remodeling of the motion-segment one to two years post-operatively. The precision of this classification allows accurate communication regarding the pathology, between providers across the globe, and more accurate comparison of results of different surgical interventions.