Changes to Rigid Asymmetrical Brace Design after Providing Deformity Measurements from 3D EOS Models in Patients with Idiopathic Scoliosis.

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Section 1 - Basic information about you and your application:

Title of research project
Changes to Rigid Asymmetrical Brace Design after Providing Deformity Measurements from 3D EOS Models in Patients with Idiopathic Scoliosis.

Project summary

The EOS scanner is a low dose bi-planar x-ray machine, taking x-rays from the front and the side at the same time, at much lower dose than conventional digital imaging. This allows the 2 views to be put together by a computer to produce a 3-dimensional model of the pelvis, and spine. At Sheffield Children’s Hospital (SCH), currently the EOS scanner is used to evaluate spinal curves in children, however the 3D modelling software is not utilised.

Scoliosis will often get worse as the child grows. We use x-rays to look for worsening of the spinal curves. For smaller curves we can use braces to reduce the risk of curve progression and reduce the number of patients requiring surgery from 52% to 28%. If we can use 3D models alongside normal x-rays to check worsening of spinal curvatures and rotation before and after the brace is fitted, we hope to improve our design of orthoses whilst keeping the radiation dose these children are exposed to as low as possible.

This is a pilot study to see if we can use the 3D modelling component of EOS bi-planar imaging to assess changes in the 3-D alignment of the spine before a brace is fitted and when patients are put in a spinal brace. EOS images are already taken as usual care, so no additional radiographs are required. We hope that creating 3D spinal reconstructions both pre and in-brace will improve patient care for scoliosis patients treated using new techniques of brace design.

Type of project

Type of research

Orthopaedic Spinal Surgery

Start date

End date

Section 2 - Purpose of the research and originality

Aims / Objectives:

This pilot study aims to evaluate the use of EOS 3D reconstructions scoliosis management for patients receiving bracing treatment. We aim to assess if EOS 3D spinal modelling compared to standard 2D spinal radiograph images changes orthotist approach to brace design. The study aimed to assess the difference between important spinal parameters used for brace design from 2D PA and lateral radiographs compared to EOS 3D modelling to analyse which planes of the spinal deformity are corrected in a newer asymmetrical over-correcting brace.

We will be evaluating:
Vertebral rotation at each vertebral level relative to a neutrally rotated pelvis.
Vertebral translation at each vertebral level.
Pelvic parameters.
All measurements available after EOS 3D reconstruction (kyphosis, lordosis, rotations, cobb angle)
Global spinal balance

1) To assess the in-brace correction of scoliosis in all 3 planes of the spine for a rigid asymmetrical overcorrecting brace designed for full-time wear (20 hours per day).
2) To determine if access to 3D models of the spine, at both the pre-brace design and in-brace assessment, would lead to differently designed braces.
3) To determine the agreement between EOS 3D spinal modelling and 2D radiograph measurement of spinal deformity parameters, isolating key differences between the two.

Background to investigation

Scoliosis is a lateral curvature of the spine. Smaller curves can be treated with a brace with many patients avoiding surgery (Weinstein 2013). Radiation exposure in patients having monitoring and treatment of scoliosis is known to be high with 2 recent systematic reviews (Metha, Loughenbury 2021). Therefore, it is important that these images are used to extract all the clinically relevant data possible. At Sheffield Children's Hospital (SCH), a PA and lateral whole spine radiograph taken using EOS microdose is 90% less radiation dose than the same images obtained using conventional radiographs. If normal dose EOS is used, the radiation dose is 20% less (Melhem 2016). All images are obtained using microdose except the radiographs at first presentation. EOS x-rays are taken standing and images of the spine are obtained in 20 seconds. They are used to assess spinal curvature and progression. If the PA and lateral EOS x-rays are obtained at the same time (bi-planar imaging), a 3D model can be generated using EOS software (Garg 2020). This can be used to assess pelvic parameters and segmental measurements from the spine in three dimensions. Whilst this adds information, currently this not of proven clinical value. The NICE Diagnostic Imaging guidance (DG1) recommended further research into the ‘clinical benefits of 3-D reconstructions’ using EOS (www.nice.org.uk/guidance/dg1).

Currently, bracing experts lack a reliable feedback mechanism once their braces are designed. They rely on expertise and clinical experience to refine their braces. EOS 3D modelling can provide valuable feedback on many different clinical parameters. These include vertebral rotations and accurate measurements in the sagittal plane (kyphosis, lordosis and sagittal balance) which are impossible from conventional lateral radiographs (Pasha 2018). So far, no published research has been done on the use of 3D feedback after bracing although work from conventional radiographs suggests lordosis is flattened by bracing (Cheung 2019).

Purpose of the research and originality(Required)

Other documents

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Reference letter: Download here
Letter of approval: Download here
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