Ehrlich M G, Houle P A, Vigliani G, Mankin H J
Arthritis Rheum. 1978 Sep-Oct;21(7):761-6. doi: 10.1002/art.1780210704.
Articular cartilage collagenase activity was determined for 28 sections obtained from twelve femoral heads. For each one square centimeter area, a section was graded by a histologic-histochemical grading system for the severity of the arthritis. Collagenase activity was found primarily in those areas of moderately severe disease, but not in mild or end stage arthritis.
