The prevalence of jumpers knee in different sports is not described, except among high -level male volleyball players where the prevalence is 40-50 % (Ferretti 1983, 1990, Lian 1996). There is reason to believe that the number is rather high in sports with high demands on the knee extensor apparatus (Karlsson 1991, Raatikainen 1994). Among sports physicians in Norway there is concern about an increasing number of athletes with jumpers knee in different sports. Therefore, we will perform an epidemiological study of the prevalence in different sports. As a part of the study the exercise load will be evaluated with regard to the prevalence of jumpers knee in the different sports. As another part of the study we will evaluate the reproducibility of history taking and clinical examination with regard to interobserver variation.
The study will be performed as a cross-sectional study among 40-70 high-level athletes in the following sports: Soccer, volleyball, wrestling, handball, athletics, cycling ice hockey, basketball and swimming. The information will be collected by a standardized interview with special attention to training background and known predisposing factors, and a VISA-score (Visentini 1998) to differentiate the degree of the disease. We will not use MRI or ultrasonographic imaging technique, since studies have shown low diagnostic sensitivity and specificity (Lian 1996, Shalaby 1999). The diagnosis is set by a typical history and clinical examination.