Editorial Commentary: Major Technical Advances in Knee Anterior Cruciate Ligament Reconstruction Address Anatomy,Biomechanics, and Healing

The surgical techniques in knee anterior cruciate ligament (ACL) reconstruction continue to evolve significantly. Improved understanding of the anatomy, biomechanics, and healing of the ACL has offered the foundation for several advances. The goal of these innovations is to successfully restore the native anatomy and biomechanical function of the native ligament, provide a stable and pain-free knee joint, allow return to prior level of activity, prevent rerupture, and prevent osteoarthritis. Taken in sum, these are lofty goals. The shift toward anatomic ACL reconstruction, development of diverse graft options and configurations, and the addition of reinforcement techniques, such as the anterolateral ligament reconstruction and lateral tenodesis techniques, are major advancements in ACL reconstruction.     

Editorial Commentary: Graft Removal Versus Retention for Septic Arthritis After Anterior Cruciate Ligament Reconstruction: Accounting for Patient Preference Flips the Script on Current Practice

Septic arthritis is a rare but potentially devastating complication after anterior cruciate ligament (ACL) reconstruction. Studies examining surgical treatment options including graft retention and removal are largely inconclusive. Although the literature indicated that 43.8% of patients who have the graft removed later go on to have a revision ACL reconstruction compared with only 6.5% among those whose graft is retained, this expected-value decision analysis found removal to be the optimal treatment for patients with septic arthritis after ACL reconstruction. This is largely based on patient preference to avoid a late reoperation for residual knee infection. These findings support the concept of utility when considering treatment options for patients with a septic knee. For some, avoiding a late reoperation for a persistent infection is the most important factor and as such graft removal may be the most appropriate treatment to produce a positive outcome among these patients despite the fact that currently, an attempt at graft retention could represent the generally preferred treatment option among practicing surgeons.     

Biomechanics and anterior cruciate ligament reconstruction

For years, bioengineers and orthopaedic surgeons have applied the principles of mechanics to gain valuable information about the complex function of the anterior cruciate ligament (ACL). The results of these investigations have provided scientific data for surgeons to improve methods of ACL reconstruction and postoperative rehabilitation. This review paper will present specific examples of how the field of biomechanics has impacted the evolution of ACL research. The anatomy and biomechanics of the ACL as well as the discovery of new tools in ACL-related biomechanical study are first introduced. Some important factors affecting the surgical outcome of ACL reconstruction, including graft selection, tunnel placement, initial graft tension, graft fixation, graft tunnel motion and healing, are then discussed. The scientific basis for the new surgical procedure, i.e., anatomic double bundle ACL reconstruction, designed to regain rotatory stability of the knee, is presented. To conclude, the future role of biomechanics in gaining valuable in-vivo data that can further advance the understanding of the ACL and ACL graft function in order to improve the patient outcome following ACL reconstruction is suggested.     

Editorial Commentary: Patellar Tendon or Hamstring: Which Kind of Anterior Cruciate Ligament Patient Are You?

The role of graft selection on clinical and functional outcomes following anterior cruciate ligament (ACL) reconstruction has gained significant attention in the orthopaedic sports medicine community in recent years. Bone–patellar tendon–bone (BPTB) and semitendinosus/gracilis hamstring tendon (HT) autografts are 2 of the most commonly used grafts, given their low failure rates, predictable outcomes, and ability to incorporate appropriately at the graft site. However, multiple studies have recently shown each of these graft options to have some potentially less-desirable characteristics in regards to outcomes in specific patient populations. More specifically, in 14- to 25-year-old athletes, HT autografts have been shown to result in decreased rotational stability, decreased return to sport rates, and increased graft failure rates. On the other hand, BPTB autografts can require a prolonged recovery period and have been associated with increased postoperative pain and long-term kneeling pain. HT and BPTB grafts are both excellent grafts; however, it is important to understand the differences in clinical and functional outcomes between these graft options for ACL reconstruction. The characteristics of the graft need to be considered and individualized for each patient who is being treated for an ACL injury.     

Editorial Commentary: Chronic Anterior Cruciate Ligament Injury Requires Reconstruction Plus Lateral Tenodesis to Control Rotational Instability: Additional Technical Complexity May Result in Complications Without Improved Outcomes

How to restore native knee kinematics following complex knee injuries is still debated and under investigation. To better reproduce the native anterior cruciate ligament (ACL), surgeons have a host of different options, including graft choice, technique, fixation method, and single-, double-, and triple-bundle techniques, etc. Isolated ACL reconstruction alone is not effective in controlling complex instability patterns, especially regarding internal and external rotations. Several techniques have been described to address such instabilities, like single- or double- bundle ACL reconstruction plus lateral extra-articular tenodesis. In truth, chronic ACL injury requires reconstruction plus lateral tenodesis to control rotational instability. Additional technical complexity may result in complications without improved outcomes. Neither single-bundle nor double-bundle techniques are “truly” anatomic. Keep it simple; keep it safe.     

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.     

Editorial Commentary: Outcomes After Anterior Cruciate Ligament Reconstruction Are Defined by Individual Anatomy,Including Both Soft Tissue and Bone Morphology: It’s All Important

Well-designed studies add to our understanding of the anatomy, biology, biomechanics, and outcomes of the anterior cruciate ligament (ACL) following injury. Despite improvements in ACL treatment, we are still unable to exactly restore the individually unique function of the native ACL due to the complexity of knee physiology. The ACL is a dynamic structure with a rich neurovascular supply, distinct bundles, and 3-dimensional architecture that function in synergy with the bony morphology to facilitate healthy knee kinematics. Furthermore, the ACL exhibits a wide range of natural, anatomic variation. Since anatomic ACL reconstruction has been defined as functional restoration of the ACL to its native dimensions and collagen orientation, in addition to restoring the native footprint, it is important to restore the native size of the ACL, as the size of the tibial insertion site can vary by a factor of 3 from patient to patient. Moreover, variations in ACL soft tissue reflect differences in bony morphology. Bony morphology influences the static and dynamic biomechanics of the knee. Several bony morphologic factors influence the outcomes following ACL reconstruction, including posterior tibial slope, femoral condylar offset ratio, and notch shape. Morphologic differences that reflect pathologic states, such as the lateral notch sign and posterolateral plateau fracture, have been shown to be associated with greater grade instability. To respect the unique nature of each patient during surgical treatment, it is necessary to perform an individualized, anatomic, and value-based ACL reconstruction.     

Peroneus longus tendon graft for anterior cruciate ligament reconstruction: A case report and review of literature

IntroductionThe anterior cruciate ligament (ACL) is one of the most frequently injured structures of the knee joint. Anterior cruciate ligament reconstruction (ACLR) provides surgical restoration of the injured ACL using the placement of graft material. The choice of graft is principal in providing optimal knee stability after surgery. Peroneus longus tendon (PLT) is an autograft modality that offers unique benefits for ACL reconstruction cases.Presentation of caseWe present a case of ACL reconstruction surgery using PLT graft in a patient with a confirmed ACL rupture. Assessment of post-surgical pain, knee stability, and ankle function were performed to determine functional outcome and donor site morbidity. The follow-up results revealed favorable recovery and improvement in all objective parameters.DiscussionPost-operative biomechanical outcomes were evaluated using the International Knee Documentation Committee (IKDC) and the American Orthopedic Foot and Ankle Score (AOFAS) score. The use of PLT in ACL reconstruction established an excellent potential for its satisfactory result and comparable to other graft modalities in widely used evidence-based findings.ConclusionPeroneus longus tendon may be considered the first-option graft in ACL reconstruction as it indicated the absence of significant post-operative morbidity.     

Editorial Commentary: Back to the Future With the Medial Patellofemoral Complex

The desire to better re-create the native anatomy in orthopaedic surgery—and especially knee ligament reconstruction—was an area of great debate and discussion approximately 10 years ago in anterior cruciate ligament (ACL) reconstruction. Our better and more detailed understanding of the anatomy, especially the insertional anatomy, of the ACL fueled the debate over the best surgical technique to maximize function, improve patient outcomes, and reduce long-term morbidity. While these discussions are still ongoing, detailed study of the medial patellofemoral complex (MPFC) anatomy is bringing us “back to the future” with similar discussions on how to best re-create this anatomy. Although specific techniques and surgical risks versus rewards will continue to be debated, our improved understanding of the anatomy of the MPFC, similar to our improved understanding of the ACL, ultimately will improve how MPFC reconstruction is performed and improve patient outcomes.     

Hamstring autograft utilization in reconstructing anterior cruciate ligament: Review of harvesting techniques,graft preparation,and different fixation methods

Rupture of the anterior cruciate ligament (ACL) is a common orthopedic injury. Various graft options are available for the reconstruction of ruptured ACL. Using the hamstring muscle as an autograft was first described in 1934, and it remains a commonly harvested graft for ACL reconstruction. Hamstring autografts can be harvested using the traditional anteromedial approach or the newer posteromedial technique. An isolated semitendinosus tendon can be used or combined with the gracilis tendon. There are numerous methods for graft fixation, such as intra-tunnel or extra-tunnel fixation. This comprehensive review discusses the different hamstring muscle harvesting techniques and graft preparation options and fixation methods. It provides a comprehensive overview for choosing the optimal surgical technique when treating patients.     

Posterior Cruciate Ligament Rehabilitation: How Slow Should We Go?

Outcomes after posterior cruciate ligament (PCL) reconstructive surgery have historically been inferior to outcomes after reconstruction of the anterior cruciate ligament (ACL). As such, some surgeons may be reluctant to recommend reconstruction of the PCL. However, recent technologic advances have substantially improved PCL reconstructive surgical outcomes. These advances include better understanding of PCL diagnosis and surgical indications; recognition of the need for repair or reconstruction of associated injuries, especially injuries to the posterolateral and posteromedial corners of the knee; PCL-specific surgical instruments including mechanical tensioning devices to restore anatomic tibial step-off; improved graft fixation techniques including primary and backup methods of fixation; use of strong graft material including advances in the procurement, processing, and usage of allograft tissue; improved surgical techniques; and advances in the understanding of knee ligament structure and biomechanics, resulting in more accurate surgical tunnel placement, achieving anatomic graft insertion sites while minimizing graft bending. Today, PCL reconstructive surgery often results in excellent function with a return to the patient’s preinjury level of activity. In contrast to accelerated rehabilitation after ACL reconstructive surgery, slow and deliberate postoperative rehabilitation is recommended to allow early healing to occur after PCL reconstructive surgery.     

Graft options for ACL reconstruction

Once the decision for anterior cruciate ligament (ACL) reconstruction has been made, the orthopedist has to decide which graft substitute will best restore normal anterior knee stability. This article will present an overview of graft options as well as fixation options most commonly used in ACL reconstructions.     

Medial collateral ligament reconstruction with allograft using a double-bundle technique

Medial collateral ligament (MCL) reconstruction has been a topic of controversy in regard to the need for surgical reconstruction as well as the type of surgical reconstruction to be performed. Combined anterior cruciate ligament (ACL) and MCL reconstruction has been found to be associated with a higher incidence of postoperative arthrofibrosis than isolated ACL reconstruction; performing these reconstructions in a staged format has been proposed to avoid this devastating complication. We present a technique for MCL reconstruction that physiometrically re-establishes both anterior and posterior stabilizing components of the MCL and is performed with a limited soft-tissue dissection. This technique can easily be combined with an ACL allograft or hamstring reconstruction without need for staged or significantly delayed procedure. The technical details of this technique allow for stable fixation of an allograft reconstruction to allow for immediate postoperative knee range of motion with low patient morbidity because of the limited surgical approach.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 4 (April), 2002: E19     

Editorial Commentary: The Anterior Cruciate Ligament May Be Safer Wearing a Suture Tape Augmentation Seat Belt: Click It or Ticket

Bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction has the most data to support its use. However, there may still be room for improvement, and younger age, insufficient rehabilitation, altered neuromuscular patterns, and precocious return to play can increase risk of graft failure. High strength suture augmentation of soft-tissue repair or reconstruction has gained traction in a variety of applications for the knee, including medial collateral and posteromedial corner, lateral collateral ligament, posterior cruciate ligament, and ACL. For ACL reconstruction, the technique consists of using either suture or suture tape fixed at the femoral and tibial ACL footprints to allow for independent tensioning to back up the separately tensioned ACL reconstruction. The static augment serves as a load-sharing device, allowing the graft to see more strain during earlier levels of graft strain, until graft elongation occurs to a critical level whereby the augment will experience more strain than the graft. Hence, the “seat belt” analogy. This is distinct from static augmentation, where the high strength suture is fixed to the graft. Static augmentation (without tensioning separately from the graft) results in a load-sharing device and increased stiffness, but potential stress shielding compared with the “seat belt.” If suture tape augmentation improves patient outcome, it is a worthwhile to “click it.”     

Nonunited avulsion fractures of the intercondylar eminence of the tibia

Summary: We report 3 cases of nonunited avulsion fracture of the intercondylar eminence of the tibia. Characteristics of the clinical symptoms were limitation of knee extension, pain at knee extension, and a small amount of anterior instability. For the patient with a normal anterior cruciate ligament (ACL), the fragment was fixed by sutures with a button after curettage of the fibrous tissue. Two patients underwent endoscopic ACL reconstruction using quadrupled semitendinosus tendon because their ACLs had degenerated. Since the technique of ACL reconstruction under arthroscopic control has been well refined, endoscopic ACL reconstruction is considered to be 1 of the surgical options for nonunited avulsion fracture with symptomatic anterior instability if the ACL is degenerated.Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 7 (October), 2000: pp 757–762     

Transverse femoral implant prominence: four cases demonstrating a preventable complication for ACL reconstruction

Anterior cruciate ligament (ACL) tear is a commonly occurring injury that often demands surgical reconstruction. Although the utility of this operation is widely accepted, many specific components, including graft fixation technique, remain controversial. Many clinicians favor transverse femoral implant fixation for soft tissue ACL grafts. This technique can be accomplished successfully; however, in a minority of the cases, the femoral implant can be excessively prominent, leading to iatrogenic postoperative iliotibial band syndrome. This article presents 4 patients that developed postoperative iliotibial band syndrome resulting from transverse femoral implant prominence. Despite achievement of knee ligamentous stability, implant prominence compromised final clinical results following ACL reconstruction. Through change in Lysholm value, we reviewed the clinical outcomes of these patients following femoral implant hardware removal for treatment of iliotibial band syndrome. On hardware removal, all patients demonstrated complete symptomatic improvement, mirroring an average Lysholm value increase of 38. We believe transverse femoral implant prominence is avoidable, and subsequent iliotibial band syndrome is a preventable postoperative complication.     

Editorial Commentary: Filling the Void in Translational Research for Lateral Extra-articular Tenodesis for Anterior Cruciate Ligament Reconstruction: Are We Saturated With Biomechanical Studies?

Anterior cruciate ligament (ACL) graft failure rates remain unacceptably high in certain populations, and researchers are examining the effect that the anterolateral ligament (ALL) has on knee stability following ACL reconstruction. Currently, most available research examining the ALL has focused on cadaveric biomechanical kinematic studies, including the effect of surgical techniques for ALL reconstruction/lateral extra-articular tenodesis (LET). However, it is critical for ongoing and future research to focus on clinical outcome measures relating to individuals who have had ALL reconstruction or LET along with their ACL reconstructions. This is what will benefit clinicians most as to the appropriate indications for when to perform an extra-articular stabilization procedure in combination with ACL reconstruction.     

The anatomy of the ACL and its importance in ACL reconstruction

The anterior cruciate ligament (ACL) anatomy is very significant if a reconstruction is attempted after its rupture. An anatomic study should have to address, its biomechanical properties, its kinematics, its position and anatomic correlation and its functional properties. In this review, an attempt is made to summarize the most recent and authoritative tendencies as far as the anatomy of the ACL, and its surgical application in its reconstruction are concerned. Also, it is significant to take into account the anatomy as far as the rehabilitation protocol is concerned. Separate placement in the femoral side is known to give better results from transtibial approach. The medial tibial eminence and the intermeniscal ligament may be used as landmarks to guide the correct tunnel placement in anatomic ACL reconstruction. The anatomic centrum of the ACL femoral footprint is 43 % of the proximal-to-distal length of lateral, femoral intercondylar notch wall and femoral socket radius plus 2.5 mm anterior to the posterior articular margin. Some important factors affecting the surgical outcome of ACL reconstruction include graft selection, tunnel placement, initial graft tension, graft fixation, graft tunnel motion and healing. The rehabilitation protocol should come in phases in order to increase range of motion, muscle strength and leg balance, it should protect the graft and weightbearing should come in stages. The cornerstones of such a protocol remain bracing, controlling edema, pain and range of motion. This should be useful and valuable information in achieving full range of motion and stability of the knee postoperatively. In the end, all these advancements will contribute to better patient outcome. Recommendations point toward further experimental work with in vivo and in vitro studies, in order to assist in the development of new surgical procedures that could possibly replicate more closely the natural ACL anatomy and prevent future knee pathology.     

Transphyseal anterior cruciate ligament reconstruction in a skeletally immature knee using anterior tibialis allograft

Anterior cruciate ligament (ACL) injury in the skeletally immature individual is being recognized with increasing frequency. Nonoperative treatment of ACL injuries in skeletally immature patients have not been favorable. Surgical treatment options for complete ACL tears include primary ligament repair, extraarticular tenodesis, transphyseal reconstruction, partial transphyseal reconstruction, and physeal-sparing reconstruction. The advantage of transphyseal reconstruction is placement of the graft tissue in an isometric position, which provides better results, according to the literature. The potential disadvantage is angular or limb-length discrepancy caused by physeal violation. Controversy exists in allograft selection about whether bone or soft tissue passes into physes. The use of standard tunnels provides reliable results, but carries the risk of iatrogenic growth disturbance from physeal injury.This article presents 4 cases of transphyseal ACL reconstruction using anterior tibialis allograft in skeletally immature patients that had satisfactory functional outcomes with no growth disturbances. This is the first report of transphyseal ACL reconstruction using anterior tibialis allograft in skeletally immature patients in the English-speaking literature. All patients underwent transphyseal ACL reconstruction using anterior tibialis tendon allograft. None of the patients had angular deformities. No early physeal arrest was measured between the preoperative and postoperative radiographs. At last follow-up, the results of the Lachman test were normal for 3 patients and nearly normal for 1 patient. All patients demonstrated full range of knee motion (comparing the reconstructed knee to the contralateral knee). The results of the pivot-shift test were normal for 3 patients and nearly normal for 1 patient. No patients reported giving way.