Pure depression fractures are classified by the AO/OTA as 41B2 fractures. They may involve any portion of the articular surface, usually centrally or laterally. CT or MR scanning will indicate the location and depth of the depression.
The lateral plateau depression fractures are classified by the AO/OTA as 41B2.1 fractures.
The medial plateau depression fractures are classified by the AO/OTA as 41B2.2 fractures. They are rare and often occur as a result of high-energy force. They may be associated with meniscal tears, ligament rupture, neurovascular lesions, and compartment syndrome.
This type of fracture can be very unstable, besides the articular depression, postero lateral corner (PLC) ligament injury should be noted. It is possible to also have a common peroneal nerve injury.