At the end of a long rest (8 hours), a character regains all lost hit points.Nope. Sorry. I appreciate the various attempts to clean up the system and standardize the mechanics (although what is with that funky XP per level table?), but this here is a deal breaker. I can't tell a story in which no one ever breaks a leg.
Admittedly previous editions were a bit sketchy on the relationship between hit points and injury, but this edition has just flat out erased it. Even if you are reduced to 0 hit points, as long as you are not killed out-right, you will be fully healed in 12 hours (4 hours to heal 1 hit point, and then one long rest to heal the rest).
Nope. Sorry. Can't do it.