Merck Manual

Please confirm that you are a health care professional

honeypot link

Perilunate and Lunate Dislocations

By

Danielle Campagne

, MD, University of California, San Francisco

Last full review/revision Jan 2021| Content last modified Jan 2021
Click here for Patient Education
Topic Resources

A perilunate dislocation is disruption of the normal relationship between the lunate and capitate. A lunate dislocation is separation of the lunate from both the capitate and the radius.

Perilunate and lunate dislocations result when great force is applied to a hyperextended wrist. They usually result from a fall on an outstretched hand or occur in a motor vehicle crash. Perilunate dislocations are more common than lunate dislocations.

These dislocations cause pain, swelling, and deformity in the wrist and proximal hand.

If a perilunate or lunate dislocation is not diagnosed and treated promptly, complications can develop. They include

  • Median nerve injury

  • Avascular necrosis of the scaphoid or lunate and deterioration of the joint (scapholunate advanced collapse).

Diagnosis of Perilunate and Lunate Dislocations

  • X-rays

Plain x-rays (anteroposterior, lateral, and oblique views) are taken. To avoid missing the diagnosis, clinicians should assess the relationship between the radius, lunate, and capitate bones on a true lateral view.

In a perilunate dislocation, the capitate is not vertically aligned with the lunate and radius on a lateral view of the wrist. The lunate and radius remain correctly aligned.

In a lunate dislocation, the lunate is rotated out of alignment into a spilled teacup configuration.

Treatment of Perilunate and Lunate Dislocations

  • Closed reduction and splinting

  • Usually surgical repair

Treatment of both perilunate and lunate dislocations is closed reduction and splinting in the emergency department. Both the wrist and elbow should be immobilized in the neutral position (eg, with a sugar tong splint).

Patients should be immediately referred to an orthopedic surgeon; most dislocations must be surgically repaired because function is better after surgical repair.

Key Points

  • Perilunate and lunate dislocations usually result from a fall on an outstretched hand or occur in a motor vehicle crash.

  • Treat these dislocations promptly to prevent complications (eg, nerve damage, deterioration of the joint).

  • Diagnose by plain x-rays (anteroposterior, lateral, and oblique views), with particular attention to the relationship between the radius, lunate, and capitate bones on a true lateral view.

  • Reduce manually and splint the wrist and elbow in the neutral position.

  • Refer patients immediately to an orthopedic surgeon because most of these dislocations must be surgically repaired to optimize function.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Test your knowledge

Hypothermia
A male patient who is homeless is brought to the emergency department (ED) after he was found disoriented and confused on the street during winter. Physical examination on route to the ED showed unreactive pupils and bradycardia. Currently, the patient is irritable and his speech is slurred. Which of the following is the most appropriate initial step in diagnosis? 
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP