Introduction
Background
Wrist injuries are common among athletes. Emergency physicians and/or family practitioners frequently perform the initial evaluation of wrist injuries and determine the initial treatment. Recognizing wrist dislocations early and properly referring patients with wrist dislocations can prevent complications, including prolonged pain and discomfort, surgery, and lost time from sports participation.
For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education article, Wrist Injury.
Related eMedicine topics:
Dislocation, Hand
Fracture, Wrist
Hand, Fracture and Dislocations: Metacarpal
Related Medscape topics:
Resource Center Exercise and Sports Medicine
Resource Center Joint Disorders
Specialty Site Orthopaedics
Frequency
United States
In a study by Larsen and Lauritsen, as many as 2.5% of all emergency department visits were made by patients with wrist injuries.1 A small number of those patients present with wrist dislocations. Subluxations and dislocations account for 10% of carpal injuries, with perilunate dislocation being the most common type of dislocation.2
Functional Anatomy
The wrist joint is composed of distal radial and ulnar surfaces, 8 carpal bones, and the proximal metacarpal bones. The distal carpal row consists of the following bones: hamate, capitate, trapezoid, and trapezium. The proximal row consists of the following bones: scaphoid, lunate, triquetrum, and pisiform.
The carpal bones are held together by a complex set of ligaments, including the interosseous, volar, and dorsal ligaments and a triangular fibrocartilage complex (TFC). The dorsal ligaments are weaker than the volar ligaments, making dorsal dislocation more common.2
Related eMedicine topic:
Hand, Anatomy
Sport-Specific Biomechanics
The mechanism of injury for a wrist dislocation is usually a fall on an outstretched hand (ie, FOOSH injury) that results in a hyperextension type of injury to the wrist. High energy is a common characteristic feature in these injuries.3 The distal row of carpal bones is commonly displaced dorsal to the proximal row. This displacement occurs as a result of a scaphoid fracture or a scapholunate dislocation, and if the force is severe, a perilunate dislocation occurs.4 Trans-scaphoid perilunate fracture-dislocation is slightly more common than perilunate dislocation.
Different posttraumatic deformity patterns can cause the lunate to lose its linear relationship with the capitate and to tilt dorsally or volarly, resulting in a collapse deformity. The most common collapse deformity is caused by the lunate dorsiflexing on the radius. This is compensated by the capitate flexing volarly. This deformity is also known as the dorsiflexed intercalated segment instability (DISI) pattern. DISI normally occurs in unrecognized scaphoid subluxations or scaphoid fractures. The opposite type of deformity is known as the volar intercalated segment instability (VISI) pattern. Although VISI can be seen in healthy patients with lax ligaments, posttraumatically, it is a result of the lunate flexing volarly on the radius as the capitate tilts dorsally.5,6 VISI also is a sign of midcarpal instability or lunotriquetral injury.
Mayfield and coworkers have classified wrist dislocation as follows (see Image 5)7 :
- Stage I – Scapholunate dislocation resulting from a tear in the scapholunate interosseous ligament and radiolunate ligament
- Stage II – Lunate-capitate subluxation resulting from injury to the capitolunate joint
- Stage III – Lunate-triquetral dislocation resulting from injury to the triquetrolunate interosseous ligament
- Stage IV – Lunate dislocation resulting from dorsal radiolunate ligament injury
Related eMedicine topics:
Distal-Third Forearm Fractures
Perilunate Fracture Dislocations
Related Medscape topics:
Resource Center Fracture
Resource Center Trauma
Specialty Site Orthopaedics
Clinical
History
The typical history for a wrist dislocation is one of an athlete who has fallen on an outstretched hand to break a fall or who has mistimed a landing, as in gymnastics.8 The patient usually presents with vague wrist pain and the sensation of clicks or clunks. Patients may also complain of decreased grip strength with minimal pain. Localized pain is sometimes reported.
Related Medscape topic:
Resource Center Exercise and Sports Medicine
Physical
- Localized tenderness, especially over the dorsoradial aspect of the wrist, may be revealed. The tenderness is worse with dorsiflexion.
- Crepitus or a click with movement and apprehension with radial or ulnar deviation are signals of instability.
- A positive ballottement test result is suggestive of wrist dislocation. To perform the ballottement test, the physician grasps the lunate between the index finger and the thumb of one hand and the triquetrum with the other hand. Volar and dorsal (forward and backward) laxity, crepitus, and pain yield a positive test finding.8
- To perform a volar and dorsal shift test, the physician stabilizes the patient's forearm with one hand and volarly and dorsally translates the patient's wrist with the other. Volar subluxation at the midcarpal joint is normal, whereas dorsal subluxation indicates scapholunate instability.4
- Tenderness in the anatomic snuffbox can indicate a carpal etiology of pain, although it more reliably suggests a scaphoid fracture.
- A decrease in grip strength may also be seen in patients with wrist injury.
- Median nerve symptoms may be present as a result of volar displacement of carpal bones into the carpal tunnel.9
- Lunate dislocation can cause volar swelling on the median nerve. This swelling causes a decrease in 2-point discrimination in the median nerve distribution due to acute carpal tunnel syndrome. Patients with lunate dislocations often prefer to hold their fingers in partial flexion because they have pain on active and passive extension.5
- Perilunate dislocation can appear with considerable swelling. A miniature "dinner-fork" deformity is often present, which is produced by dorsal displacement of the distal fracture fragments. The edge of the capitate may be palpable if the swelling is not profound.
- Scapholunate dislocation usually presents with a minimal amount of swelling, and pain is localized over the dorsal scapholunate region. Pain is increased by dorsiflexion. Tenderness over the scaphoid tuberosity may also be present.5
Related eMedicine topics:
Carpal Bone Injuries
Fracture, Wrist
Radius, Distal Fractures
Related Medscape topics:
Resource Center Fracture
Resource Center Trauma
Specialty Site Orthopaedics
Causes
- Repeated stress on carpal ligaments renders them more prone to injury, especially in athletes.
- The carpal bones serve as a link between the hands and the upper body; a great deal of force is transmitted through them.
- Sports with increased force vectors (height and speed), such as adult in-line skaters and football players,10 commonly experience such injuries. Other examples of risks are falls from a height; these occur in athletes such as gymnasts, among others.
- Although high energy is the most common cause of injury, some reports describe low-energy trauma as the cause of carpal dislocation.11
More on Wrist Dislocation |
 Overview: Wrist Dislocation |
| Differential Diagnoses & Workup: Wrist Dislocation |
| Treatment & Medication: Wrist Dislocation |
| Follow-up: Wrist Dislocation |
| Multimedia: Wrist Dislocation |
| References |
| Next Page » |
References
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Schwartz DT, Reisdorff EJ. Emergency Radiology. New York, NY: McGraw-Hill Book Co; 2000:47-75.
Cheng CY, Hsu KY, Tseng IC, Shih HN. Concurrent scaphoid fracture with scapholunate ligament rupture. Acta Orthop Belg. Oct 2004;70(5):485-91. [Medline].
Browner BD, Jupiter JB, Levine AM, Trafton PG, eds. Skeletal Trauma. Philadelphia, Pa: WB Saunders Co; 1998:1359-81.
Lichtman DM, Alexander AH, eds. The Wrist and Its Disorders. 2nd ed. Philadelphia, Pa: WB Saunders Co; 1997.
Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the wrist. Diagnosis, classification, and pathomechanics. J Bone Joint Surg Am. Dec 1972;54(8):1612-32. [Medline]. [Full Text].
Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg [Am]. May 1980;5(3):226-41. [Medline].
Reid DC. Sports Injury Assessment and Rehabilitation. New York, NY: Churchill Livingstone; 1992.
Meldon SW, Hargarten SW. Ligamentous injuries of the wrist. J Emerg Med. Mar-Apr 1995;13(2):217-25. [Medline].
Carlisle JC, Goldfarb CA, Mall N, Matava MJ. Upper extremity injuries in the National Football League. Part II: elbow, forearm, and wrist Injuries. Am J Sports Med. Jun 30 2008;epub ahead of print. [Medline].
Alt V, Sicre G. Dorsal transscaphoid-transtriquetral perilunate dislocation in pseudarthrosis of the scaphoid. Clin Orthop Relat Res. Sep 2004;426:135-7. [Medline].
Frankel VH. The Terry-Thomas sign. Clin Orthop Relat Res. Nov-Dec 1977;129:321-2. [Medline].
Martinage A, Balaguer T, Chignon-Sicard B, et al. [Perilunate dislocations and fracture-dislocations of the wrist, a review of 14 cases] [French]. Chir Main. Feb 2008;27(1):31-9. [Medline].
Infanger M, Grimm D. Meniscus and discus lesions of triangular fibrocartilage complex (TFCC): treatment by laser-assisted wrist arthroscopy. J Plast Reconstr Aesthet Surg. May 9 2008;epub ahead of print. [Medline].
Park MJ, Kim JP. Reliability and normal values of various computed tomography methods for quantifying distal radioulnar joint translation. J Bone Joint Surg Am. Jan 2008;90(1):145-53. [Medline].
Further Reading
Keywords
wrist dislocation, wrist pain, dislocated wrist, dislocation of wrist, lunate dislocation, perilunate dislocation, scapholunate dislocation, hyperextension injury of the wrist, carpal bone injuries, carpal injury, ballottement test, volar tilt test, dorsal tilt test
