It’s about the carpal rows!

Answer: SLAC wrist (scapholunate advanced collapse)

In short it’s the end stage of a scapholunate ligament disruption. Scaphoid and lunate separate more and more and the capitate migrates proximally into the gap

reference: https://radiopaedia.org/articles/scapholunate-advanced-collapse

more detail on the carpal rows: http://www.radiologyassistant.nl/en/p42a29ec06b9e8/wrist-carpal-instability.html#i43082731f0fe8