The role of navigation technology in anterior cruciate ligament reconstruction bone tunnel positioning

In the past decade, navigation technology-assisted bone tunnels positioning for anterior cruciate ligament reconstruction (ACLR) has received great attention. The purpose of this review is to summarize the navigation technologies applied in ACLR, describe the tunnel positioning accuracy of these technologies, and summarize their advantages and disadvantages, providing a basis for navigation technology to assist ACLR. This review discusses the limitations of traditional bone tunnel positioning methods in ACLR and further introduces various navigation techniques, focusing on their positioning accuracy and postoperative outcomes for patients. Additionally, it presents commercial systems utilizing reality-based technologies and examines their impact on the arthroscopic learning curve for less experienced surgeons. The osseous landmarks are currently the most used positioning method, but they still have shortcomings. Navigation technologies primarily focus on computer-assisted navigation, which, however, requires additional incisions. Virtual reality and augmented reality are mainly utilized in preoperative planning, with the best-reported positioning accuracy of augmented reality being 0.32 mm, while most other accuracies are within 3 mm. Mixed reality offers a novel approach for precise positioning, resulting in more optimal and consistent postoperative tunnel placement. Navigation technology improves the positioning accuracy of the bone tunnels and achieves good short-term results. Key to the future is long-term follow-up to assess clinical outcomes of navigation techniques.