shoulder and neck pain, vertebrae moving out of position

I had shoulder surgery two years ago on my right shoulder for three bone spurs; now my left shoulder is acting up but it is not the same kind of pain.  The pain is in the front & back from the top of the shoulder down around the bone to the arm pit.  Shoulder tends to com out of place and needs to be popped back in.  Hurts to lay on my side, lift especially if it out stretched to the left.  

I have been going to the chiropractor to have it put back into place.  He usually starts at the lower back adjusting the vertebrae back into place all the way up to the neck.  Then has me sit and will adjust the neck and then pop the shoulder in.  I can at times feel the lower back move out of position, when it does I start to feel pain between the shoulder blades and then the shoulder becomes sore and then the constant pain starts in.  I have also noticied that at times I will feel the spine move between the shoulder blades and then the lower back will have some pain.  It's as though nothing wants to stay in place.

What do you think my problems consist of and what action should I take.