Subluxation

Overview
A subluxation may have different meanings, depending on the profession or specialty involved. It implies the presence of an incomplete or partial dislocation (Latin: luxatio) of a joint or organ

Medicine
A medical subluxation is an incomplete or partial dislocation of a joint or organ. The World Health Organization (WHO) considers a subluxation to be a "significant structural displacement, and therefore visible on static imaging studies." In the spine, such a displacement may be caused by a spondylolisthesis.

Orthopedics
An orthopedic dislocation of any joint will usually need medical attention to help relocate or reduce the joint. Nursemaid's elbow is the subluxation of the head of the radius from the annular ligament. Other joints that are prone to subluxations are the shoulders, fingers, kneecaps, and hips affected by hip dysplasia. A spinal subluxation is relatively rare, but can sometimes impinge on spinal nerve roots causing symptoms in the areas served by those roots.

Ophthalmology
An ophthalmologic subluxation is called ectopia lentis, an ocular condition characterized by a displaced or malpositioned lens within the eye. Although a relatively rare disorder, subluxated lenses are frequently found in those who have had ocular trauma and those with certain systemic disorders, such as Marfan syndrome, Ehlers-Danlos syndrome and homocystinuria. Some subluxated lenses may require removal, as in the case of those that float freely or those that have opacified to form cataracts.

Chiropractic
A chiropractic subluxation is called a vertebral subluxation, which is an historical concept defined by chiropractors as a relatively common condition in which a spinal vertebra has lost its proper juxtaposition with one or both of its neighboring vertebrae. While not as extreme as a luxation, chiropractors believe they interfere with the nervous system. The WHO considers the degree of structural displacement to not necessarily be "visible on static imaging studies." Although research into the significance of the chiropractic vertebral subluxation is ongoing in chiropractic circles, the concept is rejected by mainstream medicine and progressive chiropractors. Campbel et. al. considered that the disease is the result of spinal nerve dysfunction caused by misplaced (subluxated) vertebrae. Although rejected by medical science, this concept is still accepted by a minority of chiropractors.... Indeed, many progressive chiropractors have rejected the historical concept of the chiropractic subluxation in favor of ones that more accurately describe the nature of the complex joint dysfunctions they treat.