The natural history of emergent osteoarthritis of the knee in women

Objective: We assessed the probability that mid-aged women with a Kellgren and Lawrence (K-L) score of I are likely to progress to a score of 2 or regress to a score of zero at a second time point, 2-3 years later. Methods: Osteoarthritis (OA) of measurements (weight-bearing X-rays and interviews) were undertaken in women from the Southeast Michigan population who were greater than or equal to40 years of age, and who participated in both the 1995 and 1998 measurements (N=679). Results: Of the 17.1 % of women with a 1995 K-L score of 1 in their right knee, 37.1% had a K-L score of 1 in 1998 while 32.8 % had a score of greater than or equal to2 and 30.2% had a score of zero. For 26.0% of women, the score progressed by at least one unit over the 2.5 year period whereas scores for only 7.0% of women regressed in the same time period. Women who had a K-L score of 1 in the right knee in 1995 were 2.5 times more likely to have a K-L score of 1 in 1998 <95% Cl = 1.6-3.8>; and were 2.2 times more likely to have a K-L score of 2 or greater (95% Cl=1.4-3.5) in 1998 compared with other scores. These women were 74% less likely to have a score of zero in 1998 (95% Cl=0.2-0.4). Further, other risk factors, specifically age and BMI were predictors of increasing K-L grade in 1998. Conclusion: These findings suggest that a score of 1 is part of the advancement to emergent OAK; and suggest the following criteria to characterize individuals who are at an intervenable stage on the pathway toward OAK: age greater than or equal to40, BMI greater than or equal to30, and K-L score of greater than or equal to1. From the perspective of both the individual and the examiner, these assessment characteristics are relatively simple to assess clinically. (C) 2002 OsteoArthritis Research Society Intenational. Published by Elsevier Science Ltd. All rights reserved.