Facet injury
see Facet fracture.
see Facet dislocation.
see Locked facet.
A series of descriptors describes the spectrum of injuries to the facet joint complex.
If there are multiple injuries to the same facet (for example, a small fracture and dislocation), only the highest level of injury is classified (dislocation).
If both facets on the same vertebrae are injured, the right-sided facet injury is listed before the left sided injury if the injuries are of different subcategories.
The ‘‘Bilateral’’ (BL) modifier is used if both facets have the same type of injury.
If only facet injuries are identified (no A, B, or C injury), they are listed first after the level of injury.
see F1 facet fracture.
F2 facet fracture with potential for instability (either superior or inferior facets)
F2 is a facet fracture with potential for instability (either superior or inferior facets).
Fracture fragments are either larger than 1 cm, comprise more than 40% of the lateral mass, or there are signs of displacement.
F3 Floating lateral mass
F3 is a disruption of the pedicle and lamina resulting in disconnection of superior and inferior articular processes at a given level or set of levels.
This might lead to instability of the facet joint of two motion segments.
F4 Pathologic subluxation or perched/dislocated facet
This injury type includes any subluxation or dislocation of the facet joint, with or without fracture.
BL—Bilateral
The bilateral modifier is used when the same type of facet injury is observed bilaterally on the same vertebra.