You should have a re-evaluation done including a thorough neuro examination, MRI of the cervical spine and an EMG/Nerve conduction studies.
Although is is possible that you may have a peripheral nerve entrapment syndrome like an ulnar neuropathy , recurrent or persistent cervical stenosis/foraminal stenosis/HNPs should be considered.
Is it possible you have carpal tunnel? Did the surgeon say that those problems would be fixed? If so, I would go back to him. Also, you can try a hand specialist.