Anterior cruciate ligament (ACL) reconstruction has been a challenge for the orthopedic surgeon. Nowadays, we understand the consequences of the anteromedial and rotational instability that follow the absence of a functional ACL. Arthroscopic surgery offered not only a better scope of the anatomy and reconstruction possibilities, but also the best therapeutic tool available for solid biomechanical and anatomical reconstructions.
History has shown many different therapeutic approaches to ACL reconstructions, most of them with good results in anteromedial stability. However, many recent studies have emphasized the role of rotational stability as a major variable in the final success of ACL reconstructions, specifically on the development of meniscal and articular cartilage damage.
The use of autologous graft tissue in ACL reconstructions has been a sound strategy used worldwide with good results. The use of patellar tendon–bone grafts, hamstrings, or other similar tissues has the advantage of good and rapid integration at low cost. However, taking tissues from healthy sites has a toll. Patellofemoral pain in bone-tendon-bone grafts has been well described and decreased knee flexion power with high risk of muscle sprains in hamstring grafts has also been frequently reported in athletes. Donor sites can be painful, and sometimes even more symptomatic than the surgery itself. Other problems may arise such as hematomas or neurovascular injuries. Neuropathic pain is associated equally on the surgical portals and on the donor site in many reports.
The development of tissue banks in the past 2 decades has opened a new window for ligament reconstructions. Taking the autograft off the table is an attractive option that potentially means less time, less morbidity, and faster recovery. Integration of the bank graft is similar to autografts. Biomechanical properties of tendon allografts have shown similar behavior at long follow-ups. Risk of bacterial or viral cross infections is low, but remains a concern. Modern tissue banks must follow strict protocols for harvesting, sterilization, packaging, and delivery. Demand is high and donors are scarce, especially in underdeveloped countries. Bone-tendon-bone and hamstring allografts are commonly used, as they do not require changing the original surgical technique. However, sometimes more demand exists than available tissue, so surgeons have been exploring other tendon allografts suitable for ACL reconstructions.
The anterior tibialis tendon can be considered a good allograft for knee ligament reconstructions. It is a long tough tendon that can easily measure up to 20-cm long and 10-mm wide. It is biomechanically strong enough to take the knee forces, and long enough to play with different anatomical or biomechanical reconstruction techniques in ACL or posterior cruciate ligament reconstructions.
Most of the complications related to ACL reconstructions are related to graft placement than to fixation or tissue choice. At the end of the past century, we saw a research boom on fixation devices, showing different possible advantages, more in terms of easiness than in biomechanical fixation properties. In the past decade, we witnessed the arrival of poor graft placement complications resulting in early meniscus and cartilage damage in many patients. Some studies highlighted the relevance of associated injuries, especially posterolateral instability and residual rotational deficits. The use of anatomical landmarks for better graft placement was followed by the introduction of the double-bundle technique that biomechanically replaces the posterolateral and anteromedial anatomical bands of the native ACL.
We believe a double-bundle graft provides a better anatomical and biomechanical approach to ACL reconstruction. It has been clearly shown that on the tibial and femoral insertions, footprints exist of these 2 bundles. The biomechanical studies of Freddie Fu have shown the function of each bundle on the flexion and extension of the loaded knee joint. They play a crucial role in the rotational degrees of freedom of knee motion and provide better flexion-extension and anteroposterior (AP) gliding moments.
Anatomically and biomechanically speaking, it is logical to use double-bundle reconstruction. However, it involves designing new techniques that will require a learning curve, some complications due to these new techniques may arise, and many surgeons with good experience do not have a clear reason to switch techniques because of the good results of previous methods. All the in-vitro studies favor the double-bundle techniques, whereas the contrasts in clinical follow-ups are not as different. Cost is also an issue; in many of the new techniques, more implants are required for graft fixation.
In this article, we introduce anewanatomictechniqueusing a double-bundle ACL allograft fixed by U-shape bone tunnels on the tibia, and 2 interference screws on the femur through transtibial and anteromedial portals. As this is a U-shape tibial fixation using 2 bundles, we named it the double-bundle and double-tunnel ACL reconstruction with looped proximal tibial fixation. This surgical procedure provides an anatomic reconstruction without increasing surgical time and using known arthroscopic portals. No need for different instruments is required and the 2 interference screws are the same as those used in conventional reconstructions, which results in equivalent cost.
Para leer el resto del artículo, entra a este link:
