Current evidence from studies suggests that developing erections is important, however, these studies have been small, and the evidence is not definite. Animal studies suggest that erection medication (Viagra, Levitra, Cialis) may protect erection tissue, even in the absence of erections. However, the correct treatment plan is unknown. For example, how often does a man need to take sildenafil (Viagra®) to protect his erectile function or to maximize his erectile function recovery? Is only using erection medication enough for erectile function recovery? Would penile injections, which almost ensure production of an erection, be better than using sildenafil (Viagra®), or might a combination be even better at helping recovery of erections? These are types of questions this study might answer.