Biochemical analysis of temporomandibular synovial fluid and clinical diagnosis of the temporomandibular arthrosis

A protein fraction in synovial fluid in human temporomandibular joint

Abstract

Biochemical studies on synovial fluid in the temporomandibular joint are rather rare when compared with those in the orthopedic field. In the orthopedic, several biochemical studies on synovial fluid have been reported such as the study of the proteins, sugars, enzymes, etc. So the author attempted to analyze synovial fluid in the temporomandibular joint and the data were compared with the clinical symptoms.
Objects were 10 normal and 60 pathologic samples of temporomandibular joints synovial fluid.
Synovial fluid was collected from upper joint cavity by pumping 3 times with 2 ml of 2 Xylocaine. Click or pain in the temporomandibular joint area and changes in the maxium interincisal distance before and after cavity pumping were checked and Orbito-ramus, Schüller projection and arthrogram were taken. Collected synovial fluid was centrifuged at 3, 000 rpm for 10 min, and the supernatant was obtained for analysis. Total protein amount, immunoelectrophoresis, SDS-electrophoresis, and calculation of the albumin/globulin (A/G) ratio from the SDS-electrophoretograms were performed. In addition, gel filtration and ion exchange chromatography, amino acid analysis, immunoblotting method were performed for biochemical study. Correlation coefficient between the biochemical results and clinical data was calculated using a statistic analysis program.
The results were as follows; Average of total protein amounts was 1, 259μg/ml in the pathologic synovial fluid, in contrast to 205μg/ml in the normal. Albumin appeared in normal fluid, but albumin, transferrin and IgG were found in the pathologic fluid by the immunoelectrophoresis. A/G ratio of pathologic synovial fluid was 2. 26 which was close to that of serum (1.2-2.1). A protein of 78 k in molecular weight, which was not found in normal synovial fluid or serum, appeared in pathologic synovial fluid in the SDS-electrophoresis. This 78k protein had a tendency to appear when there were pathologic changes in upper joint cavity.(84%). But in the some cases (16%), this protein did not appear in spite of pathologic changes in upper joint. From the results of clinical examination, those cases without 78k protein had a tendency to have chronic or fixed symptoms. By statistic analysis, correlation coefficient between the appearance of 78 k protein and incidence of disk deformity was 0.58. This result indicated that disk deformity may have some relation to 78 k protein appearance.