Partial articular, vertical fractures of the medial patella may be due to direct impact to the front of the knee (eg, dashboard injury).
The surgeon must not confuse a well-corticated superolateral bipartite patella (see patient examination ) with an acute fracture.
1. Partial articular, medial sagittal simple fracture (AO/OTA 34B2.1)
When the fracture pattern is simple, it is classified by AO/OTA as a 34B2.1 fracture.
2. Partial articular, medial sagittal fragmentary fracture (AO/OTA 34B2.2)
When the fracture pattern is fragmentary, it is classified by AO/OTA as a 34B2.2 fracture.