Fernandes GS, et al. - The prevalence of knee pain, radiographic knee osteoarthritis (RKOA), total knee replacement (TKR) and associated risk factors was comprehensively examined by authors in male ex-professional footballers compared with men in the general population (comparison group). Results demonstrated that the prevalence of all knee osteoarthritis outcomes (knee pain, RKOA and TKR) were two to three times higher in male ex-footballers compared with men in the general cohort group. It was discovered that knee injury served as the primary attributable risk factor. Knee osteoarthritis was found to be an occupational hazard of professional football even after adjustment for recognised risk factors.