IS Case 86: Transscaphoid Perilunate Dislocation
Imaging Sciences URMC 2008
Publication Date: 2009-05-20
Findings
There is a transverse fracture through the scaphoid with radial displacement of the distal fragment. There is ulnar shift and volar tilt of the lunate but radiolunate articulation is maintained. Capitate is migrated proximally and lunocapitate alignment is disrupted.
Diagnosis
Transscaphoid Perilunate Dislocation
Discussion
Transscaphoid perilunate dislocation or de Quervain's fracture-dislocation is a rare injury of the wrist. In the event of the fall on the outstretched hand, fracture of the ulnar styloid is sometimes associated. In this injury, the lunate and and the proximal pole of the scaphoid remain nearly aligned with the distal radius, whereas the rest of the carpal bones and the distal scaphoid fragment displace dorsally. Malrotation of the scaphoid and triquetrum causes lunate tilt and proximal migration of the capitate.
Transscaphoid fractures occur with approximately 60% of perilunate dislocations due to the unique position of the scaphoid that bridges the proximal and distal carpal rows. Because the scaphoid receives its major blood supply to the proximal pole from an artery that enters near the waist, a fracture of the waist or proximal pole may compromise the integrity of vascular supply to the proximal pole and lead to avascular necrosis.
Confirmation of adequate reduction of the scaphoid is critical on post-reduction radiographs because any malalignment will impede fracture healing and may also promote instability.
References
- Halimi KM, Jones TR, Lichota DK. Wrist dislocation. e-medicine. February 10, 2006. http://www.emedicine.com/sports/topic141.htm
- Greenspan A. Orthopedic Imaging. 4th Ed, Lippincott, Williams & Wilkins, 2004: 203.
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