There have been some studies on the burden of certain rheumatological disorders on the tendons; however, patients with familial Mediterranean fever (FMF) and Behçet's disease (BD) have not, up to now, been studied in this regard in the literature. Thus, this current study centers on ensuing changes in the tendons of these patients.

The study comprised 32 patients with FMF (13 male, 19 female), 31 with BD (18 male, 13 female) and 35 control subjects (17 male, 18 female). Sonographical evaluations were performed from the triceps, quadriceps and Achilles tendons on the non-dominant extremities of the individuals using a linear array probe of 8-16 MHz.

The mean triceps tendon (TT) thickness value of FMF patients was greater than that of BD patients (P=0.03) or the controls' (P=0.02). The mean quadriceps tendon (QT) thickness value of BD patients was greater than that of FMF patients (P=0.00) or the controls' (P=0.01). The mean Achilles tendon (AT) thickness value of BD patients was greater than that of controls' (P=0.05) only. There was not any difference between the tendon thickness measurements of either group of patients with and without arthritic involvement.

Our first and preliminary findings pertaining to increased tendon thicknesses in FMF (TT) and BD (QT and AT) patients should be complemented with future histological and clinical studies. The functional relevance of tendon thickening, its probable reflection on the rupture risk and the role of each disease related contributing factor remain to be uncovered.