I suppose it depends on EXACTLY what's wrong. Some years ago my flying shoulder'S MRI showed some tears. So I applied to a private sports clinic to have a $12,000.00 operation to fix the tears. The surgeon wouldn't operate until I had more mobility in the joint. So I underwent physical therapy to restore the lost mobility. Early on in PT treatment ( & while awaiting the surgery) I took a break to take a 6 week training course in MOntreal. I was off work up til then. The Delta hotel I stayed at had a small swimming pool that I relaxed in for a bit of exercise after class & the hot tub too.. Before too long I developed enough mobility to be able to swim (front crawl) without much pain at all. In the last few weeks I was actually able to do quite a few lengths & I felt fine.
On arrival back home, my Physio Therapist again did a mobility check to see my expected regression due to no treatment for 6 weeks. Lo & Behold he could not believe I was the same patient he saw 6 weeks ago! He immediately cleared me for surgery. In the orthopedic surgeon's office the next week the surgeon pulled prodded & otherwise manhandled my shoulder. He then kicked me out of his office saying, " You don't need surgery, I only operate on patients that need it." So back at my PT's office I asked him why didn't he recommend swimming to me earlier. " Oh I do he says, just a lot of people don't like swimming, don't like the chlorine in the water, etc." Well what do you know, I casually & accidentally swam my way out of a $12,000 shoulder surgery! Given time & PT (exercise), the body can indeed heal itself!
p.s A co-worker had the same surgery & it went badly, his body rejected the sutures, etc. Ended up with 3 surgeries to get it better, but still not right...