Temporomandibular Joint Arthroscopic Arthroplasty with Rigid Disc Fixation— Preliminary Results in Treatment of Wilkes Internal Joint Derangement Stages II-V: A 3-Year Retrospective Study

Abstract

A great deal of literature exists on the management of patients with internal derangement of the temporomandibular joint (TMJ). Ohnishi in 1975 described a technique of TMJ arthroscopy and ever since then, numerous reports have been published advocating the high degree of success with arthroscopic lysis and lavage. The largest of these studies, a 6-year multicenter retrospective analysis of 4,831 joints reveals just over a 91% favorable outcome for pain and range of motion after variations of arthroscopic surgery. As operative arthroscopy has evolved, so have the surgical techniques. McCarty and Farrar in 1979 described an open procedure for disc repositioning (discopexy). Although arthroscopic disc repositioning using semi-rigid fixation with sutures has been reported, there is no account in the literature of using rigid fixation. Previous successful treatments with open rigid fixation provide another operative option that may become standard of care as more athroscopic surgeons become familiar with it. This investigation aims to evaluate the efficacy of arthroscopic discopexy with rigid fixation (ADRF) for different stages of internal joint derangement. A retrospective chart review was performed in 66 patients involving 98 joints treated for TMJ internal derangement from 2003-2005. Of these, 32 patients underwent bilateral ADRF. 5 males and 61 females aged 14-65 with a mean age of 37 years were treated with ADRF. Inclusion criteria for the study were all patients treated with ADRF during the three year span. All patients had documented follow-up evaluations for maximum incisal opening (MIO), change in diet, and pain medication usage at 1 week, 2 weeks, 6 weeks, and 6 months post-operatively. Further inclusion criteria included those patients who underwent standard conservative treatment consisting of soft diet, occlusal splint therapy, and anti-inflammatory medication prior to surgery. These patients were then evaluated for pain, clicking, and range of motion. No exclusion criteria existed for this study. All patients’ symptoms were evaluated to assess need for surgery. Pain was evident in 92% of patients, 91% presented with clicking, and 79% presented with a decreased range of motion. 54% presented with all three symptoms. Patients were also evaluated for severity of internal derangement according to the Wilkes’ classification stages II-V. Surgical outcomes were evaluated according to changes in maximum incisal opening (MIO), diet, and pain medication usage 6 months after surgery. MIO was evaluated quantitatively 1 week before and 6 months after surgery with a millimeter ruler. Diet assessment and pain medication usage were evaluated 1 week before and 6 months after surgery with a questionnaire filled out by each patient. All data collected were transferred to a spreadsheet. 32 of 66 patients underwent bilateral ADRF (43%). 106 (100%) of the TMJ discs were fixated to their respective condyles with Linvatec bicortical smart nails in conjuction with arthroplasty. With regard to Wilkes’ classification, 23 (22%) of the total number of joints were classified as Stage II. 33 (31%) were Stage III. 45 (42%) were Stage IV. 5 (5%) were Stage V. The average MIO for all patients was: Pre-operative (29.9 mm), Post-operative (38.2 mm), and pre- and post-operative change (+12.3 mm). All patients resulted in increased MIO post-operatively. The greatest change in MIO occurred in a Stage IV patient who had ADRF and a resulting 25 mm increase. For Stage II patients who underwent ADRF, MIO increased an average of 9.5 mm, and average post-operative MIO was 37.7 mm. In addition, 7/8 patients (88%) had improved diets and 8/11 patients (73%) stopped taking pain medication 12 weeks post-operatively. Stage III patients had an average increase in MIO of 12.3 mm, and an average post-operative MIO of 38.3 mm. Improved diets occurred in 11/13 patients (85%), and 10/16 patients (63%) ceased pain medication. Stage IV patients averaged an increased MIO of 13.3 mm and average post-operative MIO of 38.1 mm. 11/14 patients (79%) had improved diets, and 12/19 patients (63%) no longer took pain medication. Stage V patients had an average MIO increase of 13 mm. Data for diet and pain medication usage were not available for these patients. 17 of the total 106 (6%) patients continued to take pain medication 12 weeks after surgery, and 2 of 98 (1.8%) underwent secondary TMJ surgery after 6 months. There were no incidents of permanent facial nerve injury, infection, or perforated tympanic membranes in any of the 98 joints. Although arthroscopic procedures to correct TMJ internal derangement have been well described in the literature, there has been no previous documentation of arthroscopically rigidly fixating a repositioned disc. Although lysis and lavage have been proven to be therapeutic for this challenging group of patients, ADRF provides another effective method of treating, and in some cases reversing the natural progression of internal joint derangement. The argument can be made that if there is a proven, time-tested procedure in lysis and lavage, then why change it? It may become prudent in certain cases that lysis and lavage fails and the patient or surgeon do not wish to go into secondary aggressivesurgery, such as partial condylectomy, open discectomy, or total joint prostheses. As shown by our orthopedic counter parts arthroscopic surgery using rigid fixation is the first line of choice before any open surgery. The preliminary results from our study thus far warrant that ADRF has its place in TMJ surgery. The overwhelming results of only 1.8% of the patients undergoing secondary surgery is a good indicator that we are going in the right direction with this procedure, and with further studies it has the potential of becoming the standard of care. Additional data from this ongoing investigation will lend more credence to these assertions.