Carola F. van Eck

Anatomic Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction Flowchart

Anatomy is the foundation of orthopaedic surgery, and the advancing knowledge of the anterior cruciate ligament (ACL) anatomy has led to the development of improved modern reconstruction techniques that approach the anatomy of the native ACL. Current literature on the anatomy of the ACL and its reconstruction techniques, as well as our surgical experience, was used to develop a flowchart that can aid the surgeon in performing anatomic ACL reconstruction. We define anatomic ACL reconstruction as the functional restoration of the ACL to its native dimensions, collagen orientation, and insertion sites. A guideline was written to accompany this flowchart with more detailed information on anatomic ACL reconstruction and its pitfalls, all accompanied by relevant literature and helpful figures. Although there is still much to learn about anatomic ACL reconstruction methods, we believe this is a helpful document for surgeons. We continue to modify the flowchart as more information about the anatomy of the ACL, and how to more closely reproduce it, becomes available.

Prospective Randomized Clinical Evaluation of Conventional Single-Bundle, Anatomic Single-Bundle, and Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction 281 Cases With 3- to 5-Year Follow-up

Background: Three different techniques of anterior cruciate ligament (ACL) reconstruction—conventional (transtibial) single bundle (CSB), anatomic single bundle (ASB), and anatomic double bundle (ADB)—have been described. Purpose: To determine if double-bundle reconstruction is needed to restore rotational stability or if anatomic placement of a single bundle can yield similar results. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: From December 2005 to December 2007, 320 patients were prospectively randomized into 3 groups: ADB, ASB, and CSB reconstruction. The average follow-up was 51.15 months (range, 39-63 months). At the final follow-up, 281 patients were available. In all groups, hamstring tendons were used with suspensory fixation on the femoral side and bioabsorbable interference screw fixation on the tibial side. The outcomes were evaluated by an independent blinded observer using the Lysholm score and subjective International Knee Documentation Committee (IKDC) form. The KT-1000 arthrometer was used to evaluate anteroposterior stability, and the pivot-shift test was used to determine rotational stability. Results: Anatomic single-bundle reconstruction resulted in better anteroposterior and rotational stability than CSB reconstruction (average side-to-side difference for anterior tibial translation was 1.6 mm in the ASB group vs 2.0 mm in the CSB group; P = .002). Negative pivot shift was 66.7% vs 41.7% (P = .003). In other parameters, the differences between groups were not statistically significant. The results of the ADB group were also superior to the ASB group for anteroposterior and rotational stability (average side-to-side difference for anterior tibial translation was 1.2 mm in the ADB group vs 1.6 mm in the ASB group; P = .002). Negative pivot shift was 93.1% vs 66.7%, respectively (P < .001), and range of motion was also significantly different (P = .005). The Lysholm score was 90.9, 91.8, and 93.0 in the CSB, ASB, and ADB groups, respectively. The difference was significant only when we compared ADB and CSB (P = .025). Subjective IKDC scores were 90.2, 90.6, and 92.1 in the CSB, ASB, and ADB groups, respectively. The difference was not significant. Conclusion: Anatomic double-bundle ACL reconstruction is significantly superior to conventional single-bundle ACL reconstruction and better than anatomic single-bundle reconstruction. Anatomic single-bundle reconstruction was superior to conventional single-bundle reconstruction. However, these differences are small and may not be clinically relevant.

Anatomic Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction, Part 1 Basic Science

Anterior cruciate ligament reconstruction is a frequently performed orthopaedic procedure. Although short-term results are generally good, long-term outcomes are less favorable. Thus, there is renewed interest in improving surgical techniques. Recent studies of anterior cruciate ligament anatomy and function have characterized the 2-bundle structure of the native ligament. During non-weightbearing conditions, the anteromedial (AM) and posterolateral (PL) bundles display reciprocal tension patterns. However, during weightbearing, both the AM and PL bundles are maximally elongated at low flexion angles and shorten significantly with increasing knee flexion. Conventional single-bundle reconstruction techniques often result in nonanatomic tunnel placement, with a tibial PL to a femoral “high AM” tunnel position. In vitro studies have demonstrated that these nonanatomic single-bundle reconstructions cannot completely restore normal anterior-posterior or rotatory laxity. Cadaveric studies suggest that anatomic single-bundle and anatomic double-bundle reconstruction may better restore knee stability. Although many cadaver studies suggest that double-bundle reconstruction techniques result in superior stability when compared with single-bundle techniques, others failed to demonstrate a clear benefit of this more complex procedure. Cadaver studies generally do not apply physiologically relevant loads and provide only a “time-zero” assessment that ignores effects of healing and remodeling after anterior cruciate ligament reconstruction. In vivo, dynamic studies offer the most comprehensive assessment of knee function after injury or reconstruction, as they can evaluate dynamic stability during functional joint loading. Studies of knee kinematics during activities such as gait and running suggest that nonanatomic single-bundle anterior cruciate ligament reconstruction fails to restore preinjury knee function under functional loading conditions. Similar studies of more anatomic single- and double-bundle surgical approaches are in progress, and preliminary results suggest that these anatomic techniques may be more effective for restoring preinjury knee function. However, more extensive, well-designed studies of both kinematics and long-term outcomes are warranted to characterize the potential benefits of more anatomic reconstruction techniques for improving long-term outcomes after anterior cruciate ligament reconstruction.

Prospective Analysis of Failure Rate and Predictors of Failure After Anatomic Anterior Cruciate Ligament Reconstruction With Allograft

Background: Anterior cruciate ligament (ACL) reconstruction is one of the most frequently performed orthopaedic procedures. Failures are a reality of surgery; to limit failures, we must first understand and quantify them. Purpose: The purposes of this study were to determine the rate and factors associated with graft failure after anatomic ACL reconstruction performed with allograft. Study design: Case series; Level of evidence, 4. Methods: All consecutive subjects who underwent anatomic single- or double-bundle ACL reconstruction with allograft between January 2007 and December 2009 were included and followed clinically. Graft failure was defined as patient-reported instability, pathological laxity during the physical examination, or evidence of a failed graft on magnetic resonance imaging or during arthroscopy. Potential predictors of graft failure that were explored included subject age, sex, height, weight, body mass index, meniscus injury, and time of return to preinjury sports. Results: There were 206 subjects included in this study: 168 double-bundle and 38 single-bundle reconstructions. Overall, 27 (13%) subjects experienced graft failure. Twenty-three (13%) double-bundle subjects failed. The characteristics associated with double-bundle graft failure were younger age (19 vs 25 years, P < .001) and earlier return to sports (at 222 vs 267 days, P = .007). Four (11%) of the single-bundle subjects failed. The characteristics associated with single-bundle graft failure were younger age (19 vs 24 years, P = .049) and increased body mass (83 vs 65 kg, P = .031). Conclusion: The overall graft failure rate after anatomic ACL reconstruction with allograft was 13%. Younger age, earlier return to sports, and a higher body weight were associated with graft failure.

Individualized anterior cruciate ligament surgery: a prospective study comparing anatomic single- and double-bundle reconstruction.

Background: Reconstruction of the anterior cruciate ligament (ACL) has become a commonly performed procedure. However, biomechanical studies have demonstrated that conventional single-bundle ACL reconstruction techniques are only successful in limiting anterior tibial translation but less effective for restoring rotatory laxity. Purpose: This study aimed to compare the results of single- and double-bundle ACL reconstruction using an anatomic technique, individualized based on the patient’s native ACL size. The authors hypothesized that there would be no difference between the results of anatomic single-bundle (ASB) and anatomic double-bundle (ADB) reconstruction when the surgical technique is individualized. Study Design: Cohort study; Level of evidence, 2. Methods: Depending on intraoperative measurements of the ACL insertion site size, patients were selected for either ASB (n = 32) or ADB (n = 69) ACL reconstruction. In all groups, hamstring tendons autograft was used with suspensory fixation on the femoral side and bioabsorbable interference screw fixation on the tibial side. The outcomes were evaluated by an independent blinded observer using the Lysholm score, subjective International Knee Documentation Committee (IKDC) form, KT-1000 arthrometer for anteroposterior stability, and pivot-shift test for rotational stability. The average follow-up was 30 months (range, 26-34 months). There were no statistically significant differences in the baseline demographics of the 2 groups. Results: There was no significant difference between the ADB and ASB groups for Lysholm score (93.9 vs 93.5), subjective IKDC score (93.3 vs 93.1), anterior tibial translation (1.5- vs 1.6-mm side-to-side difference), and pivot shift (92% vs 90% with negative pivot-shift examination). Conclusion: Anatomic double-bundle reconstruction is not superior to anatomic single-bundle reconstruction when an individualized ACL reconstruction technique is used.

Anatomic Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction, Part 2 Clinical Application of Surgical Technique

The anterior cruciate ligament has been and is of great interest to scientists and orthopaedic surgeons worldwide. Anterior cruciate ligament reconstruction was initially performed using an open approach. When the approach changed from open to arthroscopic reconstruction, a 2- and, later, 1-incision technique was applied. With time, researchers found that traditional arthroscopic single-bundle reconstruction did not fully restore rotational stability of the knee joint and a more anatomic approach to reconstruct the anterior cruciate ligament has been proposed. Anatomic anterior cruciate ligament reconstruction intends to replicate normal anatomy, restore normal kinematics, and protect long-term knee health. Although double-bundle anterior cruciate ligament reconstruction has been shown to result in better rotational stability in both biomechanical and clinical studies, it is vital to differentiate between anatomic and double-bundle anterior cruciate ligament reconstruction. The latter is merely a step closer to reproducing the native anatomy of the anterior cruciate ligament; however, it can still be done nonanatomically. To evaluate the potential benefits of reconstructing the anterior cruciate ligament in an anatomic fashion, accurate, precise, and reliable outcome measures are needed. These include, for example, T2 magnetic resonance imaging mapping of cartilage and quantification of graft healing on magnetic resonance imaging. Furthermore, there is a need for a consensus on which patient-reported outcome measures should be used to facilitate homogeneous reporting of outcomes.

The anatomic approach to primary, revision and augmentation anterior cruciate ligament reconstruction

The anatomic approach is gaining popularity in anterior cruciate ligament (ACL) reconstruction. It is predominantly applied during primary ACL reconstruction. However, following the same principles as during primary surgery, the anatomic approach can also be applied during revision and augmentation surgery. This paper discusses the surgical technique for anatomic single- and double-bundle ACL reconstruction, for primary, revision and augmentation surgery. During primary reconstruction, the choice for single- or double-bundle reconstruction and graft size should be based on ACL insertion site and femoral intercondylar notch dimensions. When there is an isolated anteromedial (AM) or posterolateral (PL) bundle rupture, augmentation of a single-bundle can be performed while protecting the integrity of the intact bundle. Especially during revision surgery, there are many potential situations the surgeon may encounter when entering the knee. There are multiple possible solutions for all of these different situations leading to an anatomic end result. Three-dimensional computed tomography (CT) scanning should be used to evaluate the current tunnel positions and determine the operative strategy.

Methods to diagnose acute anterior cruciate ligament rupture: a meta-analysis of physical examinations with and without anaesthesia.

PurposeThe aims of this meta-analysis were to determine the sensitivity and specificity of the Lachman, pivot shift and anterior drawer test for acutecomplete ACL rupture in the office setting and under anaesthesia. It was hypothesized that the Lachman test is the most sensitive and the pivot shift test the most specific. Secondly, it was hypothesized that the sensitivity and specificity of all three exams increases when the examination is performed under anaesthesia.MethodsAn electronic database search was performed using MEDLINE and EMBASE. All cross-sectional and cohort studies comparing one or more physical examination tests for diagnosing acute complete ACL rupture to an accepted reference standard such as arthroscopy, arthrotomy and MRI were included.ResultsTwenty studies were identified and included. The overall sensitivity of the Lachman test was 0.81 and the specificity 0.81; with anaesthesia, the sensitivity was 0.91 and the specificity 0.78. For the anterior drawer test, the sensitivity was 0.38 and the specificity 0.81; with anaesthesia, the sensitivity was 0.63 and the specificity 0.91. The sensitivity of the pivot shift test was 0.28 and the specificity 0.81; with anaesthesia, the sensitivity was 0.73 and the specificity 0.98.ConclusionIn the office setting, the Lachman test has the highest sensitivity for diagnosing an acute, complete ACL rupture, while all three tests had comparable specificity. When the examination was performed under anaesthesia, the Lachman test still obtained the highest sensitivity, but the pivot shift test was the most specific.Level of evidenceMeta-analysis of diagnostic test accuracy, Level II.

Anatomic anterior cruciate ligament reconstruction: a changing paradigm

Injury to the anterior cruciate ligament (ACL) of the knee is potentially devastating for the patient and can result in both acute and long-term clinical problems. Consequently, the ACL has always been and continues to be of great interest to orthopaedic scientists and clinicians worldwide. Major advancements in ACL surgery have been made in the past few years. ACL reconstruction has shifted from an open to arthroscopic procedure, in which a two- and later one-incision technique was applied. Studies have found that traditional, transtibial arthroscopic single-bundle reconstruction does not fully restore rotational stability of the knee joint, and as such, a more anatomic approach to ACL reconstruction has emerged. The goal of anatomic ACL reconstruction is to replicate the knee’s normal anatomy and restore its normal kinematics, all while protecting long-term knee health. This manuscript describes the research that has changed the paradigm of ACL reconstruction from traditional techniques to present day anatomic and individualized concepts.

Comparison of 3-Dimensional Notch Volume Between Subjects With and Subjects Without Anterior Cruciate Ligament Rupture

PURPOSE The aim of this study was to determine whether individuals with anterior cruciate ligament (ACL) injuries have smaller notch volumes than uninjured subjects. A secondary aim was to determine the correlation between intraoperative 2-dimensional (2D) notch measurements, patient demographic factors, and notch volume. METHODS Manual digital tracings of the femoral intercondylar notch perimeter were performed on axial magnetic resonance images to calculate 3-dimensional (3D) notch volume. Notch volume was compared between 50 patients with ACL injury and 50 patients without ACL injury (control subjects). From the 50 patients with ACL injury, intraoperative 2D measurements of the notch were taken. These 2D measurements and patient demographic factors were correlated to 3D notch volume, by use of the Pearson correlation coefficient. In addition, notch size was compared between men and women. All group comparisons were performed by use of unpaired t tests. RESULTS The notch volume was larger (6.5 ± 1.7 cm(3) [mean ± SD]) for the group with ACL injury compared with control subjects (5.9 ± 1.4 cm(3)); this difference approached statistical significance (P = .054). There were no significant correlations between the 2D dimensions and the 3D notch volume. Larger notch volumes were significantly correlated with increased subject height (r = 0.636, P < .001) and weight (r = 0.364, P < .001) but not body mass index (P = .269). Male patients had significantly larger notch volumes than female patients (P < .001). CONCLUSIONS Contrary to our hypothesis, there was a trend toward larger notch volumes in patients with ACL injury compared with patients without ACL injury. Intraoperative notch measurements did not correlate with 3D notch volume. Notch volume was related to patient height, weight, and gender but not body mass index. LEVEL OF EVIDENCE Level III, case-control study.