Chondromalacia Patellae grade 1, grade 2, grade 3, grade 4.
What is Chondromalacia patellae?
Chondromalacia literally means “softening of the cartilage”, and Patellae means “the knee-cap”. So Chondromalacia patellae means “softening of the articular cartilage of the knee-cap.” The articular cartilage is the cartilage lining under the knee-cap that articulates with the knee joint. Under normal circumstances, it is smooth and shiny, so that it glides smoothly along the articular groove of the femur as the knee bends. When it “softens”, it may break down, causing irregularities along the undersurface of the patella.
The ends of bones which form joints are covered by a very smooth material called articular or chondral cartilage. After injury or with disease, the condition of this surface can change. This can progress over time from becoming a bit soft to being completely absent. The loss of articular or chondral cartilage of a joint for any reason, (injury, illness, or natural wear- and- tear with aging), is called chondromalacia.
These changes compare to the difference seen between a brand-new Teflon-coated frying pan, one that has been slightly scratched by a steel scrubber, and one where the Teflon surface has flaked off completely. As with a frying pan’s Teflon surface, the greater the destruction of the articular cartilage, the poorer the function of the joint.
Important considerations when evaluating chondromalacic changes in a joint are the state of the articular surface, the extent of the cartilage involvement and the location of the lesion. These all impact the degree of symptoms.
There are several classification systems used to grade the degree of articular cartilage damage. These usually describe the extent of fibrillation of articular surfaces, the degree of softness, the depth of involvement and sometimes the size of the lesion. Some of the systems combine surface appearance and the depth of involvement under a single category and others make no such distinction. There is some subjectivity in reporting but all classification systems attempt to be as objective as possible.
Generally, a Grade I lesion is a descriptive term for articular cartilage which is soft. Grade II lesions usually show some fissuring or disruption of the articular surface to various depths. Grade III lesions are more extensive with deeper fissuring and fibrillation which may extend to the underlying subchondral bone. Grade IV is a descriptive term used to describe that the articular cartilage is destroyed, leaving the subchondral bone exposed (eburnation). Grade IV is the most objective of the grades, and is the most consistent across the classification systems.