Bipartite patella

Bipartite Patella is a condition characterized by the patella (kneecap) being divided into two separate pieces, rather than being a single bone. This condition is congenital, meaning it is present at birth, and results from the failure of the patella's secondary ossification centers to fuse during adolescence. While it is usually asymptomatic and discovered incidentally, some individuals may experience knee pain and discomfort, particularly athletes or those engaged in high-impact activities.

Etiology

The exact cause of bipartite patella is not fully understood, but it is believed to be related to genetic factors and mechanical stress on the knee. The patella typically develops from a single ossification center. However, in individuals with bipartite patella, an additional ossification center fails to fuse with the main body of the patella during development.

Classification

Bipartite patella is classified based on the location of the unfused segment:

• Type I: Located at the inferior pole
• Type II: Located at the lateral margin
• Type III: Located at the superolateral aspect, which is the most common type

Symptoms

Most individuals with bipartite patella do not experience symptoms. When symptoms do occur, they may include:

• Anterior knee pain
• Swelling around the kneecap
• Pain when kneeling or performing activities that put pressure on the knee
• Sensation of instability in the knee

Diagnosis

Diagnosis of bipartite patella typically involves a combination of patient history, physical examination, and imaging studies. X-rays are commonly used to identify the presence of a separate bone fragment. Magnetic resonance imaging (MRI) may be utilized to assess the condition of the surrounding soft tissues and to rule out other potential causes of knee pain.

Treatment

Treatment for bipartite patella is usually conservative, especially in asymptomatic individuals. Options may include:

• Rest and avoidance of activities that exacerbate symptoms
• Physical therapy to strengthen the muscles around the knee and improve joint stability
• Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation
• In cases where conservative treatment fails and symptoms persist, surgical intervention may be considered. Surgery typically involves the removal of the unfused bone fragment or fixation to promote fusion.

Prognosis

The prognosis for individuals with bipartite patella is generally excellent, particularly for those who are asymptomatic or who respond well to conservative treatment measures. Surgical outcomes are also typically favorable, with most individuals experiencing relief from symptoms and a return to their normal activities.

See Also

• Patellofemoral pain syndrome
• Knee osteoarthritis
• Patellar tendinitis