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Many quantitative MRI parameters and clinical scores have been used patients with lumbar spinal stenosis (LSS). However, the correlation between clinical scores and MRI parameters is not very clear. The objective of the study was to find out the correlation between commonly used clinical scoring systems and quantitative MRI parameters.
Methods
Eighty two patients (more than 40 years) with clinical and radiological characteristics of degenerative LSS completed 10 clinical questionnaires which included Oswestry disability index (ODI), Swiss spinal stenosis (SSS) questionnaire, Quebec pain disability scale (QPD), Visual analogue scale (VAS), modified Japanese orthopaedic association scale (mJOA), Pain disability index (PDI), Short form health survey (SF-36), Self-paced walking test (SPWT), Euro quality of life-5D (EQ-5D) and Neurogenic claudication outcome score (NCOS). Lumbosacral MRIs were performed and 8 quantitative parameters namely transverse & AP diameter of dural sac (TDD, APDD), anteroposterior diameter of spinal canal (APDS), ligamentous interfacet distance (LID), mid-sagittal diameter of thecal sac (MSDT), cross-sectional area dural sac (CSAD), lateral recess depth and angle (LRD, LRA) were measured at the maximum stenotic level at the level of the disc. The clinical and radiological parameters were then statistically analysed.
Results
There were 51 females and 31 males in the study with a mean age of 53.0253.02 ± 9.18 years. NCOS score had a moderate correlation with CSAD, LID and TDS (p<0.05,0.7>r ≥ 0.3). MSDT showed a moderate negative correlation with SSS, VAS, ODI and QPD (p<0.05,0.7>r ≥ 0.3). LRD had a moderate negative correlation with ODI and VAS score (p<0.05,0.7>r ≥ 0.3). LRA had a moderate correlation with the EQ-5D and ODI (p<0.05,0.7>r ≥ 0.3). The CSAD had a moderate negative correlation with PDI (r = −0.383, p = 0.000). For all other comparisons, there was poor or no correlation. MRI parameters showed poor or no correlation with most of components of SF-36 score.
Conclusions
A poor correlation or no correlation was noted for most of the MRI parameters when compared to commonly used clinical scores. Hence, poor MRI's don't necessarily mean poor clinical scores in LSS. The role of MRI parameters should be supplementary and overreliance on them in LSS management should be avoided.
Back pain, leg pain, neurogenic claudication and sometimes neurological deficit are the major symptoms affecting patients of LSS. A plethora of clinical scores has been used in LSS to quantify the severity and guide management.
Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ): part 4. Establishment of equations for severity scores. Subcommittee on low back pain and cervical myelopathy, evaluation of the clinical outcome committee of the Japanese Orthopaedic Association.
takes into account the neurological component. Among the commonly used scales, ODI and VAS are the most widely used scales but recently, LSS specific scales like SSS
Internal construct validity of the Swiss Spinal Stenosis questionnaire: rasch analysis of a disease-specific outcome measure for lumbar spinal stenosis.
An outcome measure of functionality in patients with lumber spinal stenosis: a validation study of the Iranian version of Neurogenic Claudication Outcome Score (NCOS).
also come into the limelight. These scales are often used to quantify the severity of symptoms associated with LSS and gauge the improvement post intervention.
Over the last decade or so, the lateral recess has also been recognized as a potential site of stenosis resulting in a description of lateral recess angle
to measure the extent of lateral recess stenosis. There are few studies available that have compared some clinical scores like ODI, VAS, SF-36 and claudication distance with only a few MRI parameters like APDD, CSAD
and have found no correlation between them. However, many of the commonly used clinical scores (SSS, NCOS, QPD, PDI, mJOA, etc.) and MRI parameters (TDD, APDS, MSDT, LID, LRA, LRD) have not been compared and correlated with each other and other parameters. The importance of such comparisons lies in the fact that they help the clinicians and researchers to gauge and predict if patients with poor MRI parameters also have poor clinical scores and vice versa or not. Hence we designed this comprehensive study to look out for correlations between ten commonly used clinical scores and eight quantitative MRI parameters in LSS patients.
2. Materials and Methods
A total of 82 patients aged more than 40 years attending the outpatient department of our hospital with clinico-radiological features suggestive of degenerative LSS over around 1.5 years were recruited for this prospective observational study. The patients were asked about the presence of low back pain, the appearance of pain in buttocks and legs on walking, the appearance of motor and sensory symptoms on walking and relief of pain symptoms on bending forward, riding a bicycle or bending over a shopping cart. These findings were supplemented with the finding of MRI showing atleast one stenotic level.
The study was conducted in a public tertiary health care facility and the patients were recruited from those attending a busy orthopaedic out-patient department at our hospital with clinical features and radiological findings suggestive of LSS. The study was registered in the university database (2018/469) and the clearance for the study was obtained from the institutional ethics committee (IEC/2018/14) and all patients provided consent.
The present study was aimed to find how the various clinical scores and quantitative MRI parameters correlate with each other. Our hypothesis was the commonly used clinical scores and MRI parameters would show poor or no correlation among each other.
The inclusion criteria were patients aged 40 years or more with the neurogenic claudication. It may or may not be associated with radiating pain on sitting or lying down. Neurogenic claudication was defined as fatigue pain and/or parasthesias one or both lower limbs which was caused by standing or walking and was relieved when the patient was sitting lying down and bending forward. MRI features with atleast one level of an osteoligamentous spinal canal narrowing and findings like ligamentum flavum thickening, degenerative disc prolapse and facetal hypertrophy were considered. The exclusion criteria included primary canal stenosis including achondroplasia, traumatic, dysplastic and isthmic causes of canal stenosis; congenital spine anomalies, prior lumbar spine surgery, polyneuropathy, myopathy, osteoporosis or kyphotic deformity/vertebral collapse in the lumbar region. All patients also underwent measurement of pulses and ankle brachial index in the lower extremity. Any patients with abnormalities in these parameters were excluded from the study. Patients with peripheral vascular disease, advanced hip, knee or ankle arthritis or any other reason that may lead to neurological and walking ability impairment were also excluded. Patients with the presence of significant leg pain on rest
Internal construct validity of the Swiss Spinal Stenosis questionnaire: rasch analysis of a disease-specific outcome measure for lumbar spinal stenosis.
The reliability of the shuttle walking test, the Swiss spinal stenosis questionnaire, the oxford spinal stenosis score, and the Oswestry disability index in the assessment of patients with lumbar spinal stenosis.
Visual analogue scales (VAS): measuring instruments for the documentation of symptoms and therapy monitoring in cases of allergic rhinitis in everyday health care: position paper of the German society of Allergology (AeDA) and the German society of Allergy and clinical immunology (DGAKI), ENT section, in collaboration with the working group on clinical immunology, Allergology and environmental medicine of the German society of otorhinolaryngology, head and neck surgery (DGHNOKHC).
Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ): part 4. Establishment of equations for severity scores. Subcommittee on low back pain and cervical myelopathy, evaluation of the clinical outcome committee of the Japanese Orthopaedic Association.
An outcome measure of functionality in patients with lumber spinal stenosis: a validation study of the Iranian version of Neurogenic Claudication Outcome Score (NCOS).
The SSS questionnaire has 3 sections with 18 questions including a section with post management questions. Post management questions were excluded from the present study. Hence, only 2 sections (12 questions) were administered giving a total score of 53 (instead of 77). For the self-paced walking test, the patients were asked to walk in a 50-m hallway at a self-selected pace with the option to stop and sit when symptoms of neurogenic claudication appeared. The distance at which symptoms of neurogenic claudication appeared was recorded in meters. For MRI parameters, MRI files were uploaded in the RadiAnt DICOM Viewer 2020.0 beta (free). The maximum stenosis level was identified and the following parameters were measured by the method as described below at the level of the disc using the same software. The various MRI parameters that were measured along with their description are represented in Table 1. Illustrative MRI images depicting how the measurements were made are represented in Fig. 1, Fig. 2, Fig. 3, Fig. 4. All the radiographic measurements were performed by two orthopaedic surgeons with over 5 years’ experience in spine surgery and were well versed and proficient with the use of the above radiological software (SG, TB) and an average of the 2 measurements was used.
Table 1Summary of the MRI parameters used in the study and their description.
MRI parameter
Description
Transverse diameter of dural sac (TDD)
Distance between lateral borders of dural sac on the level of lateral canals [18].
Antero-posterior diameter of dural sac (APDD)
The AP diameter at disc level was measured by drawing a line between the anterior and posterior border of the dural sac [16, 17].
Anteroposterior diameter of spinal canal (APDS)
It was measured at the disc level by drawing a line between the posterior border of discus and the ligamentum flavum at midline [19].
Ligamentous interfacet distance (LID)
It was measured as the distance between the inner surfaces of flaval ligaments on a line connecting the joint space of facet joints [17].
Mid sagittal diameter of thecal sac (MSDT)
It was measured on a mid-sagittal cut at the level of disc as a distance between most anterior and posterior point of the thecal sac [18].
Cross sectional area of dural sac (CSAD)
The area of the dural sac was measured using ellipse tool provided in the software [15].
Lateral recess depth (LRD)
It was measured as the distance between the most anterior point of superior articular facet and the posterior border of spinal canal at the level of superior margin of the corresponding pedicle [21, 22].
Lateral recess angle (LRA)
It was measured as the angle between the lines parallel to the floor and the roof of the lateral recess [18, 21].
Fig. 1Figure representing the points taken for measurements of linear sizes of dural sac on axial section of MRI at the level of disc: 1. Anteroposterior diameter of dural sac (APDD), 2. Transverse diameter of dural sac (TDD).
Fig. 2Figure representing the points taken for measurements of linear sizes of spinal canal on axial section of MRI at the level of disc: 1. Anteroposterior diameter of spinal canal (APDS), 2. Ligamentous interfacet distance (LID), 3. Lateral recess depth (LRD), 4. Lateral recess angle (LRA).
Fig. 3Figure representing the points taken for measurement of mid sagittal diameter of thecal sac (MSDT) at the level of intervertebral disc on mid saggital section of MRI.
Fig. 4Figure representing the use of ellipse tool for measuring cross sectional area of dural sac (CSA) on the axial section of MRI at the level of disc.
The data was entered in an excel sheet and SPSS-PC-19 was used for statistical analysis. Percentages were used to express qualitative data and mean and standard deviation were used to quantify quantitative data. Correlation between two quantitative variables was studies with spearman correlation coefficient(r). P-value < 0.05 was considered statistically significant. The value of r ≥ 0.7 was considered a strong correlation, 0.7> r ≥ 0.3 was considered a moderate correlation and r < 0.3 was considered a weak correlation.
The intraclass correlation coefficient (ICC) was used to measure reliability across radiographic measurements. ICC>0.9 was considered excellent, 0.9 > ICC>0.75 was considered good.
In this study, 82 consecutive patients were selected aged more than 40 years out of which 33 patients (40.2%) were aged less than 50 years, 22 (26.8%) were between 50 and 59 years and 27 (32.9%) of more than 60 years. The mean age was 53.02 ± 9.18 years. Among selected patients, 51 (62.2%) were females and the rest 31 (37.8%) were males. In our study, 21 patients (25.6%) had single level involvement, two levels were involved in 39 patients (47.56%), 3 or more levels involved in 22 patients (26.8%). For multi-level LSS, the maximum stenotic level was used to measure the MRI parameters. The most commonly involved maximum stenotic level was L4-L5 in 38 patients (46.3%), followed by L5-S1 in 33 patients (40.02%) and L3-L4 in 11 patients (13.4%). Isolated central canal stenosis was seen in 9 patients (11.0%) while the rest 73 patients (89%) had both central and lateral recess stenosis. The mean, median, standard deviation and range for all MRI parameters and clinical scores are represented in Table 2. The intraclass correlation coefficient (ICC) was good to excellent (range 0.8–0.96) for all radiographic measurements.
Table 2Table representing the mean, standard deviation and range for MRI parameters and various clinical scores measures in LSS patients.
MRI Parameters
Parameter
Mean ± SD
Range
Transverse diameter of dural sac (mm
10.5 ± 3.7
4.11–18.5
AP diameter of spinal canal (mm)
10.9 ± 3.3
4.78–18.7
Ligamentous interfacet distance (mm)
6.9 ± 2.6
3.12–14
AP diameter of dural sac (mm)
6.5 ± 2.1
3.33–11.6
Mid sagittal diameter of thecal sac (mm)
6.2 ± 2.4
2.19–16.9
CSA of dural sac (mm)
54.5 ± 29.5
25.87–129.5
Lateral recess depth (mm)
2.7 ± 1.0
1.09–5.33
Lateral recess angle (°)
9.9 ± 4.5
3.7–23.1
Clinical Scores
Score
Mean ± SD
Range
ODI score (/50)
33.6 ± 6.5
12–44
SSS questionnaire (/53)
33 ± 6.5
23–50
Quebec pain disability scale (/100)
69.1 ± 8.4
44–85
VAS scale (/10)
7.2 ± 1.0
5–9
mJOA scale (/18)
11.6 ± 1.9
8–16
Pain Disability index (/100)
69.7 ± 8.8
44–86
Self-Paced walking test (metres)
231.7 ± 148.8
50–700
Euro quality of life- 5D (/100)
32.1 ± 20.3
−13.9–70.7
NCOS (/100)
34.1 ± 8.9
18–54
SF-36
Physical functioning (/100)
41.5 ± 17.9
10–95
Role limitations due to physical health (/100)
23.7 ± 21.9
0–75
Role limitations due to emotional problems (/100)
30.2 ± 25.7
0–100
Energy/fatigue (/100)
39.6 ± 17.3
0–75
Emotional well-being (/100)
39.9 ± 19.4
0–80
Social functioning (/100)
39.6 ± 15.2
12.5–75
Pain(/100)
34.7 ± 15.3
0–77.5
General health (/100)
45.9 ± 17.0
10–80
Health change (/100)
24.4 ± 16.4
0–70
(AP- Anteroposterior, CSA-Cross sectional area, MRI Magnetic Resonance Imaging, mJOA-modified Japanese Orthopaedic Association, NCOS-Neurogenic Outcome Claudication Score, ODI-Oswestry Disability Index, SD- Standard Deviation, SF - 36-Short Form Health Survey, SSS-Swiss Spinal Stenosis,VAS- Visual Analogue scale).
Various clinical scores were compared with MRI parameters. The correlation coefficient and p-value of each comparison were recorded and are represented in Table 3. The neurological claudication outcome score had a moderate positive correlation with TDD (r = 0.606, p = 0.00), CSAD (r = 0.580, p = 0.00) and LID (r = 0.519, p = 0.00). MSDT had a moderate negative correlation with SSS questionnaire (r = −0.426, p = 0.00), VAS scale (r = −0.407, p = 0.00), ODI scale (r = −0.389, p = 0.00), and QPD scale (r = −0.306, p = 0.005). LRD had a significant moderate negative correlation with ODI scale (r = −0.447, p = 0.00) and VAS score (r = −0.315, p = 0.00). LRA had a moderate correlation with the EQ-5D (r = 0.536, p = 0.00) and ODI scale (r = −0.377, p = 0.00). CSAD had a moderate negative correlation with PDI (r = −0.383, p = 0.000). For all other comparison there poor or no correlation between clinical scores and MRI parameters (Table 3).
Table 3Table representing the correlation coefficients (r) and p – value for comparison among various MRI parameters and clinical scoring systems.
Table 3Table representing the correlation coefficients (r) and p – value for comparison among various MRI parameters and clinical scoring systems.
Various components of SF-36 were correlated with MRI parameters and are represented in Table 4. APDS had a significant moderate correlation with role limitations due to emotional problems (r = 0.326, p = 0.003), APDD (r = 0.305, p = 0.005) and LRA (r = −0.345, p = 0.001). Mental health had moderate correlation with LID (r = −0.308, p = 0.005) and general health with LRA (r = 0.315, p = 0.004). The other comparisons among SF-36 components and MRI parameters yielded no or poor correlation. Bodily pain, social functioning, role limitations due to physical health and physical functioning demonstrated no significant strong or moderate correlation with any of the parameters (Table 4).
Table 4Table representing the correlation coefficients (r) and p – value for comparison among various MRI parameters and components of SF-36 scale.
Table 4Table representing the correlation coefficients (r) and p – value for comparison among various MRI parameters and components of SF-36 scale.
5. Discussion
Back pain, leg pain, neurogenic claudication and in some cases neurological deficit constitute the spectrum of symptoms of LSS.
As LSS is a clinico-radiological diagnosis, both MRI parameters and clinical scores often form a part of decision making, but how these two correlate with each other is still a bone of contention.
Many of the commonly used clinical scores and MRI parameters have never been correlated with each other. Hence, the present study was designed to provide a comprehensive correlation analysis among ten commonly used clinical scores and eight quantitative MRI parameters.
Most of the studies presently available have correlated VAS and ODI score with CSAD and APDD and no significant correlation between these parameters has been found.
also found similar findings in a literature review where did not find a significant correlation between pain scores and several MRI parameters that were evaluated. A few other scores like the SPWT and SF-36 have also met a similar fate where no correlation was seen on comparison with CSAD and APDD.
A summary of available studies from literature comparing various clinical scores and MRI parameters have been presented in Table 5. Besides these popular MRI parameters (CSAD, APDD), various other MRI parameters (TDD, APDS, LID, MSDT, LRD and LRA) have gained popularity over the last decade
and comparison and correlation between these quantitative MRI parameters and commonly used clinical scores is lacking.
Table 5Summary of studies correlating MRI parameters with clinical scores.
S. No.
Author and year
Number of patients
Type of MRI
MRI parameters used
Clinical scores
Results
1
Sirvanci 2008
63
Supine
CSAD
ODI
No correlation
2
Zeifang et al., 2008
63
Supine
CSAD
SPWT
No correlation
3
Kuittinen et al., 2014
80
Supine
CSAD
VAS
No straightforward association between the stenosis of dural sac and patient symptoms or functional capacity.
ODI
4
Hong et al., 2015
117
Supine
CSAD
VAS
No correlation
ODI
SF-36
5
Andrasinova et al., 2018
84
Supine
APDD
VAS
No correlation
CSAD
ODI
SPWT
6
Kanno et al., 2012
88
Supine
CSAD
VAS
Supine MRI did not correlate.
Axial loading MRI (standing MRI)
Walking distance
Standing MRI values had moderate correlation with clinical scores.
JOA score
7
Zhou et al., 2020
110
Supine and Standing MRI
CSAD
ODI
Dural sac size on MRI was reduced significantly from supine to standing position. Standing MRI and the changes of DCSA significantly correlated with all clinical parameters
Most of the clinical scores in our study had sparring significant correlation with MRI parameters. In this study, we performed over 160 correlations and approximately only 12% of the comparison yielded a significant moderate correlation. This again reinstates the fact that radiological parameters correlate poorly to clinical scores.
It is not uncommon for patients in developing countries to be advised surgical management based on MRI imaging and patients seeking treatment based on their MRI pictures showing canal stenosis. Studies have shown that factual reporting of MRI images can result in patients having decreased improvement in pain, poor functional status and a negative perception for their spinal conditions. On the other hand, clinical reporting which takes into account both the clinical picture and imaging leads to decrease in assessment of severity of disease and cause the health care practitioners to move to less degree of interventions and surgery.
The catastrophization effects of an MRI report on the patient and surgeon and the benefits of 'clinical reporting': results from an RCT and blinded trials.
Studies relating to lumbar disc herniation have also shown that percentage of canal occupied and the size of disc herniation were not predictive of need for surgery in these cases or conservative management failure.
Dynamic Change of Dural Sac Cross-Sectional Area in Axial Loaded Magnetic Resonance Imaging Correlates with the Severity of Clinical Symptoms in Patients with Lumbar Spinal Canal Stenosis. vol. 37. 2012: 207-213
Studies have suggested that even in the asymptomatic population over 55 years, one third of patients can have moderate to severe stenosis on MRI at atleast one level.
Discographic, MRI and psychosocial determinants of low back pain disability and remission: a prospective study in subjects with benign persistent back pain.
This discussion again reiterates the fact that LSS is a clinicoradiological diagnosis but an unpredictable and complex relationship exists between most MRI parameters and clinical scores. Radiological findings alone may not justify the treatment of spinal stenosis and management decisions should be based on the degree of clinical impairment with MRI findings supplementing the same.
We acknowledge that our study is fraught with some limitations: 1) We utilized supine MRI in our study. Some studies have shown that standing MRI may better recreate spinal stenosis conditions due to axial loading of the spine and result in good correlation between clinical scores and MRI parameters.
Dynamic Change of Dural Sac Cross-Sectional Area in Axial Loaded Magnetic Resonance Imaging Correlates with the Severity of Clinical Symptoms in Patients with Lumbar Spinal Canal Stenosis. vol. 37. 2012: 207-213
However, the use of standing MRIs remains largely restricted to research and such a facility is not available widely and at our center. At present, supine MRI remains the most widely used and practical approach for diagnosis of LSS in most parts of the world and this is unlikely to change in the near future. 2) As degenerative LSS is majorly a disorder of the elderly and hence comorbidities, polypharmacy and other degenerative disorders of the lower limbs may act as confounding factors. It may have had an impact on their pain tolerance and walking distance. 3) Single-center study and heterogeneous group of patients are some other limitations.
6. Conclusion
A poor correlation or no correlation was noted for most of the MRI parameters when compared to clinical scores utilized in common practice. Hence, poor MRI's don't necessarily mean poor clinical scores in LSS. The role of MRI parameters should be supplementary and overreliance on them in LSS management should be avoided.
Funding statement
There is no funding source for this publication/study.
Ethics approval
Approval was obtained from the ethics committee of Maulana azad medical college, New Delhi. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.
Consent to participate
Informed consent was obtained from all individual participants included in the study.
Consent to publish
Patients signed informed consent regarding publishing their data and photographs.
Code availability
Not applicable.
Declaration of competing interest
Dr Siddharth Gupta, Dr Tungish Bansal, Dr Abhishek Kashyap, and Dr Sumit Sural declare that they have no conflict of interest.
Acknowledgments
None.
References
Deyo R.A.
Gray D.T.
Kreuter W.
Mirza S.
Martin B.I.
United States trends in lumbar fusion surgery for degenerative conditions.
Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ): part 4. Establishment of equations for severity scores. Subcommittee on low back pain and cervical myelopathy, evaluation of the clinical outcome committee of the Japanese Orthopaedic Association.
Internal construct validity of the Swiss Spinal Stenosis questionnaire: rasch analysis of a disease-specific outcome measure for lumbar spinal stenosis.
An outcome measure of functionality in patients with lumber spinal stenosis: a validation study of the Iranian version of Neurogenic Claudication Outcome Score (NCOS).
The reliability of the shuttle walking test, the Swiss spinal stenosis questionnaire, the oxford spinal stenosis score, and the Oswestry disability index in the assessment of patients with lumbar spinal stenosis.
Visual analogue scales (VAS): measuring instruments for the documentation of symptoms and therapy monitoring in cases of allergic rhinitis in everyday health care: position paper of the German society of Allergology (AeDA) and the German society of Allergy and clinical immunology (DGAKI), ENT section, in collaboration with the working group on clinical immunology, Allergology and environmental medicine of the German society of otorhinolaryngology, head and neck surgery (DGHNOKHC).
The catastrophization effects of an MRI report on the patient and surgeon and the benefits of 'clinical reporting': results from an RCT and blinded trials.
(3)Dynamic Change of Dural Sac Cross-Sectional Area in Axial Loaded Magnetic Resonance Imaging Correlates with the Severity of Clinical Symptoms in Patients with Lumbar Spinal Canal Stenosis. vol. 37. 2012: 207-213
Discographic, MRI and psychosocial determinants of low back pain disability and remission: a prospective study in subjects with benign persistent back pain.
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