Estenosis lumbar degenerativa: conceptos básicos, evaluación clínica y manejo / Degenerative lumbar spinal stenosis: basic concepts, clinical evaluation, treatment

La estenorraquis lumbar es la disminución del volumen del canal raquídeo en la columna. Es la causa más frecuente de dolor lumbociático y lumbocrural en población mayor de 60 años. Existen múltiples causas. La más común es la degenerativa que consiste en una disminución del canal secundario a varios factores como protrusión del disco intervertebral, hipertrofia y abombamiento del ligamento amarillo, engrosamiento de la capsula articular y por osteofitos. Los síntomas principales son el dolor lumbar irradiado a extremidades inferiores tipo lumbociática o lumbocruralgia y la claudicación neural intermitente. Generalmente no hay déficit motor ni sensitivo. La resonancia magnética es el estudio de elección para el diagnóstico, pero debe complementarse con radiografías y con frecuencia con tac para una mejor valoración de la patología. El tratamiento inicial siempre es conservador, que incluye uso de antiinflamatorios, analgésicos, relajantes musculares, kinesioterapia e infiltraciones de columna (epidurales o radiculares). La mayoría de los pacientes responden satisfactoriamente a este manejo. El tratamiento quirúrgico está indicado a los pacientes que presentan un dolor intenso, que afecta su calidad de vida y que no mejora con el tratamiento conservador. Consiste en la descompresión quirúrgica de las raíces lumbares a través de laminectomía. En ocasiones se recomienda complementar la descompresión con artrodesis específicamente cuando la estenorraquis se asocia a otras condiciones como espondilolistesis degenerativa, escoliosis, desbalance sagital o coronal, inestabilidad segmentaria y en enfermedad del segmento adyacente.

Spinal lumbar stenosis is a narrowing of the spinal canal in the lumbar spine. Is the most frequent cause of sciatic pain or cruralgia in the elderly population over 60 years old. Exist many etiologies. The most common is degenerative caused by many factors including bulging disc, hypertrophy of flavum ligament as well as facet capsule thickening and by osteophytes formation. The main symptoms of spinal stenosis are radicular pain and neurogenic claudication. Lumbar flexion usually improves the symptom and deambulation often worsens the pain. Most of the time neurologic examination is normal. The gold standard study is mri but is necessary to complement with x rays and ct to obtain a better evaluation. Initial treatment is always conservative and consists in nsaid's, muscle relaxants, physical therapy and steroid spinal injections. Most of the patients respond well to this treatment. Surgical treatment is indicated when the patient has a severe pain, quality of life is miserable and conservative treatment fails. Decompression is the gold standard surgical treatment. The addition of an arthrodesis or spinal fusion is recommended in degenerative spondylolisthesis, scoliosis, sagital or coronal imbalance, deformity correction, recurrent spinal stenosis and in cases of adjacent level disease problem.

Spinal Stenosis Grading in Magnetic Resonance Imaging Using Deep Convolutional Neural Networks.

STUDY DESIGN: Retrospective magnetic resonance imaging grading with comparison between experts and deep convolutional neural networks (CNNs). OBJECTIVE: This study aims to verify the feasibility of a computer-assisted spine stenosis grading system by comparing the diagnostic agreement between two experts and the agreement between the experts and trained artificial CNN classifiers. SUMMARY OF BACKGROUND DATA: Spinal stenosis grading is important; however, it is tedious job to check the MR images slide by slide to classify patient grades often having different opinions regarding the final diagnosis. METHODS: For 542 L4-5 axial MR images, two experts independently localized the center position of the spine canal and graded the status. Two CNN classifiers each trained with the grading label made by the two experts were validated using 10-fold cross-validation. Each classifier consisted of a CNN detection model responsible for the localization of patches near the canal and a classification CNN model to predict the spinal stenosis status in the localized patches. Faster R-CNN was used for the detection model whereas VGG network was used for the classification model. A comparison in grading agreement was carried out between the two experts as well as that of the experts and the prediction results generated by the CNN models. RESULTS: Grading agreement between the experts was 77.5% and 75% in terms of accuracy and F1 scores. The agreement between the first expert and the model trained with the labels of the first expert was 83% and 75.4%, respectively. The agreement between the second expert and the model trained with the labels of the second expert was 77.9% and 74.9%. The differences between the two experts were significant, whereas the differences between each expert and the trained models were not significant. CONCLUSION: We indeed confirmed that automatic diagnosis using deep learning may be feasible for spinal stenosis grading. LEVEL OF EVIDENCE: 4.

Redundant nerve roots in lumbar spinal stenosis: inter- and intra-rater reliability of an MRI-based classification.

PURPOSE: Patients with central lumbar spinal stenosis (LSS) have a longer symptom history, more severe stenosis, and worse postoperative outcomes, when redundant nerve roots (RNRs) are evident in the preoperative MRI. The objective was to test the inter- and intra-rater reliability of an MRI-based classification for RNR. METHODS: This is a retrospective reliability study. A neuroradiologist, an orthopedic surgeon, a neurosurgeon, and three orthopedic surgeons in-training classified RNR on 126 preoperative MRIs of patients with LSS admitted for microsurgical decompression. On sagittal and axial T2-weighted images, the following four categories were classified: allocation (A) of the key stenotic level, shape (S), extension (E), and direction (D) of the RNR. A second read with cases ordered differently was performed 4 weeks later. Fleiss and Cohen's kappa procedures were used to determine reliability. RESULTS: The allocation, shape, extension, and direction (ASED) classification showed moderate to almost perfect inter-rater reliability, with kappa values (95% CI) of 0.86 (0.83, 0.90), 0.62 (0.57, 0.66), 0.56 (0.51, 0.60), and 0.66 (0.63, 0.70) for allocation, shape, extension, and direction, respectively. Intra-rater reliability was almost perfect, with kappa values of 0.90 (0.88, 0.92), 0.86 (0.84, 0.88), and 0.84 (0.81, 0.87) for shape, extension, and direction, respectively. Intra-rater kappa values were similar for junior and senior raters. Kappa values for inter-rater reliability were similar between the first and second reads (p = 0.06) among junior raters and improved among senior raters (p = 0.008). CONCLUSIONS: The MRI-based classification of RNR showed moderate-to-almost perfect inter-rater and almost perfect intra-rater reliability.

[Classification and diagnosis of lumbar spinal stenosis]. / Klassifikation und Diagnostik der lumbalen Spinalkanalstenose.

BACKGROUND: Lumbar spinal stenosis is caused by various pathological conditions. With the diagnostic tools available, a precise classification of the condition should be made, which enables a consistent and appropriate therapeutic approach. OBJECTIVES: In the present article, the currently used classifications of lumbar spinal stenosis are discussed and the diagnostic tools are presented, focussing on the imaging descriptions of morphological changes. MATERIALS AND METHODS: This article is based on a PubMed literature search of the past 60 years and our own experiences. RESULTS: Lumbar spinal stenosis is caused mainly by degenerative changes to the spine. MR tomographic imaging can result in precise anatomical illustration and classification of the stenosis. CONCLUSIONS: Although modern imaging procedures deliver a very precise illustration of lumbar spinal stenosis, clinical symptoms make a considerable contribution to therapeutic decision-making. With the anatomical classification, differentiated surgical decompression of the spinal canal can be planned.

Texture analysis of paraspinal musculature in MRI of the lumbar spine: analysis of the lumbar stenosis outcome study (LSOS) data.

OBJECTIVE: To evaluate association of fatty infiltration in paraspinal musculature with clinical outcomes in patients suffering from lumbar spinal stenosis (LSS) using qualitative and quantitative grading in magnetic resonance imaging (MRI). MATERIALS AND METHODS: In this retrospective study, texture analysis (TA) was performed on postprocessed axial T2 weighted (w) MR images at level L3/4 using dedicated software (MaZda) in 62 patients with LSS. Associations in fatty infiltration between qualitative Goutallier and quantitative TA findings with two clinical outcome measures, Spinal stenosis measure (SSM) score and walking distance, at baseline and regarding change over time were assessed using machine learning algorithms and multiple logistic regression models. RESULTS: Quantitative assessment of fatty infiltration using the histogram TA feature "mean" showed higher interreader reliability (ICC 0.83-0.97) compared to the Goutallier staging (κ = 0.69-0.93). No correlation between Goutallier staging and clinical outcome measures was observed. Among 151 TA features, only TA feature "mean" of the spinotransverse group showed a significant but weak correlation with worsened SSM (p = 0.046). TA feature "S(3,3) entropy" showed a significant but weak association with worsened WD over 12 months (p = 0.046). CONCLUSION: MR TA is a reproducible tool to quantitatively assess paraspinal fatty infiltration, but there is no clear association with the clinical outcome in asymptomatic LSS patients.

Decompressive surgery for lumbar spinal stenosis across the Atlantic: a comparison of preoperative MRI between matched cohorts from the US and Norway.

BACKGROUND: There are no uniform guidelines regarding when to operate for Lumbar Spinal Stenosis (LSS). As we apply findings from clinical research from one population to the next, elucidating similarities or differences provides important context for the validity of extrapolating clinical outcomes. The aim of this study was to compare the morphological severity of lumbar spinal stenosis on preoperative MRI in patients undergoing decompressive surgery in Boston, USA, and Trondheim, Norway. METHODS: In this observational retrospective study, we compared morphological severity on MRI before surgical treatment between two propensity score-matched patient populations with single or two-level symptomatic LSS. We assessed the radiographic severity of LSS utilizing the Schizas classification (grade A to D). RESULTS: Following propensity score matching, demographics are balanced. In the Trondheim cohort, two levels decompression were present in 36.2% of the patients vs. 41.9% in Boston, (p = 0.396). There was no significant difference in grades A to D concerning central stenosis (p = 0.075). When dichotomized in mild/moderate (A/B) and severe /extreme (C/D), there were no significant differences in the rate of levels operated for high-grade stenosis (C/D), 67.6% in the Boston group compare to 78.1% in the Trondheim group (p = 0.088). CONCLUSIONS: Trondheim, Norway, and Boston, US, have similar radiographic thresholds of LSS for offering surgery.

The sagittal spinal profile type: a principal precondition for surgical decision making in patients with lumbar spinal stenosis.

OBJECTIVE Microsurgical decompression (MD) in patients with lumbar spinal stenosis (LSS) shows good clinical results. Nevertheless, 30%-40% of patients do not have a significant benefit after surgery-probably due to different anatomical preconditions. The sagittal profile types (SPTs 1-4) defined by Roussouly based on different spinopelvic parameters have been shown to influence spinal degeneration and surgical results. The aim of this study was to investigate the influence of the SPT on the clinical outcome in patients with LSS who were treated with MD. METHODS The authors retrospectively investigated 100 patients with LSS who received MD. The patients were subdivided into 4 groups depending on their SPT, which was determined from preoperative lateral spinal radiographs. The authors analyzed pre- and postoperative outcome scales, including the visual analog scale (VAS), walking distance, Oswestry Disability Index, Roland-Morris Disability Questionnaire, Odom's criteria, and the 36-Item Short Form Health Survey score. RESULTS Patients with SPT 1 showed a significantly worse clinical outcome concerning their postoperative back pain (VASback-SPT 1 = 5.4 ± 2.8; VASback-SPT 2 = 2.6 ± 1.9; VASback-SPT 3 = 2.9 ± 2.6; VASback-SPT 4 = 1.5 ± 2.5) and back pain-related disability. Only 43% were satisfied with their surgical results, compared with 70%-80% in the other groups. CONCLUSIONS A small pelvic incidence with reduced compensation mechanisms, a distinct lordosis in the lower lumbar spine with a high load on dorsal structures, and a long thoracolumbar kyphosis with a high axial load might lead to worse back pain after MD. Therefore, the indication for MD should be provided carefully, fusion can be considered, and other possible reasons for back pain should be thoroughly evaluated and treated.

Comparison of inter- and intra-observer reliability among the three classification systems for cervical spinal canal stenosis.

PURPOSE: The aim is to analyze the agreement between different types of physicians in terms of the inter-observer and intra-observer reliability in addition to the agreement between the experienced and non-experienced physicians with respect to three different classification systems for diagnosis of cervical spinal canal stenosis. METHODS: Total nine doctors including experienced group of three doctors and non-experienced group of six doctors classified the patients according to three different classification in an independent, blinded manner using magnetic resonance imaging (MRI) to diagnose cervical canal stenosis. MRI slice included sagittal plane (midline cut) and an image slice from each horizontal plane that penetrated the right center of each disk (C3-4, C4-5, C5-6, and C6-7) was made by PPT format. RESULTS: For the inter-observer reliability, Vaccaro et al.'s classification system showed the excellent reproducibility, followed by Muhle et al. and Kang et al. All three classification systems showed excellent reproducibility and substantial agreement in terms of the intra-observer reliability. CONCLUSIONS: All three classification systems showed excellent reproducibility and also displayed a substantial agreement. The classification system used by Vaccaro et al. was proven to be a method with substantial agreement both in the experienced group and the non-experienced group. It can be a useful classification system for simplifying communication among all physicians.

Clinical classification in low back pain: best-evidence diagnostic rules based on systematic reviews.

BACKGROUND: Clinical examination findings are used in primary care to give an initial diagnosis to patients with low back pain and related leg symptoms. The purpose of this study was to develop best evidence Clinical Diagnostic Rules (CDR] for the identification of the most common patho-anatomical disorders in the lumbar spine; i.e. intervertebral discs, sacroiliac joints, facet joints, bone, muscles, nerve roots, muscles, peripheral nerve tissue, and central nervous system sensitization. METHODS: A sensitive electronic search strategy using MEDLINE, EMBASE and CINAHL databases was combined with hand searching and citation tracking to identify eligible studies. Criteria for inclusion were: persons with low back pain with or without related leg symptoms, history or physical examination findings suitable for use in primary care, comparison with acceptable reference standards, and statistical reporting permitting calculation of diagnostic value. Quality assessments were made independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Clinical examination findings that were investigated by at least two studies were included and results that met our predefined threshold of positive likelihood ratio ≥ 2 or negative likelihood ratio ≤ 0.5 were considered for the CDR. RESULTS: Sixty-four studies satisfied our eligible criteria. We were able to construct promising CDRs for symptomatic intervertebral disc, sacroiliac joint, spondylolisthesis, disc herniation with nerve root involvement, and spinal stenosis. Single clinical test appear not to be as useful as clusters of tests that are more closely in line with clinical decision making. CONCLUSIONS: This is the first comprehensive systematic review of diagnostic accuracy studies that evaluate clinical examination findings for their ability to identify the most common patho-anatomical disorders in the lumbar spine. In some diagnostic categories we have sufficient evidence to recommend a CDR. In others, we have only preliminary evidence that needs testing in future studies. Most findings were tested in secondary or tertiary care. Thus, the accuracy of the findings in a primary care setting has yet to be confirmed.

Scoping review to develop common data elements for lumbar spinal stenosis.

BACKGROUND CONTEXT: Common data elements (CDE) represent an important tool for understanding and classifying health outcomes across settings. Although CDEs have been developed for a number of disorders, to date CDEs for lumbar spinal stenosis (LSS) have not been fully developed. To facilitate the identification of CDEs and measures to assess them, this technical study leverages the International Classification of Functioning, Disability and Health (ICF), peer-reviewed research, and a panel of experts to identify CDEs specific to LSS. PURPOSE: The study aimed to define CDEs for disease characteristics and outcomes of LSS using the World Health Organization's ICF taxonomy, and to facilitate the selection of assessment instruments for research and clinical care. DESIGN: This is a scoping review using a modified Delphi approach with a technical expert panel composed of clinicians and scientists representing the academia, policy and advocacy stakeholders, and professional associations with expertise in LSS. METHODS: This is a scoping review to identify measures that assess LSS symptoms. Thirty-one subject matter experts (SMEs) prioritized ICF codes and evaluated instruments measuring specific domains. We used a modified Delphi technique to evaluate item-level content and achieve consensus. RESULTS: SMEs prioritized 53 ICF codes; 3 received 100% endorsement, 27 received ≥90% endorsement, whereas the remaining 23 received ≥80% endorsement. Prioritized ICF codes represent diverse domains, including pain, activities and participation, and emotional well-being. The review yielded 58 instruments; we retained 24 for content analysis. CONCLUSIONS: The retained instruments adequately represent the ICFs activities and participation, and body function domains. Body structure and environmental factors were assessed infrequently. Adoption of these CDEs may guide clinical decision making and facilitate comparative effectiveness trials for interventions focused on LSS.

A novel MRI classification system for congenital functional lumbar spinal stenosis predicts the risk for tandem cervical spinal stenosis.

PURPOSE: The purpose of this study was to develop a simple and clinically useful morphological classification system for congenital lumbar spinal stenosis using sagittal MRI, allowing clinicians to recognize patterns of lumbar congenital stenosis quickly and be able to screen these patients for tandem cervical stenosis. METHODS: Forty-four subjects with an MRI of both the cervical and lumbar spine were included. On the lumbar spine MRI, the sagittal canal morphology was classified as one of three types: Type I normal, Type II partially narrow, Type III globally narrow. For the cervical spine, the Torg-Pavlov ratio on X-ray and the cervical spinal canal width on MRI were measured. Kruskal-Wallis analysis was done to determine if there was a relationship between the sagittal morphology of the lumbar spinal canal and the presence of cervical spinal stenosis. RESULTS: Subjects with a type III globally narrow lumbar spinal canal had a significantly lower cervical Torg-Pavlov ratio and smaller cervical spinal canal width than those with a type I normal lumbar spinal canal. CONCLUSION: A type III lumbar spinal canal is a globally narrow canal characterized by a lack of spinal fluid around the conus. This was defined as "functional lumbar spinal stenosis" and is associated with an increased incidence of tandem cervical spinal stenosis.

Clinical outcome of lumbar spinal stenosis based on new classification according to hypertrophied ligamentum flavum.

BACKGROUND: The ligamentum flavum hypertrophy is considered to be one of the important causes of development of lumbar spinal stenosis (LSS). Several histologic and biologic mechanisms in hypertrophied flavum have proposed. However, no study that investigated the relationship between clinical outcome and ligamentum flavum hypertrophy has been published. The purpose of this study was to identify a new classification of LSS, in ligamentous and nonligamentous stenosis, according to the cutoff value of the area proportion of the ligamentum flavum in the spinal canal, and to assess the value of surgical and conservative treatments for LSS based on the classification of the ligamentous stenosis. METHODS: A total of 230 surgical patients with LSS were evaluated based on the cross-sectional area and intraoperative findings of the ligamentum flavum. LSS was classified as ligamentous or nonligamentous stenosis, according to the cutoff value of the proportion of the ligamentum flavum in the spinal canal. Based on the classification, the results of 234 surgical patients (103 patients with spinal fusion surgery and 131 patients with spinal decompression) and 191 patients under conservative treatment with prostaglandin E1 were evaluated, 1 year after treatments. RESULTS: ROC analysis revealed that the area under the curve for the cutoff value of the proportion of the ligamentum flavum in the spinal canal was 0.4275 (sensitivity = 0.861, specificity = 0.854). Based on these criteria, ligamentous and nonligamentous stenoses were 115 and 119 in surgical patients, 97 and 94 in conservative patients, respectively. In the surgical treatment group, no significant difference was found in any of the evaluations conducted for the group with ligamentous and nonligamentous stenosis. However, in the conservative treatment group, the patients with ligamentous stenosis showed significant improvement compared with patients with nonligamentous stenosis. CONCLUSIONS: Ligamentous stenosis in LSS patients had favorable outcome on conservative treatment with prostaglandin E1 derivative.

Lumbar Spinal Stenosis: How Is It Classified?

The prevalence of lumbar spinal stenosis is approximately 9.3%, with people most commonly affected in the sixth or seventh decade of life. Patients often have pain, cramping, and weakness in their legs that is worsened with standing and walking. Although the Spine Patient Outcomes Research Trial clearly demonstrated that surgery improves health-related quality of life, treatment for lumbar spinal stenosis varies widely from the type of decompression performed to the need for fusion. This variability can be attributed largely to the lack of an accepted classification system. A good classification system serves as a common language to define the severity of a condition, guide treatment, and facilitate clinical research.

A Novel Classification and Minimally Invasive Treatment of Degenerative Lumbar Spinal Stenosis.

AIM: We conducted a novel classification system of degenerative lumbar spinal stenosis (DLSS) based on clinical manifestations and imaging (computed tomography and magnetic resonance imaging) features. We chose different minimally invasive surgical procedures according to our system. Clinical parameters and radiological findings will be assessed in the article. MATERIAL AND METHODS: A retrospective study was conducted on 96 patients undergoing minimally invasive surgery for DLSS. We chose different surgical procedures according to our novel classification system based on clinical manifestations, imaging features, and concurrence with other spinal diseases. Clinical parameters and radiological findings were assessed pre- and postoperatively. RESULTS: The mean follow up period was 24 months (range, 15~36 months). There was a statistically significant improvement in the Visual Analogue Scale (VAS) score of low back pain and leg pain after surgery (p < 0.05). According to the Japanese Orthopaedic Association (JOA) scores, the operation efficacy was excellent in 57 cases, good in 36 cases, and fair in 3 cases. According to Bridwell's criterion, the fusion rate was 96% (48/50) in patients who underwent fusion surgery. There were no cages or pedicle screws related complications. CONCLUSION: Minimally invasive surgical treatment of DLSS has satisfactory outcomes according to the novel classification, but further long-term, prospective, randomized controlled studies involving a larger study group are needed to validate the long-term efficacy.

Rule-based Cervical Spine Defect Classification Using Medical Narratives.

Classifying the defects occurring at the cervical spine provides the basis for surgical treatment planning and therapy recommendation. This process requires evidence from patient records. Further, the degree of a defect needs to be encoded in a standardized from to facilitate data exchange and multimodal interoperability. In this paper, a concept for automatic defect classification based on information extracted from textual data of patient records is presented. In a retrospective study, the classifier is applied to clinical documents and the classification results are evaluated.

Relationship between sedimentation sign and morphological grade in symptomatic lumbar spinal stenosis.

PURPOSE: We aimed to study the relationship between two morphological parameters recently described on MRI images in relation to lumbar spinal stenosis (LSS): the first is the sedimentation sign (SedS) and the second is the morphological grading of lumbar stenosis. MATERIALS AND METHODS: MRIs from a total of 137 patients were studied. From those, 110 were issued from a prospective database of symptomatic LSS patients, of whom 73 were treated surgically and 37 conservatively based on symptom severity. A third group consisting of 27 subjects complaining of low back pain (LBP) served as control. Severity of stenosis was judged at disc level using the four A to D grade morphological classification. The presence of a SedS was judged at pedicle level, above or below the site of maximal stenosis. RESULTS: A positive SedS was observed in 58, 69 and 76% of patients demonstrating B, C and D morphology, respectively, but in none with grade A morphology. The SedS was positive in 67 and 35% of the surgically and conservatively treated patients, respectively, and in 8% of the LBP group. C and D morphological grades were present in 97 and 35% of patients in the surgically and conservatively treated group, respectively, and in 18% of the LBP group. Presence of a positive SedS carried an increased risk of being submitted to surgery in the symptomatic LSS group (OR 3.5). This risk was even higher in the LSS patients demonstrating grade C or D morphology (OR 65). DISCUSSION AND CONCLUSION: One-third of surgically treated LSS patients do not present a SedS. This sign appears to be a lesser predictor of treatment modality in our setting of symptomatic LSS patients compared to the severity of stenosis judged by the morphological grade.

Measurements and classifications in spine imaging.

Imaging criteria and radiologic measurements play a key role in the diagnosis of spinal diseases. In addition, they often create the basis of classification systems that determine the severity of the disease and thereby enable a stage-related therapy. A clearly defined nomenclature for imaging findings as well as standardized and thoroughly evaluated methods of measurement are necessary to achieve a sufficiently high diagnostic accuracy. Various specialized committees dealing with the diagnosis of spinal diseases have made efforts within the last years to develop diagnostic standards. This review provides an overview of radiologic measurements and classification systems that are currently used for the diagnosis of scoliosis and degenerative diseases of the lumbar spine.

Dynamic cervical myelopathy in young adults.

PURPOSE: Non-traumatic cervical chronic joint instability in young adults is a rare and underexplored entity. We assessed the diagnostic relevance of dynamic MRI, and the clinical and radiological outcome after anterior cervical interbody fusion (ACIF) in these cases. METHODS: Six young patients (mean age 34 years) with cervical myelopathy without compression on static imaging had a dynamic MRI. Joint instability was defined by a reduction of the canal diameter on dynamic sequences. Clinical and radiological outcomes were assessed after surgery by examination, cervical X-rays, static and dynamic MRI. RESULTS: All the patients had joint instability. Four patients underwent surgery. Clinical status improved 1 year after surgery. All patients had a satisfactory fusion at 6-month follow-up and no residual compression at 1 year. CONCLUSION: Dynamic MRI can help detect a joint instability in young patients with cervical myelopathy without compression. ACIF seems to be efficient in these cases.