Joint dislocations are described in terms of the position of the distal bone in relation to the proximal bone
Diastasis is the separation of 2 normally adjacent bone parts
Dislocation is an injury resulting in loss of anatomical congruence of bones at a joint. Joint dislocations are described in terms of the position of the distal bone in relation to the proximal bone. This means that distal bones can dislocate from proximal bones, but not vice versa.
Subluxation is a term which may be used to describe incomplete dislocation.