Osteoarthritis (OA) is a common degenerative condition leading to significant pain, functional limitation, and economic loss. Generalized OA (GOA) is associated with greater morbidity and accounts for 5-25% of total OA cases depending on definition used. This paper aims to determine the frequency and pattern of GOA, compare clinical and laboratory parameters of GOA and non-GOA subjects, then identify independent associations of GOA among Nigerians with knee OA.
A cross-sectional study of 180 knee OA patients with knee and generalized OA defined using ACR criteria. Questionnaire administration was followed by physical examination and appropriate radiographs. Data was summarized using tables and figures. Multivariate regression was done to identify independent GOA associations with statistical significance p<0.05. Ethical approval was obtained for the study.
There were 180 participants with mean age 59.7±9.1 years. Twenty-eight patients (15.6%) had GOA of which 26 were female. The hip/knee/spine pattern was the commonest while hand OA was rare. Comparisons showed that GOA patients were significantly older with longer pain duration, higher pain score, more Heberden's nodes, and greater fatigue. There were no significant differences between both groups in levels of inflammatory markers and other laboratory parameters. Further analysis identified joint stiffness as the only independent association of GOA (OR 3.34, p=0.01).
A 15.6% frequency of GOA was identified among knee OA sufferers with the hip/knee/spine pattern most frequent. Nigerians with GOA are predominantly females with a large joint phenotype. Joint stiffness was the only independent association of GOA observed. Key Points • Generalized osteoarthritis occurs in 15.6% of Nigerian patients with knee osteoarthritis. • Females are predominantly affected with a large joint phenotype involving the hip/knee/spine. • Joint stiffness is an independent association of generalized osteoarthritis.