Scapholunate dissociation
What is it
An injury involving a stretch or tear of the scapholunate ligament which can affect the way the
scaphoid and lunate bones interact.
Mechanism
Often occurs when a person experiences a fall onto an outstretched hand where the wrist is
forced into a position of hyperextension and ulnar deviation which causes a stretching or tearing
of the ligaments between the scaphoid and lunate. Distal radius fractures are often associated
with scapholunate dissociation.
Clinical presentation
● History of a fall onto an outstretched hand
● Pain/clicking on the dorso-radial aspect of the wrist
● Reduced grip strength
● Tenderness 2cm distal to Lister’s tubercle on the radial side of the lunate
● Tenderness in the proximal end of the anatomical snuffbox
● Watson test: either painful or reveals dorsal movement of the scaphoid
● X-ray while gripping an object is useful for diagnosis
Management
● For incomplete tears where there is no instability of the scapholunate joint,
splinting/casting to immobilise the joint may be required
● Taping to improve stability
● Avoiding aggravating activities
● Regaining pain-free movement and strength through joint mobilisation and strengthening
exercises
● For complete tears specialist opinion is recommended as surgical intervention may be
required
