Joint dislocation, or
luxation (Latin:
luxatio) , occurs when bones in a
jointA joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
become displaced or misaligned. It is often caused by a sudden impact to the joint. The
ligamentIn anatomy, the term ligament is used to denote three different types of structures:# Fibrous tissue that connects bones to other bones. They are sometimes called "articular ligaments", "fibrous ligaments", or "true ligaments"....
s always become damaged as a result of a dislocation. A
subluxationA 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 defines both the medical subluxation and the chiropractic subluxation...
is a partial dislocation.
Occurrence
Although it is possible for any joint to become subluxed or dislocated, the most common sites it is seen in the human body are:
- Shoulder
In human anatomy, the shoulder joint comprises the part of the body where the humerus attaches to the scapula. The shoulder refers to the group of structures in the region of the joint....
s (see Dislocated shoulderA dislocated shoulder occurs when the humerus separates from the scapula at the glenohumeral joint. As the most maneuverable joint in the human body, the shoulder is the joint most vulnerable to dislocation. Approximately half of major joint dislocations seen in emergency departments are of the...
),
- Finger
A finger is a type of digit, an organ of manipulation and sensation found in the hands of humans and other primates.Normally humans have five digits, termed phalanges, on each hand . The first digit is the thumb, followed by index finger, middle finger, ring finger, and little finger or pinky...
s,
- Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the femur and tibia, and one between the femur and patella. It is the largest and most complicated joint in the human body. The knee is a mobile trocho-ginglymus , which permits flexion and extension as well...
s,
- Wrist
In human anatomy, the wrist is variously defined as the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand;...
s (most likely be accompanied by a fracture.)
- Elbow
The elbow is the region surrounding the elbow-joint—the ginglymus or hinge joint in the middle of the arm. Three bones form the elbow joint: the humerus of the upper arm, and the paired radius and ulna of the forearm....
s (most likely be accompanied by a fracture.)
Treatment
A dislocated joint can only be successfully 'reduced' into its normal position by a trained medical professional. Trying to reduce a joint without any training could result in making the injury substantially worse.
X-rays are usually taken to confirm a diagnosis and detect any fractures which may also have occurred at the time of dislocation. A dislocation is easily seen on an X-ray.
Once a diagnosis is confirmed, the joint is usually manipulated back into position. This can be a very painful process, therefore this is typically done either in A&E under
sedationSedation is a medical procedure involving the administration of sedative drugs, generally to facilitate a medical procedure with local anaesthesia.- Uses :...
or in an Operating Room under a
General anaestheticA general anaesthetic drug is an anaesthetic drug that brings about a reversible loss of consciousness...
.
It is important the joint is reduced as soon as possible, as in the state of dislocation, the blood supply to the joint (or distal anatomy) may be compromised. This is especially true in the case of a dislocated ankle, due to the anatomy of the blood supply to the foot.
Shoulder injuries can also be surgically stabilized, depending on the severity, using arthroscopic surgery.
Some joints are more at risk of becoming dislocated again after an initial injury. This is due to the weakening of the muscles and ligaments which hold the joint in place. The shoulder is a prime example of this. Any shoulder dislocation should be followed up with thorough physiotherapy.
There are some medical conditions by where joint dislocations are frequent and spontaneous, such as
Ehlers-Danlos SyndromeEhlers-Danlos Syndrome is a group of inherited connective tissue disorders, caused by a defect in the synthesis of collagen . The collagen in connective tissue helps tissues to resist deformation...
and Congenital
Hip DysplasiaHip dysplasia, developmental dysplasia of the hip or congenital dysplasia of the hip is a congenital or acquired deformation or misalignment of the hip joint.-Terminology:...
.
After care
After a dislocation, injured joints are usually held in place by a
splintA splint is a medical device for the immobilization of limbs or of the spine.It can be used:* By the Emergency Medical Services or by volunteer first responders, to immobilize a fractured limb before the transportation; it is then a temporary immobilization;* By an occupational therapist, via a...
(for straight joints like fingers and toes) or a
bandageA bandage is a piece of material used either to support a medical device such as a dressing or splint, or on its own to provide support to the body...
(for complex joints like shoulders). Additionally, the joint muscles, tendons and ligaments must also be strengthened. This is usually done through a course of physiotherapy, which will also help reduce the chances of repeated dislocations of the same joint.