Chondromalacia is a term that is commonly used by health professionals – orthopedists, physical therapists, sometimes internists - and in the United States there is even an insurance code for chondromalacia (717.7) - but the fact of the matter is it’s a completely outdated term.
It is a term that was coined towards the early part of the twentieth century by German investigators who were looking at cadaveric specimens – bodies that had been donated to science – and they found that some cadaveric specimens had cartilage lesions - an abnormality – involving the cartilage, the thick cartilage, under the kneecap. And they speculated that these cartilage lesions - which they called ‘soft cartilage’ or ‘chondro malacia’ – ‘chondro’ meaning ‘cartilage’ and ‘malacia’ meaning ‘soft’ - they figured that these chondromalacic lesions will account for the pain that living people have around the kneecap.
And so the term came to be known as chondromalacia for people who had pain at the front of the knee and it was assumed that these patients probably had ulcerations – lesions – of their articular cartilage. And this went on for years and decades until the latter half of the twentieth century when it became very clear as a result of the arthroscopy procedure that many patients with severe knee pain had no cartilage lesions and conversely some patients with significant lesions have absolutely no pain. Therefore the idea that these little lesions were the source of pain pretty much went out the window.
Nevertheless the term ‘chondromalacia’ persisted. It came to refer to anybody with pain in the front of the knee. It came to mean any cartilage lesion under the kneecap. It then came to mean any cartilage lesion in the knee. It then came to mean any cartilage lesion in the human body – the shoulder, the ankle, anywhere – any cartilage lesion was chondromalacia. It then came to mean a cartilage lesion anywhere in the animal kingdom – that dogs had chondromalacia in their shoulder. And the term suddenly ballooned out of control and meant many things to many people to the point where it meant absolutely nothing.
So what are some of these conditions? You have malalignment of the kneecap, you have referred pain from the hip or the back – yes indeed, a back problem or a hip problem can cause pain in the knee! You can have a plica, which is an embryologic band of tissue in the knee that can cause pain at the front of the knee. You can have inflammatory arthritis such as lupus or rheumatoid arthritis - and the first sign of that can be pain at the front of the knee. You can have a stress fracture in your patella.
You can have any number of conditions that can cause pain at the front of the knee.
Tightness - tightness of the quadriceps, tightness of the hamstrings, tightness of the iliotibial band that runs down the side of the leg – all of these things can cause pain at the front of the knee and yet these conditions are all completely independent -unrelated to each other. And once again, it is the doctor’s job to figure out which of these you have so as to pick the most appropriate treatment for your particular pain.
So the word chondromalacia comes from the words chondro and malacia – chondro refers to cartilage and malacia means soft – so ‘chondromalacia’ meaning ‘soft cartilage’. As an aside, it is now appreciated and it has been appreciated now at least twenty years, thirty years that the articular cartilage of the kneecap, of the patella, is by far and away the softest cartilage in the human body in the normal situation. Therefore to a certain extent chondromalacia is normal – it is normal for the articular cartilage of the patella to be a lot softer than the articular cartilage anywhere else in the human body. It is possible that a hundred years ago investigators were not aware of that, and therefore when they found that the articular cartilage of the patella was on the soft side then they have thought that this was abnormal and therefore called it chondromalacia.