Intra-articular injection of hyaluronic acid reduces total amounts of leukotriene C4, 6-keto-prostaglandin F1α, prostaglandin F2α and interleukin-1β in synovial fluid of patients with internal derangement in disorders of the temporomandibular joint

This prospective randomised study was designed to assess the effect of an intra-articular injection of sodium hyarulonate on internal derangement in disorders of the temporomandibular joint. Fifteen patients (4 men, 11 women, mean (SEM) age 33(3) Sears) with unilateral internal derangement of the temporomandibular joint without radiographic evidence of the condylar degeneration who were randomly allocated to have arachidonic acid metabolites (n=9) or cytokines (n=6) measured in synovial fluid. The preauricular area was disinfected and anaesthetised locally with 1% lignocaine hydrochloride, Synovial fluid was collected by rinsing the joint with saline 5 ml. Sodium hyaluronate 1 ml (10 mg) was then injected into the superior compartment of the temporomandibular joint, The treatment was repeated after two weeks. The effects of sodium hyaluronate on total amounts of arachidonic acid metabolites and cytokines and on symptoms was measured. Injection of sodium hyaluronate caused significant reductions in the mean (SEM) of total amounts of leukotriene C-4 (4.68 (2.27) to 0.48 (0.24) ng/joint), 6-keto-prostaglandin F-1 alpha (12.12 (2.78) to 5.19 (1.90) ng/joint), prostaglandin F-2 alpha (12.63 (5.51) to 4.21 (2.20)ng/joint), and interleukin-1 beta (100.5 (14.2) to 50.8 (13.9)pg/joint), respectively (P<0.05 in each case). The mean (SEM) pain score was significantly reduced from 2.56 (0.18) to 0.89 (0.26) (P < 0.01), the noise score from 2.18 (0.23) to 1.18 (0.18) (P < 0.05), and degree of mouth opening from 28.2 (2.5) to 34.9 (2.0) mm (P < 0.01), However, no improvement in symptoms was recorded in 1/9, 5/11, and 1/9 patients, respectively. These findings suggest that inflammation plays a part in internal derangement of the temporomandibular joint, and injection of an anti-inflammatory substance may be beneficial to such patients.