Anatomic Outside-In Reconstruction of the Anterior Cruciate Ligament Using Femoral Fixation with Metallic Interference Screw and Surgical Staples (Agrafe) in the Tibia: An Effective Low-Cost Technique

Technology Update in Management of Multi-Ligament Knee Injuries

Introduction

Multi-ligament knee injuries present in various combinations of structures around the knee joint, with or without involvement of neurovascular structures, posing significant challenges to the treating physician and therapists. Accurate diagnosis with appropriate surgical intervention and comprehensive rehabilitation to restore function and stability is, therefore, paramount. This article looks at the recent advancements in technology that are aiding in the management of these injuries.

Method

An extensive search of literature was done in PubMed, SCOPUS, and Google Scholar on this topic and the necessary information was derived from the relevant articles for this review. The progress made in the field of diagnosis, surgical management, rehabilitation and patient education tools were explored.

Discussion

A wide variety of diagnostic tools exists that are providing a more accurate evaluation of multi-ligament knee injuries both pre-operatively and post operatively. Advances in technology and techniques have aided in transforming their surgical management to a more minimally invasive approach. Patient-specific instrumentation, computer navigation and robotic-assisted surgery are in various stages of development offering enhanced precision and accuracy during ligament reconstruction procedures along with developments in digital technology and artificial intelligence.

Conclusion

Advancements in technology have transformed the management of multi-ligament knee injuries, offering new tools and techniques that enhance diagnostic accuracy, surgical precision, and rehabilitation effectiveness. Artificial intelligence and its utility have widened the horizons, while at the same time bringing in the need for regulations necessary to monitor and develop these technologies.

Analysis of the Mechanical Behavior of Porcine Graft Fixation in a Polyurethane Block Using a 3D-printed PLA Interference Screw

Objective  The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods  Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results  Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion  The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

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

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.