Preliminary results of prediction of brace treatment outcomes by monitoring brace usage
© Lou et al; licensee BioMed Central Ltd. 2009
Published: 15 January 2009
To determine whether brace treatment outcome can be predicted by brace usage in terms of wear time (quantity) and wear tightness (quality).
A brace compliance monitoring system consisting of a microcomputer and a force transducer was used to monitor how brace candidates used their braces during daily activates.
Twenty AIS subjects (13.4 ± 1.8 years) prescribed Boston braces with full time brace wear were monitored for 2 weeks and followed-up for 3 years. A prediction of curve progression model was developed. The prediction model was tested on a new full time brace wearer (9.2 years old, female, AIS, 39° Cobb angle, Apex T8).
Brace treatment outcome may be predicted from brace usage.
The curve size of the 20 subjects prior to bracing was 32 ± 8°. While in the brace, the Cobb angle improved by 9 ± 6°. At skeletal maturity, after bracing, the Cobb angle was 4 ± 9° higher than prior to bracing. The quantity and quality of brace usage was recorded. The curve progression model was:
Curve Progression = 33 + 0.12*Peterson Risk(%) - 0.48*Quality(%) - 0.52*Quantity (%) +0.0066*Quantity*Quality.
The new subject had a Peterson Risk 73%, Quantity 80% and Quality 70%. The in-brace Cobb angle was 29°. At the 4 month visit, the predicted curve progression was 2° and the out of brace curve was 40° (1°different).
The quality and quantity of brace usage plus the risk progression factor may be able to predict brace treatment outcome.