There is a growing interest in markers for cartilage degradation in synovial joints because of their potential diagnostic and prognostic value. Therefore, the aim of this study was to identify valuable degradation markers for temporomandibular joint (TMJ) osteoarthritis (OA) by comparing the relative concentrations of carboxyterminal telopeptides type I and II (CTX-I and II), cartilage oligomeric matrix protein (COMP), and prostaglandin E2 (PGE2) in the synovial fluid (SF) of TMJs with OA with those of healthy symptom-free TMJs.
In this cross-sectional case-control study, participants were recruited from the University Medical Center Groningen (Groningen, the Netherlands). Cases were defined as patients with TMJ OA, and control patients had symptom-free TMJs. The outcome variables were the relative concentrations of CTX-I, CTX-II, COMP, and PGE2 in osteoarthritic TMJ SF compared with symptom-free joints. An independent-samples Mann-Whitney U test was used to compare the relative concentrations.
Thirty cases (9 male, 21 female; mean age, 40.1 yr; standard deviation, 15.3 yr) and 10 controls (5 male, 5 female; mean age, 30.3 yr; standard deviation, 10.8 yr) were studied. No significant differences in relative concentrations of CTX-I (P = .548), CTX-II (P = .842), COMP (P = .140), and PGE2 (P = .450) were found between the groups. Unexpected low relative concentrations of CTX-I and high relative concentrations of CTX-II were observed.
Assumed changes in the SF concentration of CTX-I, CTX-II, COMP, and PGE2 in TMJ OA seem to occur proportionally. Furthermore, the unexpected large contribution of CTX-II suggests that this marker may be useful to quantify cartilage degradation in TMJ OA.