TKA patients experience less improvement than THA patients at 3 and 12 months after surgery. A retrospective observational cohort study.

PURPOSE: To investigate whether WOMAC scores changes after THA or TKA are gender and joint specific. METHODS: Retrospective cohort study. The data of 855 THA and 684 TKA patients were analyzed. RESULTS: Follow-up time (p < 0.001), gender (p < 0.001), joint (p < 0.001), and interaction FU by joint (p < 0.001) had significant effects on WOMAC total and sub-scores. Patients after TKA perceived less improvement in all dimensions in comparison to THA patients (p < 0.001). CONCLUSION: WOMAC score changes after THA or TKA are joint-specific. Patients after TKA perceived less improvement. These results can be used to adjust patients' expectations.