The patella, or kneecap sits on the front of the knee and is in fact a sesamoid bone or a bone within tendons at the front of the knee.
The kneecap can dislocate following an injury. This will result in pain, swelling and in many cases a visible deformity with the kneecap appearing on the side of the knee. The injuries can occur as a result of trauma, but in addition there are a group of patients who have a susceptibility to kneecap dislocation.
In the majority of cases, the dislocated kneecap can be pushed back into place. It is then important that following this immediate treatment, the knee is carefully assessed and investigated further with an MRI of the joint. These injuries can be associated with other injuries within the knee joint.
In many cases these injuries can be treated without surgery, often with bracing and careful physiotherapy.