Abstract
Background Scapholunate instability (SLI) has a wide range of clinical and radiological presentations.
The management depends on the stage of the disorder. Subluxation of scaphoid is pathognomonic
feature of the SLI. We describe a patient with SLI with a dislocated proximal pole
of scaphoid, out of the distal radius scaphoid fossa. The 4D (three-dimensions + time)
computed tomography (CT) scan demonstrated that the scaphoid did not reduce throughout
wrist motion.
Case Description A 20-year-old male presented with SLI following a fall skateboarding. The 4D CT scan
revealed the dislocated scaphoid that did not reduce with wrist motion. He underwent
open reduction of the proximal pole of scaphoid and SL reconstruction using flexor
carpi radialis (FCR) tendon graft with the Quad tenodesis technique. At 1 year, he
had improved pain, wrist functions, and maintained satisfactory radiological alignment.
Literature Review We are not aware of any previous description of the dorsal scaphoid dislocation in
association with scapolunate instability.
Clinical Relevance We recommend that the SLI staging classification needs to be expanded to include
dislocation (locked) stage. The 4D CT has a significant role in identifying the instability
and its reducibility.
Level of Evidence This is a level V study.
Keywords
scapholunate instability - locked scapholunate instability - scaphoid dislocation
- carpal - instability - 4D CT scan
