Follow-up of the sagittal spine by optical technique

Validity and Reliability of a Non-Radiographic Postural Analysis Device Based on an RGB-Depth Camera Comparing EOS 3D Imaging: A Prospective Observational Study

The posture-analyzing and virtual reconstructing device (PAViR) used a Red Green Blue-Depth camera as a sensor and skeleton reconstruction images were produced. This PAViR quickly analyzed the whole posture from multiple repetitive shots without radiation exposure in clothes and provided a virtual skeleton within seconds. This study aims to evaluate the reliability when shooting repeatedly and to assess the validity compared to parameters of full-body, low-dose X-rays (EOSs) when applied as diagnostic imaging. As a prospective and observational study, 100 patients with musculoskeletal pain underwent an EOS to obtain whole body coronal and sagittal images. The outcome measures were human posture parameters, which were divided by the standing plane in both EOSs and PAViRs as follows: (1) a coronal view (asymmetric clavicle height, pelvic oblique, bilateral Q angles of the knee, and center of seventh cervical vertebra-central sacral line (C7-CSL)) and (2) a sagittal view (forward head posture). A validation of the PAViR compared to the EOSs revealed that C7-CSL showed a moderate positive correlation with that of the EOS (r = 0.42, p < 0.01). The forward head posture (r = 0.39, p < 0.01), asymmetric clavicle height (r = 0.37, p < 0.01), and pelvic oblique (r = 0.32, p < 0.01) compared to those of the EOS had slightly positive correlations. The PAViR has excellent intra-rater reliability in people with somatic dysfunction. Except for both Q angles, the PAViR has fair-to-moderate validation when compared to EOS diagnostic imaging in the parameter representing coronal and sagittal imbalance. Although the PAViR system is not yet available in the medical field, it has the potential to become a radiation-free, accessible, and cost-effective postural analysis diagnostic tool after the EOS era.

Validating Surface Topography for the Measurement of the Thoracic Kyphosis Angle in Patients With Scoliosis: A Prospective Study of Accuracy

OBJECTIVE

The purpose of this study was to test the validity and determine the accuracy of surface topography in relation to photogrammetry for measuring the thoracic kyphosis angle in patients with scoliosis.

METHODS

This was a prospective, cross-sectional study of diagnostic accuracy that followed the guidelines recommended by the Standards for Reporting Diagnostic Accuracy. We consecutively included 51 participants aged 7 to 18 years. Exclusion criteria were surgical treatment of the spine, neurological disease, lower limb discrepancy greater than 1.5 cm, and body mass index above 29 kg/m². Each participant was evaluated using both a surface topography scan and photogrammetry in random order. The measurement obtained through photogrammetry was used as a reference in this study. For statistical purposes, Pearson's correlation test, Bland-Altman graphical analysis, and the receiver operating characteristic curve (P < .05) were performed.

RESULTS

The correlation between the measurements was strong and significant (r = 0.76, P < .001) with an average difference of 0.4° in the Bland-Altman analysis. The receiver operating characteristic curve area was excellent for hypokyphosis (93.4%) and good for hyperkyphosis (86.4%), both being significant (P < .005).

CONCLUSION

The agreement and strong correlation between the 2 methods indicate the validity of surface topography to measure the thoracic kyphosis angle. The surface topography provides accurate measures for the thoracic kyphosis angle with cutoff points for hypo- (33.3°) and hyperkyphosis (40.8°) for individuals with scoliosis.

Sagittal spine shape literacy in the general adult population, assessed by a novel, simple graphical tool

[Purpose] The sagittal shape of the spine is associated with back-pain, balance and quality of life. We developed, evaluated and report the responses of a graphical tool to assess sagittal spine shape knowledge (literacy). [Participants and Methods] Two hundred and fifty adults were randomly assigned, in a cross-sectional crossover study, to free-hand draw and select the “ideal” sagittal spine shape. We evaluated the inter and intra-rater reliability and agreement between tests and the sagittal and lordotic spine literacy between the drawing and selection test versions. [Results] Drawing test inter- and intra-rater agreement was 79% and 80% respectively. Drawing vs. selection agreement was 43%. More participants drew than selected the correct spine (30% vs. 21%) (p<0.001) and lumbar lordosis shape (56% vs. 42%) (p<0.001). Test order did not affect spine shape literacy scores. A significantly poorer literacy trend was observed with spine pain presence (p=0.02). [Conclusion] We developed a reliable method to evaluate spine shape literacy and established that only 21% and 42% of our sample demonstrated correct sagittal spine and lordotic spine shape literacy, respectively. The low literacy scores suggests that consideration of including spine shape literacy in health literacy and self-management programs may be warranted, especially in ageing populations.

Non-radiographic methods of measuring global sagittal balance: a systematic review

Background

Global sagittal balance, describing the vertical alignment of the spine, is an important factor in the non-operative and operative management of back pain. However, the typical gold standard method of assessment, radiography, requires exposure to radiation and increased cost, making it unsuitable for repeated use. Non-radiologic methods of assessment are available, but their reliability and validity in the current literature have not been systematically assessed. Therefore, the aim of this systematic review was to synthesise and evaluate the reliability and validity of non-radiographic methods of assessing global sagittal balance.

Methods

Five electronic databases were searched and methodology evaluated by two independent reviewers using the13-item, reliability and validity, Brink and Louw critical appraisal tool.

Results

Fourteen articles describing six methodologies were identified from 3940 records. The six non-radiographic methodologies were biophotogrammetry, plumbline, surface topography, infra-red motion analysis, spinal mouse and ultrasound. Construct validity was evaluated for surface topography (R = 0.49 and R = 0.68, p < 0.001), infra-red motion-analysis (ICC = 0.81) and plumbline testing (ICC = 0.83). Reliability ranged from moderate (ICC = 0.67) for spinal mouse to very high for surface topography (Cronbach α = 0.985). Measures of agreement ranged from 0.9 mm (plumbline) to 22.94 mm (infra-red motion-analysis). Variability in study populations, reporting parameters and statistics prevented a meta-analysis.

Conclusions

The reliability and validity of the non-radiographic methods of measuring global sagittal balance was reported within 14 identified articles. Based on this limited evidence, non-radiographic methods appear to have moderate to very high reliability and limited to three methodologies, moderate to high validity. The overall quality and methodological approaches of the included articles were highly variable. Further research should focus on the validity of non-radiographic methods with a greater adherence to reporting actual and clinically relevant measures of agreement.

Sagittal and Frontal Plane Evaluation of the Whole Spine and Clinical Outcomes after Vertebral Fractures

Although it is known that a change in any level of the spine alters biomechanics, there are not many studies to evaluate the spine as a whole in both sagittal and frontal planes. This prospective cohort study evaluates the morphology and mobility of the entire spine in patients with vertebral fractures. The Treatment Group consisted of 43 patients who underwent percutaneous balloon kyphoplasty or percutaneous balloon kyphoplasty plus fixation. The Control Group consisted of 39 healthy subjects. Spinal Mouse was used for the assessment of the curvatures and the mobility of the spine. Clinical outcomes were evaluated by Visual Analogue Scale and Oswestry Disability Index. The measurements were recorded at 15 days and 3, 6, and 12 months postoperatively. Regarding the curvatures and mobility in sagittal plane, a statistically significant increase appeared early at 3 months, for lumbar curve, spinopelvic angulation, and overall trunk inclination. In the frontal plane, most of the improvements were recorded after 6 months. Patients with osteoporotic fracture showed statistically significant lower mean value than patients with traumatic fracture. Pain and disability index showed early improvements. This study provides a comprehensive and complete picture of the functionality of the spine in patients treated with percutaneous balloon kyphoplasty.

Determination of the human spine curve based on laser triangulation

Background

The main objective of the present method was to automatically obtain a spatial curve of the thoracic and lumbar spine based on a 3D shape measurement of a human torso with developed scoliosis. Manual determination of the spine curve, which was based on palpation of the thoracic and lumbar spinous processes, was found to be an appropriate way to validate the method. Therefore a new, noninvasive, optical 3D method for human torso evaluation in medical practice is introduced.

Methods

Twenty-four patients with confirmed clinical diagnosis of scoliosis were scanned using a specially developed 3D laser profilometer. The measuring principle of the system is based on laser triangulation with one-laser-plane illumination. The measurement took approximately 10 seconds at 700 mm of the longitudinal translation along the back. The single point measurement accuracy was 0.1 mm. Computer analysis of the measured surface returned two 3D curves. The first curve was determined by manual marking (manual curve), and the second was determined by detecting surface curvature extremes (automatic curve). The manual and automatic curve comparison was given as the root mean square deviation (RMSD) for each patient. The intra-operator study involved assessing 20 successive measurements of the same person, and the inter-operator study involved assessing measurements from 8 operators.

Results

The results obtained for the 24 patients showed that the typical RMSD between the manual and automatic curve was 5.0 mm in the frontal plane and 1.0 mm in the sagittal plane, which is a good result compared with palpatory accuracy (9.8 mm). The intra-operator repeatability of the presented method in the frontal and sagittal planes was 0.45 mm and 0.06 mm, respectively. The inter-operator repeatability assessment shows that that the presented method is invariant to the operator of the computer program with the presented method.

Conclusions

The main novelty of the presented paper is the development of a new, non-contact method that provides a quick, precise and non-invasive way to determine the spatial spine curve for patients with developed scoliosis and the validation of the presented method using the palpation of the spinous processes, where no harmful ionizing radiation is present.