How can obesity contribute to osteoarthritis?

Obesity contributes to the development of osteoarthritis primarily by increasing the biomechanical stress placed on weight-bearing joints, such as the knees and hips.123

This excess weight creates mechanical forces that accelerate the deterioration of the articular cartilage that normally cushions and protects the joint. As this protective layer softens, roughens, and eventually erodes, it leads to painful bone-on-bone contact and the development of pathologic changes, including the formation of bone spurs and subchondral bone cysts. Because obesity increases the load on these structures, it is classified as a factor that can lead to secondary osteoarthritis. Consequently, weight loss is frequently recommended as a key component of treatment to reduce joint stress and manage symptoms.13