RESUMO
BACKGROUND: Although knee osteoarthritis (OA) and osteoporosis (OP) are common age-related bone disorders, the association between the two conditions remains indefinable. The aim of the present study is to investigate a possible relationship between the two conditions in post-menopausal women. METHODOLOGY: A cross-sectional study was conducted at King Khalid University Hospital, Riyadh, Saudi Arabia, after obtaining IRB approval. The study included all post-menopausal female patients above 50 years of age, who underwent dual-energy X-ray absorptiometry (DXA) scans between January 2019 and July 2021 and have clear radiological data regarding knee OA. For our study, 487 ladies satisfied our inclusion criteria with an age range of 50-94 years (mean 64.67 ±8.4). The severity of knee OA was determined according to the Kellgren and Lawrence (KL) grading system. RESULTS: The mean age and weight of all patients showed a significant association with knee OA. There was no significant association between bone quality and all parameters of bone mineral density (BMD) and T-score with the presence of knee OA. The mean age, height, weight, and BMI have a significant relationship with OP. Grade 3 of the KL classification system for knee OA is the only grade that showed a significant relationship with the presence of OP. The status of bone quality, BMD, and T-score parameters have no significant relationship with the severity subgrouping of knee OA. The BMD and the T-score of the right femoral neck have a significant correlation with BMI, which is linked to the presence of knee OA. CONCLUSION: We didn't find a clear relationship between OP or BMD and the presence of knee OA. However, our findings demonstrated that BMD, T-score of the right femoral neck, and BMI can all be utilized as predictors for the development and progression of knee OA. We recommend considering the many potential confounding variations when describing a relationship between OP and OA.
RESUMO
Background Discordance between hip and spine on dual-energy x-ray absorptiometry is a well-known problem in diagnosing osteoporosis. The prevalence and risk factors of this problem have not been studied in the Saudi population. The objective of this study was to document this discordance in our population and its possible risk factors. Materials and methods We analyzed data obtained from subjects who had dual x-ray absorptiometry (DXA) between January 2021 and December 2021 at King Khalid University Hospital, Riyadh, Saudi Arabia. Subjects with the following conditions were excluded: secondary osteoporosis, patients taking anti-osteoporotic agents, patients on steroids or hormonal replacement therapy, hyperparathyroidism, hypoparathyroidism, and chronic renal disease. A total of 1388 patients satisfied our inclusion criteria. World Health Organization (WHO) criteria for diagnosis were implemented. Major discordance was defined as osteoporosis in one site and normal in the other. Minor discordance was defined as a difference of no more than one World Health Organization diagnostic class between two sites. Bivariate statistical analysis was achieved using appropriate statistical tests (chi-square, student's t-test, one-way analysis of variance, and Pearson's correlation), based on the type of study and outcome variables. A p-value of < 0.05 and 95% CI were used to report the statistical significance and precision of results. Results A total of 1388 subjects were analyzed, of which, 1196 (86%) were females with a mean age of 58.8 (13.8 SD) and 192 were males with a mean age of 58 (18.0 SD). Lumbar osteoporosis was found in 312 (22.5%) participants while hip osteoporosis was reported in 73 (5.3%) of the participants. Major discordance was documented in 85 (6.1%) of all participants (6.3% of the male and 6.1% of the female patients). All of these subjects had lumbar spine osteoporosis with normal hip bone mineral density (BMD). Minor discordance was found in 591 patients (42.6%). Obesity (BMI > 30) was found to be a risk factor for both major (2.10-11.6, 95% CI) and minor (2.5-11.4, 95% CI) discordance. Conclusion Discordance between hip and spine BMD is common among Saudi subjects. Lumbar spine osteoporosis with normal hip BMD caused this discordance in our subjects. Obesity could be responsible for the occurrence of this discordance. Mechanisms may include higher rate of turnover in spine, technical artifacts in the measurements of lumbar spine BMD, or due to the effects of weight loading. Caution should be exercised when interpreting DXA results, especially in obese subjects.
