Why is lunate most commonly dislocated?

Mechanism. Lunate dislocations typically occur due to a fall on an outstretched hand (or during a motor vehicle injury) where there is forceful dorsiflexion of the wrist 3. There is injury of all of the perilunate ligaments, most significantly the dorsal radiolunate ligament.

What is scaphoid tubercle?

The scaphoid tubercle is a blunt, nonarticular projection adjacent to the hollowed capitate facet on the lateral edge of the bone. The tubercle is one of four attachment points for the flexor retinaculum, a fibrous band across the wrist.

What is a capitate fracture?

What is a Capitate Fracture? A broken wrist commonly occurs following a fall on an outstretched hand. A capitate fracture accounts for around 2% of all wrist fractures. The capitate is one of the eight small carpal bones that make up the wrist complex.

What is a Perilunate injury?

Perilunate dislocation and perilunate fracture dislocation are injuries that involve traumatic rupture of the radioscaphocapitate (RSC) ligament, the scapholunate interosseous (SLI) ligament, and the lunotriquetral interosseous (LTI) ligament.

How is lunate dislocation treated?

The treatment choices for perilunate and lunate dislocations are closed reduction and casting, open reduction-internal fixation-ligament repair, trapeziolunate external fixation, limited wrist arthrodesis and proximal row carpectomy.

Why is the scaphoid bone important?

The scaphoid bone is one of the carpal bones on the thumb side of the wrist, just above the radius. The bone is important for both motion and stability in the wrist joint. The word “scaphoid” comes from the Greek term for “boat.” The scaphoid bone resembles a boat with its relatively long, curved shape.

What is the clinical significance of scaphoid?

The scaphoid serves as a link between the two rows of carpal bones. With wrist movement, the scaphoid may flex from its position in the same plane as the forearm to perpendicular.

What is the function of the capitate?

Function. The carpal bones function as a unit to provide a bony superstructure for the hand. They allow movements of the wrist from side to side (medial to lateral) as well as up and down (anterior to posterior).

Can you break the capitate bone?

FRACTURES OF THE CAPITATE. Fractures of the capitate are rare and account for only 1.3% of all carpal fractures. Most of these fractures occur in association with additional carpal pathology, particularly scaphoid fractures; isolated fractures of the capitate make up only 0.3% of carpal injuries.

What is midcarpal (Central) dislocation?

Midcarpal (central carpal) dislocation describes an injury where there is dislocation of the capitate from the lunate, and subluxation of the lunate from the radius.

What is the difference between perilunate dislocation and midcarpal dislocation?

Perilunate dislocations maintain colinearity of radius and lunate while capitate and middle finger metacarpal are dorsally dislocated. Midcarpal dislocations disrupt colinearity of radius and lunate with volar tilt and volar subluxation of lunate and dorsal subluxation of capitate and middle finger metacarpal.

What are the different types of carpal dislocations?

Carpal dislocations can involve one or more carpal bones and are often combined with fractures. They are classified as (1) perilunate and lunate dislocations, in which a stage IV of lunate dislocation corresponds with perilunate dislocation; (2) perilunate fracture-dislocation; (3) scaphoid-capitate fracture syndrome; and (4) axial dislocations.

What are the symptoms of a dislocated carpal tunnel?

A carpal dislocation injury usually leads to a visible deformation of the wrist with restricted and painful active movement. Neurological deficits within the innervation zone of the median nerve can occur as a result of displacement of the lunate into the carpal tunnel.