“…The demonstration that minimally invasive USguided procedures can reliably sample the small joints as well as the large joints and, furthermore, do not require purchase of additional equipment (such as a small bore arthroscope) makes their inclusion in clinical trial protocols particularly attractive. Their adoption not only increases the potential pool of participants but also has the potential to reduce sampling bias because patients with a spectrum of disease severity can be recruited without being limited by the distribution of joints with active disease (e.g., the knee is often a preferred site for arthroscopy) (22). Intuitively, it may be assumed that US-NB retrieves tissue primarily from within, rather than at the surface of, synovial tissue, but this is not supported by the results of our study, since we demonstrated that US-NB is at least equivalent to US-P&F in obtaining synovial tissue with visible lining layer.…”