Figure 2From: Cartilage collagen damage in hip osteoarthritis similar to that seen in knee osteoarthritis; a case–control study of relationship between collagen, glycosaminoglycan and cartilage swelling The relationship between total collagen and extractable collagen pool. Total collagen was measured as hydroxyproline per wet weight and extractable collagen pool was expressed as a percentage of total amount of collagen. Open and closed circles represent OA and reference groups, respectively.Back to article page