Safety and tolerability of ultrasound-guided synovial needle biopsy in Japanese arthritis patients

Objectives: We sought to clarify the safety and tolerability of ultrasound (US)-guided synovial needle biopsy in hand and knee joints in Japanese arthritis patients. Methods: A total of nine consecutive arthritis patients were recruited and scheduled for US-guided synovial needle biopsies. Patients completed a safety questionnaire and patient-reported outcomes (PRO) data of joint pain, stiffness, and swelling pre- and postbiopsy. We also recorded patients’ characteristics and willingness to undergo a second biopsy by the same technique. All synovial needle biopsy samples were assessed with pathological and microbial examination to verify whether clinical evaluation was possible. Results: Five and 4 patients underwent US-guided biopsy from hand and knee joints, respectively. PRO data showed no significant differences in pain, swelling, or stiffness levels before and after biopsy, with a mean 11.8 samples collected per procedure. No significant complications, including joint infection, bleeding, or vasovagal signs, were reported. Histologically adequate synovial tissue was identified in 83 (78%) samples. We were able to submit the biopsy samples to pathological and bacterial analysis to exclude septic arthritis. Conclusion: We demonstrated that a minimally invasive US-guided needle biopsy is a safe and well-tolerated procedure and the synovial tissue collected was of adequate quality for pathological analysis.