→ pain or instability that affects the patella (the kneecap).

What kinds of disorders affect the kneecaps?

The kneecap bone (the patella) provides protective covering to the knee joint, and it can be affected by a number of different disorders. We often tend to classify these disorders as falling on a spectrum between pain issues and instability issues (or a mixture of both). Two common causes of kneecap pain are maltracking and osteoarthritis; another cause is a fractured bone. Common causes of instability include dislocation and subluxation.

How do kneecap disorders occur?

Maltracking is a problem with the balance of the kneecap. A normal kneecap sits in equilibrium over the joint thanks to muscles in the upper thigh. When one of these muscles becomes too strong or overactive, however, it can tighten and pull the patella away from the joint, causing pain, misalignment and even dislocation. Osteoarthritis is what happens when the protective cartilage of the bones wears away, causing them to rub painfully against each other: natural ageing, past injuries and weight are some of the potential factors in its onset. (For further detail on osteoarthritis of the knee, click here) Dislocation and subluxation are what happens when the kneecap is forced out of joint, either fully (‘true dislocation’) or partially (subluxation). The cause can be traumatic, such as a heavy fall or a blow to the knee. Or it can be congenital, where structural problems in the kneecap make it more vulnerable to dislocation – due to weak, loose or overly stretchy ligaments, for example, or because the bony groove that helps to keep the kneecap in place is abnormally shallow.

What are the symptoms of a kneecap disorder?

Maltracking of the kneecap is often accompanied by pain during movement, particularly as weight is applied to the joint when climbing stairs, or when standing up from a sitting position. It can also cause the kneecap to look visibly out of place, and in some cases the knee may give way altogether. Osteoarthritis in the kneecap can lead to discomfort at any time but, like maltracking, pain is often brought on or made worse by movement. It is sometimes also accompanied by crepitus, which is a popping or grating sensation or sound in the joint during movement. A dislocated or subluxed kneecap is likely to appear visibly out of place, and possibly swollen. Pain can be quite severe, and it may be impossible to walk or straighten the leg.

What happens next?

The range of treatments available for kneecaps varies widely depending on the nature and severity of the disorder. Many dislocations, for example, can correct themselves naturally (that is, pop back into place), though it is always best to seek further advice from a doctor. Others may require reduction (manipulation of the knee to put the patella back in place) or surgical intervention. Once the disorder has been diagnosed, we will be able to explore the full range of options available to you.