26th January 2024

Causes and risk factors 

The exact cause of OA is unknown, but it is thought to result from an interaction between genetic, biological and biomechanical factors. Heritability of hand, hip and knee OA is estimated at around 40-60%. Increasing age is the strongest risk factor for developing OA, particularly after the age of 50 years, and is more common in females than in men. Other risk factors include obesity, high bone mineral density and low oestrogen levels. Biomechanical factors such as joint injury, occupational and recreational joint stresses, articular congenital deformities, history of inflammatory arthropathy, joint laxity and reduced muscle strength can all contribute to an increased risk in the development of OA.