To compare the sensitivity of WOMAC and the two added dimensions Sport and Recreation Function and Knee Related Quality of Life in subjects with radiographic knee OA to that in controls. To study the influence of age on the reported outcomes.Outcomes were compared between subjects having had meniscectomy 21 years ago and which at time of follow-up had definite radiographic OA (N=41, mean age 57), and age- and sex-matched controls without radiographic OA (N=50, mean age 53). For the purpose of studying the impact of age, the groups were divided in two age groups, younger and older than 50 years, respectively. Close to 50% of both groups reported current physical activity levels of at least recreational golf, dancing, hiking, etc. Symptoms and function were assessed by WOMAC Osteoarthritis Index and the added dimensions Sport and Recreational Function (Sport/Rec) and Knee Related Quality of Life (QOL). A percentage score was calculated, 0 indicating extreme knee problems and 100 indicating no knee problems.The control group had mean scores of 88-98 for the different dimensions. The OA group scored significantly lower in all dimensions (P< 0.0001). The most discriminative dimensions in both age groups were Sport/Rec and QOL with mean scores of 52 and 59 (ranges 0-100).The dimensions Sport and Recreation Function, and Knee Related QOL were highly sensitive and discriminant outcomes in both age groups and should be assessed in addition to WOMAC in subjects with post-traumatic osteoarthritis of the knee.