No Cartilage Harm From Exercise in Knee Osteoarthritis (OA) Populations

A systematic review of nine randomized controlled trials (14 comparisons) examined how MRI-measured articular cartilage responds to exercise in people with knee osteoarthritis (OA). 

Key findings

The review found that exercise did not harm cartilage in the following OA groups:

• At-risk populations: No effect on cartilage defects was observed. One comparison showed improved glycosaminoglycan (GAG) content.

• Established OA: Most comparisons showed no effect on cartilage thickness, volume, or defects. Two comparisons demonstrated positive effects on collagen, while one showed negative GAG response.

Clinical takeaway

Knee-loading exercise appears to be cartilage-safe – not the “devil” it was previously believed to be. Drawing cross-over analogies to the ankle, exercise should be encouraged, or at least not discouraged, even in the setting of OA.