Clinical validity of two different grading systems for lumbar central canal stenosis: Schizas and Lee classification systems

Coflex Interspinous Stabilization with Decompression for Lumbar Spinal Stenosis: An Average 14-Year Follow-Up

Background: This study aimed to evaluate the long-term clinical usefulness and radiologic changes around the Coflex device following decompression with Coflex insertion for degenerative lumbar spinal stenosis (DLSS), with an average follow-up of 14 years. Methods: This retrospective study included 147 patients who underwent decompression and Coflex insertion for single-level DLSS at a single institution between January 2007 and December 2010. Patients with spinal stenosis unresponsive to 3 months of conservative treatment were treated surgically. The mean follow-up duration was 173.9 ± 23.7 (range, 119-214) months. Results: The mean visual analog scale score decreased from 8.22 ± 1.06 preoperatively to 2.08 ± 1.58 postoperatively. Intervertebral disc height and foramen height at the Coflex insertion site decreased by 5.3% and 2.0%, respectively, after surgery. The reoperation rate at the operated site was 25% (n = 37). A significantly higher reoperation rate was observed in patients with translational instability (odds ratio [OR], 7.77; 95% confidence interval [CI], 2.453-24.658; p < 0.01) and angular instability (OR, 1.59; 95% CI, 0.492-5.133; p < 0.001). Eight patients underwent reoperation due to rapid progression of instability within 2 years of Coflex insertion; thereafter, a similar cumulative incidence rate was consistently observed. The adjacent-segment reoperation rate was 10.8% (n = 16). Conclusions: The Coflex interspinous device helps preserve disc and foramen height but is associated with a high reoperation rate, particularly in patients with spinal instability. Therefore, careful patient selection is crucial when considering its use.

AI-based lumbar central canal stenosis classification on sagittal MR images is comparable to experienced radiologists using axial images

OBJECTIVES

The assessment of lumbar central canal stenosis (LCCS) is crucial for diagnosing and planning treatment for patients with low back pain and neurogenic pain. However, manual assessment methods are time-consuming, variable, and require axial MRIs. The aim of this study is to develop and validate an AI-based model that automatically classifies LCCS using sagittal T2-weighted MRIs.

METHODS

A pre-existing 3D AI algorithm was utilized to segment the spinal canal and intervertebral discs (IVDs), enabling quantitative measurements at each IVD level. Four musculoskeletal radiologists graded 683 IVD levels from 186 LCCS patients using the 4-class Lee grading system. A second consensus reading was conducted by readers 1 and 2, which, along with automatic measurements, formed the training dataset for a multiclass (grade 0-3) and binary (grade 0-1 vs. 2-3) random forest classifier with tenfold cross-validation.

RESULTS

The multiclass model achieved a Cohen's weighted kappa of 0.86 (95% CI: 0.82-0.90), comparable to readers 3 and 4 with 0.85 (95% CI: 0.80-0.89) and 0.73 (95% CI: 0.68-0.79) respectively. The binary model demonstrated an AUC of 0.98 (95% CI: 0.97-0.99), sensitivity of 93% (95% CI: 91-96%), and specificity of 91% (95% CI: 87-95%). In comparison, readers 3 and 4 achieved a specificity of 98 and 99% and sensitivity of 74 and 54%, respectively.

CONCLUSION

Both the multiclass and binary models, while only using sagittal MR images, perform on par with experienced radiologists who also had access to axial sequences. This underscores the potential of this novel algorithm in enhancing diagnostic accuracy and efficiency in medical imaging.

KEY POINTS

Question How can the classification of lumbar central canal stenosis (LCCS) be made more efficient? Findings Multiclass and binary AI models, using only sagittal MR images, performed on par with experienced radiologists who also had access to axial sequences. Clinical relevance Our AI algorithm accurately classifies LCCS from sagittal MRI, matching experienced radiologists. This study offers a promising tool for automated LCCS assessment from sagittal T2 MRI, potentially reducing the reliance on additional axial imaging.

Proximity Between Screw and Endplate of Upper Instrumented Vertebra Using a Cortical Bone Trajectory Screw can Increase Radiographic Adjacent Segment Degeneration Risks in Patients With Lumbar Spinal Stenosis

STUDY DESIGN

Retrospective observational study.

OBJECTIVE

To determine the proximity between the screw and endplate of the upper instrumented vertebra (UIV) using a cortical bone trajectory (CBT) screw as a predictive factor for radiographic adjacent segment degeneration (ASD) in patients surgically treated with transforaminal lumbar interbody fusion (TLIF) with CBT screws (CBT-TLIF) with lumbar spinal stenosis.

SUMMARY OF BACKGROUND DATA

The risk factors for radiographic ASD after CBT-TLIF remain unknown.

METHODS

Among patients surgically treated with CBT-TLIF at a single institute, 239 consecutive patients (80 males and 159 females) were enrolled. ASD was defined by the presence of one or more of the following three radiologic criteria on the adjacent segment: >3 mm anteroposterior translation, >10° segmental kyphosis, or >50% loss of disc height comparing immediate postoperative and one-year follow-up radiographs. Clinical and radiological features associated with the development of ASD were retrospectively measured. Univariate and multivariate analyses were performed to identify risk factors associated with radiographic ASD.

RESULTS

Radiographic ASD was observed in 71 (29.7%) cases at one-year postoperative follow-up. The preoperative Pfirrmann grade of the adjacent segment (>grade 2), multi-level fusion (>2 levels), and proximity between the tip of CBT screws and endplate on the UIV were significantly associated with radiographic ASD (OR = 3.98, 95% CI [1.06-15.05], P =0.042 versus OR = 3.03, 95% CI [1.00-9.14], P =0.049 versus OR = 0.53, 95% CI [0.40-0.72], P <0.001). The cut-off value of the distance between the tip of the screw and endplate on UIV for radiographic ASD was ~2.5 mm (right-sided CBT screw; cut-off value 2.48 mm/ left-sided CBT screw; cut-off value 2.465 mm).

CONCLUSION

Radiographic adjacent segment degeneration progression can occur when the cortical trajectory bone screw is close to the endplate of the upper instrumented vertebrae in patients with lumbar spinal stenosis undergoing fusion surgery.

Impact of the Disc Vacuum Phenomenon on Surgical Outcomes in Lumbar Spinal Stenosis: A Comparative Study between Endoscopic Decompression and Minimally Invasive Oblique Lateral Interbody Fusion

Objective: This study investigated the influence of the vacuum phenomenon (VP) on surgical outcomes in patients with lumbar spinal stenosis, comparing minimally invasive oblique lateral interbody fusion (MIS OLIF) and endoscopic decompression. Methods: A cohort of 110 patients diagnosed with lumbar spinal stenosis underwent either endoscopic decompression or MIS OLIF. Patients were classified into two groups based on the presence or absence of the VP on preoperative CT scans, non-VP (n = 42) and VP (n = 68). Radiologic and clinical outcomes, including back and leg pain assessed using the visual analogue scale (VAS), the Oswestry Disability Index (ODI), and the EuroQol-5 Dimension (Eq5D), were compared pre- and postoperatively over a 2-year follow-up period. Results: Preoperatively, the VP group exhibited significantly greater leg pain (p = 0.010), while no significant differences were observed in back pain or the ODI between the groups. In the non-VP group, decompression and fusion yielded similar outcomes, with decompression showing a better ODI score at 1 month (p = 0.018). In contrast, in the VP group, patients who underwent fusion showed significantly improved long-term leg pain outcomes compared to those who underwent decompression at both 1-year (p = 0.042) and 2-year (p = 0.017) follow-ups. Conclusions: The VP may indicate segmental instability and may play a role in the persistence of radiculopathy. Fusion surgery appears to offer better long-term relief in patients with the VP, whereas decompression alone is a viable option in non-VP cases. These findings suggest that the VP may be a useful factor in guiding surgical decision-making.

Spine-specific sarcopenia: distinguishing paraspinal muscle atrophy from generalized sarcopenia

BACKGROUND CONTEXT

Atrophy of the paraspinal musculature (PM) as well as generalized sarcopenia are increasingly reported as important parameters for clinical outcomes in the field of spine surgery. Despite growing awareness and potential similarities between both conditions, the relationship between "generalized" and "spine-specific" sarcopenia is unclear.

PURPOSE

To investigate the association between generalized and spine-specific sarcopenia.

STUDY DESIGN

Retrospective cross-sectional study.

PATIENT SAMPLE

Patients undergoing lumbar spinal fusion surgery for degenerative spinal pathologies.

OUTCOME MEASURES

Generalized sarcopenia was evaluated with the short physical performance battery (SPPB), grip strength, and the psoas index, while spine-specific sarcopenia was evaluated by measuring fatty infiltration (FI) of the PM.

METHODS

We used custom software written in MATLAB® to calculate the FI of the PM. The correlation between FI of the PM and assessments of generalized sarcopenia was calculated using Spearman's rank correlation coefficient (rho). The strength of the correlation was evaluated according to established cut-offs: negligible: 0-0.3, low: 0.3-0.5, moderate: 0.5-0.7, high: 0.7-0.9, and very high≥0.9. In a Receiver Operating Characteristics (ROC) analysis, the Area Under the Curve (AUC) of sarcopenia assessments to predict severe multifidus atrophy (FI≥50%) was calculated. In a secondary analysis, factors associated with severe multifidus atrophy in nonsarcopenic patients were analyzed.

RESULTS

A total of 125 (43% female) patients, with a median age of 63 (IQR 55-73) were included. The most common surgical indication was lumbar spinal stenosis (79.5%). The median FI of the multifidus was 45.5% (IQR 35.6-55.2). Grip strength demonstrated the highest correlation with FI of the multifidus and erector spinae (rho=-0.43 and -0.32, p<.001); the other correlations were significant (p<.05) but lower in strength. In the AUC analysis, the AUC was 0.61 for the SPPB, 0.71 for grip strength, and 0.72 for the psoas index. The latter two were worse in female patients, with an AUC of 0.48 and 0.49. Facet joint arthropathy (OR: 1.26, 95% CI: 1.11-1.47, p=.001) and foraminal stenosis (OR: 1.54, 95% CI: 1.10-2.23, p=.015) were independently associated with severe multifidus atrophy in our secondary analysis.

CONCLUSION

Our study demonstrates a low correlation between generalized and spine-specific sarcopenia. These findings highlight the risk of misdiagnosis when relying on screening tools for general sarcopenia and suggest that general and spine-specific sarcopenia may have distinct etiologies.

Percutaneous Epidural Neuroplasty for Symptomatic Lumbar Juxtafacet Cysts

Background and Objectives: The term "Juxtafacet cyst" refers to both synovial cysts and ganglion pseudocysts associated with the lumbar facet joint. As conservative treatment for the juxtafacet cyst has a minimal effect, complete excision through surgery is considered the first choice of treatment. In this study, we retrospectively reviewed the clinical outcomes of percutaneous epidural neuroplasty for symptomatic lumbar juxtafacet cysts. Materials and Methods: We conducted a retrospective review of 34 patients with symptomatic juxtafacet cysts who visited a single institute from January 2010 to September 2023. Patients who received conservative treatment for at least 6 weeks but experienced no or insufficient effects were eligible for this study. After neuroplasty, a medical history check and neurological examination were performed during follow-up at 2 weeks, 1 month, 2 months, 3 months, 6 months, and once a year thereafter. Results: The pain improved for all patients to a VAS score of 3 or less immediately after neuroplasty; however, four of those patients (11%) had pain that worsened eventually to the same level as before the procedure and required surgery. The results showed that, regardless of cyst size, in cases with severe stenosis of the spinal canal, the outcome of neuroplasty was poor and often eventually required surgery. The cyst size was not associated with the procedure results. In addition, if the cyst was present at the L4-L5 level, or if diabetes mellitus was present, the likelihood of future surgery was significant (p-value = 0.003). Conclusions: Percutaneous neuroplasty showed a better success rate than other non-surgical treatments. In addition, severe spinal stenosis (Schizas grade C or higher), L4-L5 level, or diabetes mellitus produced a high possibility of surgery due to recurrence.

Vertebral Hemangiomas: Yucesoy-Yilmaz Classification System with Corresponding Therapeutic Options

OBJECTIVE

Vertebral hemangiomas (VHs) are relatively common, symptomatic benign tumors of the spine with a reported estimated incidence up to 11%. They usually appear in the body of the vertebrae; however, they can extend into pedicles, laminae, and epidural space. They may cause pain, neurologic deficits. and fractures.

METHODS

In this retrospective, single-center study, we reviewed our cases with VH and we propose the novel classification system that evaluates these lesions per their views on magnetic resonance imaging and clinical findings under 4 main categories.

RESULTS

Our novel classification system proposes that grade I lesions occupy less than 50% of the vertebral body, whereas grade II lesions occupy more than 50% and grade III lesions occupy the whole corpus. Grade IV lesions show an epidural and pedicular extension. We propose that grade I lesions may not be worthwhile for follow-up, whereas asymptomatic grade II (a) lesions to be worthy for a biannual imaging and symptomatic thoracolumbar grade II (b) and thoracolumbar grade III lesions to be considered for percutaneous vertebroplasty. We imply that decompression, posterior spinal instrumentation, and open vertebroplasty may be performed for thoracolumbar grade IV lesions. We further consider cervical grade IIb, III, and grade IV lesions as operable because of the disadvantages of percutaneous vertebroplasty.

CONCLUSIONS

We suggest that our novel classification system may be useful for the determination of diagnostic and therapeutic procedures in the management of VH. Further multicentric trials on larger series are warranted to validate this system and popularize its utility in larger populations.

Relationship between lumbar spinal stenosis and axial muscle wasting

BACKGROUND CONTEXT

Although the effect of lumbar spinal stenosis (LSS) on the lower extremities is well documented, limited research exists on the effect of spinal stenosis on the posterior paraspinal musculature (PPM). Similar to neurogenic claudication, moderate to severe spinal canal compression can also interfere with the innervation of the PPM, which may result in atrophy and increased fatty infiltration (FI).

PURPOSE

This study aims to assess the association between LSS and atrophy of the PPM.

STUDY DESIGN

Retrospective cross-sectional study.

PATIENT SAMPLE

Patients undergoing MRI scans at a tertiary orthopedic center for low back pain or as part of a preoperative evaluation.

OUTCOME MEASURES

The functional cross-sectional area (fCSA) and percent fatty infiltration (FI) of the PPM at L4.

METHODS

Lumbar MRIs of patients at a tertiary orthopedic center indicated due to lower back pain (LBP) or as a presurgical workup were analyzed. Patients with previous spinal fusion surgery or scoliosis were excluded. LSS was assessed according to the Schizas classification at all lumbar levels. The cross-sectional area of the PPM was measured on a T2-weighted MRI sequence at the upper endplate of L4. The fCSA and fatty infiltration (FI) were calculated using custom software. Crude differences in FI and fCSA between patients with no stenosis and at least mild stenosis were tested with the Wilcoxon signed-rank test. To account for possible confounders, a multivariable linear regression model was used to adjust for age, sex, body mass index (BMI), and disc degeneration. A subgroup analysis according to MRI indication was performed.

RESULTS

A total of 522 (55.7% female) patients were included. The median age was 61 years (IQR: 51-71). The greatest degree of moderate and severe stenosis was found at L4/5, 15.7%, and 9.2%, respectively. Stenosis was the least severe at L5/S1 and was found to be 2% for moderate and 0.2% for severe stenosis. The Wilcoxon test showed significantly increased FI of the PPM with stenosis at any lumbar level (p<.001), although no significant decrease in fCSA was observed. The multivariable regression model showed a significant increase in FI with increased LSS at L1/2, L2/3, and L3/4 (p=.013, p<.01 and p=.003). The severity of LSS at L4/5 showed a positive association with the fCSA (p=.019). The subgroup analysis showed, the effect of LSS was more pronounced in nonsurgical patients than in patients undergoing surgery.

CONCLUSIONS

In this study, we demonstrated a significant and independent association between LSS and the composition of the PPM, which was dependent on the level of LSS relative to the PPM. In addition to neurogenic claudication, patients with LSS might be especially susceptible to axial muscle wasting, which could worsen LSS due to increased spinal instability, leading to a positive feedback loop.

Deep learning-based reconstruction for acceleration of lumbar spine MRI: a prospective comparison with standard MRI

OBJECTIVE

To compare the image quality and diagnostic performance between standard turbo spin-echo MRI and accelerated MRI with deep learning (DL)-based image reconstruction for degenerative lumbar spine diseases.

MATERIALS AND METHODS

Fifty patients who underwent both the standard and accelerated lumbar MRIs at a 1.5-T scanner for degenerative lumbar spine diseases were prospectively enrolled. DL reconstruction algorithm generated coarse (DL_coarse) and fine (DL_fine) images from the accelerated protocol. Image quality was quantitatively assessed in terms of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) and qualitatively assessed using five-point visual scoring systems. The sensitivity and specificity of four radiologists for the diagnosis of degenerative diseases in both protocols were compared.

RESULTS

The accelerated protocol reduced the average MRI acquisition time by 32.3% as compared to the standard protocol. As compared with standard images, DL_coarse and DL_fine showed significantly higher SNRs on T1-weighted images (T1WI; both p < .001) and T2-weighted images (T2WI; p = .002 and p < 0.001), higher CNRs on T1WI (both p < 0.001), and similar CNRs on T2WI (p = .49 and p = .27). The average radiologist assessment of overall image quality for DL_coarse and DL_fine was higher on sagittal T1WI (p = .04 and p < .001) and axial T2WI (p = .006 and p = .01) and similar on sagittal T2WI (p = .90 and p = .91). Both DL_coarse and DL_fine had better image quality of cauda equina and paraspinal muscles on axial T2WI (both p = .04 for cauda equina; p = .008 and p = .002 for paraspinal muscles). Differences in sensitivity and specificity for the detection of central canal stenosis and neural foraminal stenosis between standard and DL-reconstructed images were all statistically nonsignificant (p ≥ 0.05).

CONCLUSION

DL-based protocol reduced MRI acquisition time without degrading image quality and diagnostic performance of readers for degenerative lumbar spine diseases.

CLINICAL RELEVANCE STATEMENT

The deep learning (DL)-based reconstruction algorithm may be used to further accelerate spine MRI imaging to reduce patient discomfort and increase the cost efficiency of spine MRI imaging.

KEY POINTS

• By using deep learning (DL)-based reconstruction algorithm in combination with the accelerated MRI protocol, the average acquisition time was reduced by 32.3% as compared with the standard protocol. • DL-reconstructed images had similar or better quantitative/qualitative overall image quality and similar or better image quality for the delineation of most individual anatomical structures. • The average radiologist's sensitivity and specificity for the detection of major degenerative lumbar spine diseases, including central canal stenosis, neural foraminal stenosis, and disc herniation, on standard and DL-reconstructed images, were similar.

Correction of Spinal Sagittal Alignment after Posterior Lumbar Decompression: Does Severity of Central Canal Stenosis Matter?

STUDY DESIGN

This study adopted a retrospective study design.

PURPOSE

Our study aimed to investigate the impact of central canal stenosis severity on surgical outcomes and lumbar sagittal correction after lumbar decompression.

OVERVIEW OF LITERATURE

Studies have evaluated sagittal correction in patients with central canal stenosis after lumbar decompression and the association of stenosis severity with worse preoperative sagittal alignment. However, none have evaluated the impact of spinal stenosis severity on sagittal correction.

METHODS

Patients undergoing posterior lumbar decompression (PLD) of ≤4 levels were divided into severe and non-severe central canal stenosis groups based on the Lee magnetic resonance imaging (MRI) grading system. Patients without preoperative MRI or inadequate visualization on radiographs were excluded. Surgical characteristics, clinical outcomes, and sagittal measurements were compared. Multivariate logistic regression was performed to determine the predictors of pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and pelvic incidence minus lumbar lordosis (PI-LL).

RESULTS

Of the 142 patients included, 39 had severe stenosis, and 103 had non-severe stenosis. The mean follow-up duration for the cohort was 4.72 months. Patients with severe stenosis were older, had higher comorbidity indices and levels decompressed, and longer lengths of stay and operative times (p <0.001). Although those with severe stenosis had lower lordosis, lower SS, and higher PI-LL mismatch preoperatively, no differences in Delta LL, SS, PT, or PI-LL were observed between the two groups (p >0.05). On multivariate regression, severe stenosis was a significant predictor of a lower preoperative LL (estimate=-5.243, p =0.045) and a higher preoperative PI-LL mismatch (estimate=6.192, p =0.039). No differences in surgical or clinical outcomes were observed (p >0.05).

CONCLUSION

Severe central lumbar stenosis was associated with greater spinopelvic mismatch preoperatively. Sagittal balance improved in both patients with severe and non-severe stenosis after PLD to a similar degree, with differences in sagittal parameters remaining after surgery. We also found no differences in postoperative outcomes associated with stenosis severity.

Independent inter and intra-observer agreement of the Schizas's classification of degenerative lumbar stenosis: Comparison among three levels of surgical training

INTRODUCTION AND OBJECTIVES

Lumbar spinal stenosis is a common age-related condition that affects the quality of life. Multiple classifications have been developed to quantify the severity of stenosis affecting comparison between studies and homogenous communication among surgeons and researchers. Even though this classification has not shown a direct clinical correlation, Schizas's classification appears to be a simple method to assess stenosis. Our objective was to evaluate the inter and intraobserver independent agreement of the Schizas's classification to assess stenosis severity. Additionally, we aimed to compare agreement among three levels of training in spine surgery.

MATERIALS AND METHODS

An independent inter and intra observer agreement was conducted among junior, senior orthopedic residents and attending spine surgeons. Ninety lumbar levels from 30 patients were evaluated by 16 observers. Weighted kappa agreement was used.

RESULTS

Overall interobserver and intraobserver agreement was of 0.57 (95% CI=0.52-0.63) and 0.69 (0.55-0.79), respectively. Interobserver agreement according to level of training yielded values of 0.53 (0.46-0.60) for junior residents, 0.61 (0.54-0.67) for senior residents and 0.67 (0.59-0.74) for attendings. Intraobserver agreement was of 0.54 (0.48-0.60) for junior, 0.60 (0.55-0.66) for senior and 0.66 (0.60-0.72) for attendings.

CONCLUSION

The Schizas's classification showed moderate interobserver and substantial intraobserver agreement. Among attending surgeons, substantial inter and intraobserver agreement was observed. The classification allowed acceptable communication among trained spine surgeons.

Independent inter and intra-observer agreement of the Schizas's classification of degenerative lumbar stenosis: Comparison among three levels of surgical training

INTRODUCTION AND OBJECTIVES

Lumbar spinal stenosis is a common age-related condition that affects the quality of life. Multiple classifications have been developed to quantify the severity of stenosis affecting comparison between studies and homogenous communication among surgeons and researchers. Even though this classification has not shown a direct clinical correlation, Schizas's classification appears to be a simple method to assess stenosis. Our objective was to evaluate the inter and intraobserver independent agreement of the Schizas's classification to assess stenosis severity. Additionally, we aimed to compare agreement among three levels of training in spine surgery.

MATERIALS AND METHODS

An independent inter and intra observer agreement was conducted among junior, senior orthopedic residents and attending spine surgeons. Ninety lumbar levels from 30 patients were evaluated by 16 observers. Weighted kappa agreement was used.

RESULTS

Overall interobserver and intraobserver agreement was of 0.57 (95% CI=0.52-0.63) and 0.69 (0.55-0.79), respectively. Interobserver agreement according to level of training yielded values of 0.53 (0.46-0.60) for junior residents, 0.61 (0.54-0.67) for senior residents and 0.67 (0.59-0.74) for attendings. Intraobserver agreement was of 0.54 (0.48-0.60) for junior, 0.60 (0.55-0.66) for senior and 0.66 (0.60-0.72) for attendings.

CONCLUSION

The Schizas's classification showed moderate interobserver and substantial intraobserver agreement. Among attending surgeons, substantial inter and intraobserver agreement was observed. The classification allowed acceptable communication among trained spine surgeons.

Magnetic Resonance Imaging Grading Systems for Central Canal and Neural Foraminal Stenoses of the Lumbar and Cervical Spines With a Focus on the Lee Grading System

Magnetic resonance imaging (MRI) is a standard imaging modality for diagnosing spinal stenosis, which is a common degenerative disorder in the elderly population. Standardized interpretation of spinal MRI for diagnosing and grading the severity of spinal stenosis is necessary to ensure correct communication with clinicians and to conduct clinical research. In this review, we revisit the Lee grading system for central canal and neural foraminal stenosis of the cervical and lumbar spine, which are based on the pathophysiology and radiologic findings of spinal stenosis.

The current state of radiodiagnostics of degenerative changes in the lumbar spine (literature review)

Examination of the spine using radiological methods remains the most frequently conducted study in the outpatient practice of almost any radiologist. In most cases, changes in the spine are degenerative and dystrophic in nature. These changes in the spine are the leading cause of loss of activity among adults and the elderly, and cover a wide range of age-related structural changes. It is of great importance to understand the possibilities and limitations of radiological methods of diagnostics. The description of morphological changes observed in degenerative and dystrophic changes requires the use of unified terminology and classifications among clinicians and radiologists.The aim. To present modern concepts in the assessment of degenerative changes of the spine using radiological methods. A description of the standardized international nomenclature of intervertebral disc pathology and current classifications of spinal canal stenosis are presented.Material and methods. For literature search, we used electronic databases MEDLINE (PubMed), eLibrary, EMBASE and Cochrane Library with a selection of sources published from 2000 to 2021. We analyzed the works devoted to the diagnosis of degenerative changes in lumbar spine and to degenerative stenosis.Conclusion. The key to productive communication between physicians is the uniformity or standardization of terminology and definitions used. It is important that the protocol of description, its terms, semantic expressions be uniform and understandable to specialists who are involved in the diagnosis and treatment of the spine. Magnetic resonance imaging is a valuable method in the diagnosis of degenerative changes of the spinal column, but it has its limitations.

Probability for surgical treatment in patients with lumbar spinal stenosis according to the stenotic lesion severity: a 5-10-year follow-up study

BACKGROUND

We aimed (1) to clarify difference in the natural history of lumbar spinal stenosis (LSS) with respect to surgical treatment according to severity of stenosis on magnetic resonance imaging (MRI) using qualitative grading system and (2) to estimate surgical probabilities depending on radiological severity.

METHODS

With the design of retrospective observational study, a total of 1,248 patients diagnosed with LSS between 2011 and 2014 at our hospital were followed up for the mean duration of 7.7 years (5.17-9.8 years). We investigated severity of central and foraminal stenoses on initial MRI using qualitative grading system and whether surgical treatment was performed. Logistic regression models were used to identify risk factors for surgery.

RESULTS

During the mean follow-up period of 7.7 years, grade 3 maximal central stenosis showed the highest percentage of surgical treatment (57.9%-62.3%) with no significant difference in surgical probabilities according to concomitant foraminal stenosis. Surgical probabilities in grade 2 and 3 maximal foraminal stenosis, were 22.2%-62.3% and 33.3%-57.9%, respectively, depending on concomitant central stenosis. Maximal central stenosis of grades 1, 2, and 3 (odds ratio [OR]: 1.79, 2.21, and 6.26, respectively), and maximal foraminal stenosis of grades 2 and 3 (OR: 2.22 and 2.12, respectively) were significant risk factors for surgical treatment.

CONCLUSIONS

The high grades of maximal central and foraminal stenoses were risk factors for surgical treatment. Surgical probabilities were 57.9%-62.3% in grade 3 maximal central stenosis, 22.2%-62.3% and 33.3%-57.9%, respectively, in grade 2 and 3 maximal foraminal stenosis during the mean follow-up period of 7.7 years. These results indicate that the natural history of LSS differs according to grade of maximal central and foraminal stenoses.

Automatic Grading of Disc Herniation, Central Canal Stenosis and Nerve Roots Compression in Lumbar Magnetic Resonance Image Diagnosis

AIM

Accurate severity grading of lumbar spine disease by magnetic resonance images (MRIs) plays an important role in selecting appropriate treatment for the disease. However, interpreting these complex MRIs is a repetitive and time-consuming workload for clinicians, especially radiologists. Here, we aim to develop a multi-task classification model based on artificial intelligence for automated grading of lumbar disc herniation (LDH), lumbar central canal stenosis (LCCS) and lumbar nerve roots compression (LNRC) at lumbar axial MRIs.

METHODS

Total 15254 lumbar axial T2W MRIs as the internal dataset obtained from the Fifth Affiliated Hospital of Sun Yat-sen University from January 2015 to May 2019 and 1273 axial T2W MRIs as the external test dataset obtained from the Third Affiliated Hospital of Southern Medical University from June 2016 to December 2017 were analyzed in this retrospective study. Two clinicians annotated and graded all MRIs using the three international classification systems. In agreement, these results served as the reference standard; In disagreement, outcomes were adjudicated by an expert surgeon to establish the reference standard. The internal dataset was randomly split into an internal training set (70%), validation set (15%) and test set (15%). The multi-task classification model based on ResNet-50 consists of a backbone network for feature extraction and three fully-connected (FC) networks for classification and performs the classification tasks of LDH, LCCS, and LNRC at lumbar MRIs. Precision, accuracy, sensitivity, specificity, F1 scores, confusion matrices, receiver-operating characteristics and interrater agreement (Gwet k) were utilized to assess the model's performance on the internal test dataset and external test datasets.

RESULTS

A total of 1115 patients, including 1015 patients from the internal dataset and 100 patients from the external test dataset [mean age, 49 years ± 15 (standard deviation); 543 women], were evaluated in this study. The overall accuracies of grading for LDH, LCCS and LNRC were 84.17% (74.16%), 86.99% (79.65%) and 81.21% (74.16%) respectively on the internal (external) test dataset. Internal and external testing of three spinal diseases showed substantial to the almost perfect agreement (k, 0.67 - 0.85) for the multi-task classification model.

CONCLUSION

The multi-task classification model has achieved promising performance in the automated grading of LDH, LCCS and LNRC at lumbar axial T2W MRIs.

Comparison of lumbar degenerative disc disease using conventional fast spin echo T2W MRI and T2 fast spin echo dixon sequences

OBJECTIVES

To compare the grading of lumbar degenerative disc disease (DDD), Modic end-plate changes (MEPC) and identification of high intensity zones (HIZ) on a combination of sagittal T₁weighted turbo spin echo (T₁W TSE), T₂weighted fast spin echo (T₂W FSE) and short tau inversion recovery (STIR) sequences (routine protocol) with a single sagittal T₂W FSE Dixon MRI sequence which provides in-phase, opposed-phase, water only and fat only images in a single acquisition (Dixon protocol).

METHODS

50 patients underwent lumbar spine MRI using the routine protocol with the addition of a T₂W FSE Dixon sequence. DDD grade, MEPC and HIZ for each disc level were assessed on the routine and Dixon protocols. Each protocol was reviewed independently by three readers (consultant musculoskeletal radiologists with 26-, 8- and 4 years' experience), allowing assessment of inter-reader agreement and inter protocol agreement for each assessed variable.

RESULTS

The study included 17 males and 33 females (mean age 51 years; range 8-82 years). Inter-reader agreement for DDD grade on the routine protocol was 0.57 and for the Dixon protocol was 0.63 (p = 0.08). Inter-reader agreement for MEPC on the routine protocol was 0.45 and for the Dixon protocol was 0.53 (p = 0.02), and inter-reader agreement for identification of the HIZ on the routine protocol was 0.52 and for the Dixon protocol was 0.46 (p = 0.27). Intersequence agreement for DDD grade ranged from 0.61 to 0.97, for MEPC 0.46-0.62 and for HIZ 0.39-0.5.

CONCLUSION

A single sagittal T₂W FSE Dixon MRI sequence could potentially replace the routine three sagittal sequence protocol for assessment of lumbar DDD, MEPC and HIZ resulting in ~60% time saving.

ADVANCES IN KNOWLEDGE

Grading of lumbar DDD, presence of Modic changes and high intensity zones were compared on sagittal T₁W TSE, T₂W FSE and STIR sequences with a T₂W FSE Dixon sequence, with fair-to-good correlation suggesting that three conventional sequences could be replaced by a single Dixon sequence.

Degenerative Lumbar Stenosis Surgery: Predictive Factors of Clinical Outcome-Experience with 1001 Patients

BACKGROUND

Degenerative lumbar spinal stenosis (DLSS) carries a high risk of morbidity and represents a financial burden to society. A late diagnosis can lead to severe disability. Although lumbar decompressive surgery has been widely used worldwide, the proper preoperative factors to define the ideal candidates for decompression are missing.

METHODS

A total of 1001 patients who had undergone decompressive surgery from 2012 to 2019 for DLSS were screened for the presence of 9 clinical and radiological parameters. For all cases, the differences between the baseline and postoperative Oswestry disability index were calculated and the results categorized as 5 different classes (ranging from very poor outcomes to excellent outcomes) according to the specific scores. Generalized ordinal logistic regression was then used to analyze the significance of the 9 parameters (coded as dummy variables) in predicting the outcome as measured by Oswestry disability index improvement after surgery.

RESULTS

Of the 9 parameters, 8 were found to be significant predictors. The radiological grade of compression was the strongest, followed by polyneuropathy, obesity, symptom duration, gait autonomy, radicular deficits, American Society of Anesthesiologists score, and level of surgery. In contrast, previous back surgery was not predictive of the outcome.

CONCLUSIONS

Our findings have indicated that the ideal candidate for surgery will have the following preoperative characteristics: Schizas grade D, no signs of peripheral polyneuropathy, body mass index <30 kg/m², symptom duration of <2 years, gait autonomy <100 m, no radicular deficits, 1 level of stenosis, and an American Society of Anesthesiologists score of 1, 2, or 3.