Investigating the relationship between internal spinal alignment and back shape in patients with scoliosis using...

Area of Science:

• Orthopedics and Biomechanics
• Medical Imaging and Technology

Background:

• Optical 3D surface scanning is a non-ionizing technique for evaluating spinal deformities like scoliosis.
• Current 'back-shape-to-spine' approaches show moderate correlations between 3D back surface data and radiographic spinal alignment.
• A deeper understanding of how scoliosis affects back shape is needed to improve 3D scanning accuracy for internal spinal alignment (ISL) estimation.

Purpose of the Study:

• To explore the potential of PCdare software in investigating the relationship between ISL and 3D back shape in idiopathic scoliosis.
• To conduct a comparative study evaluating different study protocols for 3D surface scanning in scoliosis assessment.
• To assess the inter- and intrarater reliability (IIR) of PCdare software when used by students compared to clinicians.

Main Methods:

• A comparative study involved 252 patients with idiopathic scoliosis, analyzing posture alignment errors and Cobb angle correlations.
• An IIR study used PCdare with 6 clinicians and 10 students on 7 patients, with validation against PACS.
• PCdare software facilitated semi-automatic registration of 3D surface scans with biplanar radiographs for ISL estimation.

Main Results:

• Students using PCdare achieved outcomes comparable to clinicians, with low median Cobb angle differences (0.06° interclass, ≤4.2° intrarater).
• PCdare showed high correlation with PACS (0.94-0.95) and good accuracy in posture alignment error (median RMSE 5-8.1 mm).
• Correlation coefficients between ISL and spinous process line (SPL) ranged from 0.64 to 0.99, indicating a strong relationship.

Conclusions:

• PCdare software is reliable and user-friendly, enabling students to achieve results comparable to clinicians in scoliosis assessment.
• The study highlights the importance of markers and posture alignment in 3D scanning protocols for accurate ISL estimation.
• PCdare software shows significant potential for advancing non-ionizing assessment of spinal deformities, improving scoliosis understanding.