Subluxation

A subluxation may have different meanings, depending on the medical specialty involved. It implies the presence of an incomplete or partial dislocation of a joint or organ. The World Health Organization (WHO) defines both the medical subluxation and the chiropractic subluxation. It contrasts the two and states in a footnote that a medical subluxation is a "significant structural displacement, and therefore visible on static imaging studies."

Orthopedics
An orthopedic subluxation of any joint will sometimes require 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, ribs, wrists, ankles, and hips affected by hip dysplasia. A spinal subluxation can sometimes impinge on spinal nerve roots, causing symptoms in the areas served by those roots. In the spine, such a displacement may be caused by a fracture, spondylolisthesis, rheumatoid arthritis, severe osteoarthritis, falls, accidents, and other traumas. People with frequent subluxations are known as hypermobile. This is common in Ehlers-Danlos Syndrome.

Ophthalmology
An ophthalmologic subluxation is called ectopia lentis, an ocular condition characterized by a displaced or malpositioned lens within the eye. 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, Loeys-Dietz 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.

Dentistry
A dental subluxation is a traumatic injury in which the tooth has increased mobility but has not been displaced from the mandible or maxilla. This is a common condition and one of the most common dental traumatic disorders. Dental subluxation is a non-dental-urgency condition, i.e., unlikely to result in significant morbidity if not seen within 24 hours by a dentist, and usually treated conservatively: good oral hygiene with 0.12% chlorhexidine gluconate mouthwash, a soft and cold diet, and avoidance of smoking for several days. In painful situations, a temporary splinting of the injured teeth may relieve the pain.

Subluxation may also occur in the mandible from the articular groove of the temporal bone. The mandible can dislocate in the anterior, posterior, lateral, or superior position. Description of the dislocation is based on the location of the condyle in comparison to the temporal articular groove.