Joint dislocation

A joint dislocation, also called luxation, occurs when there is an abnormal separation in the joint, where two or more bones meet. A partial dislocation is referred to as a subluxation. Dislocations are commonly caused by sudden trauma to the joint like during a car accident or fall. A joint dislocation can damage the surrounding ligaments, tendons, muscles, and nerves. Dislocations can occur in any major joint (shoulder, knees, hips) or minor joint (toes, fingers). The most common joint dislocation is a shoulder dislocation. The treatment for joint dislocation is usually by closed reduction, that is, skilled manipulation to return the bones to their normal position. Only trained medical professionals should perform reductions since the manipulation can cause injury to the surrounding soft tissue, nerves, or vascular structures.

A joint dislocation, also called luxation, occurs when there is an abnormal separation in the joint, where two or more bones meet. A partial dislocation is referred to as a subluxation. Dislocations are commonly caused by sudden trauma to the joint like during a car accident or fall. A joint dislocation can damage the surrounding ligaments, tendons, muscles, and nerves. Dislocations can occur in any major joint (shoulder, knees, hips) or minor joint (toes, fingers). The most common joint dislocation is a shoulder dislocation. The treatment for joint dislocation is usually by closed reduction, that is, skilled manipulation to return the bones to their normal position. Only trained medical professionals should perform reductions since the manipulation can cause injury to the surrounding soft tissue, nerves, or vascular structures.

Signs and symptoms

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 the 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 their 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.

Diagnosis

Initial evaluation of a suspected joint dislocation begins 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. Imaging studies are frequently obtained to assist with diagnosis and to determine the extent of injury.

Treatment

Epidemiology

Each joint in the body can be dislocated, however, there are common sites where most dislocations occur. The most common dislocated parts of the body are discussed as follows: Dislocated shoulder Anterior shoulder dislocation is the most common type of shoulder dislocation, accounting for at least 90% of shoulder dislocations. Anterior shoulder dislocations have a recurrence rate around 39%, with younger age at initial dislocation, male sex, and joint hyperlaxity being risk factors for increased recurrence. The incidence rate of anterior shoulder dislocations is roughly 23.1 to 23.9 per 100,000 person-years. Young males have a higher incidence rate, roughly four times that of the overall population. Recurrent anterior shoulder dislocations have a higher rate of labrum tears (Bankart lesion) and humerus fractures/dents (Hill-Sachs lesion) compared to initial dislocations. Shoulder dislocations account for 45% of all dislocation visits to the emergency room. Elbow The incidence rate of elbow dislocations is 5 to 6 per 100,000 persons per year. Posterior dislocations are the most common type of elbow dislocations, comprising 90% of all elbow dislocations. Wrist Overall, injuries to the small bones and ligaments in the wrist are uncommon. Lunate dislocations are the most common. Finger 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. The most common dislocations are in the proximal interphalangeal (PIP) joints. Hip Posterior and anterior hip dislocation 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. Knee The majority of knee dislocations (64.5%) are caused by trauma to the knee, with more than half caused by car and motorcycle accidents. The incidence rate of initial patellar dislocations is roughly 32.8 per 100,000 person years. Nearly 41% of knee dislocations have an associated fracture, with the majority of these fractures in one of the legs. Nerve injury occurs in about 15.3% of knee dislocations, while major artery injury occurs in 7.8% of knee dislocations. More than half (53.5%) of knee dislocations have an associated torn meniscus. Quadriceps tendon rupture occurs up to 13.1% of the time, and patellar tendon rupture occurs 6.8% of the time. Foot and Ankle A lisfranc injury is a dislocation or fracture-dislocation injury at the tarsometatarsal joints. A 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. They represent 1–2% of all dislocations and are caused by high energy trauma. A total talar dislocation has high rates of complications but is rare. 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. Weakening of the ligaments can put the ankle at risk for dislocation. An ankle dislocation without fracture is rare, due to the strength of ligaments surrounding the ankle.

Gallery

File:Dislocated finger.jpg| Dislocation of the left index finger File:Pinkie.jpg|Radiograph of right fifth phalanx bone dislocation File:Dislocated finger x-ray.JPG|Radiograph of left index finger dislocation File:Reduce dislocated spine, c. 1300.jpg|Depiction of reduction of a dislocated spine, c. 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 of ventral dislocation of the radial head. There is calcification of annular ligament, which can be seen as early as 2 weeks after injury. File:Radiographie d’une luxation postérieur du coude gauche sans fracture.jpg|X-ray of left elbow posterior joint dislocation without fracture

Text derived from https://en.wikipedia.org/w/index.php?oldid=1373840562 under CC BY-SA 4.0; modifications have been made.