Hello and hope you are doing well.
The numbness in the hands may not be related to the hip replacement surgery. This can be due to nerve compression of carpal tunnel. In this the median nerve is compressed at the wrist in a place called the carpal tunnel. Symptoms begin with numbness and tingling of the first three or two fingers from the thumb side. Then the numbness or tingling can spread upwards to the arms. Nerve conduction studies are quite diagnostic. Treatment is usually by splints and steroid injections. Please consult your primary care physician for further evaluation.
Hope this helped and do keep us posted.
I had a partial hip replacement with titanium and no ill effects. Have you checked the internet?