Bracing improves clinical outcomes but does not affect the medial knee joint space in osteoarthritic patients during gait

Osteoarthritis (OA) of the knee is commonly treated through the use of medial compartment unloading braces which have been shown to improve clinical symptoms. The objective of this study was to assess the effects of a medial compartment unloading brace on biomechanical measurements and clinical outcomes. We hypothesized that brace usage would lead to increased medial joint space and improved clinical outcomes. Ten patients with medial compartment OA were prescribed a medial compartment unloading brace and underwent dynamic biplane radiograph imaging while walking with and without the brace. The Western Ontario and McMaster University Osteoarthritis (WOMAC) Index was used to assess pain before brace wear and at the time of testing. The 3D position and orientation of the femur and tibia were determined using a model-based tracking technique. Patients saw an average improvement of 33 % in their WOMAC scores (p = 0.01). This study failed to detect any statistically significant changes in the functional joint space, knee kinematics, or contact centre location between the braced and unbraced condition (n.s.). The data from this study, using a highly accurate (+/- 0.6 mm and +/- 0.6A degrees) 3D radiograph analysis of dynamic tibiofemoral motion, suggest that the brace is ineffective at increasing joint space. However, it was shown to be effective in improving clinical outcome and therefore should continue to be prescribed to patients even though the mechanism of its effectiveness remains unknown. IV.