A 5° lateral heel tilt (comes out to about 5 mm lateral height) has been tried many times with mediocre results. They made it more likely by eliminating those with partellofemoral issues, and demanding a 2% reduction in KAM =external knee adduction moment (markers and 3d analysis needed for that). Still, drop in pain was only 0.7/10 after 8 weeks.
Arthritis Rheumatol. 2019 Jan 7. doi: 10.1002/art.40808. [Epub ahead of print]
The Efficacy of a Lateral Wedge Insole for Painful Medial Knee Osteoarthritis after Prescreening:A Randomized Clinical Trial.
Felson DT et al
Comment – too bad really