History: Wrist Pain
Answer: Trans-scaphoid Perilunate dislocation
-lunate still "normal" position while other carpal bones dislocate dorsally ++ assoc scaphoid fx! (count the proximal row!)
Mechanism: high-energy trauma (MVA) or FOOSH (fall on outstretched hand)
Injury: torn radioscaphoid, scapholunate & lunotriquetral ligaments.
Look for the scaphoid fx!
-Frontal: lunate appears triangular ("pie sign") & overlaps capitate
-Lateral: lunate "normal"w other carpal bones dislocated (typically dorsal). Somtimes slight palmar tilt from the capitate trying to get back to normal -capitate not sitting in "cup" of lunate
Perilunate Dislocation is often confused with LUNATE dislocation.
Although there are similarities, just remember what is actually dislocating.
Is the lunate dislocated?
NO,but other bones dislocated? = PERI-lunate dislocation