sexual dysfunction

[JDG]

I had cervical diskectomy c5-c7 with fusion 11/2001. Ever since then I have not been able to have an orgasm. For a couple of years after the surgery I could maintain an erection using Viagra, but I could not achieve an orgasm nor ejaculate. I still have erections in the morning and sometimes during the day. I cannot maintain an erection when attempting intercourse or masturbation. Nowadays Viagra has little effect. Any ideas?