A newly developed 2 mm needle arthroscope with high-definition for orthopedic outpatient knee joint examination.

Currently, the diagnosis of orthopedic joint diseases relies mainly on magnetic resonance imaging (MRI), which is valuable for detecting bone injuries, as well as lesions in intra-articular cartilage, ligaments, bone marrow, synovium, and other areas. However, MRI has significant drawbacks. Firstly, MRI cannot provide detailed pathological assessments of joint interiors comparable to arthroscopic examination results. Secondly, MRI is costly, imposing substantial financial burdens on patients with each additional site examined clinically. Lastly, MRI resources are scarce in medical institutions due to widespread applications beyond joint examinations, requiring appointments days in advance. Each examination is limited to one site, taking approximately 20-30 min per session; multiple sites necessitate sequential examinations, entailing considerable time costs and potentially delaying diagnoses. The development of needle arthroscopy (NA) for outpatient knee joint examinations offers more accurate and detailed visualization of knee joint pathologies compared to traditional MRI imaging, with lower economic and time costs. Moreover, NA provides a valuable diagnostic alternative for patients unsuitable for MRI examinations. In-office needle arthroscopy (IONA) also enables orthopedic surgeons to deliver more comprehensive medical services beyond diagnostic examinations. Based on this theory, we have designed and manufactured a 2 mm-diameter lens arthroscope useable under local anesthesia in outpatient settings to examine tissue injuries within knee joints. The needle arthroscope objective 2 mm has an 85°field of view, a 30°viewing angle, and an imaging resolution of 10 lp/mm. This device provides clear imaging of cartilage surfaces, ligaments, synovium, and other soft tissues inside cadaveric knee joints, enabling more detailed and accurate evaluations of knee joint tissue pathologies. This method facilitates convenient, efficient joint examinations with lower economic and time costs, serving as a viable alternative to knee joint MRI examinations.