Anatomic Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACLR) techniques have substantially evolved over the past several decades, driven by evidence that nonanatomic techniques increase the risk for instability, loss of motion, surgical failure, and posttraumatic osteoarthritis. Early techniques used transtibial femoral tunnel drilling, although improved understanding of the anatomy and biomechanics has led to independent femoral tunnel. Anatomic ACLR requires careful consideration of the native ACL dimensions and orientation. Although there is significant variation between patients, understanding of anatomic patterns allows for reliable identification of the ACL footprints and appropriate tunnel positioning, particularly in chronic injuries where the remanent ACL stump is degraded or absent. The femoral tunnel should be placed low and posterior on the lateral femoral condyle using the lateral intercondylar and bifurcate ridges as landmarks. The center of the tibial footprint can be determined by referencing the medial tibial spine and posterior border of anterior horn of lateral meniscus. Measurement of the dimensions of the native ACL and intercondylar notch is also critical for determining graft size and minimizing the risk of impingement, with a goal of reconstructing 50% to 80% of the tibial footprint area. Clinical outcome studies have demonstrated superior anteroposterior and rotatory knee stability with low surgical revision rates (reported between 3% and 5%). By adhering to the principles of anatomic ACLR, surgeons can produce an appropriately sized and located graft for the individual patient, thereby best restoring native knee kinematics and maximizing function. The aim of this infographic is to highlight essential features of anatomic ACLR techniques, which a focus on the native anatomy and surgical planning to achieve an anatomic ACLR.     

All-Inside Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed knee operations. An “all-inside” technique creates bone sockets for ACL graft passage, as opposed to more traditional full bone tunnels, and typically incorporates suspensory fixation instead of screw fixation to secure the graft. This technique may be indicated for any ACL reconstruction surgery, where adequate bone stock exists to drill sockets and to use cortical fixation. The technique may be used with all soft tissue, as well as bone plug ACL grafts and autograft hamstring or quadriceps tendon; most allograft tendon options may be performed with an all-inside technique. Advantages include anatomic tunnel/socket placement, decreased postoperative pain and swelling, minimal hardware, appropriate graft tensioning and retensioning, and circumferential graft to bone healing. Tips for successful all-inside surgery include matching graft diameter to socket diameter, drilling appropriate length sockets based on individual graft length, so as not to “bottom out” the graft and confirming cortical button fixation intraoperatively. Potential complications include graft-socket mismatch, full-tunnel reaming, and loss of cortical fixation. Multiple studies have shown the all-inside technique to have similar or superior biomechanical properties and clinical outcomes compared to the more traditional full-tunnel ACL reconstruction techniques.     

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures performed by orthopaedic surgeons. The procedure has improved significantly since its inception in 1900 and continues to be intensively studied with outcomes receiving considerable attention. Traditional ACL reconstruction techniques have focused on one portion of the ACL—the anteromedial bundle. Single-bundle ACL reconstruction is the criterion standard and has provided good to excellent results, with many athletes being able to return to sports; however, recently, some authors have noted persistent instability with functional testing and degenerative radiographic changes after single-bundle ACL reconstruction. As a result, several centers have attempted to improve upon the single-bundle technique by reconstructing both the anteromedial and posterolateral bundles of the ACL. This article will present the embryologic, anatomic, and biomechanical rationale for double-bundle ACL reconstruction. In addition, the latest outcomes of double-bundle ACL reconstruction will be presented.     

All-Inside Anterior Cruciate Ligament Graft-Link Technique: Second-Generation, No-Incision Anterior Cruciate Ligament Reconstruction

We describe an anatomic, single-bundle, all-inside anterior cruciate ligament (ACL) graft-link technique using second-generation Flipcutter guide pins (Arthrex, Naples, FL), which become retrograde drills, and second-generation cortical suspensory fixation devices with adjustable graft loop length: femoral TightRope (Arthrex) and tibial ACL TightRope-Reverse Tension (Arthrex). The technique is minimally invasive using only four 4-mm stab incisions. Graft choice is no-incision allograft or gracilis-sparing, posteriorly harvested semitendinosus material. The graft is sutured 4 times through each strand in a loop and linked, like a chain, to femoral and tibial adjustable TightRope graft loops. With this method, graft tension can be increased even after graft fixation. The technique may be modified for double-bundle ACL reconstruction.     

Hybrid Anterior Cruciate Ligament Reconstruction: Introduction of a New Technique for Anatomic Anterior Cruciate Ligament Reconstruction

Recently, anatomic or double-bundle reconstruction of the anterior cruciate ligament (ACL) has been presented in an effort to more accurately restore the native anatomy. These techniques create 2 tunnels in both the femur and tibia to reproduce the bundles of the ACL. However, the increased number of tunnels, particularly on the femoral side, has raised some concerns among authors and surgeons. We describe a technique to reconstruct the 2 distinct bundles of the ACL by using a single femoral tunnel and 2 tibial tunnels, the “hybrid” ACL reconstruction. The femoral tunnel is drilled through an anteromedial arthroscopy portal, which allows placement in a more anatomic position. Fixation in the femur is achieved with a novel device that separates a soft-tissue graft into 2 independently functioning bundles. Once fixed in the femur, the anteromedial and posterolateral bundles of the graft are passed through respective tunnels at the anatomic footprint on the tibia. These bundles are independently tensioned, which creates a reconconstruction that is similar to the native ACL. The technique presented provides surgeons with an alternative to other double-bundle techniques involving 4 tunnels.     

Allograft Use in Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures performed by orthopedic surgeons. While autograft reconstruction remains the gold standard, allograft tissues have become a controversial option for ACL reconstruction. No data currently exist regarding recent trends in graft choices, and no consensus exists over which graft type is most appropriate for which patient. In this article, we examine trends in ACL graft choice at our institution, and review the pertinent information a surgeon must consider when making this decision. We reviewed operating room records from 2002 to 2008 to determine trends in graft choice for primary single bundle ACL reconstruction. Total number of procedures performed, graft choices, and patient ages were recorded. Patients were divided into the following age groups: less than 16, 16 to 20, 21 to 30, 31 to 40, 41 to 50, and over 50. Percent of ACL reconstructions using allograft was calculated for each year, as well as for each age group. Data were analyzed for trends in ACL graft choice over this time period as well as for trends in graft choice by age. We hypothesized that the rate of allograft use in primary ACL reconstruction had increased over time and that allograft use was associated with higher patient age. We also review the risks, safety, and standards for tissue procurement. Allograft use increased significantly (p < 0.001) from 2002 (17%) to 2008 (46%). There was also a significant difference (p < 0.001) in average age of patients receiving allografts (40.4 years) and autografts (26.4 years). Allograft use was significantly associated with higher patient age (p < 0.05) and increased with each successive age group from a rate of 9.9% in patients under 16 to 79.9% in patients over 50. Our study found that allograft use in primary ACL reconstruction has significantly increased from 2002 to 2008 and is significantly more common in older patients.