Synovial fluid detection in intra-articular injections using a bioimpedance probe (BIP) needle-a clinical study.

Intra-articular glucocorticoid injections are the recommended treatment for active arthritis, but accurate positioning of the needle may be challenging. Inexperienced physicians might decide not to inject because an unsuccessful injection impairs clinical outcome and may lead to complications; however, choosing not to inject may impair or delay the best possible treatment. Here, we address this problem by introducing a novel Bioimpedance Probe (BIP) Needle-guidance method that was tested in a clinical study. The BIP Needle was utilized for detection of synovial fluid. It measures real-time bioimpedance spectra and identifies when the needle tip is in contact with the synovial fluid. Injections into 80 joints with active arthritis were performed by an experienced rheumatologist using the BIP Needle. The location of the BIP Needle was ensured by aspiration of synovial fluid, absence of resistance during injection, and/or using real-time ultrasound imaging. Sensitivity and specificity of the device for synovial fluid detection were 86 % (CI 75-93 %) and 85 % (CI 74-92 %), respectively. The BIP Needles showed high spatial resolution and differentiated the synovial fluid from the surrounding tissues. However, lack of synovial fluid, anatomic variability, and intra-articular structures challenged the technology. The BIP Needles provided adequate results in intra-articular injections. Performance of the device was good even in small joints, which may be the most difficult for inexperienced physicians. Further performance improvement can be expected when more data is collected for mathematical models. Overall, this novel method showed potential to be used in real-time needle guidance.

Effectiveness of anakinra in rheumatic disease in patients naive to biological drugs or previously on TNF blocking drugs: an observational study.

The aim of this study was to evaluate the effectiveness of IL-1 inhibition in rheumatic disease using real-life, observational methods. We analyzed data from 47 patients collected from the national ROB-FIN for rheumatic disease. Commonly used, validated measures of efficacy and adverse effects were documented and analyzed. The series contains 47/1,135 patients (mean age 47+/-11 years, range 25-73, females 83%) on anakinra of whom 39 patients suffered from rheumatoid arthritis (RA), two presented with psoriatic arthritis, and four with juvenile RA. At 3 months (26/40), 46% reached American College of Rheumatology (ACR) 20 and 27% ACR 50. In patients naive to biological drugs, the response rate at 3 months was 60% for ACR 20 and 20% for ACR 50. At follow-up of the total series, ACR responses at 6 and 12 months were 69/56% for ACR 20 and 23/22% for ACR 50. These data give room for IL-1 suppression when treating patient with rheumatic disease. Careful selection of patients, together with combining anakinra with disease-modifying antirheumatic drugs, perhaps adds effectiveness. For treating clinicians in Finland, these results are encouraging, as reimbursed treatment alternatives for patients refractory to all other therapies are still few.