Fig. 1
Graphical representation of left and right joint similarity. Data for left (y axis) and right (x axis) knees are plotted for joint grade (a), concentration of protein (c Pro ) (c), and concentration of hyaluronan (c HA ) (e); the red line represents the line of perfect concordance while the black line is the reduced major axis of the data. The difference between left and right knees is plotted against the average of left and right knees for joint grade (b), cPro (d), and cHA (f); dashed lines represent the mean difference while red lines represent ± two standard deviations of the individual differences. n = 15–18 donors