A new diagnostic parameter for patellofemoral pain.

PURPOSE Q-angle measurement procedure have not been well standardised. There is a lack of consensus about subject position and knee flexion angle while measuring the Q-angle. Morover Q-angle value which obtained in a single position is a static value and gives an information about the subject's current position. The aim of this study is to obtain a more significant parameter which includes different postures (supine, standing, sitting) and different knee flexion angles instead of a single Q-angle in a fixed position. At the same time this parameter must be functional and dynamic,not a static value like Q-angle. We named this parameter as ΔQ. METHODS Our study was applied on case and control groups. All subjects in both groups were male. Case group was consisted of 14 subjects who had patellofemoral pain. Control group was consisted of 14 subjects who had normal knees and normal lower extremities with no reported knee problems. We obtained 3 different Q-angle values and 3 different ΔQ values for each subject in both groups. Pearson correlation analysis was used for investigation of continuous variables in normal distribution, Spearman correlation analysis was used in abnormal distribution. t test was used in the comparison of values. Logistic regression analysis(forward conditional mod) was used for detecting of determinants of pain. RESULTS ΔQ1s of both groups were found as the only statistical significant predictive value for patellofemoral pain. CONCLUSION There is not an agreement about a standardised q-angle measurement procedure in the literature. Moreover, present procedures provide information about a single and fixed position. In this situation Q-angles which obtained in these fixed positions are static values. We think that we can overcome these problems with this new value. ΔQ contains multiple q-angles and gives information about all. Also it is a dynamic value for being oriented to position change. Therefore, ΔQ is an useful indicator for evaluating patellofemoral pain.