How long would antibiotic therapy typically be tried?

Hi doctor,

Four months before, I was diagnosed with P. acnes infection. It resulted from a shoulder stabilization 12 months earlier. I have had two surgeries for this. One to take the biopsies which diagnosed the infection and another to remove the sutures and clean out the shoulder joint. My surgeon chose to retain the three anchors against the wish of my infectious disease doctor. I have been on Penicillin for three months and my shoulder pain shows no signs of improvement. My CRP remains high, although it has been slowly coming down. The results have been 34, 30, 30 and 21.

When I was first diagnosed I was told that the infection responds well to treatment, I would have a six-week course of oral antibiotics and surgery, and then I would be fine. Now, three months got over and every time I see the infectious disease doctor and I just get told my CRP is not good enough and I was put on more antibiotics. I saw my surgeon again recently and he has finally accepted that the P. acnes is the cause of my pain and was not a contaminant. He is now saying that the anchors will most likely need to be removed if a prolonged course of antibiotics do not work. This is a major surgery as he will need to grind away the bone because the anchors are tight. I will then need a bone graft as a big chunk of my glenoid will be gone. I really do not want more surgery as I have already had four in the past 18 months.

I am wondering about the likelihood of curing the infection with antibiotics. How long would antibiotic therapy typically be tried? And if it appears that the antibiotics are not working, then what are the implications of not having surgery or antibiotics and instead living with the infection? Other than continued shoulder pain, what are the consequences if we did not treat it? I am thinking it might just resolve on its own with time.