Feasibility of an adjustable-angle arthroscope during ACL femoral tunnel creation: an ex vivo porcine knee study.

OBJECTIVE: Building on prior device development and bench-based visual-field validation, this exploratory study evaluated the feasibility of an adjustable-angle arthroscope for ACL femoral tunnel creation in an ex vivo porcine knee model and descriptively compared femoral tunnel position measurements and procedural time with a conventional 30° arthroscope. METHODS: Ten fresh porcine knee specimens were allocated to an adjustable-angle arthroscope group or a conventional 30° arthroscope group (n = 5 each). The operational target point was defined as the intersection 5 mm from the inferior and posterior cartilage margins of the medial wall of the lateral femoral condyle; this standardized experimental target was not assumed to represent the native porcine or human ACL footprint center. All procedures were performed by one orthopaedic surgeon who was experienced in ACL reconstruction and was a member of the device-development team. CT-based three-dimensional reconstruction and gross anatomical measurement were used to determine distances A and B, and operative time and measurement reliability were recorded. Group-level outcomes were summarized descriptively. RESULTS: On CT three-dimensional reconstruction, distances A and B were 4.93 ± 0.79 mm and 7.27 ± 0.85 mm, respectively, in the adjustable-angle group and 6.68 ± 1.15 mm and 8.98 ± 1.17 mm, respectively, in the 30° group. Gross anatomical measurements were 4.9 ± 0.7 mm and 7.1 ± 0.8 mm in the adjustable-angle group and 6.7 ± 1.2 mm and 9.0 ± 1.3 mm in the 30° group. Mean operative time was 14.23 ± 1.00 min and 14.46 ± 1.21 min, respectively. Interobserver ICCs were 0.91 and 0.90, and intraobserver ICCs were 0.97 and 0.97. CONCLUSION: This study successfully developed an adjustable-angle arthroscope based on a hinge-linkage mechanism and demonstrated, through quantitative testing, that it provided greater visual-field coverage than conventional 30° and 70° fixed-angle arthroscopes. By enabling dynamic multiangle visualization within a single arthroscopic system, this device may provide a more flexible visualization strategy for complex arthroscopic procedures and has potential clinical applicability.