Mixed model analysis demonstrated statistically significant differences between groups in favor of the HA-HL group at weeks 1, 6, 12, and 24, whereas the difference between groups at week 18 remained borderline significant (difference 3.4 mm, p = 0.051; Table 3 and Fig. 2 ).
injection of HA-HL was rapidly achieved and the statistically significant between-group differences in pain intensity in favor of HA-HL in our study approached or exceeded the 5 mm difference, which is considered clinically relevant for symptomatic slow-acting drugs for OA (SYSADOA) [ 27 ], at most time points, and was significantly in favor of HA-HL at all time points, except for week 18, when it reached only borderline significance.