Blevins JL, et al. - Through a retrospective cohort study of rheumatoid arthritis (RA) patients, the researchers hypothesized that patients who underwent primary total knee arthroplasty (TKA) for RA would have different preoperative expectations in comparison to osteoarthritis (OA) patients, and that postoperative satisfaction would relate to specific postoperative pain and functional domains. Lesser expectations, deteriorated Visual Analogue Scale (VAS) pain, and worse Knee injury and Osteoarthritis Outcome Score (KOOS) Pain, Symptoms, and Activities of Daily Living were observed in RA patients, prior to operation. However, VAS and these 3 KOOS subdomains had markedly larger improvements at 2 years, attaining absolute scores to OA patients. Patient satisfaction was seen in both VAS and these 3 KOOS subdomains. High rates of attaining minimum clinically important differences in Short Form-12 (SF-12) physical component scores and all 5 KOOS subdomains was recognized in RA and OA patients. Further, a greater proportion of RA patients obtained minimum clinically important differences in KOOS Symptoms. Hence, in comparison to OA, RA patients had lower baseline expectations. Although, greater improvements in KOOS and SF-12 subdomains were observed in RA patients, and there was no difference in satisfaction as that to OA patients post-TKA.