Case Report : 23 yr old lady with clinical scapholunate dissociation on MRI shows ill definition of scapholunate ligament (volar component more than others) with oedema/ ill definition of radio lunate ligament substantiating the clinical diagnosis.
Teaching points by Dr MGK Murthy, MRI technician:Mr Rammurti
1.Scapholunate dissociation results from the scapholunate ligament disruption/ injury with more important dorsal component , 3 mm thick(short, transversely oriented collagen fibers)/
volar component ( 1mm thick) ,intermediate component (fibrocartilage) meniscus shape
2. Injury to scapholunate ligament (complete tear of the dorsal component) and radiolunate ligament will result in scapholunate dissociation. Mayfield et al. have proposed a 4 stage process to describe perilunar wrist instability where scapholunate dissociation represents stage 1 .
3 Most responsible for SLAC (Scapho Lunate Advanced Collapse) (capitate stationed between scaphoid and lunate ). Present late and Xray may show Terry Thomas sign on AP with widened Scapho lunate distance ( more than 4mm) / Rotation of scaphoid to make it look end on = signet ring. Surgery is effective to prevent SLAC
Scapholunate dissociation: MRI
4/ 5Oleh Habifa