Gill TJ, et al. - Authors compared the effectiveness, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging (MRI) and surgical diagnostic arthroscopy. With regard to the diagnosis of intra-articular, nonligamentous knee joint pathology, needle-based diagnostic imaging that could be used in the office setting was statistically equivalent to surgical diagnostic arthroscopy. Compared to MRI, a more detailed and accurate diagnostic assessment of intra-articular knee pathology could be provided with in-office diagnostic imaging. A safe, accurate, real-time, minimally invasive diagnostic modality was provided with the in-office diagnostic imaging to evaluate intra-articular pathology without the need for surgical diagnostic arthroscopy or high-cost imaging.