Biomechanical Properties of the All-Inside Anterior Cruciate Ligament Graft: A Scoping Review of Laboratory Evidence on Graft Configuration and Fixation

Background: There are limited comparisons of graft configurations and fixation methods for the all‐inside anterior cruciate ligament (ACL) technique based on a laboratory investigation. Purpose/Hypothesis: This review aimed to evaluate the biomechanical data from controlled laboratory studies on different graft configurations and fixation methods in correlation to graft strength and stability in all‐inside ACL reconstruction. It was hypothesized that graft configuration and supplementary fixation would significantly contribute to graft strength and stability. Study Design: Scoping review. Methods: A literature search was conducted via PubMed on January 15, 2025, including studies that examined all‐inside ACL graft techniques in a controlled biomechanical manner; reported data on stiffness and/or ultimate load to failure, and utilized cadaveric, porcine, or bovine tendons with cyclic loading and pull‐to‐failure testing protocols. A total of 150 studies were shortlisted before being narrowed down to 11 biomechanical studies, with descriptive statistical analysis performed. Results: This review demonstrated that quadrupled ACL grafts outperformed tripled grafts in stiffness and load to failure. Adjustable-loop devices provided robust primary fixation, while supplementary fixation further enhanced graft stability. Overall, 3 failure modes emerged: graft failure, fixation failure, and suture failure, directly linked to surgical technique choices. Findings established evidence‐based benchmarks for optimizing all‐inside ACL reconstruction outcomes. Conclusion: Our search and review demonstrated that a quadruple‐folded graft with the side‐to‐side suturing technique, suspended by 2 adjustable‐loop devices with additional tensioning and knot tying, and supplementary fixation with tibial reinforcement appears to offer the most stability. This has the potential to optimize functional recovery after ACL reconstruction via improved graft stability and reduced rerupture rates.