PREVALANCE OF KNEE CHONDROCALSINOSIS IN PATIENT WITH PRIMARY KNEE OSTEOARTHRITIS IN RHEUMATOLOGY CLINICS OF IRAN UNIVERSITY OF MEDICAL SCIENCES AND HEALTH SERVICES(2000-2001)

This observative study was aimed to assess the frequency of knee chondrocalcinosis in patients (pt.s) with knee osteoarthritis (OA), older than 40 years, came to rheumatology clinics. 65 pt.s with mean age of 59.3 years (SD=9.1206) and range of ages 42-81 years were collected. 56 of then female and rest (9) male. 9.23% [confidence Interval (CI) 3.46.19.01] had chondrocalcinosis and grade 4 OA according to kellgren classification, all older than 60 years. It showed a prevalence of 19.35% (CI: 7.45-37.47) for chondrocalcinosis above 60 years old, suggesting the increase of its incidence with advanced age and severity of OA. Among all pt.s (65) that 84.6% (CI: 73.5-92.36) of them had advanced OA. There were only 7.69%(CI: 2.5-17) of pt.s with bone cyst. The female to male ratio of OA was 6.2 to 1, showing the higher frequency in females, the same ratio of chondrocalcinosis was 2 to 1 showing the higher frequency in males. Only 10.77% (CI: 4.4-20.9) of all pt.s were smoke and nobody of pt.s with chondrocalcinosis were smoke. 87.7% (CI: 77.2-94.5) of pt.s with OA were overweight or obese. In pt.s with chondrocalcinosis (6), 1/3 of them were normal weight, 1/3 were overweight, and 1/3 were obese 61.5% (CI 48.6-73.3) of pt.s had buchard’s node or Heberden’s node or both, that showed the higher frequency of them primary OA. Most of the pt.s (66.15%) had isolated decreasing of articular space in medial tibiofemoral joint.