Patella chondromalacia is a very specific condition relating to the cartilage on the underside of the kneecap. The condition causes the cartilage to soften and wear away causing pain and discomfort. Because of similarities in symptoms, Patella Chondromalacia often gets lumped together with other knee overuse injuries such as runner's knee or jumper's knee.
These injuries usually happen to athletes - those who use their leg muscles more than the average person. However, all it takes is an imbalance in the foot, ankle, shin, femur or quadriceps to begin the injury process to the knee which, in turn, can lead to Patella Chondromalacia. Of course, an accident that jars the kneecap or crushes it also has the potential to lead to the condition.
In order to explain the difference between Patella Chondromalacia and other injuries, a general understanding of the knee and how it is put together is in order. The femur, or thighbone, is connected to the tibia (shinbone) by ligaments and tendons. The tendons of the femur are connected to the large, powerful muscles of the thigh called quadriceps.
The kneecap rides in an indentation called the trochlear groove on the end of the femur. There is cartilage at the end of the tibia and the femur as well as the back of the kneecap. It acts as a cushion to allow the bones to move over each other smoothly without wearing any of them away in the process.
The kneecap is able to ride over the femur because it is attached by a tendon through the back of it. In this way, the bones and ligaments work together as a giant pulley system with the kneecap being the pulley. This set-up augments the strength of the quadriceps by about 30%, and also allows for the smooth extension of the lower leg. When there is a misalignment in the system, the knee can make compensations.
It can ride a little to the left or right of the trochlear groove, for instance. The knee can even twist, because this pulley system is not a tight, rigidly working set-up. If it was resistant to little bends or twists or could not "give" when the leg moved in an awkward motion, the knee and its ligaments would be injured constantly.
Aside from the instant pain of an accident, usually, there is a more subtle way that the knee signals the start of a problem. The main clue is a dull pain in the front of the knee during an activity. For runners or athletes, this pain will be during your workout. It won't be debilitating, at first; just a dull ache. Sometimes, the pain will not be localized to a specific part of the knee, but will be generalized.
If you keep working out, hoping to "work through" the pain, it will only get worse. When this happens, the pain will start to interfere with your workouts and you will be more likely to seek the help of a doctor. For those of us who are not athletes, our injuries will be related to the misalignment of the leg with relation to the knee.
Especially in the case of misalignment of the whole knee joint, it is important to realize that the onset of pain is not the beginning of our trouble, but actually the result of years’ worth of improper wear on the cartilage under the kneecap. Our pain will occur during our everyday activities. Walking on uneven ground, climbing or descending stairs or even sitting quietly with our knees bent comfortably will cause pain. This is just a signal of what will come if steps are not taken to relieve the misalignment of the knee.
It is when treatment for pain fails to help the patient that Patella Chondromalacia will be a consideration. In addition to the pain in and around your knee, there will be a grinding feeling under your kneecap whenever it is in use. Sometimes, this grinding will even be heard by others when you bend your knee.
If you can move your kneecap with your hands and feel the grinding yourself, that is another indication. Also, your knee will tend to get "stuck" and not be able to bend or straighten. However, the only definitive way to know if you have Patella Chondromalacia is with an MRI or an arthroscopy of the knee. Your doctor will be able to see the evidence of the cartilage being worn away. Treatment options can then be discussed with your health care professional.