Increased Risk of Subsequent Osteoarthritis in Individuals with Previous Joint Injury
Gelber, et al (Ann Int Med 133:321-328, 2000) prospectively examined the relationship of knee and hip injury in young adult life to the subsequent development of osteoarthritis (OA) in the corresponding joint(s).
1321 men and women medical student participants of the Johns Hopkins Precursors Study were followed for a median of 36 years. The mean age at study entry (baseline) was 26 years, and at follow-up was 61.4 + 8.9 years. The majority of participants were white males, consistent with the makeup of medical school classes before 1970. Knee and/or hip injury and diagnosis of OA were made by self-report based on published clinical (and radiological, where available) criteria.
Overall, 141 participants reported a joint injury during adolescence or young adulthood (knee alone, n=111; hip alone, n=16; injuries at both sites, n=14). Of these, 96 developed osteoarthritis of the knee (n=64) or of the hip (n=27). The cumulative incidence of knee OA by 65 years of age was 13.9% in participants who had a knee injury, and 6.0% in those who did not (P=0.0045, relative risk 2.95 [95% CI, 1.35 to 6.34]). Joint injuries that occurred after study entry also increased the risk for developing OA (relative risk 5.17 for knee, and 3.50 for hip, OA).
Conclusions: These findings demonstrate that individuals have a substantially increased risk of developing OA of the knee and/or hip later in life if a traumatic injury occurred to that joint. Such individuals should be the targets for primary prevention of OA.
Editorial Comment: Prior studies have suggested that joint injury is a risk factor for the development of OA. However, these were cross-sectional or case-control studies, and usually evaluated middle-aged or older individuals. The current study is unique because it prospectively evaluated individuals in whom the timing of the joint injury in young life could be pinpointed. Importantly, it confirms the relationship of joint injury to OA. One of the weaknesses of the study is that the diagnosis of OA was not always confirmed radiograhically.