eMedicine Specialties > Sports Medicine > Wrist and Hand

Wrist Dislocation: Differential Diagnoses & Workup

Author: Kadeer M Halimi, DO, Department of Emergency Medicine, Texas A&M University Health Sciences Center
Coauthor(s): Derek K Lichota, MD, Assistant Professor, Department of Surgery, Texas A&M University College of Medicine; Senior Staff, Department of Orthopedics, Division of Sports Medicine, Scott and White Memorial Hospital
Contributor Information and Disclosures

Updated: Aug 21, 2008

Differential Diagnoses

Carpal Bone Injuries
Hamate Fracture
Hand Dislocation

Other Problems to Be Considered

Workup

Laboratory Studies

  • Laboratory studies typically are not necessary in the evaluation of wrist dislocations if the history includes acute injury.

Related Medscape topic:
Specialty Site Pathology & Lab Medicine

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 than 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 C s should be easily visualized. The 4 C s are the convexity of the distal radius, the convexity and the concavity of the lunate, and the convexity of the capitate (see Image 6).
    • 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).4
    • 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 C s. 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.12 On the clenched-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°.2  This rotation causes the scaphoid to be viewed end-on, producing the classic signet-ring sign (see Image 4).  
  • Magnetic resonance imaging (MRI) can be considered for patients with wrist pain or instability but who have normal radiographic findings. MRI may be less important in patients with a ligament injury; in these patients, arthrography may be considered.

Related Medscape topics:
Specialty Site Orthopaedics
Specialty Site Radiology

More on Wrist Dislocation

Overview: Wrist Dislocation
Differential Diagnoses & Workup: Wrist Dislocation
Treatment & Medication: Wrist Dislocation
Follow-up: Wrist Dislocation
Multimedia: Wrist Dislocation
References
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References

  1. Larsen CF, Lauritsen J. Epidemiology of acute wrist trauma. Int J Epidemiol. Oct 1993;22(5):911-6. [Medline].

  2. Schwartz DT, Reisdorff EJ. Emergency Radiology. New York, NY: McGraw-Hill Book Co; 2000:47-75.

  3. 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].

  4. Browner BD, Jupiter JB, Levine AM, Trafton PG, eds. Skeletal Trauma. Philadelphia, Pa: WB Saunders Co; 1998:1359-81.

  5. Lichtman DM, Alexander AH, eds. The Wrist and Its Disorders. 2nd ed. Philadelphia, Pa: WB Saunders Co; 1997.

  6. 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].

  7. Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg [Am]. May 1980;5(3):226-41. [Medline].

  8. Reid DC. Sports Injury Assessment and Rehabilitation. New York, NY: Churchill Livingstone; 1992.

  9. Meldon SW, Hargarten SW. Ligamentous injuries of the wrist. J Emerg Med. Mar-Apr 1995;13(2):217-25. [Medline].

  10. 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].

  11. Alt V, Sicre G. Dorsal transscaphoid-transtriquetral perilunate dislocation in pseudarthrosis of the scaphoid. Clin Orthop Relat Res. Sep 2004;426:135-7. [Medline].

  12. Frankel VH. The Terry-Thomas sign. Clin Orthop Relat Res. Nov-Dec 1977;129:321-2. [Medline].

  13. 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].

  14. 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].

  15. 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].

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Further Reading

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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

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Contributor Information and Disclosures

Author

Kadeer M Halimi, DO, Department of Emergency Medicine, Texas A&M University Health Sciences Center
Kadeer M Halimi, DO is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.

Coauthor(s)

Derek K Lichota, MD, Assistant Professor, Department of Surgery, Texas A&M University College of Medicine; Senior Staff, Department of Orthopedics, Division of Sports Medicine, Scott and White Memorial Hospital
Disclosure: Nothing to disclose.

Medical Editor

Craig C Young, MD, Professor, Departments of Orthopedic Surgery and Community and Family Medicine, Medical Director of Sports Medicine, Sports Medicine Fellowship Director, Medical College of Wisconsin
Craig C Young, MD is a member of the following medical societies: American Academy of Family Physicians, American College of Sports Medicine, American Medical Society for Sports Medicine, Phi Beta Kappa, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Russell D White, MD, Professor of Medicine, Department of Community and Family Medicine, University of Missouri-Kansas City School of Medicine, Truman Medical Center Lakewood
Disclosure: Nothing to disclose.

CME Editor

Jon B Whitehurst, MD, Clinical Instructor of Surgery, University of Illinois College of Medicine; Partner and Executive Board Member, Rockford Orthopedic Associates; Orthopedic Chairman, Rockford Memorial Hospital
Jon B Whitehurst, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America
Disclosure: Nothing to disclose.

Chief Editor

Sherwin SW Ho, MD, Associate Professor, Department of Surgery, Section of Orthopedic Surgery and Rehabilitation Medicine, University of Chicago
Sherwin SW Ho, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America
Disclosure: Nothing to disclose.

 
 
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