AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Wrist injuries are common among athletes. Emergency physicians 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.

Frequency

United States

In a study by Larsen, as many as 2.5% of all ED visits were made by patients with wrist injuries. 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 (Schwartz, 2000).

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 (Schwartz, 2000).

Sport Specific Biomechanics

The mechanism of injury usually is a fall on an outstretched hand resulting in a hyperextension type of injury to the wrist. High energy is a common characteristic feature in all these injuries (Chun-Ying, 2004). The distal row of carpal bones commonly is 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 (Browner, 1998). 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 pattern (DISI). DISI normally occurs in unrecognized scaphoid subluxations or scaphoid fractures. The opposite type of deformity is known as volar intercalated segment instability pattern (VISI). 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 (Lichtman, 1997; Linscheid, 1972). VISI also is a sign of midcarpal instability or lunotriquetral injury.

Mayfield and coworkers have classified wrist dislocation as follows (see Image 5):

• 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

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

The typical history 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 (Ried, 1992). 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.

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 (Ried, 1992).
• 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 (Browner, 1998).
• Tenderness in the anatomic snuffbox can indicate a carpal etiology of pain, though 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 (Meldon, 1995).
• 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 (Lichtman, 1997).
• Perilunate dislocation can appear with considerable swelling. A miniature dinner-fork deformity often is present. 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 (Lichtman, 1997).

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, commonly experience such injuries. Other examples of risks are falls from 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 (Alt, 2004).

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to be Considered

Distal radius fracture
Distal radial-ulnar joint injury or subluxation
TFC tear
Scaphoid fracture
Scaphoid nonunion
DISI/VISI
de Quervain tenosynovitis
Septic wrist
Gout

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• Laboratory studies typically are not necessary if the history includes acute injury.

Imaging Studies

• Plain radiographs are helpful.
  
  
  • Obtain posteroanterior (PA) and lateral radiographs in all patients who present with a history of acute wrist trauma.
  
  
  
  • PA and lateral radiographs should also be obtained with 10- to 15-lb traction on the upper arm.
  
  
  
  • The normal PA view should show 2 rows of carpal bones in a normal anatomic position with uniform joint spaces of no more that 1-2 mm. No overlap should be seen between the carpal bones or between the distal ulna and the radius.
  
  
  
  • On a normal lateral radiograph, the 4 Cs should be easily visualized. The 4 Cs are convexity of the distal radius, the convexity and the concavity of the lunate, and the convexity of the capitate.
  
  
  
  • A longitudinal axis aligns the radius, the lunate, the capitate, and the third metacarpal bone. The scapholunate angle is normally 30-60° (see Image 6) (Browner, 1998).
  
  
  
  • One order of obtaining radiographs is as follows:
    
    
    1. Anteroposterior (AP) and/or PA views, with the lateral view as a screening test
    
    
    
    2. Navicular series
    
    
    
    3. Possibly, a clenched-fist view with radial and ulnar deviation. (This forces the capitate head into the scapholunate joint and widens it if laxity is present.)
    
    
    
    4. Possibly, traction views
    
    
    
    5. Possibly, comparison views, especially in patients with nonfused growth plates
        
  • Radiographic findings for the various types of dislocation are as follows:
    
    
    • Lunate dislocation: On the usual PA image, the lunate has a trapezoidal shape that changes with flexion and extension. In this type of dislocation, the lunate is displaced volarly and rotated with the capitate. The rest of the carpal bones are in a normal anatomic position in relation to the radius. On the lateral radiograph, the lunate has the classic spilled-teacup sign from the disruption of the 4 Cs. On the PA image, the lunate has a triangular or pie shape (see Image 1).
    
    
    
    • Perilunate dislocation: The lunate is in a normal anatomic position with respect to the radius, and the rest of the carpal bones are displaced dorsally. On the PA radiograph, crowding is evident between the proximal and distal carpal bones (see Images 2-3).
    
    
    
    • Scapholunate dislocation (rotary subluxation of the scaphoid): On a PA radiograph, the scapholunate space is usually greater than 4 mm, a scenario also known as the Terry-Thomas sign, named after the British comic with frontal dental diastema (Frankel, 1977). On the clinched-fist and PA views with the wrist in ulnar deviation, the scapholunate gap is increased. The scaphoid rotates to a more transverse position when the ligaments between the lunate and scaphoid are interrupted, increasing the scapholunate angle to greater than 60° (Schwartz, 2000). This rotation causes the scaphoid to be viewed end-on, producing the classic signet-ring sign (see Image 4).  
       
• MRI can be considered for patients with wrist pain or instability but normal radiographic findings. MRI may be less important in patients with a ligament injury; in these patients, arthrography may be considered.

TREATMENT

Section 6 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Acute Phase

Rehabilitation Program

Physical Therapy

The rehabilitation of wrist injuries can be divided into 5 phases, as follows (Lichtman, 1997):

• Phase I: Control inflammation and edema by using rest, ice, compression, and elevation (RICE).



• Phase II: Restore the normal soft-tissue environment by using modalities such as scar massage, whirlpool therapy, and elastomer application.



• Phase III: Increase the range of motion (ROM).



• Phase IV: Increase strength.



• Phase V: Work on hardening and/or conditioning.

Proper pain control and anti-inflammatory medication are the cornerstone of all phases of rehabilitation.

Occupational Therapy

Occupational therapy can be an essential part of rehabilitation, depending on the expertise of the therapist and the motivation of the patient.

Medical Issues/Complications

An expected outcome of the surgery is some loss of motion. The goal of surgery and rehabilitation is to minimize the loss of motion in the athlete.

Surgical Intervention

Closed reduction of the dislocation can be attempted after a complete neurovascular examination is performed and proper radiographs are obtained. The patient should be adequately anesthetized by means of an axillary block or general anesthesia. Closed reduction may be difficult if not impossible; the patient should be advised that open reduction may be needed.

For a perilunate dislocation, initial dorsiflexion is followed by gradual volar flexion. Pronation is then used to reduce the capitate back into the lunate (Lichtman, 1997).

For a lunate dislocation, the steps of perilunate reduction are followed by the operators stabilizing the lunate with their thumb as the capitate is brought into palmar flexion. The initial stages of reduction reproduce perilunate dislocation before final reduction.

With a scapholunate dislocation, the wrist is dorsiflexed and radially deviated.

Once closed reduction is attempted, PA and lateral images are obtained to confirm adequate reduction. The carpal bones are then pinned by using Kirschner wire because closed reduction is rarely effective by itself. If closed reduction is not successful, the surgeon must attempt open reduction. The wrist is then placed in a cast for 4-6 weeks.

Consultations

Promptly consult an orthopedic specialist.

Other Treatment

Most complications can be avoided with prompt diagnosis and treatment.

Recovery Phase

Rehabilitation Program

Physical Therapy

The type of physical therapy depends on the needs of the individual patient. Therapeutic modalities may be continued throughout the recovery phase, in addition to ROM and strengthening activities as needed.

Maintenance Phase

Rehabilitation Program

Physical Therapy

The goal of the maintenance phase is to regain full strength and ROM of the wrist to enable the patient to complete his or her functional daily activities and to gradually return to sports participation or work. The patient independently functions in a work hardening or sport-specific training program during this phase to continue strengthening to the affected upper extremity.

MEDICATION

Section 7 of 11  

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• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Pain control is essential in providing quality patient care to those with wrist dislocations. Pain control ensures patient comfort and aids physical therapy regimens.

Drug Category: Nonsteroidal anti-inflammatory drugs (NSAIDs)

These agents are most commonly used for the relief of mild to moderate pain. Effects of NSAIDs in treatment of pain tend to be patient specific, yet ibuprofen is usually the drug of choice (DOC) for initial therapy. Other NSAIDs may also be used.

COX-2 inhibitors may be considered in patients with adverse effects to the NSAIDs discussed here.

Drug Category: Analgesics

Pain control is essential to providing the quality of care for patients with wrist dislocations. Pain control ensures the patient's comfort and aids in physical therapy regimens. Many analgesics have sedating properties that benefit patients with fractures. Hydrocodone and oxycodone preparations are generally more effective and better tolerated than other narcotic-acetaminophen combinations, such as those containing codeine.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Return to Play

Athletes with wrist injuries are advised not to return to play until full recovery has been achieved.

Complications

• A missed or late diagnosis may lead to complications.

• Carpal tunnel syndrome may result.

• Malunion or nonunion may occur. This is a misnomer because no fracture occurs; therefore, malunion or nonunion is not technically possible. Stiffness may be present. On rare occasions, late instability or apposition of the carpal bones may occur.

• Degenerative joint disease is possible.

Prevention

Wrist injuries can be prevented by implementing proper technique; maintaining good strength; maintaining good flexibility; and, if the sport permits, using wrist guards.

Prognosis

If the diagnosis is established early (<3 mo) and if the proper treatment is administered, the prognosis is excellent.

Education

Athletes should be educated about how to recognize wrist injuries. Seeking early medical attention for wrist injuries is important and should be emphasized to athletes. Proper technique, flexibility, and strengthening should also be emphasized.

For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education article, Wrist Injury.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Failure to diagnose wrist dislocations
• Failure to perform a complete neurological examination, with resultant median nerve damage
• Avascular necrosis of the lunate (Kienböck disease)

MULTIMEDIA

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Lunate dislocation. Posteroanterior projection of the wrist showing the pie shape of the lunate.
	View Full Size Image
Media type:  X-RAY

Media file 2:  Perilunate dislocation. On the posteroanterior radiograph, crowding is evident between the proximal and distal carpal bones.
	View Full Size Image
Media type:  X-RAY

Media file 3:  Perilunate dislocation. The lunate is in a normal anatomic position with respect to the radius. The rest of the carpal bones are displaced dorsally.
	View Full Size Image
Media type:  X-RAY

Media file 4:  Scapholunate dislocation. The scapholunate space usually is greater than 4 mm, a scenario also known as the Terry-Thomas sign. Rotation of the scaphoid causes the scaphoid to be viewed end-on, producing the classic signet-ring sign.
	View Full Size Image
Media type:  X-RAY

Media file 5:  Progressive perilunar instability pattern reported by Mayfield et al. Stage I involves scaphoid instability; stage II, scaphoid and capitate instability; stage III, scaphoid, capitate, and triquetrum instability; and stage IV, lunate dislocation.
	View Full Size Image
Media type:  Image

Media file 6:  On a normal lateral radiograph, the 4 Cs should be easily visualized. The 4 Cs are the convexity of the distal radius, the convexity and the concavity of the lunate, and the convexity of the capitate. A longitudinal axis aligns the radius, the lunate, the capitate, and the third metacarpal bone. The scapholunate angle is normally 30-60°.
	View Full Size Image
Media type:  Image

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

• Alt V, Sicre G. Dorsal transscaphoid-transtriquetral perilunate dislocation in pseudarthrosis of the scaphoid. Clinical Orthopaedics Related Research. Sept 2004;426:135-7. [Medline].
• Browner BD. Skeletal Trauma. Philadelphia, Pa: WB Saunders Co; 1998:1359-1381.
• 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].
• Frankel VH. The Terry-Thomas sign. Clin Orthop Relat Res. Nov-Dec 1977;(129):321-2. [Medline].
• Larsen CF, Lauritsen J. Epidemiology of acute wrist trauma. Int J Epidemiol. Oct 1993;22(5):911-6. [Medline].
• Lichtman DM, Alexander AH. The Wrist and Its Disorders. 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].
• Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg [Am]. May 1980;5(3):226-41. [Medline].
• Meldon SW, Hargarten SW. Ligamentous injuries of the wrist. J Emerg Med. Mar-Apr 1995;13(2):217-25. [Medline].
• Ried DC. Sports Injury Assessment and Rehabilitation. New York, NY: Churchill Livingstone; 1992.
• Schwartz DT, Reisdorff EJ. Emergency Radiology. New York, NY: McGraw-Hill Book Co; 2000:47-75.

Article Last Updated: Feb 10, 2006