Clinical StudyClinical and radiographic degenerative spondylolisthesis (CARDS) classification
Introduction
Lumbar degenerative spondylolisthesis (DS) is a common, acquired, pathologic condition that can lead to disabling back or leg pain. Although surgery is commonly required for patients with severe symptoms secondary to DS, there are no universally accepted treatment guidelines. Many surgeons routinely perform spinal fusion when decompressing the neural structures for symptoms of neurogenic claudication or radiculopathy. This approach is based, in part, on the work by Herkowitz and Kurz [1], who demonstrated superior clinical outcomes for patients undergoing noninstrumented fusion for DS compared with those who underwent laminectomy alone. In recent years, fusion for DS has commonly been supplemented with instrumentation, which has been shown to enhance the rate of successful arthrodesis [2]. Recently, it has become increasingly common to encounter patients undergoing interbody fusion for DS [3], [4], [5]. At the other end of the spectrum, some surgeons perform a decompression without fusion, especially when using a minimally invasive approach that preserves the midline structures [6], [7], [8], [9]. Another subset of surgeons advocate the use of dynamic instrumentation without fusion to address the potential instability after decompression [10]. Clearly, more clarity is needed to define the optimal treatment strategies for this common clinical condition.
A major difficulty with studying or discussing treatment approaches to DS is the heterogeneous nature of the condition. Radiographically, a wide range is seen in the magnitude of vertebral translation, intervertebral disc collapse, sagittal alignment, and mobility with flexion and extension, parameters that have been previously demonstrated to change the biomechanical loading environment of spinal elements [11] and also affect loads placed on spinal instrumentation. Based on these differences, optimal treatment strategies may vary to address the biomechanical goals of the specific case but no classification scheme has ever been developed to encourage discussion and investigation of anatomic variations in DS. Such a scheme should be simple and reproducible so that clinicians and researchers can easily define the subgroup of a given patient and then apply a research or treatment approach designed for a more homogeneous subgroup instead of the entire disease spectrum.
The present study was undertaken to develop and test the reliability among spine surgeons of a simple, four-part classification scheme for patients with DS. The purpose of this classification scheme is to subdivide the wide spectrum of DS into reproducible subgroups to facilitate communication between clinicians and promote high quality outcomes research to be performed.
Section snippets
Radiographic measurement survey
A prior radiographic survey was conducted [12] involving 304 patients with L4–L5 DS. In this survey, measurements were taken of anterior and posterior disc heights, vertebral translation, and vertebral movement with flexion and extension. This survey demonstrated a wide range of values for each of the measured parameters. The data from each measured parameter were continuous, without any natural “breaks” in data that could be used to subcategorize DS patients.
Selection of clinical and morphologic characteristics for the classification scheme
Given the absence of any useful
Type A: advanced disc space collapse without kyphosis
This subgroup is characterized by complete collapse of the disc space with bony apposition of adjacent vertebral end plates that would prevent further axial settling. For Type A designation, the disc space collapse may be symmetric with nearly parallel end plates (Fig. 2) or asymmetric with bony apposition along only the posterior margin of the end plate (Fig. 3). In the Type A subgroup, no kyphosis between the end plates on any lateral radiographic view should be seen.
Type B: disc partially preserved with translation of 5 mm or less
This subgroup is
Discussion
The wide range of radiographic parameters seen with DS is indicative of a heterogeneous disease for which a “one size fits all” treatment approach may overtreat or undertreat a significant percentage of the patient population. Given how frequently DS is encountered in clinical practice, it may seem surprising that no classification scheme for this condition entered common usage. A wide range of surgical approaches have been advocated in the scientific literature including simple decompression
Conclusion
A new classification scheme for lumbar DS is proposed based on radiographic and clinical criteria. This scheme is shown to have high inter- and intraobserver reliabilities. Use of the CARDS classification scheme should facilitate communication between clinicians and enhance the quality of outcomes research in the field of DS.
References (35)
- et al.
The effect of a radiographic solid fusion on clinical outcomes after minimally invasive transforaminal lumbar interbody fusion
Spine J
(2011) - et al.
Methods of formal consensus in classification/diagnostic criteria and guideline development
Semin Arthritis Rheum
(2011) - et al.
Single-level instrumented posterolateral fusion versus non-instrumented anterior interbody fusion for lumbar spondylolisthesis: a prospective study with a 2-year follow-up
J Orthop Sci
(2011) - et al.
Operative management of degenerative scoliosis: an evidence-based approach to surgical strategies based on clinical and radiographic outcomes
Neurosurg Clin N Am
(2007) - et al.
The effect of sagittal alignment on adjacent joint mobility after lumbar instrumentation–a biomechanical study of lumbar vertebrae in a porcine model
Clin Biomech (Bristol, Avon)
(2004) - et al.
Degenerative lumbar spondylolisthesis with spinal stenosis. A prospective study comparing decompression with decompression and intertransverse process arthrodesis
J Bone Joint Surg Am
(1991) - et al.
1997 Volvo award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation
Spine
(1997) - et al.
Surgical treatment of adult degenerative spondylolisthesis by instrumented transforaminal lumbar interbody fusion in the Han nationality
J Neurosurg Spine
(2009) - et al.
Utility of minimum clinically important difference in assessing pain, disability, and health state after transforaminal lumbar interbody fusion for degenerative lumbar spondylolisthesis
J Neurosurg Spine
(2011) Posterolateral lumbar fusion for degenerative spondylolisthesis: experiences of a modified technique without instrumentation
J Med Assoc Thai
(1997)
The dynamic neutralization system for the spine: a multi-center study of a novel non-fusion system
Eur Spine J
Degenerative spondylolisthesis: does fusion method influence outcome? Four-year results of the spine patient outcomes research trial
Spine
Success and failure of minimally invasive decompression for focal lumbar spinal stenosis in patients with and without deformity
Spine
Dynamic stabilization for degenerative lumbar scoliosis in elderly patients
Spine
The stabilizing system of the spine. Part II. Neutral zone and instability hypothesis
J Spinal Disord
A radiographic analysis of degenerative spondylolisthesis at the L4-5 level
J Neurosurg Spine
The measurement of observer agreement for categorical data
Biometrics
Cited by (45)
A Review of the Main Classifications of Lumbar Spondylolisthesis
2023, World NeurosurgeryClinical Correlations to Specific Phenotypes and Measurements With Classification Systems: Lumbosacral Spine
2021, Atlas of Spinal Imaging: Phenotypes, Measurements and Classification SystemsThe clinical and radiographic degenerative spondylolisthesis classification and its predictive value
2024, Archives of Orthopaedic and Trauma Surgery
FDA device/drug status: Approved (Pedicle Screws), (Interbody Cages).
Author disclosures: CKK: Nothing to disclose. ASH: Royalties: Aesculap (B), Amedica (C), Biomet (F), Stryker (B), Stock Ownership: Amedica (30,000 shares), Vertiflex (B), Benvenue ($10,000 invested), Lifespine (unknown), Paradigm Spine ($10,000 invested), PSD ($10,000 invested), Spinal Ventures (less than 1% of company, value unknown). AS: Nothing to disclose. JDK: Nothing to disclose. JAR: Consulting: Pfizer Inc. (B); Grants: Depuy Spine (D). KER: Consulting: Globus Medical (C); Speaking and/or Teaching Arrangements: Depuy/Synthes (B). ARV: Royalties: Depuy (C), Medtronic (F), Stryker Spine, Biomet Spine (F), Globus, Aesculap (B), Nuvasive; Stock Ownership: Replication Medica (B), Globus, K-2 Medical (F), Paradigm Spine (F), Stout Medical, Spine Medica (D), Computational Biodynamics (B), Progressive Spine Tach (F), Spinology (C), Small Bone Innovations (E), NeuCore (B), Cross Current (E), Syndicom (B), In Vivo (B), Flagship Surgical (D), Advanced Spinal Intellectual Properties, Cytonics (B), Bonove Orthopedics (E), Electrocore (D), Gamma Spine (B), Location Based Intelligence (D), Flow Pharma (B), RSI (B), Rothman Institute and Related Properties (F), Innovative Surgical Design, Spinicity (D); Consulting: Stout Medical (F), Gerson Lehrman Group (B), Guidepoint Global (B), Medacorp (B), Innovative Surgical Design; Scientific Advisory Board/Other Office: AO Spine, Innovative Surgical Design, Association of Collaborative Spine Research, Spinicity; Grants: Stryker, Nuvasive (F), Cerapedics (B). TJA: Royalties: Depuy (H), Biomet spine (F); Consulting: Depuy (C), Facetlink (C); Scientific Advisory Board/Other Office: Rothman Institute (Nonfinancial), MAB-United Healthcare (B), CSRS (Nonfinancial), SRS/IMAST (Nonfinancial). DGA: Royalties: Depuy Spine (G) and Medtronic (D); Consulting: Depuy Spine/Synthes (C), Medtronic (A), Globus (A).
The disclosure key can be found on the Table of Contents and at www.TheSpineJournalOnline.com.
This study had no outside funding and presents no conflict of interest.