Jan Mianowski

Background: Needle arthroscopy can alter not only portal size but also the diagnostic and treatment pathway by enabling direct visualization under local anesthesia and selected limited interventions. Its diffusion across joints, however, may be outpacing clinical validation. Methods: This PRISMA-ScR-guided review mapped PubMed/MEDLINE-indexed primary publications from database inception through 31 July 2026. The quantitative flow is therefore an auditable but incomplete evidence map rather than a complete census of the technology; studies indexed exclusively outside PubMed may have been missed. Backward reference-list screening was used as a completeness check, while earlier Scopus, Web of Science, and Cochrane histories were retained as sensitivity sources and not pooled into the quantitative flow. Two reviewers independently screened and charted records using a shared form. Reports were de-duplicated by PMID, DOI, and normalized title and characterized by anatomy, design, application, platform, outcomes, harms reporting, study-design hierarchy, and principal methodological limitation. Technical or cadaveric feasibility was analyzed separately from clinical and comparative evidence. Results: The final map comprised 105 unique primary publications: 49 technical, 41 clinical, and 15 cadaveric. Technical and cadaveric reports (64/105, 61.0%) outnumbered clinical reports (41/105, 39.0%), limiting estimation of clinical effectiveness. Ninety publications (85.7%) appeared from 2021 onward; the 2026 count is incomplete because the search ended on 31 July. For descriptive display across the complete map, nine reports (8.6%) were in Levels I–II and 93 (88.6%) in IV–V; among the 41 clinical reports, 29 (70.7%) were IV–V and 12 (29.3%) were I–III. NanoScope accounted for 87 of 107 platform mentions (81.3%). Diagnostic and second-look applications had the most consistent comparative rationale, but lesion-specific estimates varied by joint and reference standard. Reported harms were generally minor where surveillance was described, but rare-harm inference was limited by small samples and inconsistent adverse-event ascertainment. Conclusions: The field remains promising but unproven: technical breadth exceeds comparative clinical validation. Because the quantitative evidence map is PubMed/MEDLINE-only and dominated by technical, cadaveric, and IV–V reports, current evidence is insufficient to estimate clinical effectiveness or justify replacement of MRI or conventional arthroscopy. Needle arthroscopy should therefore be viewed as an indication-specific complement and a hypothesis-generating technology rather than a replacement platform. Multicentre comparative studies and randomized trials, where ethically and practically feasible, are needed to test patient benefit and clinical application.