What is Bipartite Patella?

Bipartite patella is a condition that affects the patella, or kneecap. Doctors estimate that approximately 1 percent of the population experiences this condition, but the number may be higher because the condition is typically asymptomatic. A patient often receives a diagnosis of bipartite patella when the knee is X-rayed for some other reason.

Bipartite patella occurs when the kneecap does not fuse properly after birth. Rather than forming one bone, the kneecap is two separate bones joined by a piece of fibrous tissue. The kneecap still functions properly, and baring any problems, the condition is not treated.

There are occasions when someone suffering from bipartite patella will develop symptoms and require medical attention. The tissue connecting the two pieces of bone can become swollen or irritated. Symptoms of this include swelling in the area over the kneecap, and pain when attempting to fully extend or bend the knee.

Complications typically arise in this condition when the knee receives an injury, due to impact, or suffers from overuse. The delicate nature of the tissue holding the two sections of kneecap together mean that is does not require a tremendous impact to create damage. Many people are surprised when they develop knee pain that appears out of proportion to the impact that they received. When this happens, an X-ray often reveals that the patient has bipartite patella.

For minor pain that develops from overuse, treatment is generally conservative. Anti-inflammatory medications, rest and modifying many of the activities the patient participates in may be enough to reduce inflammation, and allow the pain to dissipate. More aggressive treatment is required if the knee pain does not subside. These treatments include immobilizing the knee with a brace or steroid injections.

After six months of treatment with less aggressive measures, or if the pain is the result of direct trauma, the patient may require surgery. The first surgical option involves removing the smaller portion of bone from the kneecap entirely, while the second involves releasing the muscle that attaches to the smaller piece of bone. Both of these options relieve the pressure on the tissue joining the bones together.

For cases of bipartite patella that involve two, relatively similarly sized sections of bone, the doctor may choose to leave both pieces of the bone in place and attach them to one another with screws. This reduces the chance that the patient will develop arthritis later as a result of removing a large section of bone. A reduction in pain and improvement in the range of motion of the knee typically occurs within one month of surgery.