Synonyms in a broader sense
Patella fracture, transverse patella fracture, longitudinal patella fracture, longitudinal patella fracture, transverse patella fracture, patella arthrosis, retropatella arthrosis, patella fracture, patella fracture, knee
Definition
In case of a patella fracture, the patella fractures into several parts. This can result in longitudinal, transverse or mixed fractures. The therapy of a patella fracture depends crucially on the type of fracture.
Epidemiology
Patella fractures account for approximately 1% of all fractures.
Causes
In most cases it is a fall on the bent knee joint. The force of the direct impact breaks the kneecap into two or more fragments. In traffic accidents, a patella fracture can also occur when the bent knee joint is struck.
These injuries are also referred to in modern German as “dashboard injuries”. In exceptional cases, sudden flexion of the knee joint, which is maximally stretched muscularly, can lead to a patella fracture. Another rare cause is dislocation of the kneecap (patella luxation), which can lead to lateral shearing of the patella.
Classification
Basically one differentiates between transverse fractures, so-called transverse fractures, and longitudinal fractures (longitudinal fractures), which break along the leg axis. Furthermore, the number of fracture fragments is included in the classification. The position of the fragments in relation to each other is also examined, so that one speaks of non-displaced (non-dislocated) and displaced (dislocated) fractures. Classification of the AO (Arbeitsgemeinschaft für Osteosynthese) In addition to the well-known AO classification, there are many other classifications which we will not discuss here.
- Type A: longitudinal fractures
- Type A1: non-displaced longitudinal fracture
- Type A2: dislocated longitudinal fracture
- Type A3: longitudinal fracture with additional fragment
- Type B: transverse fractures
- Type B1: Pole break without joint participation
- Type B2: simple transverse fracture
- Type B3: transverse fracture with additional fragment or double transverse fracture
- Type C: Multiple fragment fractures
- Type C1: Multiple fragment fracture without dislocation
- Type C2: Multiple fragment fracture (dislocation less than 2mm)
- Type C3: Multiple fragment fracture with bursting (dislocation greater than 2mm)
transverse fracture – longitudinal fracture – multi-fragment fracture
