Very interesting.  I went to "health" on Yahoo and typed in "compartment
syndrome.  There were 15  different examples.   Take your pick -- comes
from an injury.  Good luck to the boy for quick recovery.  

fasciotomy.  Fascia are the membranes that enclose muscles and such.
Compartment syndrome is a true surgical emergency, when bleeding or
other fluid accumulation increases the pressure inside a compartment
(e.g., a muscle group in the leg).  Fasciotomy is a series of incisions
in the fascia, which allow the pressure to reduce. Without it, the
pressure can cut off blood supply and cause gangrene.

In your example, probably more than a few people were suspicious enough
to move quickly.  This is a condition that is sometimes hard to
recognize, but needs prompt surgical intervention. I once had to fly
cross-continent after breaking my ankle, and the orthopedist was
emphatic about using a brace rather than a cast -- if I didn't have a
way to relieve pressure, I could lose a leg in 5-6 hours.  Tight casts
can make marginal compartment syndrome much worse.