Technical considerations in revision anterior cruciate ligament surgery

Revision ACL surgery is a technically demanding enterprise that requires meticulous preoperative planning and tempered postoperative expectations on the patient's part. Despite the complexities of the procedure, it is becoming more common as an increasing number of primary ACL reconstructions are being performed, expanding the pool of patients at risk for failure. Candidates for revision surgery should be selected carefully, focusing on those patients with recurrent instability rather than pain as their primary complaint. A thorough history and physical examination is essential, taking care to identify additional patholaxity that might contribute to a failed ACL reconstruction. To optimize outcomes, surgeons must take care to avoid common pitfalls in index and revision procedures. Femoral and tibial tunnels should be positioned anatomically, and staged bone grafting procedures should be considered if revision graft fixation may be compromised by tunnel defects. The type of graft must be carefully selected, appropriately tensioned, and securely fixed. Surgeons should have a number of techniques and instruments at their disposal for performing each of these steps, as the highly variable presentation of failed ACL reconstructions demands a versatile approach. Ultimately, with cautious rehabilitation, these techniques will allow for restoration of knee stability and, in many cases, an improvement in activity level.     

Medial portal technique for single-bundle anatomical Anterior Cruciate Ligament (ACL) reconstruction

The aim of the paper is to describe the medial portal technique for anatomical single-bundle anterior cruciate ligament (ACL) reconstruction. Placement of an ACL graft within the anatomical femoral and tibial attachment sites is critical to the success and clinical outcome of ACL reconstruction. Non-anatomical ACL graft placement is the most common technical error leading to recurrent instability following ACL reconstruction. ACL reconstruction has commonly been performed using a transtibial tunnel technique in which the ACL femoral tunnel is drilled through a tibial tunnel positioned in the posterior half of the native ACL tibial attachment site. ACL reconstruction performed using a transtibial tunnel technique often results in a vertical ACL graft, which may fail to control the combined motions of anterior tibial translation and internal tibial rotation which occur during the pivot-shift phenomenon. The inability of a vertically oriented ACL graft to control these combined motions may result in the patient experiencing continued symptoms of instability due to the pivot-shift phenomenon. The medial portal technique in which the ACL femoral tunnel is drilled through an anteromedial or accessory anteromedial portal allows consistent anatomical ACL tunnel placement. This paper describes the advantages of the medial portal technique, indications for the technique, patient positioning, proper portal placement, anatomical femoral and tibial tunnel placement, graft tensioning and fixation.     

Editorial Commentary: Osseous Anatomy of the Knee in Female Patients is a Significant Risk Factor for Anterior Cruciate Ligament Injury and Anterior Cruciate Ligament Graft Failure

Risk for anterior cruciate ligament (ACL) injury is greater in female than in male patients for a myriad of reasons, with osseous anatomy about the knee proving to be one significant risk factor for ACL injury and/or ACL graft failure. While femoral intercondylar notch size/shape and posterior tibial slope have been well-examined in this regard for their contribution to potential ACL injury, morphology of the lateral femoral condyle is a newer entity that may be linked to risk for ACL injury. Smaller/stenotic femoral intercondylar notches, increased posterior tibial slope of the lateral tibial plateau, and increased posterior condylar depth of the lateral femoral condyle have all been shown to increase risk for ACL injury and/or ACL graft failure. Such associations provide knee surgeons with food for thought when considering procedures such as notchplasty, staged anterior closing wedge high tibial osteotomy, and anterolateral ligament reconstruction/augmentation at the time of primary or revision ACL reconstruction. Further investigation into the links between pre-operative imaging parameters and outcomes following such concomitant procedures is required in order for any significant conclusions to be drawn.     

Revision anterior cruciate ligament reconstruction: an update

With the rising number of anterior cruciate ligament (ACL) reconstructions performed, revision ACL reconstruction is increasingly common nowadays. A broad variety of primary and revision ACL reconstruction techniques have been described in the literature. Recurrent instability after primary ACL surgery is often due to non-anatomical ACL graft reconstruction and altered biomechanics. Anatomical reconstruction must be the primary goal of this challenging revision procedure. Recently, revision ACL reconstruction has been described using double bundle hamstring graft. Successful revision ACL reconstruction requires an exact understanding of the causes of failure and technical or diagnostic errors. The purpose of this article is to review the causes of failure, preoperative evaluation, graft selection and types of fixation, tunnel placement, various types of surgical techniques and clinical outcome of revision ACL reconstruction.     

Extra-articular lateral reconstruction technique.

This article describes an anterolateral reconstruction procedure that, when used in combination with an intra-articular anterior cruciate ligament (ACL) reconstruction, restores rotary and anterior knee stability. We believe that failing to recognize lateral instabilities and to perform an extra-articular reconstruction is an under-recognized cause of failure of ACL reconstruction. We also describe the indications, medical histories, and physical examination tests used to determine when an anterolateral reconstruction is needed. One should suspect a compromise of the lateral structures when presented with a failed ACL reconstruction in which the tunnels, the graft, and the rehabilitation all seem to have been done properly, or when a prior lateral procedure has been attempted and failed. In our experience, if a second ACL reconstruction is undertaken without the benefit of a lateral reconstruction, it may fail as well.     

Evaluation of bone incorporation of patellar tendon autografts and allografts for ACL reconstruction using CT

Anterior cruciate ligament (ACL) reconstruction is a relatively common orthopedic procedure, with patellar tendon frequently a graft source. However, controversy exists regarding the decision to use autograft or allograft patellar tendon tissue. This experimental study used computed tomography (CT) to compare the percentage of bone graft incorporation following ACL reconstruction using autografts and allografts. Fifty consecutive patients undergoing ACL reconstruction were included in the study. The tibial bone plug was imaged with CT 1 week, 2 months, and 5 months postoperatively. Four images from each completed scan were analyzed for percentage of incorporation of the bone graft. The results of autograft and allograft incorporation for each of the time intervals were compared. No statistically significant difference was found in the amount of bone incorporation at the tibial bone plug 1 week, 2 months, and 5 months. Clinical concerns regarding slower or less complete healing of allograft bone tissue compared to autograft are not supported with regard to the grafts studied.     

Revision anterior cruciate ligament reconstruction surgery

In 1995, it was reported that 60,000 to 75,000 anterior cruciate ligament (ACL) reconstructions were being performed annually in the United States. Successful long-term results are achieved in 75% to 95% of these patients, but 8% have unsatisfactory results due to recurrent instability and graft failure. With the increasing popularity of this procedure, ACL revision surgery has also become increasingly common. While the techniques described for ACL revision have been varied, the overall results in the literature do not compare favorably with primary ACL reconstruction. The proper execution of revision ACL reconstruction requires precise preoperative planning to assess the cause of initial failure and avoid repeating the same mistakes with revision reconstruction. Graft choice, hardware removal, revision notchplasty, tunnel placement, and method of fixation are key points for a successful result. The causes of ACL failure, the technical aspects of revision ACL surgery, and the reported results of revision ACL surgery are reviewed.     

Tunnel position and graft orientation in failed anterior cruciate ligament reconstruction: a clinical and imaging analysis

Purpose  

It has been reported that technical error in positioning the graft tunnel is the most common problem in anterior cruciate ligament (ACL) reconstruction. The objective of this study was to quantitatively evaluate femoral and tibial tunnel positions and intra-articular graft orientation of primary ACL reconstruction in patients who had undergone revision ACL reconstruction. We postulated that this patient cohort had a nonanatomically positioned tunnel and graft orientation.     

Radiographic evaluation of anterior cruciate ligament graft failure with special reference to tibial tunnel placement

Graft failure in anterior cruciate ligament (ACL) reconstruction can result from anterior placement of the tibial tunnel. Conventional radiographic evaluation of this problem does not take into account potential changes in tibio-femoral relationship caused by ACL instability. A retrospective radiographic evaluation of failed as well as successful ACL reconstructions was carried out. Both published radiographs as well as those obtained of patients treated by the authors were evaluated for tibial tunnel placement, roof impingement, and tibial position relative to the femur. In the second part of the study, the radiographs were obtained under standard conditions in both failed ACL reconstructions and normal knees. The results of both parts of the study indicate that lateral radiographs of the extended knee with ACL instability are likely to show subtle anterior tibial subluxation. The subluxation can give the impression of roof impingement on the graft. However, the majority of the failed knees had similar tibial tunnel placement compared with successful reconstructions and would appear unimpinged once corrected for subluxation. The diagnosis of graft impingement by the femoral intercondylar roof has to take into account potential tibial subluxation. Impingement as a cause graft failure may be less common than previously thought.Arthroscopy 1998 Mar;14(2):206-11     

Anterior Cruciate Ligament Reconstruction: A New Technique for Achilles Tendon Allograft Preparation

We describe a new technique in Achilles tendon allograft preparation for use in anterior cruciate ligament (ACL) reconstruction that allows for secure bony interference fixation on each side of the joint and aperture fixation for all patients. In addition, preparation of the graft in this manner avoids some problems that are frequently encountered with patellar tendon allografts, including graft tunnel mismatch and limited availability. Previous studies have reported successful results with Achilles tendon allograft use in ACL reconstruction with soft tissue fixation in the tibial tunnel. Bony interference fixation on the tibial side can be achieved by suturing a free bone plug to the tendon end of an Achilles allograft. We use a 9-mm circular oscillating saw to harvest a free 30-mm length bone plug from the remaining calcaneal bone block. This is then sutured directly to the tendon end of a bone-Achilles tendon allograft with the use of No. 1 nonabsorbable suture placed through 3 equally spaced drill holes in the free bone plug. Tendon length between the bone plugs can be individually set for each patient at a distance equivalent to the length of the native ACL (intra-articular distance between the femoral and tibial tunnels). After graft passage, the construct is tensioned and secured with interference screws, similar to a traditional bone–patellar tendon–bone graft. The senior author (S.G.) has performed 40 procedures with excellent results and reports no cases of tibial fixation failure. Biomechanical and long-term follow-up studies are in progress.     

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.     

Insufficiency fracture of the tibial plateau after anterior cruciate ligament reconstructive surgery: a case report and review of the literature

Peri-articular fractures after anterior cruciate ligament (ACL) reconstructive surgery are rare. To our knowledge, this case documents the first insufficiency fracture of the tibial plateau after ACL reconstruction, which presented three weeks after the procedure. A 25-year-old female recreational soccer player suffered an insufficiency fracture of the tibial plateau, extending 1.5 mm into the anterior wall of tibial tunnel and medial compartment under the anterior horn of medial meniscus, which presented as a diagnostic challenge. Clinically, the fracture mimicked a low-grade infection of the surgical site, while radiographically, the fracture resembled an avulsion fracture, later confirmed as a tibial tunnel fracture with computed tomography. With the ACL graft integrity not in jeopardy, four weeks of non-weightbearing and a delayed post-operative rehabilitation program was effective in allowing the fracture to heal. Good functional outcome was achieved after conservative management, with minimal loss of terminal knee extension and minimal pain at 22-month follow-up.     

Revision of failed anterior cruciate ligament reconstruction

Failures of ACL reconstruction still occur despite improved arthroscopic methods and new technical instruments. The reasons for failures, which are mostly related to technical surgical errors, must be recognized, analyzed, and considered for the planning and execution of revision ACL surgery. This review article describes the reasons for failed ACL reconstructions, indications, preoperative evaluation, planning, and performance of the operative procedure as well as the issue of rehabilitation. The strategies are evaluated for graft selection, staging of the revision, and the steps of the operative procedure including hardware removal, tunnel placement, graft fixation, or additional operations. Special attention is given to the dilemma of arthrofibrosis and its management in ACL revision cases. Since the results are worse after revision than following primary ACL surgery, the operative procedure has to be tailored to the needs of the patient, planned carefully, and performed by an experienced knee surgeon.     

Revision anterior cruciate ligament reconstruction

Revision ACL surgery is indicated in patients who present with pathologic anterior laxity on clinical examination that reproduces their symptoms of instability during activities of daily living or athletic activities. The goals of the revision ACL surgery are to stabilize the knee, prevent further injury to the articular cartilage and menisci, and maximize the patient's function. Successful revision ACL surgery requires a thorough preoperative evaluation, including a detailed history, physical examination, and radiographic evaluation. Preoperative planning begins with a determination of the mechanisms of failure for the initial ACL reconstruction. Often a primary, as well as secondary cause, for failure can be identified. The determination of the cause of failure is the first step in a carefully-constructed treatment plan, which includes consideration of skin incisions to be used, method of graft removal, hardware removal, the need for a staged procedure or concomitant surgery, graft material selection, tunnel placement, graft fixation, and postoperative rehabilitation protocol. Despite the most meticulous planning, unanticipated findings may be encountered in the operating room, and the preoperative plan should have enough flexibility to accommodate these developments. Finally, it is crucial to counsel the patient preoperatively to limit his or her expectations regarding their surgical outcome. Given the complexity of revision ACL reconstruction, patient expectations must be adjusted to realistically match the potential for success. With proper planning, attention to detail, and appropriate patient expectations, revision ACL surgery can result in a beneficial and satisfying patient outcome.     

Combined intra-articular and extra-articular reconstructions for anterior tibial subluxation

This article describes several procedures that combine intra-articular techniques with extra-articular techniques to stabilize the knee with anterior tibial subluxation. The procedures detailed are reconstruction using the semitendinosus tendon and the iliotibial tract; tenodesis using a strip of iliotibial tract combined with intra-articular reconstruction of the anterior cruciate ligament with the central third of the patellar tendon; "mini-reconstruction"; and a procedure utilizing a vascularized patellar tendon graft plus "dynamic" augmentation.     

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: Remember the Risk Factors During Individualized,Anatomic, Value-Based Anterior Cruciate Ligament Reconstruction

Understanding the etiology behind anterior cruciate ligament (ACL) reconstruction failure is a complex topic still being investigated heavily. The 3 classes of failure are technical, traumatic, and biologic. Technical errors are most common and most frequently reflect tunnel malposition. In addition, tibial slope has long been understood to be a risk factor for failed ACL reconstruction. Although not routinely performed at time of primary ACL reconstruction, osteotomy may be considered in the setting of failed ACL reconstruction. Relative quadriceps weakness is a risk factor, and we recommend sport-specific return-to-play testing as well as benchmarks for relative quadriceps strength before full return to activity. Revision ACL reconstruction is associated with both increased costs and worse patient outcomes, so every effort should be made to give patients the best chance of success after the index surgery. Whereas this begins with understanding the patient’s history and risk factors for failure, it crescendos with careful attention to the individually variable factors that make each case unique, tailoring one’s management to ensure that each patient receives an anatomic, individualized, and value-based ACL reconstruction.     

The effect of isolated popliteus tendon complex injury on graft force in anterior cruciate ligament reconstructed knees

Failure to diagnose injury to the posterolateral structures has been found to increase the forces experienced by the anterior cruciate ligament (ACL) and ACL grafts which may cause their subsequent failure. An isolated injury to the popliteus complex (PC) consisting of the popliteus tendon and popliteofibular ligament is not uncommon. Therefore, the purpose of this study was to discover if an isolated injury to the PC can significantly affect the forces experienced by the ACL graft under external loading conditions. We hypothesised that, under external tibial torque, the ACL graft will experience a significant increase in force, in knees with PC injury compared to the intact PC condition. Under varus tibial torque (10 N m), we observed minimal changes in the varus tibial rotation due to isolated sectioning of the PC in an ACL reconstructed knee (P > 0.05). Consequently, no significant increase in the ACL graft force was observed under varus tibial torque. In contrast, sectioning the PC resulted in a significant increase in the external tibial rotation compared to the intact PC knee condition under the external rotational tibial torque (5 N m) at all flexion angles (P < 0.05). These changes in kinematics under external tibial torque were manifested as elevated ACL graft forces at all selected flexion angles (P < 0.05). Prompt diagnosis of isolated PC injury and its treatment are warranted to prevent potential failure of ACL reconstruction.     

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With Anatomic Aimers

Graft positioning is a key issue in anterior cruciate ligament (ACL) reconstruction and even more sensitive in double-bundle reconstruction, where 2 tunnels have to be drilled within the ACL footprints at both the femoral and tibial insertion sites. Specific ancillary instruments have been developed to facilitate the positioning of the 4 sockets necessary when performing anatomic double-bundle ACL reconstruction. This technical note describes the rationale and the step-by-step method of using the specific aimers developed for this purpose. However, a prerequisite for successful double-bundle ACL reconstruction is a good knowledge of ACL footprint anatomy.