Yes, I know many surgeons call arthrocentesis a "minor procedure", and that bothers me. It is less invasive than arthroscopy and arthroplasty...but it's STILL invasive. And you are not the first person who has had undesirable results from arthrocentesis, believe me on that one. I really, really try to stay unbiased when people post...but in your case, I feel very strongly about this: For now, stick to CONSERVATIVE treatments. Your function is still pretty good. I know you're not used to a smaller opening, so it feels frustrating to you, but your function truly could be a lot worse. If you stick with conservative treatments, and do your ROMs like Dyan suggested, then there is a good chance that your opening will increase more. It may not go back to 56mm (who knows for sure), but either way, surgery is not the "cure-all" that some people expect it to be. I don't want to seem like I'm playing doctor or trying to sound discouraging, but it just doesn't seem that surgery would be justified in your case. Also, you said your pain isn't too severe, so try to manage it with a soft diet and possibly medications, heat, ice, relaxation, etc.