OBJECTIVES: Osteoarthritis (OA), a degenerative condition of the articular cartilage, primarily affects the knee joint and surgery is often required for late-stage patients.  The number of total knee arthroplasties (TKAs) is expected to grow to 3.48 million procedures by 2030 in the US alone.  However, the devices lack an ideal safety profile.  The objective of this study was to examine real-world outcomes among OA patients post-knee replacement. METHODS: Data from the 2012 U.S. National Health and Wellness Survey, an Internet health survey administered to a representative sample of adults, were used. Respondents who reported experiencing OA, with the knee being the only joint affected, and who reported having had joint surgery in the past year were considered to have had a knee replacement.  A matched control group was identified as a comparator to the knee replacement group by using a propensity score matching method (matching variables include demographics and health history).  Knee replacement respondents and matched controls were compared with respect to the Short Form-36v2, activity impairment (from the Work Productivity and Activity Impairment questionnaire), and healthcare resource utilization using ANOVA tests. RESULTS: 102 respondents were identified as part of the knee replacement group (52.0% male, 57.9 years).  Compared with matched controls (n=102), those in the knee replacement group reported significantly worse physical health status (42.5 vs. 47.6, p<.05) though equivalent mental health status (49.7 vs. 49.0, p=.67).  Levels of activity impairment (38.0% vs. 27.0% impairment, p<.05) and healthcare resource utilization (physician visits: 7.3 vs. 4.5, p<.05; emergency room visits: 0.6 vs. 0.2, p<.05; and hospitalizations: 0.6 vs. 0.2, p<.05) were all significantly higher among the knee replacement group relative to matched controls.  CONCLUSIONS: These results suggest a significant burden among knee replacement respondents across both health status and economic outcomes.  Improved management of these patients may have significant societal benefits.