Contents

SynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyReferences
Carpometacarpal joint of thumb dislocation
Other Resources UpToDate PubMed

Carpometacarpal joint of thumb dislocation

Contributors: Aabra Ahmed MD, Danielle Wilbur MD
Other Resources UpToDate PubMed

Synopsis

Causes / typical injury mechanism:
  • First carpometacarpal (CMC) dislocations usually occur due to axial loading while the thumb is in flexion.
  • The overwhelming majority of first CMC dislocations occur dorsally.
  • This is a rare dislocation (less than 1% of hand fractures / dislocations) due to the anatomy of the joint and abundance of ligament stability.
Classic history and presentation:
  • High-speed trauma to the CMC, usually resulting in a dorsal dislocation.
  • Often missed due to distracting associated high-energy injuries.
  • Axial loading of the thumb can also occur after punching injuries or participation in sports.
Prevalence:
  • Age – Usually occurs in second to fifth decade.
  • Sex / gender – More common in male patients.
Risk factors: Trauma and degenerative disease.

Pathophysiology: There are a total of 16 ligaments that stabilize the first CMC joint. Four of these are thought to be the most important in stabilizing the joint: the volar, intermetacarpal, dorsoradial, and dorsal oblique ligaments. The dorsoradial and volar ligaments are most commonly torn / sheared off during dislocations.

Codes

ICD10CM:
S63.006A – Unspecified dislocation of unspecified wrist and hand, initial encounter

SNOMEDCT:
281503004 – Dislocation of carpometacarpal joint

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

To perform a comparison, select diagnoses from the classic differential

Subscription Required

Best Tests

Subscription Required

Management Pearls

Subscription Required

Therapy

Subscription Required

References

Subscription Required

Last Reviewed:11/13/2023
Last Updated:11/27/2023
Copyright © 2024 VisualDx®. All rights reserved.
Carpometacarpal joint of thumb dislocation
Print  
Copyright © 2024 VisualDx®. All rights reserved.