Joint Dislocation

Joint dislocations can be sustained during contact sports and physical activities [1] such as football, basketball, wrestling, gymnastics, skiing, etc. Dislocations also occur as a result of a direct blow to the joint during a traffic collision. Additionally, individuals with connective tissue disease tend to have ligamentous laxity and hence may be predisposed to joint dislocation. Individuals susceptible to falls are also prone to this type of injury.

Generally, the clinical presentation of dislocation is characterized by joint deformity, swelling, and discoloration. Moreover, the affected joint exhibits a restricted range of motion and pain with movement. Bruises and abrasions may also be apparent.

The most predominant joint dislocation is that of the glenohumeral, or shoulder joint [2] as a result of its high range of motion [3]. It is responsible for more than half of athletic-related dislocations in high school students [2].

The second most frequently dislocated joint is the elbow [4], in which nearby structures are typically disrupted as well [3].

Also prevalent are finger injuries since the digits are vulnerable to trauma [3]. They are often accompanied by hand and wrist injuries as well [5].

The ankle is a commonly involved site in sports injuries. Specifically, ankle dislocations are typically accompanied by fractures [6].

While rare in sports, hip dislocations are very serious due to complications such as avascular necrosis of the femoral head, which requires urgent medical care [7].

Also uncommon in sports are knee dislocations, which are associated with neurovascular injuries, especially that of the popliteal artery [4] and peroneal nerve [8].

Complications

Dislocated joints may encompass injuries of nearby nerves, blood vessels, ligaments, tendons, and muscles. Also, repaired dislocations may be prone to repeated injuries and the development of arthritis with aging.

Physical exam

The exam consists of numerous components. Initially, the clinician will note findings such as the symmetry, swelling, color, shape, and overall appearance of the affected joint in comparison to the normal one. Very importantly, the joint's range of motion and special maneuvers are also tested. Also crucial is the neurovascular evaluation, which includes a thorough neurologic exam and a check of the pulses. Note that the neurovascular assessment should be performed pre- and post-reduction [3] [9].

The workup for joint dislocation consists of the patient's history, physical exam, and the appropriate imaging. Very importantly, the clinician should elicit a detailed account regarding the incident and mechanism of injury.

Shoulder dislocation is best diagnosed with radiography, particularly the anteroposterior (AP), axillary lateral, and scapular Y-views [1]. Other modalities such as ultrasonography may be required to rule out fractures [10].

To evaluate an elbow dislocation, AP and lateral radiographs are obtained prior to and after reduction to ensure the neurovascular status is sound and the reduction is successful. Ultrasonography [11] and computed tomography (CT) imaging are helpful in assessing other structures.

A digit dislocation is identified with pre and post-reduction radiographs with AP, true lateral, and oblique views [12].

An ankle dislocation is examined with AP, lateral and oblique radiographic views before and after reduction. Additionally, CT scanning is used for display of fractures and alignment.

In traumatic cases, the hips are evaluated with an AP radiograph and CT scanning of the pelvis and hips. Lateral views or CT imaging are warranted in cases with negative AP film but dislocation is still suspected [13].

Knee assessment is conducted with radiography prior to ligament stress tests and after reduction [14]. Also, duplex ultrasonography detects the presence vascular injury [15].

1. Sofu H, Gürsu S, Koçkara N, et al. Recurrent anterior shoulder instability: Review of the literature and current concepts. World J Clin Cases. 2014; 2(11):676-682.
2. Benjamin HJ, Hang BT. Common acute upper extremity injuries in sports. Clin Pediatric Emerg Med. 2007;8(1):15-30.
3. Skelley NW, McCormick JJ, Smith MV. In-game Management of Common Joint Dislocations. Sports Health. 2014;6(3):246-255.
4. Hodge DK, Safran MR. Sideline management of common dislocations. Curr Sports Med Rep. 2002;1(3):149-155.
5. Elfar JC, Yaseen Z, Stern PJ, Kiefhaber TR. Individual finger sensibility in carpal tunnel syndrome. J Hand Surg Am. 2010;35(11):1807-1812.
6. Title CI, Katchis SD. Traumatic foot and ankle injuries in the athlete. Orthop Clin North Am. 2002;33(3):587-598.
7. Smith MV, Sekiya JK. Hip instability. Sports Med Arthrosc. 2010;18(2):108-112.
8. Niall DM, Nutton RW, Keating JF. Palsy of the common peroneal nerve after traumatic dislocation of the knee. J Bone Joint Surg Br. 2005;87(5):664-667.
9. Cohen MS, Hastings H-II. Acute elbow dislocation: evaluation and management. J Am Acad Orthop Surg. 1998;6(1):15-23.
10. Akyol C, Gungor F, Akyol AJ, et al. Point-of-care ultrasonography for the management of shoulder dislocation in ED. Am J Emerg Med. 2016; 34 (5):866-70.
11. Lee KS, Rosas HG, Craig JG. Musculoskeletal ultrasound: elbow imaging and procedures. Semin Musculoskelet Radiol. 2010; 14(4):449-60.
12. Gilbert TJ, Cohen M. Imaging of acute injuries to the wrist and hand. Radiol Clin North Am. 1997; 35(3):701-25.
13. Wylie JD, Abtahi AM, Beckmann JT, Maak TG, Aoki SK. Arthroscopic and imaging findings after traumatic hip dislocation in patients younger than 25 years of age. J Hip Preserv Surg. 2015;2(3):303-9.
14. Bouaicha S. The acute knee injury - practical considerations. Praxis (Bern 1994). 2014;10(8):439-44.
15. Knudson MM, Lewis FR, Atkinson K, Neuhaus A. The role of duplex ultrasound arterial imaging in patients with penetrating extremity trauma. Arch Surg. 1993; 128(9):1033-7; discussion 1037-8.