What does subluxation refer to?

Subluxation is defined as a condition where there is a partial displacement of the articulating surfaces of a joint, which means that while the bone surfaces are not fully separated, they are not in their normal position either. This leads to a situation where some contact between the bone surfaces is still maintained, albeit in an abnormal alignment.

The choice highlighting "partial contact of bone surfaces remains" accurately describes this condition. In subluxation, the bone surfaces are not completely displaced from one another, distinguishing it from a complete dislocation, where the bones are entirely separated and no contact remains. This concept is critical in clinical settings because recognizing subluxation can lead to appropriate treatment options such as physical therapy, manipulation, or other interventions aimed to restore proper alignment and function to the joint.

In contrast, a complete displacement of the bone articulating surfaces characterizes full dislocation, while injury to the outer ankle bone and temporary constriction of blood vessels do not pertain to the definition or concept of subluxation and involve different medical conditions.