Objective: To assess the diagnostic value of blindly performed synovial biopsies in carefully selected patients with unclassified arthritis.
Methods: Synovial tissue was obtained blindly under local anaesthesia. The Arthroforce III take-apart 3.5 mm needle and 1.5 mm grasping forceps were used for this purpose.
Results: Four patients with unclassified arthritis could be diagnosed properly based upon examination of synovial tissue of the knee obtained by an easy-to-perform blind biopsy. The arthritis of the four patients was diagnosed as being part of Erdheim-Chester disease, sarcoidosis, multicentric reticulohistiocytosis and arthritis caused by foreign-body material, respectively.
Conclusions: Analysis of synovial tissue obtained during a blind biopsy procedure has diagnostic potential in carefully selected patients with unclassified arthritis. The common denominator in all the cases presented was a differential diagnosis consisting of a rheumatological disease with characteristic histological features.