Extending the straight leg raise test for improved clinical evaluation of sciatica: validity and diagnostic performance with reference to the magnetic resonance imaging

Comparison of Magnetic Resonance Imaging with Electrodiagnosis in the Evaluation of Clinical Suspicion of Lumbosacral Radiculopathy

(1) Background: The diagnosis of lumbosacral radiculopathy involves anamnesis, an assessment of sensitivity and strength, diagnostic imaging-usually magnetic resonance imaging (MRI)-and electrodiagnostic testing (EDX), typically electromyography (EMG), and electroneurography (ENG). MRI evaluates the structures supporting the spinal cord, while EDX evaluates root functionality. The present study aimed to analyze the concordance of MRI and EDX findings in patients with clinically suspected radiculopathy. Additionally, we investigated the comparison between these two reference tests and various clinical variables and questionnaires. (2) Methods: We designed a prospective epidemiological study of consecutive cases with an observational, descriptive, cross-sectional, and double-blind nature following the STROBE guidelines, encompassing 142 patients with clinical suspicion of lumbosacral radiculopathy. (3) Results: Of the sample, 58.5% tested positive for radiculopathy using EDX as the reference test, while 45.8% tested positive using MRI. The comparison between MRI and EDX in the diagnosis of radiculopathy in patients with clinical suspicion was not significant; the overall agreement was 40.8%. Only the years with symptoms were comparatively significant between the positive and negative radiculopathy groups as determined by EDX. (4) Conclusion: The comparison between lumbar radiculopathy diagnoses in patients with clinically suspected pathology using MRI and EDX as diagnostic modalities did not yield statistically significant findings. MRI and EDX are complementary tests assessing different aspects in patients with suspected radiculopathy; degeneration of the structures supporting the spinal cord does not necessarily imply root dysfunction.

Is the Straight Leg Raise Suitable for the Diagnosis of Radiculopathy? Analysis of Diagnostic Accuracy in a Phase III Study

The straight leg raise test (SLR) has been proposed to detect increased nerve mechanosensitivity of the lower limbs in individuals with low back pain. However, its validity in the diagnosis of lumbosacral radiculopathy shows very variable results. The aim of this study was to analyse the diagnostic validity of the SLR including well-defined diagnostic criteria (a change in symptoms with the structural differentiation manoeuvre and the reproduction of the patient's symptoms during the test or the asymmetries in the range of motion or symptoms location between limbs) in a sample of participants in phase III with suspicion of lumbar radiculopathy using the electrodiagnostic studies (EDX) as the reference standard. A phase III diagnostic accuracy study was designed. In total, 142 individuals with suspected lumbosacral radiculopathy referred for EDX participated in the study. Each participant was tested with EDX and SLR. SLR was considered positive using three diagnostic criteria. The sensitivity of the SLR for Criterion 3 was 89.02% (CI 81.65-96.40), the specificity was 25.00% (CI 13.21-36.79), and the positive and negative likelihood ratios were 1.19 (CI 1.01-1.40) and 0.44 (0.21-0.94), respectively. SLR showed limited validity in the diagnosis of lumbosacral radiculopathy. The incorporation of more objective diagnostic criteria (asymmetry in range of motion or localisation of symptoms) improved the diagnostic validity but the imprecision of the confidence intervals limited the interpretation of the results.

Therapists' experiences with implementing new documentation practices for low back pain in electronic health care records: an interview study

OBJECTIVE

Clinical practice is constantly changing with new guidelines being published, changes in patients' preferences but also by new qualitative requirements for therapists and institutional surveys on delivered care. Electronic health records (EHR) are used for all these purposes. We involved physiotherapists and occupational therapists in an intervention to change documentation practice in their electronic health record for low back pain (LBP) and later evaluated the feasibility of the new health records. The aim of the present study was to explore therapists' experiences working with the new EHR.

RESULTS

Three themes were identified thru interviews: (I) Facilitators and motivators towards implementation, (II) Changing routines as a group and (III) Obstacles against successful implementation. This study identifies a need for involving therapists and management for successful change of electronic health care records usage in municipalities. However, difficulties were encountered in meeting documentation of practice requirements and obtaining sufficient data quality in the EHR for data to be used for daily use, quality assessment and research. In this small descriptive study, developing an EHR that simultaneously serves treatment plans, quality assessment, and research purposes was not expressed being feasible. Further research in this area is needed.

Comparison of magnetic resonance imaging findings among sciatica patients classified as centralizers or non-centralizers

OBJECTIVE

To compare if the degenerative findings from MRI differ between the sciatica patients classified as centralizers (CEN) and non-centralizers (Non-CEN) according to the McKenzie Method of mechanical diagnosis and therapy.

STUDY DESIGN

A cross-sectional study.

METHODS

Patients (N = 100) referred to a spine clinic of a single tertiary hospital for specialist consultation for sciatica. The McKenzie-based assessment was performed by the mechanical diagnosis and therapy-trained physiotherapists. Clinical data and prevalence of lumbar MRI findings were compared between the groups.

RESULTS

There was no significant difference in leg pain intensity between the groups. The Non-CEN had significantly more intense back pain, mean 56 (SD 30) and were more disabled 44 (SD 15) compared to the CEN mean 41 (SD 25) and mean 31 (11), measured with a visual analogue scale (0-100), and the Oswestry Disability Index (0-100), respectively. The CEN had more severe degenerative findings on MRI than the Non-CEN: vertebral end-plate changes were 63% and 43%; mean Pfirrmann's disc degeneration lumbar summary score was 12.8, and 10.6; and severity score of total damage was 12.0 and 10.1, respectively. There were differences neither in disc contour changes nor nerve root stenosis on MRI.

CONCLUSIONS

Sciatica patients classified as non-centralizers had significantly more severe back pain, and were significantly more disabled than centralizers, who instead had more severe degenerative findings on MRI. Thus, classification to non-centralizers by the McKenzie method seems not predict higher incidence of degenerative findings on MRI compared to centralizers.

Longitudinal Movements and Stiffness of Lower Extremity Nerves Measured by Ultrasonography and Ultrasound Elastography in Symptomatic and Asymptomatic Populations: A Systematic Review With Meta-analysis

This study was aimed at analyzing the effectiveness of ultrasonography (US) and ultrasound elastography (UE) in evaluating longitudinal sliding and stiffness of nerves. In line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, we analyzed 1112 publications (range: 2010-2021) extracted from MEDLINE, Scopus and Web of Science focusing on specific outcomes, including shear wave velocity (m/s), shear modulus (kPa), strain ratio (SR) and excursion (mm). Thirty-three papers were included and evaluated for overall quality and risk of bias. From the analysis of data concerning 1435 participants, mean shear wave velocity (SWV) in the sciatic nerve was 6.70 ± 1.26 m/s in controls and 7.51 ± 1.73 m/s in participants presenting with leg pain; in the tibial nerve, mean SWV was 3.83 ± 0.33 m/s in controls and 3.42 ± 3.53 m/s in participants presenting with diabetic peripheral neuropathy (DPN). The mean shear modulus (SM) was 20.9 ± 9.33 kPa for sciatic nerve, whereas it was an average of 23.3 ± 7.20 kPa for the tibial nerve. Considering 146 subjects (78 experimental, 68 controls) no significant difference was observed in SWV when comparing participants with DPN with controls (standard mean difference [SMD]: 1.26, 95% confidence interval [CI]: 0.54, 1.97), whereas a significant difference was observed in the SM (SMD: 1.78, 95% CI: 1.32, 2.25); furthermore, we found significant differences between left and right extremity nerves (SMD:1.14. 95% CI: 0.45, 1.83) among 458 participants (270 with DPN and 188 controls). No descriptive statistics are available for excursion because of the variability in participants and limb positions, whereas SR is considered only a semiquantitative outcome and therefore not comparable among different studies. Despite the presence of some limitations in study designs and methodological biases, on the basis of our findings, we can conclude that US and UE are effective methods in assessing longitudinal sliding and stiffness of lower extremity nerves in both symptomatic and asymptomatic subjects.

Extending the straight leg raise test for improved clinical evaluation of sciatica: validity and diagnostic performance with reference to the magnetic resonance imaging

BACKGROUND

The straight leg raise test (SLR) is one of the most utilized and studied physical tests in patients with low back pain (LBP) for the detection of lumbar disc herniation (LDH), showing high sensitivity and heterogeneous or low specificity. The high incidence of asymptomatic 'pathologic' findings in the magnetic resonance imaging (MRI) scans may cause verification bias to these results. We studied an extended SLR (ESLR) by adding location-specific structural differentiation movements (hip internal rotation or ankle dorsiflexion) to the traditional SLR for it to better differentiate neural symptoms from musculoskeletal. Previously, the ESLR has shown almost perfect interrater reliability between examiners and ability to detect sciatic patients. In this study, we investigated whether a 'positive' ESLR finding is associated with pathology seen on MRI.

METHODS

Forty subjects comprised the study population, 20 in sciatic group and 20 in control group. The ESLR was performed 'blinded' to the subjects. After the ESLR, each subject's lumbar MRI was evaluated. The MRIs were analyzed independently by 2 senior radiologists and a spine specialist clinician. The ESLR and MRI results were cross-tabulated. To obtain the odds ratio (OR) with positive ESLR or SLR results for LDH or nerve root compression (NC), a binary logistic regression analysis with subjects' age, gender, height and weight was performed. ESLR's validity was assessed by combination of interrater agreement and percentage prevalence of both LDH and NC.

RESULTS

Of sciatic (ESLR+) patients, 85 % had LDH and 75 % NC in the MRI. Not surprisingly, MRI showed a very high incidence of 'false-positive' findings with the ESLR negative group. The ESLR showed 0.85 sensitivity and 0.45 specificity for LDH and 0.75 sensitivity and 0.50 specificity for NC. A positive result in the ESLR was found to be strongly associated with for both LDH and NC: the OR was 8.0 (p = 0.028) and 5.6 (p = 0.041), respectively.

CONCLUSIONS

The ESLR shows high validity in detecting neural symptoms and is strongly associated with pathology seen in the MRI when judged positive. We suggest the use of ESLR in clinical practice as a part of clinical examination, where it may prove to be a valuable tool in detecting patients with sciatic symptoms.