Biomechanical comparison of anterior cruciate ligament reconstruction fixation methods and implications on clinical outcomes

Abstract

Anterior cruciate ligament reconstruction (ACLR) is one of the more common surgeries encountered by orthopaedic surgeons, which has its inherent challenges due to the complex anatomy and biomechanical properties required to reproduce the function and stability of the native ACL. Multiple biomechanical factors from graft choice and tunnel placement to graft tensioning and fixation methods are vital in achieving a successful clinical outcome. Common methods of ACLR graft fixation in both the primary and revision setting are classified into compression/interference, suspensory, or hybrid fixation strategies with multiple adjunct methods of fixation. The individual biomechanical properties of these implants are crucial in facilitating early post-operative rehabilitation, while also withstanding the shear and tensile forces to avoid displacement and early graft failure during graft osseointegration. Implants within these categories include the use of interference screws (IFSs), as well as suspensory fixation with a button, posts, surgical staples, or suture anchors. Outcomes of comparative studies across the various fixation types demonstrate that compression fixation can decrease graft-tunnel motion, tunnel widening, and graft creep, at the risk of damage to the graft by IFSs and graft slippage. Suspensory fixation allows for a minimally invasive approach while allowing similar cortical apposition and biomechanical strength when compared to compression fixation. However, suspensory fixation is criticized for the risk of tunnel widening and increased graft-tunnel motion. Several adjunct fixation methods, including the use of posts, suture-anchors, and staples, offer biomechanical advantages over compression or suspensory fixation methods alone, through a second form of fixation in a second plane of motion. Regardless of the method or implant chosen for fixation, technically secure fixation is paramount to avoid displacement of the graft and allow for appropriate integration of the graft into the bone tunnel. While no single fixation technique has been established as the gold standard, a thorough understanding of the biomechanical advantages and disadvantages of each fixation method can be used to determine the optimal ACLR fixation method through an individualized patient approach.

Modified Implant Fixation Technique Is an Alternative for Patients with an Anterior Cruciate Ligament Tear in Limited Resource Settings: A Comparison Functional Outcome Study with Polyether Ether Ketone and Bioabsorbable Screws

“…The different types of fixation methods used in ACL reconstruction are typically categorized as compression, suspension, or hybrid fixation. Regardless of the implant chosen for fixation, secure fixation is paramount to avoid graft displacement and to allow graft integration into the bone tunnel [3,4].…”

“…The choice of implant, such as polyether ether ketone (PEEK) interference screws that offer secure fixation with reduced complication risks and MRI compatibility, and bioabsorbable screws, which naturally degrade, minimizes complications [3,5]. In a study by Devandri et al, the ACL reconstruction procedure in Indonesia was limited due to a low budget for reimbursement of the national insurance program.…”