Patterns of knee osteoarthritis in a hospital setting in sub-Saharan Africa

Osteoarthritis (OA), the most prevalent joint disease in adults, ranks among the top 5 causes of disability. The burden of OA is expected to be greater in developing countries, where life expectancy is increasing and access to joint replacement therapy is not readily available. Risk factors associated with knee OA in Africa may differ from those identified in other parts of the world. This study aimed to establish the prevalence, clinical presentation, and associated factors of knee OA in two large referral centers in Cameroon. Between February and July 2012, we performed a cross-sectional analysis of 148 patients with knee OA followed at two rheumatology units in Douala. We included all patients with mechanical knee pain, who fulfilled the 1986 ACR for the classification and reporting of knee OA. One thousand four hundred ninety-six patients with musculoskeletal complaints were seen; 148 (9.9%) with knee OA were analyzed. Mean age was 56.9 ± 10.7 years, 75% were females, and 68% were post-menopausal. The VAS of pain at the time of diagnosis was higher than 50/100 mm in 64.2% of patients. Mean pain duration was 1 year (7 months-3.5 years). Obesity (BMI > 30) was present in 52% of patients, hypertension in 37.2%, and diabetes in 8.8%. Knee x-ray showed 35.5% of patients with grades III and IV on Kellgren and Lawrence classification. Bilateral bi-compartmental knee OA was found in 38.5% of patients and bilateral tricompartmental in 14.2%. The mean Lequesne disability index (LDI) was 8.4 ± 2.8. Pain intensity did not correlate with radiological findings whereas there was an association between pain and LDI. Knee OA is not rare among patients in Cameroon. Multiple factors including limited access to health care may account for why knee OA patients present at later stages of the disease with severe disability.