2025 ISAKOS Biennial Congress Paper
Differences in the Visible Range Within the Elbow Joint Using NanoScope™ Based on Experience
Sho Yamauchi, MD, Nagoya JAPAN
Tetsuya Takenaga, MD, PhD, Nagoya, Aichi JAPAN
Satoshi Takeuchi, MD, PhD, Toyohashi JAPAN
Keishi Takaba, MD, PhD, Nagoya, Aichi JAPAN
Jumpei Inoue, MD, Pittsburgh, PA UNITED STATES
Ono Tomoya, MD, Nagoya JAPAN
Masahiro Nozaki, MD, PhD, Nagoya, Aichi JAPAN
Hideki Murakami, MD, PhD, Nagoya JAPAN
Masahito Yoshida, MD, PhD, Nagoya, Aichi JAPAN
Department of Musculoskeletal Sports Medicine, Research and Innovation, Nagoya City University Graduate School of Medical Sciences, Nagoya, JAPAN
FDA Status Not Applicable
Summary
This study assessed elbow arthroscopy using the NanoScope™ in Thiel-embalmed specimens, finding that while both experienced and less experienced surgeons achieved 100% visibility in checkpoints of anterior joint space, visibility in posterior joint space was significantly reduced, likely due to soft tissue obstructions, indicating the need for additional working portals to enhance visualization.
Abstract
Introduction
Elbow arthroscopy is a minimally invasive tool for diagnosing and treating various conditions. However, due to the limited space in the elbow joint, there are risks such as potential damage to neurovascular tissues and cartilage. Needle scopes were developed in the 1990s, offering a smaller diameter for such procedures, and have since been applied to various joints. Despite these advancements, the level of experience needed to proficiently use needle scopes remains unclear. This study aimed to assess visibility during elbow arthroscopy using the NanoScope™, a needle arthroscopy device.
Methods
This study included ten Thiel-embalmed elbow specimens (mean age 89.2 ± 7.8 years). Patients with osteoarthritis or contractures (flexion <120°) were excluded. The procedure was performed by three experienced surgeons with more than 15 years of arthroscopy experience (ME group) and three surgeons with limited elbow arthroscopy experience (LE group), defined as those who had performed five or fewer elbow arthroscopy procedures. None of the surgeons had prior experience using the NanoScope™.The procedure involved inserting a 1.9-mm needle arthroscope (NanoScope™, Arthrex, Naples, FL, USA) into four standard portals: anterolateral (ALP), anteromedial (AMP), lateral (LP), and posterior (PP). Through the ALP, the coronoid fossa (①), humeral trochlea (②), anterior medial capsule (③), coronoid process (④), and proximal radioulnar joint (⑤) were observed. The AMP allowed visualization of the radial head (⑥), humeral capitulum (⑦), anterior lateral capsule (⑧), and radial fossa (⑨). The LP provided access to the articular surface of the radial head (⑩), humeral capitulum (⑪), proximal radioulnar joint (⑫), and humeroulnar joint (⑬). Finally, the PP enabled observation of the olecranon tip (⑭), the border between trochlea cartilage and olecranon fossa (⑮), the lateral edge of the olecranon (⑯), the medial edge of the olecranon (⑰), and the posterior aspect of the lateral epicondyle (⑱).
The visibility of each checkpoint was calculated. The percentage of visibility was compared among checkpoints and between the ME and LE groups using Fisher’s exact test, with significance set at p < .05. The study was approved by the Institutional Review Board.
Results
In the ME group, visibility was 100% for all checkpoints accessed through the ALP, AMP, and LP portals. However, visibility through the PP was lower (56.7-86.7%). In the LE group, visibility through the ALP and AMP was also 100%, but visibility through the LP was slightly reduced compared to the ME group. The visibility of the posterior checkpoints through the PP was lower (53.3-83.3%). There were no significant differences in checkpoint visibility between the ME and LE groups.
Discussion
The NanoScope™ is effective for visualizing the anterior joint space and humeroulnar joints, regardless of the surgeon’s experience level. However, both groups experienced reduced visibility in the posterior compartment, likely due to obstruction from soft tissues. This suggests that additional working portals may be necessary to improve visualization in this area.