Why does my hand fracture have a pulsating feeling?

Not elevated. The blood supply to the hand is so good that any injury will throb for 2-4 days after injury or surgery. Keeping the injured part above the level of the heart will minimize this. Throbbing after this interval may represent a problem that should be evaluated by your treating doctor.
Throbbing is normal. Put your hand higher than your heart...The throbbing dissipates. When uninjured, the nerve endings don't notice the pulsation of your heart, but once swollen from an injury, there is less room for the swelling, and the pulsation pushes against your nerve endings, which is why you feel the throbbing. Elevating your hand will decrease that feeling.