Measurement of Lumbar Lordosis: A Comparison of 2 Alternatives to the Cobb Angle

Evaluation of lumbar lordosis in symptomatic individuals and comparative analysis of six different techniques: a retrospective radiologic study

PURPOSE

The aim of this study; evaluate lumbar lordosis (LL) in symptomatic individuals with six different techniques and to examine the techniques comparatively. Thus, to provide an overview of lumbal lordosis and techniques.

METHODS

Cobb L1-L5, Cobb L1-S1, Posterior Tangent, tangential radiologic assessment of lumbar lordosis (TRALL), vertebral centroid measurement of lumbar lordosis (CLL) and Risser Ferguson measurement techniques were used to assess LL from radiographs of 175 symptomatic adults. Correlations between techniques and relationship between the measurements obtained, gender and age were analyzed. Also ınterclass correlation (ICC) analyzed. Bland-Altman plots were performed to compare the techniques with Cobb.

RESULTS

ICC for all methods were greater than 0.96. For each method, no difference in LL was observed with respect to gender or age (p > 0.05). High positive correlation was observed between the Risser Ferguson, Posterior Tangent, Cobb L1-L5, Cobb L1-S1 and CLL techniques (p < 0.001), and moderate positive correlation between TRALL and all other techniques (p < 0.001).

CONCLUSION

In this study, it was found that the mean lumbar lordosis values of symptomatic participants were lower than most of the other asymptomatic studies in the literature and there was no significant difference in lumbar lordosis values in terms of gender and age in symptomatic individuals. Based on statistical findings, Risser Ferguson can be used to assess LL. These results and the data obtained as a result of the comparative examination of techniques according to age groups and gender will benefit clinicians and those working in the field by providing a better understanding LL.

Evaluation of the accuracy of new modalities in the assessment and classification of lumbar lordosis: A comparison to Cobb's angle measurement

Background

Because of the association of lumbar lordosis with some clinical conditions such as low back pain, the chiropractic field has emphasized the significance of evaluating the lumbar lordotic status, by measuring Cobb's angle, regarded as the radiological gold standard, for the assessment of lumbar lordosis, on lateral radiographs. However, research has shown that this technique has some considerable drawbacks, mostly in terms of low accuracy and high variability between clinicians when compared with other radiological modalities. The main objective was to compare the diagnostic accuracy of newly established radiological measurements with one of Cobb's angle methods, for the characterization of lumbar lordosis status in a sample of Lebanese patients aged 15 and above.

Material and methods

This retrospective single-center study consisted of measuring Cobb's L1-S1 and Cobb's L1-L5 angles, along with the novel established measurements which are the derivative and the normalized surface area, on 134 lateral radiographs of the lumbar spine of Lebanese patients aged fifteen years old and above, gotten from the Radiology department at Zahra'a's Hospital in Beirut, performed by two observers using MATLAB. Inter-rater agreement was assessed by calculating the Intra-class correlation coefficients. Spearman correlation was analyzed between both Cobb's angle methods and with the derivative and normalized area respectively. 54 patients of the sample were diagnosed by two radiologists, according to their LL status. ROC curve analysis was performed to compare the diagnostic accuracy of the four techniques used. Data were analyzed with IBM SPSS Statistics 23.0 (NY, USA); P < 0.05 was considered statistically significant.

Results

According to the ROC curve analysis the new methods, which are the derivative and the normalized surface area, displayed lower diagnostic accuracy (AUCderivative = 0.818 and 0.677, AUCsurface area = 0.796 and 0.828) than Cobb's L1-L5 (AUCL1-L5 = 0.924 and 0.929 values) and L1-S1 (AUCL1-S1 = 0.971 and 0.955) angles, in the characterization of hypo and hyperlordotic patients, respectively, in our Lebanese sample consisting of patients aged 15 and above, because of their lower area under the curve's values compared to the traditional Cobb's techniques. The Cobb's L1-S1 has shown to have the highest diagnostic accuracy among the four methods to characterize normal patients from hypo and hyperlordotic ones, by referring to its highest area under the curve's values. However, the sensitivity of Cobb's L1-L5 angle in characterizing hyperlordotic patients was similar to the one of the normalized surface area with a value of 100%.Conclusion: among the four modalities, the new methods didn't show a better diagnostic accuracy compared to the traditional modalities. Cobb's L1-S1 displayed the highest diagnostic accuracy despite its drawbacks. Further prospective studies are needed to validate the cut-offs obtained for Cobb's L1-S1 angle in our sample.

Comprehensive analysis of muscles wasting in disc herniation

Neuromuscular reeducation of the muscles that stabilize the spine is the basis of conservative treatment of disc herniation. Therefore, it is important to investigate how these muscles are affected by disc herniation. The aim of this study was to investigate the effect of disc herniation, herniation severity, patient age, and biomechanics on the lumbar stabilizer muscles. A total of 330 individuals, including 261 patients with disc herniations and 69 without disc herniation participated in this study. The cross-sectional areas (CSAs) of the lumbar stabilizer muscles and the lumbar lordosis angle were evaluated by magnetic resonance imaging (MRI), according to the severity of the disc herniation and the patient's age. In the patients with disc herniation, the CSAs of the quadratus lumborum (QL) and the multifidus (MF) muscles were decreased. The psoas major (PM) muscle CSA was higher in the patients with sequestered discs than in those with protruded and extruded discs. A negative relationship between the sagittal curve and the PM muscle CSA was found. In addition, MF muscle CSA was found to decrease at age 45 years and over. Although disc herniation negatively affects muscle CSAs, no linear relationship was found between the severity of the herniation and the muscle CSA. In addition, the PM muscle was found to be a strong compensatory muscle in disc herniation.

Augmenting the Cobb angle: Three-dimensional analysis of whole spine shapes using Bézier curves

BACKGROUND AND OBJECTIVE

The identification and classification of pathological spinal deformities poses a major challenge to any diagnostician. First, available medical images are usually two-dimensional projections, obscuring elaborated spatial information. Second, several measurement techniques with different thresholds for certain clinical syndromes make it difficult to classify measured results. Here, a method is presented to augment and standardize the analysis of spinal shapes in three dimensions.

METHODS

Regarding the first limitation, (semi-)automatic, three-dimensional segmentation techniques of medical images have already been developed. To overcome the second, we propose here a representation of the whole spine by a Bézier curve using the vertebral centers as control points. After normalization, a differential-geometric approach yields information on curvature and torsion at each spinal level as well as in between.

RESULTS

Based on literature data and multi-body simulations, we show how these quantities alter with individual posture and during motion. Robustness with respect to missing data is investigated. Approaches towards the identification of spinal disorders are motivated.

CONCLUSION

Our results emphasize the need for individualizable identification and classification of spinal deformities and give an outlook on how it might be achieved. The presented methodology constitutes the first fully three-dimensional analysis of spinal shapes, i.e. without the requirement of certain physiological planes (e.g. the sagittal plane) or landmarks (e.g. the apex vertebra).

Spinal mobility in radiographic axial spondyloarthritis: criterion concurrent validity of classic and novel measurements

Background

Limitations in spinal mobility are a characteristic feature of Axial Spondyloarthritis. Current clinical measurements of spinal mobility have shown low criterion-concurrent validity. This study sought to evaluate criterion-concurrent validity for a clinically feasible measurement method of measuring spine mobility using tri-axial accelerometers.

Methods

Fifteen radiographic-Spondyloarthritis patients were recruited for this study. Two postural reference radiographs, followed by three trials in forward, left and right lateral bending were taken. For all trials, three measurements were collected: tape (Original Schober’s, Modified Schober’s, Modified-Modified Schober’s, Lateral Spinal Flexion Test and Domjan Test), followed immediately by synchronized radiograph and accelerometer measurements at end range of forward and bilateral lateral flexion. The criterion-concurrent validity of all measurement methods was compared to the radiographic measures using Pearson’s correlation coefficients. A Bland-Altman analysis was conducted to assess agreement.

Results

In forward bending, the accelerometer method (r = 0.590, p = 0.010) had a stronger correlation to the radiographic measures than all tape measures. In lateral bending, the Lateral Spinal Flexion tape measure (r = 0.743, p = 0.001) correlated stronger than the accelerometer method (r = 0.556, p = 0.016). The Domjan test of bilateral bending (r = 0.708, p = 0.002) had a stronger correlation to the radiographic measure than the accelerometer method.

Conclusions

Accelerometer measures demonstrated superior criterion-concurrent validity compared to current tape measures of spinal mobility in forward bending. While a moderate correlation exists between accelerometer and radiographs in lateral bending, the Lateral Spinal Flexion Test and Domjan Test were found to have the best criterion-concurrent validity of all tests examined in this study.