Minimally invasive needle arthroscopy versus conventional arthroscopy for treatment of bacterial knee arthritis: protocol of a pragmatic, multicenter, randomized, controlled, non-inferiority trial (MINA-TRIAL)

Abstract Background Recent innovation offers the possibility for joint drainage under local anaesthesia for the treatment of bacterial arthritis of the native knee, using minimally invasive needle arthroscopy (MINA). Compared with conventional arthroscopy, MINA enables immediate bedside management and obviates the need for regional or general anaesthesia, thereby reducing the burden of the operating room on staff, while increasing availability for other procedures. Given these potential benefits, we propose a pragmatic randomized controlled trial to evaluate the clinical effectiveness and cost-effectiveness of MINA compared with conventional arthroscopy in the treatment of bacterial knee arthritis. Methods The MINA-trial is a national, multicenter, pragmatic, non-inferiority, randomized controlled trial. Patients aged 18 years or older diagnosed with suspected bacterial arthritis of the knee will be randomized into either MINA or conventional arthroscopy for drainage of the knee joint. We aim to recruit 146 patients from six hospitals across the Netherlands. Patient reported outcomes will be conducted at baseline, 3 and 6 months, as well as at 1, 2, 5, and 10 years post-intervention. The primary outcome is the Knee Injury and Osteoarthritis Outcome Score (KOOS) – Function in Daily Living subscale (ADL) at 6 months. Secondary outcomes, determined at several follow-up moments up to 10 years, include the iMTA Medical Consumption Questionnaire (iMCQ) and iMTA Productivity Cost Questionnaire (iPCQ), all KOOS subscales, EuroQol-5 Dimension-5 Level (EQ-5D-5L) utility score, Numeric Rating Scale (NRS) for pain scores, subjective patient satisfaction score and several clinical and procedural outcomes. A cost-effectiveness analysis will be performed at 6 months. Discussion The MINA-trial will be the first trial to determine the clinical effectiveness and cost-effectiveness of MINA compared to conventional arthroscopy in the management of patients with bacterial arthritis of the knee. The results of the proposed study may have a direct impact on national and international guidelines for optimizing the treatment of bacterial knee arthritis, potentially bringing a paradigm shift in its surgical management and opening new doors to healthcare costs and time reduction in surgical care. Trial registration This study is approved by the Amsterdam UMC Medical Research Ethics Committee and prospectively registered in the Overview of Medical Research in the Netherlands (OMON) on 12/02/2025 (Registration number: NL-OMON57912, https://onderzoekmetmensen.nl/nl/trial/57912 ).