LG, I have a few new words for your vocabulary: platelets-rich plasma therapy, needle tenotomy. I just underwent ultrasound-guided PRP therapy combined with needle tenotomy on my right knee to deal with tendonopathy in that area, which was chronic and preventing me from playing tennis.
Apparently it's also done on the shoulder. The point of this exercise is to cause inflammation in the area, where the inflammation causes vascularization and healing of tendons. May also clear scar tissue present in the tendons. I'm hopeful, but it hurts like a b*tch though right now. Based on clinical papers, mostly anecdotal, I'm very optimistic. There are few randomized clinical studies though, because it would be barbaric to do a randomized placebo study.
It's not covered by insurance in the US, but if it works, it's worth $800 to me.