Background:The relationship between osteoporosis and osteoarthritis (OA) is complex and contradictory. Some studies suggest a protective effect of OA in osteoporosis [1-2]. However, other studies show that increased bone mineral density (BMD) in OA not only does not reduce the risk of fractures, but can also increase it [3-4].Objectives:To assess the 10-year probability of osteoporotic fractures using the FRAX calculator in women with OA of the knee joint.Methods:The study included 22 women (average age 63.7±1.01 years) diagnosed with ACP of the knee joint according to the ACR criteria (1991). The Control Group included 24 conditionally healthy women without OA knee joint, with an average age of 63.6±1.37 years.The BMD (g/cm2) and the T-criterion (standard deviation, SD) of the neck of the femur and lumbar spine (LI-LIV) were evaluated by the method of two-power X-ray absorption (DXA) (apparatus «Lunar Prodigy Primo», USA). 10-year probability of major osteoporotic fractures (clinically significant fracture of the spine, distal fracture of the forearm, fracture of the proximal femur, or fracture of the shoulder) and fracture of the proximal thigh with the FRAX calculator (version 3.5 for Russian population).Results:An osteopenic syndrome in the cohort under investigation was found in 42 (91.3%) patients, of whom osteopenia in 24 (52.2%) women and osteoporosis in 18 (39.1%). A normal BMD is registered in 4 (8.7%) patients.In the group of patients with knee joint OA, only 2 (9.1%) of women had a normal BMD, 11 (50.0%) of osteoporosis, and 9 (40.9%). Osteopenic syndrome is generally found in 20 (90,9%) patients.In the control group, osteopenic syndrome has been diagnosed in 22 (91,7%) of whom: osteopenia in 13 (54.2%), osteoporosis in 9 (37.5%) patients. Two (8.3%) women had a normal BMD. There were no statistically significant differences in the structure of the osteopenic syndrome among the studied groups (p=0.961).An analysis of the 10-year probability of major osteoporotic fractures found that women with OA knee joint had the above probability of 12.3±0.91, and in the control group 14.2±1.06 (p=0.085).The 10-year probability of fracture of the proximal femur in women with OA was statistically less significant than in the control group: 1.55 (0.70;1.98) and 2.10 (1.20;2.95), (p=0.031), respectively.Conclusion:The total incidence of the osteopenic syndrome in the cohort under investigation was 91.3% (90.9% in women with OA, 91.7% in the control group). The frequency of registration of osteopenia and osteoporosis in women with OA did not differ statistically significantly from the control group. The probability of major osteoporotic fractures within 10 years was comparable in these groups. The probability of a proximal femur fracture in women with OA was statistically significant, but not clinically significant, compared to the control group.References:[1]Yamamoto Y, Turkiewicz A, Wingstrand H, et al. Fragility Fractures in Patients with Rheumatoid Arthritis and Osteoarthritis Compared with the General Population. J Rheumatol. 2015 Nov;42(11):2055-8.[2]Vala CH, Kärrholm J, Kanis JA, et al. Risk for hip fracture before and after total knee replacement in Sweden. Osteoporos Int. 2020 May;31(5):887-895.[3]Kim BY, Kim HA, Jung JY, et al. Clinical Impact of the Fracture Risk Assessment Tool on the Treatment Decision for Osteoporosis in Patients with Knee Osteoarthritis: A Multicenter Comparative Study of the Fracture Risk Assessment Tool and World Health Organization Criteria. J Clin Med. 2019 Jun 26;8(7):918.[4]Soh SE, Barker AL, Morello RT, et al. Applying the International Classification of Functioning, Disability and Health framework to determine the predictors of falls and fractures in people with osteoarthritis or at high risk of developing osteoarthritis: data from the Osteoarthritis Initiative. BMC Musculoskelet Disord. 2020 Feb 29;21(1):138.Disclosure of Interests:None declared
Addressing bias in prediction models by improving subpopulation calibration
