Which of the following is defined as a complete loss of articulation in a joint?

The correct answer is Luxation, which refers to a complete dislocation of a joint where the joint surfaces are no longer in contact. This loss of articulation impairs the normal function of the joint and can result from trauma or injury. Luxation is significant because it often requires medical intervention to relocate the joint properly and address any associated damage to surrounding structures like ligaments, tendons, and cartilage.

Understanding this term is crucial in the context of joint injuries, as it distinguishes between different levels of joint displacement. For instance, subluxation, another term often associated with joint injuries, refers to a partial dislocation where the joint surfaces are still somewhat in contact. This highlights a key difference and helps in the appropriate management of injuries.

In the context of a concussion, while it involves injury to the brain due to trauma, it is not related to joint articulation. Muscle guarding, on the other hand, is a protective mechanism the body uses to restrict movement in an injured area, but it does not signify a loss of articulation. Each of these terms has a specific meaning and relevance in sports medicine and rehabilitation, which underscores the importance of understanding the precise definitions.