Roentgenographic classifications of hemophilic arthropathy. Comparison of three systems and correlation with clinical parameters.

In 105 knees, the roentgenographic classifications of hemophilic arthropathy of Arnold and Hilgartner, of Pettersson et al., and of a new system were compared. The amount of interobserver agreement (between two observers) was good for all three systems and, for all three, there was a good correlation between progressive severity of the lesion and decreasing function of the joint. The system of Pettersson et al. was better than that of Arnold and Hilgartner for grading severe arthropathy, but it was not better than the new, simplified system. The new system is a four-sign, 7-point classification, in contrast to the eight-sign, 13-point system of Pettersson et al.