Although the spectra obtained from OA cartilage is broadly similar to that obtained from nonpigmented AKU cartilage, the most intense part of the glycine HN signal showed a drift to lower chemical shift. Our interpretation is that OA cartilage showed an intermediate level of collagen triple helix degradation; more than non-pigmented AKU cartilage and less than pigmented AKU cartilage, and that glycyl radical formation can also be a relevant mechanism in OA cartilage degradation. Our work supports the idea that AKU is an extreme form of common osteoarthritis which can be used to model the earliest age-related degenerative changes to joint cartilage.