Osteoarthritis (OA) of the knee is often associated with OA of hands, which are non weight-bearing joints, in the commonly termed generalized OA. In this study, we investigated the differences between knee OA patients with hand OA and those without hand OA, with respect to constitutional and radiographic variables.
Consecutive female patients with symptomatic tibiofemoral OA visiting our outpatient clinic were included in this study. Among them, 37 patients with polyarticular hand OA (GOA group) as well as 37 age-matched patients without hand OA (KOA group) were randomly selected. For a control group, 37 age-matched healthy women, with neither knee pain nor clinical nodes in the hands were randomly chosen from subjects who underwent health care examination in the community. Physical constitutional and radiographic findings were compared between the groups.
The results indicated that BMI (body mass index) was significantly higher in the KOA group than in the controls, whereas there was less of an association in the GOA group. Between the GOA and KOA groups, there were no radiographic differences in varus or valgus deformity of the knee, patellof emoral OA, chondrocalcinosis, or ossification at the enthesis of the patella, although the patients in the GOA group had OA in various joints of the hands.
The results suggest that some undetermined systemic factors, rather than only mechanical stress to the articular cartilage, may play a role in the pathogenesis of knee OA associated with hand OA.