ONE-YEAR PERFORMANCE OF POLYACRYLAMIDE HYDROGEL VS. HYALURONIC ACID IN AGE, BMI AND KELLGREN-LAWRENCE SUBGROUPS: A SUBGROUP ANALYSIS OF A RANDOMISED STUDY. (April 2022) - Bliddal, H.; Beier, J.; Hartkopp, A.; Conaghan, P.G.; Henriksen, M.