Knee osteoarthritis (OA) is a condition that leads to functional deficits in the afflicted. Quantifying these deficits in a clinical population and relating them to bone changes in the distal femur is crucial to identifying potential impairment in archaeological populations. This study provides a hybrid knee OA grading system linking MRI observations of clinical populations and direct bone observations on skeletal populations. This system is then related to 28 pain, disability, and activity limitation outcome variables provided by the OA Initiative through frequency distributions, probability profiles, and Spearman's rank correlations. The results suggest that while the five outcome variables with the highest probabilities were common to males and females, bone changes in knee OA impact males and females differently. Copyright © 2012 John Wiley & Sons, Ltd.