2016 Volume 23 Pages 119-127
The aim of this study was to investigate the relationship between the alignment of rearfoot and the knee in patients with medial knee osteoarthritis. The patients were classified into pronated or supinated groups based on calcaneus bisector angle. Subsequently, the relationship between the rear foot alignment and femorotibial angle, Kellgren-Lawrence classification, medial joint space as well as pain were investigated. No correlation was found between the rearfoot alignment and the femorotibial angle. Thus it was suggested that the rearfoot would not be affected by it. However, the rearfoot alignment demonstrated correlations with Kellgren-Lawrence classification, medial joint space and pain while walking or climbing stairs. More pronation of the rear foot was found with smaller medial joint space. It was therefore speculated that there would be a mechanism to reduce loading on the medial side of the knee by pronating the rearfoot. If pronation of the rearfoot itself could already reduce pain, an insole with lateral wedge that would further pronate the rearfoot might not be very effective. Moreover, excessive pronation could lead to reverse screw home movement. In conclusion, an insole for patients with medial osteoarthritis should be designed based on the condition of rearfoot.
