Mixed-effects linear regression models will be used to evaluate temporal trends and differences in the two groups for specific outcomes: VAS pain, VAS stiffness, FIHOA and PCS and MCS from SF-36 questionnaires. In these types of statistical models, the effects of the covariates and their standard errors are correctly estimated taking into account the hierarchical structure of the data (i.e., patients and visits). For the compute of SF-36s Z score will be used mean and SD of U.S. general population. Data analysis will be performed using Stata vers 13.0 software. Descriptive statistics will be used to summarize data as frequencies (categorical variables) or mean +/-SD (continuous variables) as appropriate. P values <0.05 is considered statistically significant.