Hi, Thanks for writing in. While the neck problem surgery might solve the problem with arms and shoulders, it is important to discuss any numbness during sex. The nerves supplying sex organs originate in the lower back from lumbar area. These pass through the lumbar spine and any obstruction in the nerve pathway causes variable neurological symptoms including pain and numbness. It is possible that the disc disease affecting his neck is also present in the lower back region. This can be known by doing a lumbar sacral spine MRI scan. Talking to the doctor might help in better clinical evaluation and early diagnosis of any correctable disease condition and symptoms relief leading to better quality of life.