Patella fractures are typically due to direct trauma as in a fall or direct blow to the knee.
Fractures may be missed on the AP view or misdiagnosed as a bipartate fracture. To avoid these pitfalls look closely at the lateral view and consider getting a sunrise view of the knee (better visualizes the patella). Finally, unilateral bipartate patella are very rare so consider an x-ray of the contralateral knee if you are considering this as your diagnosis.
Surgery should be considered for:
Fractures with displacement greater than 3 mm.
Individuals that have lost there externsor mechanism as it is indicative of a tear in the extensor retinacula.
