It has an unusual structure which gives it its special characteristics - there are very few cells, and those that exist are in spaces called 'lacunae', with the lacunae supported within the background substance or 'matrix' of the cartilage.
Articular cartilage is nourished only by the fluid within the joint, and this, together with its strange cellular structure, means than it heals very poorly - which is of major importance in degenerative joint disease.
There is confusion in the medical terminology about the word 'cartilage', as patients use it one way and doctors another, and doctors create further confusion by using it the patient way when talking to patients and the doctor way when talking to doctors.
When doctors say to each other 'cartilage' they mean the gristle or shiny white surface at the ends of the long bones anywhere in the body. Other words for this include 'articular cartilage' and 'hyaline cartilage'. However, when patients use the term, usually in the plural - cartilages - they mean the wedge-shaped shock absorbers of the knee, sandwiched between the thighbone (femur) and the shinbone (tibia) - which should correctly be called the 'meniscus'.
It is damage to the joint or hyaline cartilage which is called 'arthritis' and in the knee all efforts are geared towards preventing any damage or breakdown of this all-essential joint surface, as it has a poor blood supply and does not heal well if damaged.
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