Quadriceps Tendon Graft for Anterior Cruciate Ligament Reconstruction: THE GRAFT OF THE FUTURE!

Anterior cruciate ligament (ACL) reconstruction is one of the most common orthopaedic surgeries performed on active people in the world. One of the most important surgical decisions is graft type for use in the reconstruction. Despite extensive research on optimal graft choice for ACL reconstruction, discrepancy exists among practicing surgeons' graft preference. Recently, the quadriceps tendon has gained popularity for use as a graft source for ACL reconstruction.The all soft tissue quadriceps graft offers many advantages over other autograft choices. Histologically it has 20% more collagen fibrils per cross-sectional area than the patellar tendon (PT). Biomechanically, its ultimate load is 70% > than that of a similar width PT graft, while its modulus is more similar to the native ACL than either the PT or hamstring graft. Anatomically the quadriceps tendon has significantly more volume than the PT. Thus, even after harvest of the quadriceps graft, the remaining quadriceps tendon is still 80% stronger than the intact PT!The length and cross-sectional area of the quadriceps tendon graft can be tailored to the needs of the patient. On any patient over 5 feet tall, a graft length of 7 cm can be obtained. Because the thickness of the tendon is almost twice the thickness of the same patient's PT, a graft diameter from 7 to 11 mm can easily be achieved. Thus, this graft can be customized for both primary and revision surgeries.Harvest site morbidity is minimal. An incision less than 2 cm in an area with no significant cutaneous nerves without harvest of any patella bone leads to no significant harvest site pain, numbness, or palpable defect.Clinical outcomes using this graft are excellent. Our prospective data on nearly 1,000 grafts, with a mean patient age of 20 years old, show a 4.2% failure rate. Thus, the all soft tissue quadriceps graft will be the surgical choice for ACL reconstruction for future athletes.     

Vordere Kreuzbandersatzplastik

Rupture of the anterior cruciate ligament (ACL) is the most frequent ligamentous injury in the knee. The goal of its surgical reconstruction is the restoration of stability so that the roll-and-glide mechanism is as close as possible to normal. The indications for reconstruction are becoming more numerous. The tendons most commonly used for grafts are the patellar, hamstring and quadriceps tendons; the one selected depends on the patient’s needs. Despite technical improvements (in placement and fixation of the grafts), the risk of technical failures and intraoperative complications is still up to 20%. Besides the well-known problems with graft harvesting, the windshield-wiper effect and incorrect placement of the drilling tunnels are the most common reasons for revision surgery.     

Anterior cruciate ligament reconstruction failure after tibial shaft malunion

Anterior cruciate ligament (ACL) reconstruction is common, with >100,000 procedures performed each year in the United States. Several factors are associated with failure, including poor surgical technique, graft incorporation failure, overly aggressive rehabilitation, and trauma. Tibial shaft fracture is also common and frequently requires operative intervention. Failure to reestablish the anatomic alignment of the tibia may cause abnormal forces across adjacent joints, which can cause degenerative joint disease or attritional failure of the surrounding soft tissues. This article describes a case of ACL reconstruction failure after a tibial fracture that resulted in malunion. Excessive force across the graft from lower-extremity malalignment and improper tunnel placement likely contributed to the attritional failure of the graft. This patient required a staged procedure for corrective tibial osteotomy followed by revision ACL reconstruction. This article describes ACL reconstruction failure, tibial shaft malunions, their respective treatments, the technical details of each procedure, and the technical aspects that must be considered when these procedures are done in a staged manner by 2 surgeons.     

Editorial Commentary: During Anterior Cruciate Ligament Reconstruction,Lateral Extra-Articular Procedures Have Risks and Should be Reserved for Proper Indications: Do Not LET ALL Revision Anterior Cruciate Ligament Reconstructions Be the Same

Recently, there has been renewed interest in performing a lateral extra-articular procedure (LEAP), either an anterolateral ligament (ALL) reconstruction or a LET (lateral extra-articular tenodesis) to address a deficiency of the anterolateral complex (ALC) of the knee during anterior cruciate ligament (ACL) reconstruction. The ALC consists of the superficial and deep aspects of the iliotibial band with its Kaplan fiber attachments on the distal femur, along with the ALL, a structure within the anterolateral capsule. The ALC functions to provide anterolateral rotatory stability as a secondary stabilizer of the ACL. The evidence to date is that the addition of a LEAP to a revision ACL reconstruction may reduce the risk of repeat graft failure and rotatory laxity. However, in some cases, performing a LEAP may not confer any additional benefit and add unwarranted risk including lateral pain, reduced quadriceps strength, longer time to recovery, and overconstraint of the lateral compartment with associated cartilage damage. Perhaps LEAP is best indicated for high-risk patients (young, active in pivoting sports, high-grade pivot-shift, generalized ligamentous laxity or knee hyperextension, Segond fracture, chronic ACL lesion, lateral femoral notch sign, lateral coronal plane laxity, concurrent meniscus repair, or ALC injury on magnetic resonance imaging). Other modifiable risk factors should not be ignored (graft choice, graft size, tunnel position, graft fixation, associated injuries such as a lateral meniscal root tear, or anatomic factors such as an increased posterior tibial slope). Do not LET ALL revision anterior cruciate ligament reconstructions be the same! A lateral extra-articular procedure may sometimes, but not always, reduce the risk of further failure.     

Editorial Commentary: Managing Excessive Posterior Slope in Anterior Cruciate Ligament Reconstruction: Where Do We Draw the Line?

When an anterior cruciate ligament (ACL) reconstruction fails, surgeons often rush to critique graft placement, graft choice, size, and fixation amongst other factors. One often-overlooked but important risk factor for noncontact failure of ACL reconstruction is tibial alignment. Although the deleterious effects of varus and valgus malalignment have been well established, recent research calls attention to excess posterior tibial slope as an underappreciated risk factor for failure of ACL reconstruction.     

Decreased quadriceps activation measured hours prior to a noncontact anterior cruciate ligament tear

STUDY DESIGN: Case report. BACKGROUND: Decreased quadriceps activation has been shown to be present following anterior cruciate ligament (ACL) injury, but its presence prior to ACL injury is unknown. The purpose of this case report was to describe the level of quadriceps activation measured hours before a noncontact ACL injury in an individual who previously demonstrated known biomechanical risk factors for ACL injury. CASE DESCRIPTION: A 23-year-old female (height, 176.9 cm; mass, 72.4 kg), sustained a left noncontact ACL injury while landing from a jump stop during a recreational basketball game. This case was unique because data regarding landing biomechanics and quadriceps force and activation were gathered in 2 separate, unrelated studies prior to injury. OUTCOMES: Peak external knee abduction moment (-65.3 Nm) during a drop jump landing 8 months prior to injury indicated elevated risk for ACL injury. Involved quadriceps central activation ratios (CAR) were obtained 1 week (CAR, 0.81) and 4 hours (CAR, 0.77) prior to injury. Strength and CAR (0.76) measurements changed very little within 36 hours of injury and both strength, and activation (CAR, 0.90) improved following surgical reconstruction and formal rehabilitation. DISCUSSION: An individual with known biomechanical risk factors for ACL injury may compound risk for noncontact ACL injury if decreased quadriceps activation is also present. LEVEL OF EVIDENCE: Prognosis, level 4.     

Editorial Commentary: Risk Factors of Cyclops Syndrome in Quadriceps Autograft Anterior Cruciate Ligament Reconstruction: More Helpful Data in Weighing Graft Choice

Arthrofibrosis after anterior cruciate ligament (ACL) reconstruction can be a devastating complication with risk factors and causes not well established. Cyclops syndrome is a subtype involving localized scar anterior to the graft, which is typically treated with arthroscopic debridement. ACL quadriceps autograft is a newly popular graft option for which clinical data continue to develop. However, recent research shows possible increased risk of arthrofibrosis with quadriceps autograft. Possible causes include inability to achieve active terminal knee extension after extensor mechanism graft harvesting; patient characteristics, including female sex, and social, psychological, musculoskeletal, and hormonal differences; larger graft diameter; concomitant meniscus repair; exposed collagen fibers of the graft abrading the fat pad or tibial tunnel or intercondylar notch; smaller notch size; intra-articular cytokine; and biomechanical stiffness of the graft.     

Editorial Commentary: Anterior Cruciate Ligament Suture Repair Could Have High Failure Rates in Active Athletes of All Ages

When it comes to anterior cruciate ligament (ACL) injury and surgery, age is a proxy for early return to strenuous sports. In addition, premature return to sport is a risk factor for reinjury after ACL surgery. Thus, when considering ACL suture repair as an alternative to ACL graft reconstruction, we must consider that failure rates may be influenced by patient demographic variables, particularly age and activity. In the end, treatment options for young patients who are highly active and eager to make a timely return to sport after ACL injury require careful evaluation.     

Editorial Commentary: Goldilocks and the Three Grafts: Managing Tendon Harvest and Graft Length Problems in Autograft Anterior Cruciate Ligament Reconstruction

Autograft hamstring tendon harvest in anterior cruciate ligament (ACL) reconstruction can occasionally result in a graft length that is inadequate for creation of a robust ACL graft. Patients at risk for an abnormally short hamstring may also be high risk for ACL reinjury. Graft augmentation with allograft may be a suboptimal solution to this problem. Therefore, a reliable means for preoperative estimation of hamstring tendon length by magnetic resonance imaging measurement could avoid this pitfall. However, even with a reliable correlation between magnetic resonance imaging measurement and actual harvested tendon length, establishing a simple, clinically relevant threshold below which hamstring grafts should be avoided remains elusive. By contrast, all-soft-tissue quadriceps autograft avoids the potential length problems inherent to both bone tendon bone (graft–tunnel mismatch) and hamstring tendon grafts, but intermediate- and long-term outcome studies are still needed to validate all-soft-tissue quadriceps autograft in ACL reconstruction.     

Quadriceps protects the anterior cruciate ligament.

The aim of this study is to show that the quadriceps is the primary muscular restraint to anterior tibial translation during closed kinetic chain activities such as running, jumping, walking, and standing. It is my hypothesis that the quadriceps vector is directed superiorly during open kinetic chain knee extension and inferiorly during closed kinetic chain knee extension. My methods involve vector analysis based on a lateral radiograph of the normal human knee and muscle ultrasound. My results show that the quadriceps vector is directed superiorly for open kinetic chain knee extension and inferiorly for closed kinetic chain knee extension. The inferiorly directed quadriceps vector has an anterior femoral-tibial or posterior tibial-femoral component, which protects the anterior cruciate ligament (ACL) from anterior tibial-femoral shear. Therefore during closed kinetic chain activities, the quadriceps protects the ACL regardless of the activity of the hamstrings. Given that the quadriceps is much stronger than the hamstrings, has better leverage at low knee flexion angles, and a favorable vector with regard to the ACL during closed kinetic chain activities, and since most activities of daily living, sports, and non-contact ACL injuries occur with the foot on the ground, then it can be concluded that the quadriceps is the primary ACL protagonist. My findings have the following implications: (1) weak quadriceps are a risk factor for non-contact ACL injuries, (2) strong quadriceps are important for ACL injury prevention and rehabilitation, and (3) preservation of quadriceps strength is an important surgical goal.     

Anatomic anterior cruciate ligament reconstruction utilizing the double-bundle technique

The goal of every orthopaedic surgeon should be to restore anatomy as close as possible to normal. Intense research on reconstruction of the anterior cruciate ligament (ACL) and an advancing knowledge of the anatomy and function of the 2 primary bundles of the ACL have led to techniques of ACL reconstruction that more closely restore normal anatomy. Restoring the ACL footprint is one of the most important goals of the surgery, and the choice between anatomic single-bundle and double-bundle ACL reconstruction is determined by the anatomical features of each patient. After reconstruction, the graft undergoes a complex, lengthy process of remodeling; therefore, inappropriate (early), aggressive rehabilitation can lead to graft failure and compromise the patient's outcome. The purpose of this article is to provide an overview of the anatomy and function of the ACL, the methods for anatomic single-bundle and double-bundle ACL reconstruction, and our recommendations for postoperative rehabilitation.     

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.     

Editorial Commentary: Blood Flow Restriction Therapy Prior to Anterior Cruciate Ligament Reconstruction: Small Effects Require Accurate Measurements

A recent research study showed that blood flow restriction (BFR) therapy was safe and well tolerated but failed to demonstrate efficacy as a modality that provides greater gains in quadriceps strength when added to a standard home program in patients awaiting anterior cruciate ligament (ACL) reconstruction. Despite employing a validated method of measurement, the results were highly variable, indicating the need for measurements with sufficient accuracy to detect the small, but potentially meaningful, gains in quadriceps strength that’s been attributed to BFR. The results inform future investigations of BFR prior to ACL surgery by demonstrating the need for accurate methods of measurements when the anticipated effects are small.     

Revision ACL Reconstruction: Principles and Practice

IntroductionThe incidence of anterior cruciate ligament reconstruction (ACLR) surgeries is increasing and so is the number of revision surgeries for a failed ACLR. The spectrum of ACL failure includes symptoms of recurrent instability, pain, and/or stiffness.DiscussionFactors contributing to ACL failure may be classified as patient-related, surgeon-related, and biological factors. Of these, tunnel malposition and recurrent trauma are the most common causes. Detailed patient assessment, imaging, and studying details of the index surgery are critical prior to planning revision surgery. Infection has to be ruled out prior to planning any reconstructive surgical procedure. Osseous malalignment in the coronal or sagittal planes would also need correction along with or prior to revision ACL surgery. Revision ACL reconstruction maybe performed as a one-stage or two-stage procedure. Severe tunnel dilatation, infection, or arthrofibrosis necessitates a two-stage approach. Autografts are preferred for revision ACL due their lesser re-tear rates and better outcomes. Associated meniscus tears and cartilage injuries are more common in revision than in primary surgery and need to be managed appropriately. Extra-articular reconstruction for controlling anterolateral instability is frequently required as well.ConclusionRevision ACL reconstruction is a complex undertaking due to limited graft options, compromised anatomy and high frequency of associated injuries. Patient expectations must be tempered because functional outcomes and return to pre-injury sports are inferior to a primary surgery.     

Editorial Commentary: The Ratio of Tibial Slope and Meniscal Bone Angle is a Strong Predictor for Anterior Cruciate Ligament Injury: A Steep Hill and a Shallow Speed Bump are a Hazardous Combination

The lateral tibial posterior slope (LTPS) and the lateral meniscal bone angle (MBA) are important geometrical features of the knee joint and have therefore been of interest in the setting of anterior cruciate ligament injury (ACL) and ACL reconstruction. An emerging body of evidence suggests that LTPS is an independent risk factor for primary and recurrent ACL injury. Furthermore, biomechanical and clinical evidence is emphasizing the crucial contribution of the lateral meniscus to rotatory knee stability. Thus, not surprisingly, the MBA has also been shown to be an independent risk factor regarding ACL injury. The ratio of LTPS and MBA is a relatively new idea but has shown to be highly predictive for primary and recurrent ACL injury and may be used to identify patients at high risk of ACL reconstruction failure.     

Rekonstruktion des vorderen Kreuzbandes

The treatment of ruptures of the anterior cruciate ligament (ACL) plays an essential role for both clinicians and resident physicians. To date many questions regarding the outcome as well as ACL reconstruction techniques have not yet been conclusively clarified. Whether reconstruction of the ACL protects the knee from osteoarthritis is still unproven; however, it is well known that an unstable knee joint is more vulnerable to secondary injuries, such as meniscal tears. Thus, early ACL reconstruction is recommended to minimize the risk of these secondary injuries. Three alternative sources of material for autologous ACL reconstruction are commonly utilized. An accessory hamstring (i.e. semitendinosus tendon with or without the gracilis tendon), a central strip of the patellar tendon with bone blocks and a central strip of the quadriceps tendon with or without bone block are the most common donor tissues used in autografts. Besides selection of the type of graft, the tendon diameter also plays a crucial role. Some progress has recently been made with respect to tunnel placement. The aim is to find an anatomical tunnel position. Reconstruction of both the anteromedial and the posterolateral ACL bundles helps to rebuild the anatomy of the original ACL; however, scientifically this approach did not lead to any improvement in the results. For fixation techniques a differentiation is made between aperture, extracortical and implant-free fixation. Generally, re-ruptures are less common than revisions as a result of graft ruptures due to technical mistakes during surgery. The most common mistakes concern tunnel placement and graft fixation. Also overlooked instability can have a negative influence on the outcome of ACL reconstruction.     

Quadriceps tendon-patellar bone autograft for anterior cruciate ligament reconstruction: a technical note

The quadriceps tendon autograft can be used for primary and revision anterior cruciate ligament (ACL) reconstruction. Despite several successful clinical reports, graft fixation issues remain, and the ideal technique for fixation continues to be controversial. We present a technique of ACL reconstruction with quadriceps tendon autograft (QTA) using a patellar bone block. The tendon end is fixed in the femoral tunnel and the bone plug in the tibial tunnel using reabsorbable interference screws. The advantages of this technique are related to the increase in stiffness of the graft, the achievement of a more anatomic fixation, and a reduction in synovial fluid leakage.     

Allograft anterior cruciate ligament reconstruction: indications, techniques, and outcomes

The anterior cruciate ligament (ACL) is an important stabilizer of the knee against translational and rotational forces. The goal of anatomic reconstruction of the ACL-deficient knee is to re-create a stable knee that will allow for return to sport and prevent recurrent injury. Multiple graft options exist for ACL reconstruction, and each option has unique advantages and disadvantages. With appropriate patient selection, each graft can be utilized to optimize patient outcomes. Allograft options limit morbidity following ACL reconstruction, but care must be taken with surgical technique and postoperative rehabilitation to allow for graft incorporation. An understanding of the surgical technique and differences between graft options will allow the patient, surgeon, and physical therapist to maximize outcomes following ACL reconstruction.     

Editorial Commentary: Revision Anterior Cruciate Ligament Using Soft Tissue Autograft Quadriceps Is Effective but Not Recommended for All Comers

The average revision rate is between 3.2% and 11.1%following primary anterior cruciate ligament (ACL) reconstructions,¹ and an objective failure rate of 13.7% has been reported for revision ACLR.² Prior implants, positioning of tunnels, and muscle weakness from the prior reconstruction present challenges. Additionally, graft choice for the revision reconstruction is restricted, depending on the primary reconstruction. Revision ACL reconstruction with the all-soft tissue quadriceps tendon autograft is a viable option with 83.3% of the patients surpassing the minimally clinically significant difference for International Knee Documentation Committee (IKDC) scores, which is similar to outcomes for revision ACL reconstruction (ACLR) using bone-patella-bone and hamstring tendon autografts. Furthermore, objective strength data suggest that it is possible to achieve equal limb symmetry index strength ratios even in the setting of prior bone-patella tendon-bone autograft. However, although I am cautiously optimistic regarding soft tissue quadriceps autograft in revision ACLR, I would be hesitant to recommend it for all comers. In my experience, young high school/collegiate female athletes with primary reconstruction using BPTB autograft may not be able to tolerate a secondary insult to the extensor mechanism via quadriceps tendon (QT) autograft harvest, where hematoma and arthrofibrosis could be concerns. Furthermore, increased posterior tibial slope may require evaluation and treatment, and the addition of a lateral extra-articular tenodesis may reduce residual rotatory laxity in ACL revision patients.