📌 Scapholunate Ligament Tear in Distal Radius Fractures

https://youtube.com/shorts/XWBREO-XWTo

 

Why this matters

Scapholunate ligament (SLL) tears are common in distal radius fractures, especially intra-articular and complex patterns.
Many are clinically silent at initial reduction, but untreated instability can progress to SLAC wrist.
These injuries are often not isolated, frequently associated with lunotriquetral ligament, dorsal intercarpal ligament, or TFCC injury.

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Key anatomy

The SLL is the only primary stabilizer of the scapholunate joint.
It is a true intra-articular, intrinsic wrist ligament composed of three components:
• Dorsal band – thickest, strongest, and most critical for stability
• Volar band – obliquely oriented, allowing physiologic motion
• Proximal (membranous) band – weakest, fibrocartilaginous
Among these, the dorsal component is the key biomechanical restraint and the most important target for imaging and repair.

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Pathomechanics

Disruption of the SLL breaks the intercalated connection between the scaphoid and lunate.
The scaphoid rotates into volar flexion, driven by its articulation with the trapeziotrapezoidal complex,
while the lunate follows the triquetrum into dorsal extension.
This results in D-S-I wrist alignment, abnormal carpal kinematics, and progressive degeneration.

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Imaging pearls

Radiographs provide indirect assessment only—evaluate the scapholunate interval, scapholunate angle, cortical ring sign, and carpal arcs, always comparing with the contralateral wrist.
MRI is best for assessing ligament integrity and associated soft-tissue injuries, with particular attention to the dorsal band.
MR or CT arthrography improves detection of partial and complete tears; contrast communication between compartments strongly suggests SLL disruption.
Dynamic imaging (clenched-fist views or cine techniques) helps identify dynamic scapholunate instability.

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Take-home message

In distal radius fractures, do not stop at the fracture.
Always assess carpal alignment and scapholunate stability—
because missing an SLL tear today may mean diagnosing SLAC wrist tomorrow.

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#ScapholunateLigament, #DistalRadiusFracture, #WristMRI, #HandRadiology, #CarpalInstability, #DISI, #SLACWrist, #MSKRadiology, #WristInjury, #OrthopedicImaging, #VibeCase

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https://youtu.be/oOljlLbNxzs

https://open.spotify.com/episode/3GhECCfresEJAaYeWIf8CX?si=DN4dlImvTdictecqiVSxVA

📌 Scapholunate Ligament Tear in Distal Radius Fractures