Osteoarthritis.

There are few studies on the prevalence, pattern or clinical course of osteoarthritis (OA) in the tropics. The studies that have been carried out, however, indicate that on the whole there is a lower prevalence of OA than found in Western countries. In addition, the pattern of joint involvement may be different with less common involvement of the hip relative to the knee and polyarticular OA is uncommon in many parts of the tropics. It also seems likely that a significant number of these patients in the tropics have OA secondary to various infections including pyogenic, tuberculous and parasitic infections. There is an urgent need to confirm these observations and to identify possible genetic, developmental or environmental factors influencing the expression of OA in the tropics. In addition degenerative arthropathies, such as Mseleni's disease, present in some parts of the tropics, merit further study. With increasing life-expectancy and improved health-care in many parts of the tropics, OA will become an increasingly prevalent and important condition with associated morbidity and socio-economic implications for these countries.