SCORING PREVALENCE AND SEVERITY IN GONARTHRITIS - THE SUITABILITY OF THE KELLGREN-AND-LAWRENCE SCALE

In clinical and epidemiological studies the Kellgren & Lawrence (K&L) scale was mainly used in the past to determine the radiological preval ence and severity of gonarthritis. The dependency of this scoring syst em on the presence of osteophytes has been criticised, and owing to it s varying reliability, its appropriateness in cross-sectional and long itudinal studies is questioned. It was the purpose of this study to te st whether the dependency of the K&L scale on the presence of osteophy tes is reflected in a higher correlation of the overall score with a s eparate scoring of 'osteophytes' than with other radiological features . Furthermore we compared the inter- and intrarater reliability with t he reliability of individual radiological features. Knee radiographs o f 40 patients were graded according to the K&L scale and for the prese nce and severity of five separate radiological features of osteoarthri tis. We found a moderate correlation of the K&L scale with the radiolo gical features of 'osteophytes', 'joint space narrowing' and 'flatteni ng of condyles'. The intra- and inter-rater reliability of the K&L sca le was higher than the reliability of the individual radiological feat ures. The K&L scale seems not to be strongly dependent on the presence of osteophytes, i.e. there is not a higher correlation of the overall score with that feature than with other radiological features.