Prognostic indicators of the outcome of arthrocentesis: a short-term follow-up study

OBJECTIVES: Arthrocentesis of the temporomandibular joint (TMJ) is purported to be an effective modality in the treatment of patients with closed-lock symptoms. The purpose of this study was to determine whether the clinical findings of disk displacement without reduction associated with pain in the TMJ are related to the discovery of TMJ osteoarthrosis (OA) through the use of magnetic resonance (MR) imaging and whether the presence of OA affects the treatment outcome of patients who undergo arthrocentesis of the TMJ. STUDY DESIGN: The study population consisted of 38 patients with TMJ pain who were assigned a clinical diagnosis of unilateral internal derangement (ID) of the TMJ, type III (disk displacement without reduction), in combination with capsulitis/synovitis (C/S) and an MR imaging diagnosis of disk displacement without reduction in the painful TMJ only. Before the patients underwent arthrocentesis, bilateral sagittal and coronal MR images were obtained to confirm the presence or absence of ID and OA. The preoperative and postoperative levels of TMJ function with respect to pain and mandibular range of motion were evaluated and compared. Multiple logistic regression analysis was used to compute the odds ratios for successful outcomes for OA (n = 24) versus unsuccessful outcomes for TMJs (n = 14). RESULTS: The preoperative data revealed a significant relationship between the clinical diagnosis of TMJ ID type III with C/S and the discovery of OA on MR images (P =.048). At the 2-month follow-up, a clinical evaluation revealed a significant reduction in TMJ pain during function (P =.000); a significant reduction in the clinical diagnoses of ID type III (P =.000), and C/S (P =.000); and a significant increase in the mandibular range of motion (P =.000). The patients with successful outcomes were more likely to be associated with an MR imaging finding of OA than were the patients with unsuccessful outcomes. (10.4 odds ratio; P =.016). CONCLUSIONS: Our preliminary findings suggest that the presence of OA revealed on MR images is related to clinical pain; furthermore, OA proved to be an important prognostic determinant of successful arthrocentesis.