Correlation between arthroscopic diagnosis of osteoarthritis and synovitis of the human temporomandibular joint and keratan sulfate levels in the synovial fluid

Purpose: The specific aims of this investigation were to determine if there is a relationship between an arthroscopic diagnosis of synovitis and osteoarthritis, and if the presence of synovitis influences the level of cartilage degradation, as evidenced by keratan sulfate levels in the synovial fluid. Patients and Methods: Arthroscopic surgery was performed on 114 temporomandibular joints in 88 patients who had significant pain or dysfunction and whose condition had failed to improve with conservative treatment. Synovial fluid aspirates were obtained immediately before arthroscopy and used for the determination of keratan sulfate levels. Arthroscopic examination included assessment of the presence or absence of osteoarthritis and synovitis. Results: Synovitis was present in 90% of joints, and osteoarthritis was present in 62% of joints examined arthroscopically. Both osteoarthritis and synovitis existed in 57% of the joints. Joints with an arthroscopic diagnosis of synovitis had significantly lower levels of keratan sulfate in the synovial fluid aspirates than joints with osteoarthritis. Synovial fluid aspirates from temporomandibular joints with osteoarthritis had significantly higher levels of keratan sulfate than synovial fluids from joints without osteoarthritis. Conclusions: Osteoarthritis and synovitis are common diagnoses and are often present concurrently in patients with symptomatic temporomandibular joints. Osteoarthritis is associated with elevated keratan sulfate levels; however, the elevation of keratan sulfate is less in patients with concomitant synovitis.