ObjectivesThe main objective was to investigate 5-year outcomes in patients with knee osteoarthritis, randomised to one of two non-surgical treatments.SettingTwo outpatient clinics.ParticipantsAt baseline, 100 patients with radiographic and symptomatic knee osteoarthritis not found eligible for knee replacement (KR) were included. Main exclusion criteria were average score above 75 of the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales pain, symptoms, function of daily living and quality of life; KOOS4and average knee pain the previous week greater than 60 mm on a 100 mm visual analogue scale.InterventionsPatients were randomised to supervised non-surgical treatment consisting of patient education, supervised exercise, weight loss, insoles, and pain medication (the MEDIC treatment) or written advice. The 12-week MEDIC treatment included patient education, neuromuscular exercise, insoles and a dietary weight loss programme and/or pain medication if needed and written advice consisted of two leaflets.Primary and secondary outcome measuresPrimary outcome was 5-year mean change for KOOS4. Secondary outcomes included KOOS subscales, self-reported health, usage of pain medication and self-reported physical activity.ResultsThirty-nine (78%) and 36 (72%) from the MEDIC and written advice groups responded at 5 years. There were no between-group differences in KOOS4(difference 5.3 (95% CI −1.5 to 12.1) or any secondary outcomes. However, the 95% CI included the minimal clinically important difference for the main outcome.Seventy-six percent of the MEDIC group and 66% of the written advice group experienced clinically important improvements in KOOS4.Fifteen patients (30%) from the MEDIC group and 17 (34%) from the written advice group received KR in the index knee. Undergoing KR did not result in a statistically significant greater improvement in KOOS4(difference 6.1 (95% CI −1.1 to 13.4).ConclusionsNo statistically significant differences between supervised non-surgical treatment and written advice were demonstrated at 5 years. Most patients experienced clinically important improvements, irrespective of initial treatment strategy or KR.Trial registration numberNCT01535001; ClinicalTrials.gov.