A joint dislocation, also called luxation, occurs when there is an abnormal separation in the
joint
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw ...
, where two or more bones meet.
[Dislocations. Lucile Packard Children’s Hospital at Stanford. Retrieved 3 March 2013]
A partial dislocation is referred to as a
subluxation
A subluxation is an incomplete or partial dislocation of a joint or organ.
According to the World Health Organization (WHO), a subluxation is a "significant structural displacement", and is therefore always visible on static imaging studies, suc ...
. Dislocations are often caused by sudden
trauma
Trauma most often refers to:
* Major trauma, in physical medicine, severe physical injury caused by an external source
* Psychological trauma, a type of damage to the psyche that occurs as a result of a severely distressing event
*Traumatic i ...
on the joint like an impact or fall. A joint dislocation can cause damage to the surrounding
ligament
A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the:
* Peritoneal li ...
s,
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
s,
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
s, and
nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system.
A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...
s. Dislocations can occur in any major joint (shoulder, knees, etc.) or minor joint (toes, fingers, etc.). The most common joint dislocation is a shoulder dislocation.
Treatment for joint dislocation is usually by closed
reduction, that is, skilled manipulation to return the bones to their normal position. Reduction should only be performed by trained medical professionals, because it can cause injury to soft tissue and/or the nerves and vascular structures around the dislocation.
Symptoms and signs
The following symptoms are common with any type of dislocation.
* Intense pain
* Joint instability
* Deformity of the joint area
* Reduced muscle strength
* Bruising or redness of joint area
* Difficulty moving joint
* Stiffness
Causes
Joint dislocations are caused by trauma to the joint or when an individual falls on a specific joint. Great and sudden force applied, by either a blow or fall, to the joint can cause the bones in the joint to be displaced or dislocated from normal position. With each dislocation, the ligaments keeping the bones fixed in the correct position can be damaged or loosened, making it easier for the joint to be dislocated in the future.
Some individuals are prone to dislocations due to congenital conditions, such as
hypermobility syndrome and Ehlers-Danlos Syndrome. Hypermobility syndrome is genetically inherited disorder that is thought to affect the encoding of the connective tissue protein’s collagen in the ligament of joints. The loosened or stretched ligaments in the joint provide little stability and allow for the joint to be easily dislocated.
Diagnosis
Initial evaluation of a suspected joint dislocation should begin with a thorough patient history, including mechanism of injury, and physical examination. Special attention should be focused on the neurovascular exam both before and after
reduction, as injury to these structures may occur during the injury or during the reduction process.
Subsequent imaging studies are frequently obtained to assist with diagnosis.
* Standard
plain radiographs, usually a minimum of 2 views
** Generally, pre- and post-reduction X-rays are recommended. Initial X-ray can confirm the diagnosis as well as evaluate for any concomitant fractures. Post-reduction radiographs confirm successful reduction alignment and can exclude any other bony injuries that may have been caused during the reduction procedure.
** In certain instances if initial X-rays are normal but injury is suspected, there is possible benefit of stress/weight-bearing views to further assess for disruption of ligamentous structures and/or need for surgical intervention. This may be utilized with
AC joint separations.
** Nomenclature: Joint dislocations are named based on the distal component in relation to the proximal one.
*
Ultrasound
Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...
** Ultrasound may be useful in an acute setting, particularly with suspected shoulder dislocations. Although it may not be as accurate in detecting any associated fractures, in one observational study ultrasonography identified 100% of shoulder dislocations, and was 100% sensitive in identifying successful reduction when compared to plain radiographs. Ultrasound may also have utility in diagnosing AC joint dislocations.
** In infants <6 months of age with suspected
developmental dysplasia of the hip (congenital hip dislocation), ultrasound is the imaging study of choice as the proximal femoral epiphysis has not significantly ossified at this age.
* Cross-sectional imaging (
CT or
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
)
** Plain films are generally sufficient in making a joint dislocation diagnosis. However, cross-sectional imaging can subsequently be used to better define and evaluate abnormalities that may be missed or not clearly seen on plain X-rays. CT is useful in further analyzing any bony aberrations, and CT angiogram may be utilized if vascular injury is suspected. In addition to improved visualization of bony abnormalities, MRI permits for a more detailed inspection of the joint-supporting structures in order to assess for ligamentous and other soft tissue injury.
Treatment
A dislocated joint usually can be successfully
reduced into its normal position only by a trained medical professional. Trying to reduce a joint without any training could substantially worsen the injury.
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.
[Dias, J., Steingold, R., Richardson, R., Tesfayohannes, B., Gregg, P. (1987). The conservative treatment of acromioclavicular dislocation. British Editorial Society of Bone and Joint Surgery. 69(5): 719–722.]
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 the
emergency department
An emergency department (ED), also known as an accident and emergency department (A&E), emergency room (ER), emergency ward (EW) or casualty department, is a medical treatment facility specializing in emergency medicine, the acute care of pati ...
under
sedation or in an
operating room under a
general anaesthetic
General anaesthetics (or anesthetics, see spelling differences) are often defined as compounds that induce a loss of consciousness in humans or loss of righting reflex in animals. Clinical definitions are also extended to include an induced coma ...
.
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
Arthroscopy (also called arthroscopic or keyhole surgery) is a minimally invasive surgical procedure on a joint in which an examination and sometimes treatment of damage is performed using an arthroscope, an endoscope that is inserted into the ...
.
The most common treatment method for a dislocation of the Glenohumeral Joint (GH Joint/Shoulder Joint) is exercise based management. Another method of treatment is to place the injured arm in a sling or in another immobilizing device in order to keep the joint stable.
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.
On field reduction is crucial for joint dislocations. As they are extremely common in sports events, managing them correctly at the game at the time of injury, can reduce long term issues. They require prompt evaluation, diagnosis, reduction, and postreduction management before the person can be evaluated at a medical facility.
After care
After a dislocation, injured joints are usually held in place by a
splint (for straight joints like fingers and toes) or a
bandage
A 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 or to restrict the movement of a part of the body. When used with a dressing, the dressing is applie ...
(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.
For glenohumeral instability, the therapeutic program depends on specific characteristics of the instability pattern, severity, recurrence and direction with adaptations made based on the needs of the patient. In general, the therapeutic program should focus on restoration of strength, normalization of range of motion and optimization of flexibility and muscular performance. Throughout all stages of the rehabilitation program, it is important to take all related joints and structures into consideration.
Epidemiology
* Each joint in the body can be dislocated, however, there are common sites where most dislocations occur. The following structures are the most common sites of joint dislocations:
*
Dislocated shoulder
A dislocated shoulder is a condition in which the head of the humerus is detached from the shoulder joint. Symptoms include shoulder pain and instability. Complications may include a Bankart lesion, Hill-Sachs lesion, rotator cuff tear, or i ...
** Shoulder dislocations account for 45% of all dislocation visits to the emergency room.
Anterior shoulder dislocation, the most common type of shoulder dislocation (96-98% of the time) occurs when the arm is in external rotation and abduction (away from the body) produces a force that displaces the humeral head anteriorly and downwardly.
Vessel and nerve injuries during a shoulder dislocation is rare, but can cause many impairments and requires a longer recovery process.
There is a 39% average rate of recurrence of anterior shoulder dislocation, with age, sex, hyperlaxity and greater tuberosity fractures being the key risk factors.
*
Knee
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...
:
Patellar dislocation
A patellar dislocation is a knee injury in which the patella (kneecap) slips out of its normal position. Often the knee is partly bent, painful and swollen. The patella is also often felt and seen out of place. Complications may include a patella ...
** Many different knee injuries can happen. Three percent of knee injuries are acute traumatic patellar dislocations. Because dislocations make the knee unstable, 15% of patellas will re-dislocate.
** Patellar dislocations occur when the knee is in full extension and sustains a trauma from the lateral to medial side.
*
Elbow
The elbow is the region between the arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and the media ...
: Posterior dislocation, 90% of all elbow dislocations
*
Wrist
In human anatomy, the wrist is variously defined as (1) the Carpal bones, carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known ...
: Lunate and Perilunate dislocation most common
*
Finger
A finger is a limb of the body and a type of digit, an organ of manipulation and sensation found in the hands of most of the Tetrapods, so also with humans and other primates. Most land vertebrates have five fingers ( Pentadactyly). Chambers ...
: Interphalangeal (IP) or metacarpophalangeal (MCP) joint dislocations
** In the United States, men are most likely to sustain a finger dislocation with an incidence rate of 17.8 per 100,000 person-years.
Women have an incidence rate of 4.65 per 100,000 person-years.
The average age group that sustain a finger dislocation are between 15 and 19 years old.
*
Hip
In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint.
The hip region is ...
: Posterior and anterior
dislocation of hip
A hip dislocation is when the thighbone (femur) separates from the hip bone (pelvis). Specifically it is when the ball–shaped head of the femur (femoral head) separates from its cup–shaped socket in the hip bone, known as the acetabulum. Th ...
** Anterior dislocations are less common than posterior dislocations. 10% of all dislocations are anterior and this is broken down into superior and inferior types.
Superior dislocations account for 10% of all anterior dislocations, and inferior dislocations account for 90%.
16-40 year old males are more likely to receive dislocations due to a car accident.
When an individual receives a hip dislocation, there is an incidence rate of 95% that they will receive an injury to another part of their body as well.
46–84% of hip dislocations occur secondary to traffic accidents, the remaining percentage is due based on falls, industrial accidents or sporting injury.
* Foot and Ankle:
**
Lisfranc injury
A Lisfranc injury, also known as Lisfranc fracture, is an injury of the foot in which one or more of the metatarsal bones are displaced from the tarsus.
The injury is named after Jacques Lisfranc de St. Martin, a French surgeon and gynecolo ...
is a dislocation or fracture-dislocation injury at the tarsometatarsal joints
**
Subtalar dislocation, or
talocalcaneonavicular dislocation, is a simultaneous dislocation of the talar joints at the talocalcaneal and talonavicular levels. Subtalar dislocations without associated fractures represent about 1% of all traumatic injuries of the foot and 1-2 % of all dislocations, and they are associated with high energy trauma. Early closed reduction is recommended, otherwise open reduction without further delay.
** Total talar dislocation is very rare and has very high rates of complications.
** Ankle Sprains primarily occur as a result of tearing the ATFL (anterior talofibular ligament) in the Talocrural Joint. The ATFL tears most easily when the foot is in plantarflexion and inversion.
** Ankle dislocation without fracture is rare.
Gallery
File:Dislocated finger.jpg, Dislocation of the left index finger
File:Pinkie.jpg, Radiograph
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...
of right fifth phalanx bone
The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bon ...
dislocation
File:Dislocated finger x-ray.JPG, Radiograph
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...
of left index finger dislocation
File:Reduce dislocated spine, c. 1300.jpg, Depiction of reduction of a dislocated spine, ca. 1300
File:MCCdislocation.PNG, Dislocation of the carpo-metacarpal joint.
File:Dislocated Finger XRay.png, Radiograph of right fifth phalanx dislocation resulting from bicycle accident
File:Dislocated Finger.JPG, Right fifth phalanx dislocation resulting from bicycle accident
File:Lightbulb sign - posterior shoulder dislocation - Roe vor und nach Reposition 001.jpg, Shoulder dislocation before (left) and after (right) being reduced
File:X-ray of ventral dislocation of the radial head with calcification of annular ligament.jpg, X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...
of ventral dislocation of the radial head. There is calcification of annular ligament, which can be seen as early as 2 weeks after injury.
See also
*
Buddy wrapping
Buddy wrapping, also called neighbour strapping or buddy taping, is the act of bandaging a damaged or particularly a fractured finger or toe together with a healthy, uninjured one. The bandage or medical tape is usually stiff, not allowing the ...
*
Major trauma
Major trauma is any injury that has the potential to cause prolonged disability or death. There are many causes of major trauma, blunt and penetrating, including falls, motor vehicle collisions, stabbing wounds, and gunshot wounds. Dependin ...
*
Physical therapy
*
Projectional radiography
Projectional radiography, also known as conventional radiography, is a form of radiography and medical imaging that produces two-dimensional images by x-ray radiation. The image acquisition is generally performed by radiographers, and the images ...
*
Listhesis, olisthesis, or olisthy
References
External links
{{DEFAULTSORT:Joint Dislocation
Contortion
Joints
Dislocations, sprains and strains
Emergency medical procedures