Comparison between Oxford Cobbmeter and digital Cobbmeter for measurement of Cobb angle in adolescent idiopathic scoliosis

A mobile application tool for standing posture analysis: development, validity, and reliability

Background

Using mobile application for postural assessments has been drawing a rising interest due to widespread use of smartphones. Although there are some mobile applications in use, validated mobile tools for accurate postural assessment are still warranted.

Aims

This study aimed to develop Fizyoprint mobile application tool to assess standing posture and investigate the validity and reliability of the application in young adults.

Methods

A convenience sample of 20 young adults (12 men and 8 women with a mean age of 21.3 ± 2.2 years) and 2 physiotherapists as raters participated in the study. The participant’s digital images were obtained from the anterior, posterior, and right lateral sides. The raters selected the anatomic reference points by using digital markers in the app screen, and the Fizyoprint application, with Turkish language option, calculated a total of 26 posture variables, including 11 distance and 15 angle variables. Each participant was assessed twice (1-week interval) by 2 raters with Fizyoprint. Inter- and intra-rater reliabilities were estimated using the intraclass correlation coefficient. The BioTonix™ posture analysis system was used for validation.

Results

A total of 80.7% (21 variables) indicated acceptable to excellent intra-rater reliability results. A total of 57.7% (15 variables) were found to be acceptable to excellent for inter-rater measurements. The results confirmed the validity of the Fizyoprint application for testing the standing posture.

Conclusions

Fizyoprint application is a new, valid, free mobile tool with acceptable concordance with BioTonix™ postural analysis system for assessing standing posture. Further studies are warranted to test the current application in different populations and musculoskeletal conditions.

Mobile Applications for Assessing Human Posture: A Systematic Literature Review

Smartphones are increasingly incorporated with features such as sensors and high resolution cameras that empower their capabilities, enabling their use for varied activities including human posture assessments. Previous reviews have discussed methods used in postural assessment but none of them focused exclusively on mobile applications. This paper systematically reviews mobile applications proposed for analyzing human posture based on alignment of the body in the sagittal and coronal plane. The main digital libraries were searched, 26 articles published between 2010 and 2020 were selected, and 13 mobile applications were identified, classified and discussed. Results showed that the use of mobile applications to assist with posture assessment have been demonstrated to be reliable, and this can contribute to clinical practice of health professionals, especially the assessment and reassessment phases of treatments, despite some variations when compared to traditional methods. Moreover, in the case of image-based applications, we highlight the advantage that measurements can be taken with the assessor at a certain distance with respect to the patient’s position, which is an important function for assessments performed in pandemic times such as the outbreak of COVID-19.

The effect of added fat on the accuracy of Cobb angle measurements in CT SPR images: A phantom study

INTRODUCTION

Adolescent idiopathic scoliosis (AIS) is a spinal deformity that mostly affects females aged between 10 and 17 years old. Cobb's method is the gold standard for assessing AIS. Being overweight is a common characteristic in AIS patients; therefore, the aim of this study is to investigate the effect fat mass has on the accuracy of Cobb angle measurements in 10-year-old female AIS patients.

METHODS

A purpose-built phantom representing an AIS patient was scanned after adding several thicknesses of lard fat (0,2,4 and 8 cm). The phantom was scanned in an antero-posterior position using the scout mode of the CT scanner. 18 observers performed Cobb angle measurements on the images.

RESULTS

The average Cobb angle at 0 cm of fat was 10.83° (SD = 3.06), at 2 cm it was 10.90° (SD = 3.16), at 4 cm it was 10.64° (SD = 3.06) and at 8 cm it was 10.88° (SD = 3.02). No significant difference was observed between the measurements at these thicknesses.

CONCLUSION

Cobb angle measurements are not affected by the presence of fat.

IMPLICATIONS FOR PRACTICE

When assessing overweight AIS patients, it not necessary to manipulate the acquisition parameters, which could lead to increased patient dose, in order to get more accurate Cobb angle measurement.

Oxford Cobbometer Versus Computer Assisted-Software for Measurement of Cobb Angle in Adolescent Idiopathic Scoliosis

OBJECTIVE

The objective was to compare Cobb angle measurements performed using an Oxford Cobbmeter and digital computer software (Surgimap) in a series of 83 adolescent idiopathic scoliosis (AIS) patients.

METHODS

Two independent observers measured the Cobb angles for 123 curves on 83 consecutive long radiographs of patients with AIS using both Oxford Cobbmeter and digital computer software (Surgimap). The measurements were repeated a week. Curves were classified according to the severity into mild, moderate, and severe. The results were statistically analyzed for intraobserver and interobserver reliability.

RESULTS

The mean Cobb angle was 48.12° ± 19.75° (range, 10.54°-110.76°). Globally the results of curve measurements were comparable between and within both observers using both methods, with small mean differences. According to intraclass correlation coefficient, there was high inter- and intraobserver high agreement for both methods. All readings were > 0.9. There was a good interobserver (κ = 0.745, 0.693) and a very good interobserver agreement (κ = 0.810, 0.804) for both methods for curve classification. However, poor agreement was observed as regards to the measurement time, being less with Oxford Cobbometer.

CONCLUSION

The results of this study indicate that the Surgimap digital computer software measurement is an equivalent measuring tool to the Oxford Cobbmeter in Cobb angle measurement. Both have high intra and interobserver agreement for measurement and for curve classification, with small measurement differences. Oxford Cobbmeter is advantageous in being quicker, and therefore it is the method of choice for manual measurement, where PACS (patient archiving and communication system) or digital system is not available.

Newfangled Procedures Using X-ray to Determine the Cobb Angle in Patients with Scoliosis: An Updated Systematic Review

BACKGROUND

Scoliosis is a three-dimensional deformity of the spine. It is usually assessed by measuring Cobb angle. Nowadays, due to increasing effectiveness of image processing and machine vision, willingness to apply these methods has improved considerably in determining scoliosis of Cobb angle.

METHODS

In accordance with the PRISMA guideline, a broad electronic search of all English language literature was conducted on the topic through four databases, including MEDLINE, Web of Science, Scopus, and the Cochrane Library from 2012 (last search date from earlier review) to 30 March 2017.

RESULTS

Twelve studies were included. 90% labeled high-quality were selected for analysis. Eighty percent of the selected studies were published in the period between 2012 and 2017. Three new procedures were used to measure the Cobb angle. One study used automated procedure (7%), two studies used smartphone procedure (14%), and nine studies used the semiautomatic procedure of Cobb measurement (79%). Seven studies reported reproducibility and repeatability. Reproducibility range was 0.72 to 1 in reporting of ICC. Repeatability has a high range in three separated methods.

CONCLUSION

Computerized assessment method (Automatic and Semi-automatic) is most commonly performed in Cobb measurement. Semi-automatic is an effective measurement option for computerized assessment Cobb angle. There is no significant difference between manual, computer- based, and smartphone-based methods in described measures.

The Sagittal Thoracic Modifier Component of the Lenke Classification System in Moderate and Severe Adolescent Idiopathic Scoliosis: Reliability and Reproducibility of Measurements Among 5 Observers

STUDY DESIGN

A prospective radiographic study.

SUMMARY OF BACKGROUND DATA

As the importance of the spinal sagittal profile becomes increasingly evident, there is a need to ensure that the measuring methods used to evaluate thoracic kyphosis (TK) are both accurate and reproducible.

OBJECTIVE

The purpose of the following study was to determine the intraobserver and interobserver variability of measurements of the sagittal profile in moderate and severe thoracic scoliosis.

METHODS

Five experienced Faculty Spine surgeons independently reviewed thirty standing long 30-inch cassette lateral radiographs of preoperative moderate and severe curves ≥50 degrees of adolescent idiopathic scoliosis (AIS) patients on 2 different occasions. The parameters measured were the vertebral endplate clarity and measurability of the sagittal angle from D5 to D12 and categories of thoracic sagittal modifier. κ statistics and Intraclass Correlation Coefficient (ICC) were used for analysis.

RESULTS

The interobserver percentage of agreement for the Sagittal modifier was 58% in both trials. The mean κ coefficient value was only moderate 0.43 (range, 0.14-0.66) for both trials. The number of the vertebral endplates that were difficult to identify was 201 of 300 measurements (67%). There was a predominance of difficulty to identify vertebral endplate clarity in all curve types.

CONCLUSIONS

The results of this study yielded poor to moderate interobserver reliability of the thoracic sagittal profile component of the Lenke classification system in moderate and severe AIS. This was attributed to the difficulty in identification of the vertebral endplates. The current standard lateral radiographs routinely used in AIS patients have inherent difficulties and limitations to visualize, identify, and analyze the thoracic endplates in moderate and severe curves.

Smartphone applications validated for joint angle measurement: a systematic review

Mobile health apps are growing constantly in number and popularity. Some mobile apps are used for clinical assessment, and consequently need to be verified and validated appropriately, along with the mobile platform, to ensure their safe and effective operation. We review the current literature on available smartphone goniometric apps validated for joint angle measurement and their main psychometric characteristics. A literature search of Medline and Scopus databases was performed to select papers on smartphone commercial apps validated for joint angle measurement and relevant to Physical Medicine and Rehabilitation. A platform search verified whether the selected apps were still available for download. The literature search identified 126 papers in Medline and 113 in Scopus, 49 of which were selected. They dealt with the validation of 23 apps, eight of which were no longer available and therefore excluded from the review. Psychometric characteristics of the selected apps were robust, but heterogeneity of the studies did not enable comparisons between apps to identify the most valid one. The increase in the number of apps and validation studies highlights the growing interest in this new approach for measuring body angles. Given the precarious commercial availability of some apps, when research is the goal, it is advisable to select apps with the longest durability. A need continues to exist for validation studies on available apps focused on goniometric measurement in gait or during performance of therapeutic exercises in neurological and orthopedic disorders.

Validity of a Smartphone Application (Sagittalmeter Pro) for the Measurement of Sagittal Balance Parameters

OBJECTIVE

The study was aimed to compare the validity, reproducibility, precision, and efficiency of a picture archiving and communication system (PACS) and a smartphone application, which is an educative app to easily measure sagittal balance parameters (SagittalMeter Pro), for measuring spinopelvic sagittal parameters.

METHODS

Three spine surgeons measured lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) on standing posteroanterior radiographs of 30 patients using PACS and SagittalMeter Pro. Measurements were repeated a week after the original measurements. Intraobserver and interobserver variabilities and reliabilities of each parameter (LL, PI, SS, and PT) were calculated for both techniques. Comparisons were performed using the paired t-test. Results are expressed as mean ± standard deviation and P values of < 0.05 were considered significant.

RESULTS

PACS to SagittalMeter Pro differences between the mean absolute values of LL, PI, SS, PT were 0.50°, 0.82°, 0.81°, 0.34°, respectively, and intraobserver and interobserver variabilities were similar. Excellent intraobserver and interobserver reliabilities were obtained for PACS and SagittalMeter Pro as demonstrated by values >0.86 and >0.84, respectively. Measurement times for PACS and SagittalMeter Pro were 36.63 ± 7.55 and 14.57 ± 1.96 seconds, respectively, and this difference was significant (P = 0.001).

CONCLUSIONS

The study shows PACS and SagittalMeter Pro are equivalent in terms of their abilities to measure spinopelvic sagittal parameters, and that the time required to obtain measurements was significantly less for SagittalMeter Pro. We believe that SagittalMeter Pro may be helpful when planning spinal surgery.

Validity of a smartphone protractor to measure sagittal parameters in adult spinal deformity

BACKGROUND CONTEXT

Smartphones have become an integral tool in the daily life of health-care professionals (Franko 2011). Their ease of use and wide availability often make smartphones the first tool surgeons use to perform measurements. This technique has been validated for certain orthopedic pathologies (Shaw 2012; Quek 2014; Milanese 2014; Milani 2014), but never to assess sagittal parameters in adult spinal deformity (ASD). This study was designed to assess the validity, reproducibility, precision, and efficiency of using a smartphone protractor application to measure sagittal parameters commonly measured in ASD assessment and surgical planning.

PURPOSE

This study aimed to (1) determine the validity of smartphone protractor applications, (2) determine the intra- and interobserver reliability of smartphone protractor applications when used to measure sagittal parameters in ASD, (3) determine the efficiency of using a smartphone protractor application to measure sagittal parameters, and (4) elucidate whether a physician's level of experience impacts the reliability or validity of using a smartphone protractor application to measure sagittal parameters in ASD.

STUDY DESIGN/SETTING

An experimental validation study was carried out.

METHODS

Thirty standard 36″ standing lateral radiographs were examined. Three separate measurements were performed using a marker and protractor; then at a separate time point, three separate measurements were performed using a smartphone protractor application for all 30 radiographs. The first 10 radiographs were then re-measured two more times, for a total of three measurements from both the smartphone protractor and marker and protractor. The parameters included lumbar lordosis, pelvic incidence, and pelvic tilt. Three raters performed all measurements-a junior level orthopedic resident, a senior level orthopedic resident, and a fellowship-trained spinal deformity surgeon. All data, including the time to perform the measurements, were recorded, and statistical analysis was performed to determine intra- and interobserver reliability, as well as accuracy, efficiency, and precision. Statistical analysis using the intra- and interclass correlation coefficient was calculated using R (version 3.3.2, 2016) to determine the degree of intra- and interobserver reliability.

RESULTS

High rates of intra- and interobserver reliability were observed between the junior resident, senior resident, and attending surgeon when using the smartphone protractor application as demonstrated by high inter- and intra-class correlation coefficients greater than 0.909 and 0.874 respectively. High rates of inter- and intraobserver reliability were also seen between the junior resident, senior resident, and attending surgeon when a marker and protractor were used as demonstrated by high inter- and intra-class correlation coefficients greater than 0.909 and 0.807 respectively. The lumbar lordosis, pelvic incidence, and pelvic tilt values were accurately measured by all three raters, with excellent inter- and intra-class correlation coefficient values. When the first 10 radiographs were re-measured at different time points, a high degree of precision was noted. Measurements performed using the smartphone application were consistently faster than using a marker and protractor-this difference reached statistical significance of p<.05.

CONCLUSIONS

Adult spinal deformity radiographic parameters can be measured accurately, precisely, reliably, and more efficiently using a smartphone protractor application than with a standard protractor and wax pencil. A high degree of intra- and interobserver reliability was seen between the residents and attending surgeon, indicating measurements made with a smartphone protractor are unaffected by an observer's level of experience. As a result, smartphone protractors may be used when planning ASD surgery.

Reliability analysis of Cobb measurement in degenerative lumbar scoliosis using endplate versus pedicle as bony landmarks

OBJECTIVES

Degenerative changes of endplates in older patients and tilting of vertebral body in lumbosacral lordosis could make an accurate identification of endplates for the Cobb measurement difficult. Pedicles have been proposed as alternative landmarks because they are usually better visualized, and offer similar clinical validity to the endplates. The objective of this study was to investigate the reliability of the pedicle method of Cobb measurement in degenerative lumbar scoliosis and compare it with the traditional endplate method.

METHODS

Two hundred and eighty-four radiographs of degenerative lumbar scoliosis were evaluated. The radiographs were classified into groups based on the patient's age (< 60 years, 60 to 80 years, and > 80 years), level of lower end vertebra (LEV) (LEV at L5, and LEV at or above L4), and curve severity (< 20°, 20° to 40°, and > 40°). Three observers independently measured the radiographs using the endplate and pedicle methods twice with an interval of 1 week. The intra- and interobserver reliabilities were calculated using intraclass correlation coefficients (ICC).

RESULTS

The intra- and interobserver ICC values were better for all observers in the > 80 years age group using the pedicle method. The intraobserver ICC values of pedicle method were also better in the LEV at L5 group, and the interobserver ICC values showed a slightly better consistency with the pedicle method. For patients with > 40° curves, the intraobserver ICC values for all observers as well as interobserver ICC values were better using the endplate method.

CONCLUSION

The reliabilities of the endplate and pedicle methods for degenerative lumbar scoliosis were both excellent. The pedicle method might be better in older patients (> 80 years) and those with LEV at L5; while the endplate method could have some strength in severe cases (> 40°).