Braces optimized with computer-assisted design and simulations are lighter, more comfortable, and more efficient than plaster-cast braces for the treatment of adolescent idiopathic scoliosis

Study Design

Feasibility study to compare the effectiveness of 2 brace design and fabrication methods for treatment of adolescent idiopathic scoliosis: a standard plaster-cast method and a computational method combining computer-aided design and fabrication and finite element simulation.

Objectives

To improve brace design using a new brace design method. Summary of Background Data

Initial in-brace correction and patient's compliance to treatment are important factors for brace efficiency. Negative cosmetic appearance and functional discomfort resulting from pressure points, humidity, and restriction of movement can cause poor compliance with the prescribed wearing schedule.

Methods

A total of 15 consecutive patients with brace prescription were recruited. Two braces were designed and fabricated for each patient: a standard thoracolumbo-sacral orthosis brace fabricated using plaster-cast method and an improved brace for comfort (NewBrace) fabricated using a computational method combining computer-aided design and fabrication software (Rodin4D) and a simulation platform. Three-dimensional reconstructions of the torso and the trunk skeleton were used to create a personalized finite element model, which was used for brace design and predict correction. Simulated pressures on the torso and distance between the brace and patient's skin were used to remove ineffective brace material situated at more than 6 mm from the patient's skin. Biplanar radiographs of the patient wearing each brace were taken to compare their effectiveness. Patients filled out a questionnaire to compare their comfort.

Results

NewBraces were 61% thinner and had 32% less material than standard braces with equivalent correction. NewBraces were more comfortable (11 of 15 patients) or equivalent to (4 of 15 cases) standard braces. Simulated correction was simulated within 5° compared with in-brace results.

Conclusions

This study demonstrates the feasibility of designing lighter and more comfortable braces with correction equivalent to standard braces. This design platform has the potential to further improve brace correction efficiency and its compliance.

Uncontrolled Keywords

• Scoliosis
• Thoracolumbo-sacral orthosis
• Brace simulation
• CAD/CAM
• Comfort