Accuracy of photogrammetry for detecting adolescent idiopathic scoliosis progression

3D Back Contour Metrics in Predicting Idiopathic Scoliosis Progression: Retrospective Cohort Analysis, Case Series Report and Proof of Concept

Adolescent Idiopathic Scoliosis is a 3D spinal deformity commonly characterized by serial radiographs. Patients with AIS may have increased average radiation exposure compared to unaffected patients and thus may be implicated with a modest increase in cancer risk. To minimize lifetime radiation exposure, alternative imaging modalities such as surface topography are being explored. Surface topography (ST) uses a camera to map anatomic landmarks of the spine and contours of the back to create software-generated spine models. ST has previously shown good correlation to radiographic measures. In this study, we sought to use ST in the creation of a risk stratification model. A total of 38 patients met the inclusion criteria for curve progression prediction. Scoliotic curves were classified as progressing, stabilized, or improving, and a predictive model was created using the proportional odds logistic modeling. The results showed that surface topography was able to moderately appraise scoliosis curvatures when compared to radiographs. The predictive model, using demographic and surface topography measurements, was able to account for 86.9% of the variability in the future Cobb angle. Additionally, attempts at classification of curve progression, stabilization, or improvement were accurately predicted 27/38 times, 71%. These results provide a basis for the creation of a clinical tool in the tracking and prediction of scoliosis progression in order to reduce the number of X-rays required.

Photogrammetry Applied to Neurosurgery: A Literature Review

Photogrammetry refers to the process of creating 3D models and taking measurements through the use of photographs. Photogrammetry has many applications in neurosurgery, such as creating 3D anatomical models and diagnosing and evaluating head shape and posture deformities. This review aims to summarize the uses of the technique in the neurosurgical practice and showcase the systems and software required for its implementation. A literature review was done in the online database PubMed. Papers were searched using the keywords "photogrammetry", "neurosurgery", "neuroanatomy", "craniosynostosis" and "scoliosis". The identified articles were later put through primary (abstracts and titles) and secondary (full text) screening for eligibility for inclusion. In total, 86 articles were included in the review from 315 papers identified. The review showed that the main uses of photogrammetry in the field of neurosurgery are related to the creation of 3D models of complex neuroanatomical structures and surgical approaches, accompanied by the uses for diagnosis and evaluation of patients with structural deformities of the head and trunk, such as craniosynostosis and scoliosis. Additionally, three instances of photogrammetry applied for more specific aims, namely, cervical spine surgery, skull-base surgery, and radiosurgery, were identified. Information was extracted on the software and systems used to execute the method. With the development of the photogrammetric method, it has become possible to create accurate 3D models of physical objects and analyze images with dedicated software. In the neurosurgical setting, this has translated into the creation of anatomical teaching models and surgical 3D models as well as the evaluation of head and spine deformities. Through those applications, the method has the potential to facilitate the education of residents and medical students and the diagnosis of patient pathologies.

Development and validation of a semi-automated measurement tool for calculating consistent and reliable surface metrics describing cosmesis in Adolescent Idiopathic Scoliosis

Adolescent Idiopathic Scoliosis (AIS) is a 3D spine deformity that also causes ribcage and torso distortion. While clinical metrics are important for monitoring disorder progression, patients are often most concerned about their cosmesis. The aim of this study was to automate the quantification of AIS cosmesis metrics, which can be measured reliably from patient-specific 3D surface scans (3DSS). An existing database of 3DSS for pre-operative AIS patients treated at the Queensland Children's Hospital was used to create 30 calibrated 3D virtual models. A modular generative design algorithm was developed on the Rhino-Grasshopper software to measure five key AIS cosmesis metrics from these models-shoulder, scapula and hip asymmetry, torso rotation and head-pelvis shift. Repeat cosmetic measurements were calculated from user-selected input on the Grasshopper graphical interface. InterClass-correlation (ICC) was used to determine intra- and inter-user reliability. Torso rotation and head-pelvis shift measurements showed excellent reliability (> 0.9), shoulder asymmetry measurements showed good to excellent reliability (> 0.7) and scapula and hip asymmetry measurements showed good to moderate reliability (> 0.5). The ICC results indicated that experience with AIS was not required to reliably measure shoulder asymmetry, torso rotation and head-pelvis shift, but was necessary for the other metrics. This new semi-automated workflow reliably characterises external torso deformity, reduces the dependence on manual anatomical landmarking, and does not require bulky/expensive equipment.

The accuracy of computerized biophotogrammetry in diagnosing changes in the cervical spine and its reliability for the cervical lordosis angle

BACKGROUND

Accuracy studies of biophotogrammetry protocols require standardization similar to radiography.

OBJECTIVE

To estimate the diagnostic accuracy of a biophotogrammetric assessment protocol for cervical hyperlordosis, compared to radiography, and its intra- and inter-examiner reliability for measuring the cervical lordosis angle.

METHODS

A study of diagnostic accuracy in women complaining of cervical pain. Two photos were taken using the CorelDraw biophotogrammetric protocol and one radiograph using the Cobb C1-C7 method. The Intra- and Inter-examiner reliability was calculated using the Kappa index and the intraclass correlation coefficient (ICC). The Bland-Altman plot and the ROC curve were presented.

RESULTS

The sample consisted of 19 women. The accuracy of biophotogrammetry was 94.73% and the reliability between biophotogrammetry and radiography presented an ICC of 0.84 and a Kappa of 0.87. The excellent intra (ICC = 0.94) and inter-examiner (ICC = 0.86) reliability of the biophotogrammetry was confirmed. The area under the ROC curve was 93.5%. The Bland-Altman plot indicated differences between the two instruments close to the mean (1.5∘).

CONCLUSION

The biophotogrammetric protocol proved to be accurate in diagnosing cervical hyperlordosis, with excellent reliability between the biophotogrammetric and radiographic assessments. It also demonstrated excellent intra- and inter-examiner reliability in measuring the cervical lordosis angle.

Scoliosis: Brace treatment - from the past 50 years to the future

OBJECTIVE

This paper deals with scoliosis treatment over the past 50 years. The review of the literature from the point of view of the current formation of opinion. From conservative forms of treatment, the pendulum has swung to surgical measures. To visualize this temporarily rejection of conservative treatment is the goal of this article.

MATERIALS AND METHODS

A review of the literature over the last 50 years was performed from the perspective of current opinion, this with a pinch of personal experience in bracing and scoliosis surgery since 1972. The MESH terms (scoliosis, idiopathic scoliosis, adolescent idiopathic scoliosis) are presented in their number in a flow diagram and the publications on conservative therapies (brace, physiotherapy) are compared to surgical therapies (surgery).Opinions of "eminences" in the 1980s have been replaced by the rules of evidence-based medicine (EBM) at end of the 1990s. This transition will be visualized in the graph of PubMed statistics. In a statement, the future scoliosis treatment is derived from history.

RESULTS

The total number of publications shows a ratio of brace to surgery of 13.9% and physiotherapy to surgery of 6.7% for the MESH terms "scoliosis". When "scoliosis" is supplemented with "idiopathic", the brace to surgery ratio changes from 24.5% and physiotherapy to surgery 8.2%. Focusing on adolescent scoliosis the addition of "adolescent" changes the brace to surgery ratio from 24.8% and physiotherapy to surgery 8.1%. In the total number of publications, "adolescent idiopathic scoliosis" is treated by 25.26%. The patient numbers of our own scoliosis outpatient clinic (1482 patients) over the last 15 years show a ratio of brace (Cobb angle 20°-50° brace-indication) to surgery (Cobb angle >50° indication to surgery) of 1 to 0.06. The scientific focus on surgical therapy is evident from the figures of PubMed mentioned. The number of conservative publications shows a depression in the 1990s. In the remainder of this article, opinion-forming developments are outlined and supported by literature citations, responsible for the recovery of publications on conservative scoliosis treatment. New technologies provide additional treatment options.

CONCLUSIONS

In this sense, brace therapy is a success story with a future in the digital world of AI (artificial intelligence), mathematical model calculations, and production perhaps from the 3D printer. The central message from the history of the last 50 years is: "The scientific review of treatment results is essential for the further acceptance of brace treatment."

Evaluation of Self-Perceived Body Image in Adolescents with Mild Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is the most prevalent types of scoliosis, affecting up to 3% of children around the world. The progression of AIS can cause alteration in psychological components such as self-perceived body image and self-identity, which negatively affect the teenager quality of life (QoL). The mainly aim of this cross-sectional study is to investigate how mild AIS impacts self-perceived body image in young people. Fifteen participants (mean age = 14.47 ± 2.825) of both sexes (male = 5; female = 10) with a curve magnitude from 10° up to 25° completed the Scoliosis Research Society Patient Questionnaire (SRS-22), the Trunk Appearance Perception Scale (TAPS) and were subject to spinal analysis and photogrammetry. Results display statistical differences between self-perceived body image and other SRS-22 domains (Hotelling t2= 70.29; F(3,12) = 20.08; p < 0.001). Additionally, the regression model, which better explained the self-perceived variability, was fit by function/activity, pain, and mental health domains (F(4,10) = 4.39; p = 0.029; R2 = 0.545). Although AIS was not severe, it negatively affected participants self-perceived body image. More attention in AIS qualify of life is needed, and early treatments could be necessary to prevent psychological impairments self-perception related.

Validity and test-retest reliability of photogrammetry in adolescents with hyperkyphosis

BACKGROUND

A variety of noninvasive instruments have been introduced in the literature to assess thoracic curvature, although the psychometric properties of many of these instruments have not been satisfactory. Photogrammetry is a safe, accessible, and reliable technique. However, its validity in adolescents with hyperkyphosis has not yet been investigated.

OBJECTIVES

To investigate the validity and test-retest reliability of photogrammetry in the measurement of thoracic kyphosis among adolescents with hyperkyphosis.

METHODS

Fifty adolescents with hyperkyphosis participated in this study. The kyphosis angle was measured using radiography and photogrammetry. A two-way random model of the intraclass correlation coefficient (ICC_2,3) was used to estimate relative reliability. Absolute reliability was assessed by calculating the standard error of the measurements (SEM) and the minimal detectable change (MDC). Pearson's correlation coefficient was calculated to evaluate the validity of the photogrammetry technique. Bland-Altman plots were plotted to determine the agreement between the angles measured by radiography and photogrammetry.

RESULTS

There was a strong correlation between the values obtained from the photogrammetry technique and those from the radiography method (r = 0.94). The 95% limits of agreement indicated that the photogrammetric measurements of thoracic kyphosis angle might range from 2.4 degrees greater to 10.2 degrees lower than the Cobb radiographic angle. Photogrammetric measurements of thoracic kyphosis showed excellent test-retest reliability (ICC = 0.97; SEM = 1.67; MDC = 4.62).

CONCLUSION

High reliability of photogrammetry technique and its strong correlation with radiographic Cobb angle support the application of this technique for the measurement of thoracic kyphosis in clinical practice.

An ontology-based module of the information system ScolioMedIS for 3D digital diagnosis of adolescent scoliosis

BACKGROUND AND OBJECTIVE

Conventional information systems are built on top of a relational database. The main weakness of these systems is impossibility to define stable data schema ahead when the knowledge of the system is evolving and dynamic. The widely accepted alternatives to relational databases are ontologies that can be used for designing information systems. Many research papers describe various methods for improving reliability and precision in generating the type of the Lenke classification based on the image processing techniques or a computer program, but all of them require radiograph images. The main objective of this paper is to demonstrate the development of an ontology-based module of the information system ScolioMedIS for adolescent idiopathic scoliosis (AIS) diagnosis and monitoring, which uses optical 3D methods to determine the Lenke classification of AIS and to avoid harmful effects of traditional radiation diagnosis.

METHODS

For creating an ontology-based module of the ScolioMedIS we used the following steps: specification, conceptualization, formalization and implementation. In the specification and conceptualization phase we performed data collection and analysis to define domain, concepts and relationships for ontology design. In the formalization and implementation stage we developed the OBR-Scolio ontology and the ontology-based module of the ScolioMedIS. The module employs the Protégé-OWL API, as a collection of Java interfaces for the OBR-Scolio ontology, which enables the creating, deleting, and editing of the basic elements of the OBR-Scolio ontology, as well as the querying of the ontology.

RESULTS

The ontology-based module of ScolioMedIS is tested on the datasets of 20 female and 15 male patients with AIS between the ages of 11 and 18, to categorize spinal curvatures and to automatically generate statistical indicators about the frequency of the basic spinal curvatures, degree of progression or regression of deformity and statistical indicators about curvature characteristics according to the Lenke classification system and Lenke scoliosis types. Results are then compared with analysis of the Lenke classification of 315 observed patients, performed using traditional radiation techniques.

CONCLUSIONS

This part of the system allows continuous monitoring of the progression/regression of spinal curvatures for each registered patient, which may provide a better management of scoliosis (diagnosis and treatment).

A Strain Distribution Sensing System for Bone-Implant Interfaces Based on Digital Speckle Pattern Interferometry

This paper aims to provide an effective measurement method for the distribution of deformations and strains focusing on the response to external loading of bone-implant interfaces. To achieve this target, a novel speckle interference imaging method is proposed by introducing phosphate buffer saline medium, in which the samples were completely placed into a phosphate buffer saline solution medium to stable the water molecules. The stability of interferometry imaging is analyzed by using the concepts of co-occurrence matrix and moment of inertia. A series of experiments to measure load-driven deformation and strain in the bone-implant interface was carried out, and the experiments results were analyzed and discussed. It shows that the proposed method is feasible and effective for the no-contact strain measurements of biomaterials in a physiological condition. The proposed strain distribution sensing system will contribute to evaluating computational simulations and improving selection of implant designs and materials.