Presentation
Long-standing left knee discomfort.
Patient Data




Mild degenerative bone changes are seen.
Tripartite patella is noted
Case Discussion
An x-ray of the left knee was obtained due to long-standing left knee discomfort. Incidental finding of multipartite patella is seen, which is considered a normal anatomic variant. It is usually asymptomatic and not necessarily the cause of the patient's complaint when encountered on imaging. The fragmented patella has smooth, well-corticated margins distinguish this from a patella fracture. However, the unfused ossification centers that are attached to the patella can be affected by direct trauma causing anterior knee pain.
In multipartite patella, the volume of the true patella plus that of the smaller ossification centers is greater than that expected of a normal patella. The differential diagnosis is a patellar fracture, where the volume of the fractured components is equivalent to that of a normal patella.
According to the saupe classification, it is considered type III which is the most common form where the superolateral pole of the patella is the site of segmentation.