This study was designed to investigate osteoarthritic changes (i. e., degenerative changes of the articular cartilage) associated with internal derangement of the temporomandibular joint. One hundred seventy-one joints in 129 patients who had a diagnosis of anterior disc displacement without reduction were studied by image analysis (tomography and MR imaging) and arthroscopy. The tomographic and MR findings were compared with the arthroscopic findings of the upper joint compartment to assess the degree of correspondence between these diagnostic techniques. The following results were obtained.
1) There was little correlation between the prevalence of sign of cartilage degeneration (fibrillation, ulceration, bony destruction) at the articular surface of the eminence and the presence or absence of whole bony deformation as evaluated by tomographic findings. There was also little correlation between the degree of disc displacement on MR and arthroscopic findings. There was significant correlation between the presence of disc deformation and arthroscopic findings which revealed the articular surface of the eminence (p<0.05, x2=5.119). Analysis of the relationship between the presence of disc deformation and arthroscopic findings revealed the articular surface of the eminence to be pathological in 29 % of cases without MR evidence of disc deformation. Cartilage degeneration was seen arthroscopically in 56 % of cases with disc deformation.
2) There was significant correlation between the presence of disc deformation and arthroscopic findings which revealed the disc surface (p<0.01, x2=12.855). Analysis of the relationship between the presence of disc deformation and arthroscopic findings revealed the surface of the disc to be pathological in only 7 % of cases without MR evidence of disc deformation. Disc degeneration was seen arthroscopically in 59 % of cases with disc deformation.
The above findings suggest that the frequency of osteoarthritic changes in the upper joint compartment is related to disc deformation.
