The technique is antiquated and could use a little something of a shake up thanks to new technology.
Setting castings in plaster is centuries old and has a variety of uncomfortable problems. Scanning and imaging of the body are common place in the medical field in order to diagnose injuries and illnesses, but the ability to create prosthesis and custom fixtures directly from those scans is brand spanking new, from printed bones and teeth implants to entire artificial limbs. The parts either fit to the contours of your body or are exact replicas of the body part which they replace.
This technique now produces a superior cast taken directly from a 3D scan of the broken body part and 3D prints a cast from the digital negative. The cast is designed with snap fits which enclose the arm, keeping it from moving, but making it accessible to air and hands. Much more comfortble.
Just another simple example where the medical field can benefit from applying new technologies (additive manufacturing/3D printing) to ones that are already pervasive in the medical field (3D scanning and imaging.)