Bone Tunnel Placement Determination Method for 3D Images and Its Evaluation for Anterior Cruciate Ligament Reconstruction

App-based analysis of the femoral tunnel position in ACL reconstruction using the quadrant method

PURPOSE

The purpose of this study was to examine the intra- and interobserver variability of an app-based analysis of the femoral tunnel position using the quadrant method in primary anterior cruciate ligament reconstruction.

MATERIALS AND METHODS

Between 12/2020 und 12/2021 50 patients who underwent primary anterior cruciate ligament reconstruction were included in this retrospective study. Intraoperative strictly lateral fluoroscopic images of the knee with marked femoral tunnel were analyzed by four observers using the quadrant method. For retest reliability analysis, measurements were repeated once by 2 observers after 4 weeks.

RESULTS

The femoral tunnel position of all included patients averaged 27.86% in the depth relation and 15.61% in the height relation. Statistical analysis showed an almost perfect intra- and interobserver reliability in the depth and height relation. The ICC was 0.92 in the depth relation and 0.84 in the height relation. The Pearson's correlation coefficient in the depth and height relation of observer 1 (0.94/0.81) was only slightly different from the Pearson's correlation coefficient of observer 2 (0.92/0.85). The app-based tunnel analysis took on average 59 ± 16 s per measurement.

CONCLUSION

The femoral tunnel analysis with the app-based quadrant method has an almost perfect intra- and interobserver reliability. By smartphone camera, a fast and highly accurate, if necessary also intraoperative, control of the tunnel position can be performed.

LEVEL OF EVIDENCE

Level 3-diagnostic retrospective cohort study.

Integration of Square Fiducial Markers in Patient-Specific Instrumentation and Their Applicability in Knee Surgery

Computer technologies play a crucial role in orthopaedic surgery and are essential in personalising different treatments. Recent advances allow the usage of augmented reality (AR) for many orthopaedic procedures, which include different types of knee surgery. AR assigns the interaction between virtual environments and the physical world, allowing both to intermingle (AR superimposes information on real objects in real-time) through an optical device and allows personalising different processes for each patient. This article aims to describe the integration of fiducial markers in planning knee surgeries and to perform a narrative description of the latest publications on AR applications in knee surgery. Augmented reality-assisted knee surgery is an emerging set of techniques that can increase accuracy, efficiency, and safety and decrease the radiation exposure (in some surgical procedures, such as osteotomies) of other conventional methods. Initial clinical experience with AR projection based on ArUco-type artificial marker sensors has shown promising results and received positive operator feedback. Once initial clinical safety and efficacy have been demonstrated, the continued experience should be studied to validate this technology and generate further innovation in this rapidly evolving field.