Correlation between pain and arthroscopic features of synovitis: A logical approach to verify correlations of TMJ pain

Pain is the most irritating symptom that drives temporomandibular disorders (TMD) patients to seek treatment. Murakami et al., 1991 could not prove correlation between the pain intensity and the severity of synovitis. In order to examine these ambiguous results we designed this study to include a specified homogenous group of patients suffering pure joint pain as diagnosed by the Research diagnostic criteria (RDC/TMD). Then, using a reliable characteristic pain index scoring system (CPI) we estimated the degree of correlation between CPI and synovitis. Methods: The charts of sixty patients who had undergone TMJ arthroscopic intervention from 2009 to 2012 were retrospectively reviewed. Only 23 charts were included, 19 females and 4 males, patients’ ages ranged from 16 to 58 years and they have suffered a pure joint pain as diagnosed by RDC. The preoperative records of the RDC/TMD axis II and the characteristic pain index (CPI) were compared and correlated to their arthroscopic synovitis grading score. The arthroscopic synovitis was graded and scored using a six items scoring system from 1 to 6. The grading was based on both; the severity of synovitis (mild, moderate and severe) as well as the distribution within the joint either focal or distributed. Statistical analysis was performed using the Spearman correlation coefficient 2-tailed test. Results: Only 23 charts that matched the designed criteria together with their video documentation were included. While remaining charts were excluded because of; missing data or damaged video DVD (15 cases) and heterogonous pain source or other systemic diseases (22 cases). A significant correlation between CPI and synovitis was proved. Conclusion: CPI is well correlated to the arthroscopic grading of synovitis when patients suffering exclusive joint pain are accurately diagnosed and carefully selected and included in the inclusion criteria.