What is a bipartite patella?

Definition: A bipartite patella occurs when the patella, or kneecap, occurs as two separate bones. Instead of fusing together in early childhood, the patella remains separated. A bipartite patella is usually not a problem; it occurs in at least 1 percent of the population, and perhaps more.

When is a bipartite patella a problem?
In some people who have a bipartite patella, the fibrous tissue that connects the pieces of bone can become inflamed and irritated. The tissue that connects the two parts of bone is called a synchondrosis. A symptomatic bipartite patella is usually the result of a minor trauma or injury, but the knee pain persists.

How is a bipartite patella diagnosed?
A bipartite patella is most commonly diagnosed as an incidental finding. This means that most often an X-ray was obtained to evaluate the knee for another reason, and the bipartite patella was seen on the X-ray. A bipartite patella is only concerning if it is symptomatic. Common symptoms of an inflamed bipartite patella include:

• Pain directly over the kneecap
• Swelling at the synchondrosis
• Painful range of motion of the knee

What is the treatment of a bipartite patella?
In most cases, no treatment is needed for patients diagnosed with a bipartite patella. In the few patients who develop persistent symptoms as a result of their bipartite patella, there are surgical treatment options. The surgery usually consists of removing the smaller fragment of bone or detaching the muscle that inserts on the smaller piece of bone.

_{Sources: "Bipartite Patella" Orthopaedic Care Textbook: The Southern Orthopaedic Association, 2006.}