Arthroplasty or arthrotomy Is an open surgical procedure done under anesthesia and lasts up to one to two hours. The recovery time for arthroplasty is longer, usually five weeks, and it is more painful than arthrocentesis. An incision is made in front of the ear, the TMJ space is opened, and the correction is made. The reshaping of the temporomandibular joint is called arthroplasty.