@David55,
Welcome to BoneSmart.

The numbness and foot drop problems are nerve problems. I can't answer if your symptoms are a result of your THR. Only someone who examines you will be able to determine what is causing your symptoms.
Call your surgeon and let them about your numbness and foot drop, they should refer you to a neurologist for a full examination, likely to include a nerve conduction study.
You need to be seen ASAP. Call now or in the morning.
Once you see your surgeon and a neurologist, you may be referred to an orthotist for your foot drop so you do not continue to fall.
Please post your surgery date, a moderator will add it to your signature for you. Having the exact date will help us properly advise you. Thanks!
Keep us posted on how you are doing,
Chris