Validity of an instrumented knee brace compared to 3D motion navigation: A cadaveric investigation

The aim of this study was to test the accuracy and the reliability of 3-dimensional angular measurements of an instrumented knee brace compared to the gold standard navigation system optoelectronic cameras-based. Thirteen cadaveric bodies were used to calculate kinematic knee parameters. Three exercises were performed, 100 degrees flexion (FLEX100), internal/external rotation with a 30 degrees flexion (ROT30), and the pivot shift test (PS). The reliability was excellent with an ICC (95%) > 0.90. The agreement between the two systems showed excellent correlation in the F/E axis for FLEX100 and PS (sigma ((Flex/Ext)) > 0.95) and strong correlation in the I/E axis for ROT30 (sigma((Rot Int/Ext)) > 0.939). The root mean square error (RMSE) was under 5 degrees for all exercises considering the soft tissue artifact (STA) for the F/E axis. Consequently, the instrumented knee brace exposed high reliability and accuracy which could end up on clinical interpretations thanks to the previous measures.

Automated summary

This study aimed to assess the accuracy and reliability of 3-dimensional angular measurements of an instrumented knee brace compared to optoelectronic cameras-based navigation system, showing excellent reliability, strong correlation between the two systems, and acceptable measurement errors within an applicable range.