Read that 2-3% of adults can grow 2 inches or more 10-20 yrs after puberty end. any truth to that? do their bones never fuse & if so what causes that?

Myth: Adults begin to shrink later in life rather than grow taller. There are rare individuals with constitutional delay of growth that continue into their early 20's.These have a delay in the onset of puberty and slow progression through its stages. Most adults see fusion of growth centers by 17, and this can easily be determined by an x-ray of the wrist/hand.The 2% cited is a myth.