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How is lunate dislocation diagnosed?

How is lunate dislocation diagnosed?

Diagnosis. Acute volar lunate dislocations are usually diagnosed by a lateral view radiographs of the affected wrist, which demonstrates a “spilled teacup” sign where the lunate is displaced volarly and rotated while the metacarpals, carpus and distal radius remain in anatomic alignment.

Which test is used to determine if the lunate bone is dislocated?

Scaphoid Shift Test (Watson Test) Examiner passively moves patient’s wrist into ulnar deviation and slight extension.

What test should be done if you suspect a dislocated lunate in the wrist?

Your doctor will assess any damage done to the nerves, blood vessels, and tendons that supply the hand and wrist. Next, they’ll likely take an X-ray of your hand and forearm to confirm a diagnosis. If your doctor suspects that you have an injured ligament, they may also use an MRI to help them make a diagnosis.

How do you assess a lunate dislocation in the hand?

Suspect lunate dislocations in any patient with an appropriate mechanism of injury (FOOSH) and tenderness of the wrist. On PA X-ray of the wrist, evaluate Gilula’s arcs; look for “piece of pie” sign. On lateral X-ray of the wrist, evaluate the 4 C’s; look for “spilled teacup” sign.

What ligaments are involved in a lunate dislocation?

The lunate lies between the scaphoid and triquetrum and is intimately attached to both through the scapholunate (SL) and lunotriquetral (LT) intercarpal ligaments. These 2 major intercarpal attachments maintain the lunate in a state of balance between the opposing forces.

What is a Kirk Watson Test?

Watson’s test is used by physicians to diagnose scapholunate instability. This test has a low specificity and sometimes is positive for capito-lunate instability. As many as 20% of normal wrists will also have a ‘clunk’.

How do you tell if a wrist is dislocated?

Symptoms of dislocation or fracture include:

  1. Bruising.
  2. Deformity.
  3. Extreme and immediate pain.
  4. Inability to use joint or limb normally.
  5. Numbness.
  6. Redness.
  7. Swelling.
  8. Weakness.

Is lunate dislocation painful?

In most cases, patients that have a volar lunate dislocation will present with wrist pain, usually following an accelerated fall or other accident. This is a painful condition that is more likely to occur in younger individuals or individuals, who experience accidents that exert a lot of force on their wrist.

Is lunate palpable?

This covers all the bones in the proximal row except for the lunate which is difficult to palpate due to the overhang of the radial rim and the overlying extensor tendons, even when the wrist is flexed.

What is a lunate dislocation?

Lunate dislocation. Dr Craig Hacking ◉ ◈ and Dr Andrew Dixon ◉ et al. Lunate dislocations are an uncommon traumatic wrist injury that require prompt management and surgical repair. The lunate is displaced and rotated volarly. The rest of the carpal bones are in a normal anatomic position in relation to the radius.

What does lateral radiograph lunate dislocation look like?

lunate overlaps the capitate and has a ‘triangular’ or ‘piece of pie’ appearance. lateral radiograph lunate seen displaced and angulated volarly. ‘spilled teacup’ appearance. lunate does not articulate with capitate or radius (as opposed to perilunate dislocation where the lunate remains aligned with the radius)

What is the role of CT in the diagnosis of dislocation?

Plain film is normally sufficient to diagnose the dislocation (assuming there is no interpretation error), however, CT plays an important role in assessing for associated occult fractures; the most common and important being scaphoid fracture.

Can a radiologist miss a dislocation on a carpal tunnel scan?

Unfortunately, dislocations can often be missed by radiologists. Carpal alignment needs to be carefully assessed on all radiographs. The majority of cases involve dorsal dislocation of the capitate and carpus relative to the lunate which remains in near-normal alignment with the radius.

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