What is Patellar Instability?
The kneecap (patella) connects the muscles of the front of the thigh to the shinbone (tibia). The
thighbone (femur) has a groove that enables the kneecap to move up or down as you bend or
straighten your leg. A groove that is uneven or too shallow will result in a partial or complete knee
dislocation. This could also occur as the result of an acute trauma to the knee, such as a sharp
blow sustained through a fall.
Symptoms of patellar instability may include:
- Buckling of the knee
- Knee slips off to one side
- Stiffness of the joint
- Pain when sitting
- Swelling of the joint
Diagnosis typically consists of a physical examination, where the doctor will evaluate the strength of
the thigh muscles or take measurements to see if the bones are out of alignment. The doctor may
ask the patient to walk around, or to straighten and bend the knee. X-rays may be necessary to
determine how the kneecap fits into its specified groove.
Treating Kneecap Dislocation
The initial step in treating kneecap dislocation is returning it to its proper groove in a process known
as reduction. This can occur spontaneously, but will sometimes require your doctor to administer a
gentle push to get it back in place. For chronic cases of kneecap dislocation, or a dislocation that
damages the underside of the kneecap and the end of the thighbone, arthroscopic surgery will be
recommended. Nonsurgical treatments such as exercise and a brace are recommended when the
kneecap is only partially dislocated. This will help to strengthen the muscles of the thigh to help hold
the knee in place. Cycling is the most common form