Background: Temporomandibular joint (TMJ) disorders affect roughly 5% of the population. Chronic closed lock is one of the more common temporomandibular disorders and is characterized by limited mouth opening and various degrees of joint pain and dysfunction. 

Objectives: To evaluate the efficacy and safety of arthroscopic lysis and lavage of the TMJ to treat limited mouth opening in patients suffering from chronic closed lock. 

Methods: This is a retrospective analysis of the medical records of 47 patients with chronic closed lock treated with arthroscopic lysis and lavage. Patients were diagnosed preoperatively with closed lock of the TMJ and were unresponsive to previous conservative therapy. Three outcome variables were used to assess the efficacy of treatment: maximal mouth opening, subjective evaluation of overall improvement by the patient (on a 3 grade scale: “excellent,” “fair,” and “poor”), and length of hospital stay. In addition, complications were reported. 

Results: The maximal mouth opening values increased from a mean of 27 ± 4.7 mm preoperatively to a mean of 38 mm ± 5.4 mm postoperatively. The subjective evaluation of overall improvement was “excellent” in 15 patients (32%), “fair” in 21 (45%), and “poor” in 11 (23%). Success was defined as a maximal mouth opening of 35 mm or more after arthroscopy, and not reporting a “poor” result in the subjective evaluation. This was achieved in 36 patients, yielding a success rate of 77%. The mean length of hospital stay was less than one day (0.78 days). The complication rate was low (8%) and all complications resolved within 2 weeks. 

Conclusion: Arthroscopic lysis and lavage is a simple, safe, and efficient minimally invasive intervention for the treatment of chronic closed lock of the TMJ.