Minimally Invasive Ultrasound-guided Synovial Biopsy Using SuperCore Biopsy Instrument

Background: To develop a new method for synovial biopsy with ultrasound (US) guidance and a semi-automatic SuperCore biopsy instrument. Materials and Methods: Twenty-two patients (8 men and 14 women, median age 57 years (range 22–79 years)) with active arthritis or tenosynovitis were enrolled from April 2012 through October 2012. Each patient had one joint or tendon biopsied. US examination was performed to determine the optimal synovial site for biopsy. After skin disinfection and local anaesthesia, a portal was established using a trephine needle as needed. An 18-gauge SuperCore biopsy needle was placed into the target synovial site via the portal or just percutaneously under US guidance with free hand technique. Repeated needle passes and cuts to obtain 3-10 pieces of synovial tissues in each joint. The success of biopsy was defined as identification of synovium on histological examination. Results: Synovium of 21 joints (10 knees, 6 wrists, 3 ankles, 1 elbow and 1 metacarpophalangeal joint) were biopsied. One patient had biopsy of flexor digitorum tendon sheath. All biopsies obtained adequate amounts of synovial tissues for histologic reading with a success rate of 100%. Synovial lining was identified in 18 (85.7%) of 21 joints. The patient with flexor digitorum tenosynovitis was proven to have mycobacterial infection by histological examination. All patients tolerated the procedures well, and no complication was observed during 2-week follow up. Conclusions: US-guided synovial biopsy using SuperCore biopsy instrument is a promising method for synovial research. It has the advantages of simple, mini-invasiveness and high success rate. The complication is rare.