Bipartite Patella
What is it? This is formed when two portions of the patella bone develop separately and are attached by only fibrous or cartilaginous tissue. The smaller portion of the two patellar pieces is usually in the supero-lateral corner of the patella. The condition is often bilateral.
How does it present? It is usually painless and found incidentally on knee x-rays. It can often be confused with a fractured patella. Occasionally there can be an injury to the fibrous union and this area can be painful.
Common exam findings: In the cases of injury to the fibrous union of the bipartite patella, there may be some mild swelling or tenderness over the region.
Tests and treatment: Knee x-rays with sunrise view will often reveal the bipartite patella. If differentiation from a patellar fracture needs to be determined, x-rays of the other knee may be helpful, since the condition is often bilateral. If the fibrous union of the bipartiate patella is injured, conservative treatment with a knee immobilizer, keeping the knee in extension, may be attempted for several weeks. Those not responding should be referred to orthopedics for possible excision of the bipartite patella.