Well, you could certainly lose the use of the hand and possibly wrist. However, modern repair techniques would probably be effective unless the damage was very extensive.
Generally, if the damage is basic, repairs are done with a local or general anaesthetic, suturing the torn ligaments and layers together.
If the damage is more serious, sometimes micro surgery is required, using a microscope thew surgeon looks into while working. This can repair nerves, ligaments, muscles or blood vessels.
In either case, the patient would need a tetanus jab, lots of antiseptic, sutures visible on the skin, and probably some bandaging.
