Degree of Anterolateral Ligament Injury Impacts Outcomes After Double-Bundle Anterior Cruciate Ligament Reconstruction

Anterolateral knee complex considerations in contemporary anterior cruciate ligament reconstruction and total knee arthroplasty: a systematic review

The anterolateral ligament (ALL) was first described in 1879 in the context of Segond fractures, which correlate with a 75-100% chance of an anterior cruciate ligament (ACL) tear or a 66-75% chance of a meniscal tear. The purpose of this paper is to provide an updated comprehensive review on the anterolateral ligament complex of the knee focusing on the: (1) anatomy of the ALL/ALC; (2) associated biomechanics/function; and (3) important surgical considerations in contemporary anterior cruciate ligament (ACL) reconstruction and total knee arthroplasty (TKA). A systematic review of studies on ALL was conducted on Pubmed/MEDLINE and Cochrane databases (May 7th, 2020 to February 1st, 2022), with 20 studies meeting inclusion/exclusion criteria. Studies meeting inclusion criteria were anatomical/biomechanical studies assessing ALL function, cadaveric and computer simulations, and comparative studies on surgical outcomes of ALLR (concomitant with ACL reconstruction). Eight studies were included and graded by MINOR and Newcastle-Ottawa scale to identify potential biases. The anatomy of the ALL is part of the anterolateral ligament complex (ALC), which includes the superficial/deep iliotibial band (including the Kaplan fiber system), iliopatellar band, ALL, and anterolateral capsule. Multiple biomechanical studies have characterized the ALC as a secondary passive stabilizer in resisting tibial internal rotation. Given the role of the ALC in resisting internal tibial rotation, lateral extra-articular procedures including ALL augmentation may be considered for chronic ACL tears, ACL revisions, and a high-grade pivot shift test. In the context of TKA, in the event of injury to the ALC, a more constrained implant or soft-tissue reconstruction may be necessary to restore appropriate knee stability.

Frequency of anterolateral ligament tears and ramp lesions in patients with anterior cruciate ligament tears and associated injuries indicative for these lesions-a retrospective MRI analysis

OBJECTIVES

To assess the frequency of anterolateral ligament (ALL) tears and ramp lesions (RL) detected with MRI in patients with anterior cruciate ligament (ACL) tears and to describe associated injuries indicative for these lesions.

METHODS

In this retrospective study, 164 patients with surgically verified ACL tears were included. Preoperative MRI scans were reviewed for ALL tears and different types of RL. All coexisting meniscal tears, tears of the medial (MCL) and lateral collateral band (LCL), and posterior-medial tibial bone marrow edema (BME) were recorded. The frequency of ALL tears and RL was assessed and coexisting injuries were correlated using Pearson's chi-square test. A p < 0.05 was defined as statistically significant. In cases of multiple testing, Bonferroni's correction was applied.

RESULTS

ALL tears and RL combined were detected in 28 patients (17.1%), ALL tears in 48 patients (29.3%), and RL in 54 patients (32.9%) which were significantly associated to each other. ALL tears were significantly associated with tears of the posterior horn of the lateral meniscus (PHLM), BME, and with tears of the LCL and MCL. RL were significantly associated with tears of the posterior horn of the medial (PHMM) and PHLM, with BME, and with tears of the LCL.

CONCLUSIONS

ACL tears are associated with RL or ALL tears in about one-third of cases and with both lesions combined in about one-fifth of cases. ALL tears and RL are significantly associated with additional posttraumatic injuries, which can thus be indicative of these lesions.

KEY POINTS

• ACL tears were associated with ramp lesions or ALL tears in about one-third of the cases. • Ramp lesions and ALL tears were significantly associated with each other, tear in the PHLM, tear in the LCL, and BME. • ALL tears were more frequently associated with instable classified ramp lesion type 4b and type 5.

Untreated Injuries to the Anterolateral Capsular Structures Do Not Affect Outcomes and Kinematics after Anatomic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Injuries to the anterolateral complex (ALC) may contribute to increased rotatory knee laxity. However, it has not been evaluated whether such injuries affect in vivo kinematics when treated in situ. The purpose of this study was to determine the grade of ALC injury and its effect on kinematic and clinical outcomes of ACL-injured patients 24 months after anatomic ACL reconstruction. It was hypothesized that injury to the ALC would be significantly related to patient-reported outcomes (PROs) and in vivo knee kinematics during downhill running.

METHODS

Thirty-five subjects (mean age: 22.8 ± 8.5 years) participating in a randomized clinical trial to compare single- and double-bundle ACL reconstruction were included in the study. Subjects were divided into two groups based on the presence or absence of injury to the ALC, as determined on MRI scans performed within 6 weeks of injury. None of the patients underwent treatment for these ALC injuries. At 24 months, PROs, including the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Knee injury and Osteoarthritis Outcome Score (KOOS) and in vivo knee kinematics during downhill running, were obtained. Pivot-shift test results, PROs and in vivo knee kinematics were compared between groups with and without ALC injury using the Pearson's Chi Squared test and Mann-Whitney U test with significance set at p < 0.05.

RESULTS

The average interval between injury and performing the MRI scans was 9.5 ± 10 days. ALC injury was observed in 17 (49%) study participants. No significant differences were detected in PROs and in vivo kinematics between subjects with and without ALC injury (n.s.).

CONCLUSION

The findings of this study demonstrate that MRI evidence of an ALC injury does not significantly affect in vivo knee kinematics and PROs even in individuals with a high-grade ALC injury. Injuries to the ALC as observed on MRI might not be a useful indication for an anterolateral procedure.

Association Between Anterior Tibial Subluxation of Lateral Compartment and High-Grade Knee Laxity in Patients With Anterior Cruciate Ligament Deficiency

BACKGROUND

High-grade knee laxity and excessive anterior tibial subluxation (ATS) are correlated with poor clinical outcomes in patients with anterior cruciate ligament (ACL) deficiency and share similar risk factors; however, the association between excessive ATS and high-grade knee laxity remains unclear.

PURPOSE

To identify the association between excessive ATS and high-grade knee laxity in patients with ACL deficiency and determine the possibility that ATS can predict high-grade knee laxity.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 226 patients who underwent ACL reconstruction between May 2018 and March 2022 were analyzed in the present study; the high-grade group consisted of 113 patients who had a grade 3 result on the preoperative anterior drawer test, Lachman test, or pivot-shift test while under anesthesia, and the low-grade group consisted of 113 matched patients. The ATS values for medial and lateral compartments (ATSMC and ATSLC) were measured on magnetic resonance imaging while patients relaxed the quadriceps in the supine position under no anesthesia. The optimal cutoff values of ATSMC and ATSLC for high-grade knee laxity were determined using receiver operating characteristic curves. Univariate and multivariate logistic regression analyses with stratification were performed to identify the association between excessive ATS and high-grade knee laxity.

RESULTS

Compared with the low-grade group, the high-grade group had a longer time from injury to surgery; higher rates of medial meniscus posterior horn tear (MMPHT), lateral meniscus posterior horn tear (LMPHT), and anterolateral ligament (ALL) abnormality; and larger lateral tibial slope, ATSMC, and ATSLC. The optimal cutoff value was 2.6 mm (sensitivity, 52.2%; specificity, 76.1%) for ATSMC and 4.5 mm (sensitivity, 67.3%; specificity, 64.6%) for ATSLC in predicting high-grade knee laxity. After adjustment for covariates, ATSLC ≥4.5 mm (odds ratio [OR], 2.94; 95% CI, 1.56-5.55; P = .001), MMPHT (OR, 2.62; 95% CI, 1.35-5.08; P = .004), LMPHT (OR, 2.39; 95% CI, 1.20-4.78; P = .014), and ALL abnormality (OR, 2.09; 95% CI, 1.13-3.89; P = .019) were associated with high-grade knee laxity. The association between excessive ATSLC and high-grade knee laxity was validated in patients with acute ACL injury as well as those with chronic ACL injury.

CONCLUSION

Excessive ATSLC was associated with high-grade knee laxity in patients who had ACL deficiency, with a predictive cutoff value of 4.5 mm. This study may help surgeons estimate the degree of knee instability more accurately before anesthesia and may facilitate preliminary surgical decision-making, such as appropriate graft choices and consideration of extra-articular augmentation.

A Review of Current Concepts of the Anterolateral Complex of the Knee

The anterolateral complex (ALC) of the knee has gained increased interest over the last decades due to the high revision rates of anterior cruciate ligament reconstruction (ACLR). Furthermore, in patients with an ACL tear, the injury of at least one of the ALC's anatomic structures has been shown to be significantly higher, thus affecting its secondary stabilizing role at the knee joint. As such, ACLR augmentation techniques, that embrace the ALC, have been proposed recently, and indications for these procedures are still evolving. This review aims to present and discuss the most current anatomical, biomechanical, and imaging data, current reconstruction techniques, and the clinical results of ALC reconstruction.

Effect of Anterolateral Structure Augmentation on Graft Maturity After Anterior Cruciate Ligament Reconstruction: A Clinical and MRI Follow-up of 2 Years

BACKGROUND

Anterolateral structure augmentation (ALSA) has been applied to prevent residual rotatory instability and lower clinical failure rates after anterior cruciate ligament (ACL) reconstruction (ACLR); however, the effect of combined ALSA on the maturity of ACL grafts remains unknown.

PURPOSE

To evaluate the graft maturity and patient-reported outcomes in patients who underwent double-bundle ACLR with or without ALSA.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 92 patients who underwent double-bundle ACLR between January 2016 and July 2019 were included in the present study-44 patients with isolated ACLR (ACLR group) and 48 patients with combined ACLR and ALSA (ALSA group). Demographic characteristics, intraoperative findings, and patient-reported outcomes were prospectively collected. On postoperative magnetic resonance imaging at the 2-year follow-up, the signal-to-noise quotient (SNQ) values were separately calculated for 6 sections of the ACL graft, including the femoral intratunnel graft (FTG), intra-articular graft (IAG), and tibial intratunnel graft (TTG) of the anteromedial bundle (AMB) and the posterolateral bundle (PLB). Superior graft maturity was usually indicated by lower SNQ values.

RESULTS

The rates of return to preinjury sports were 47.9% and 27.3% in the ALSA and ACLR groups, respectively (difference, 20.6% [95% CI, 1.3%-40%]; P = .042). The AMB demonstrated significantly lower SNQ values in the ALSA group than in the ACLR group (FTG, 7.04 ± 3.65 vs 9.44 ± 4.51 [P = .006]; IAG, 6.62 ± 4.19 vs 8.77 ± 5.92 [P = .046]; TTG, 6.93 ± 3.82 vs 8.75 ± 4.55 [P = .040]). The SNQ values were significantly lower in the ALSA group for 2 of the 3 sections of the PLB (IAG, 7.73 ± 4.61 vs 9.88 ± 5.61 [P = .047]; TTG, 5.88 ± 3.10 vs 8.57 ± 4.32 [P = .001]). Partial lateral meniscectomy was correlated with higher SNQ values of the TTG in the AMB (β = 0.27; P = .009) and the PLB (β = 0.25; P = .008), with both groups pooled. Higher body mass index, smaller ACL graft-Blumensaat line angles, larger AMB graft diameters, and lower postoperative Tegner scores were also associated with inferior maturity in specific regions of the ACL graft.

CONCLUSION

A combination of ACLR and ALSA is a desirable option to improve the maturity of ACL grafts for patients who are young or expected to return to pivoting sports. Meanwhile, further investigations with higher levels of evidence and longer periods of follow-up are warranted.

Double-Bundle Versus Single-Bundle Anterior Cruciate Ligament Reconstruction in Patients With Significant Passive Anterior Tibial Subluxation

BACKGROUND

Passive anterior tibial subluxation (PATS) is often observed in patients with anterior cruciate ligament tears. Postoperative outcomes of double-bundle (DB) and single-bundle (SB) anterior cruciate ligament reconstruction (ACLR) with significant PATS (>6 mm) are unclear.

HYPOTHESIS

DB-ACLR could achieve better stability and clinical outcomes than SB-ACLR in patients with PATS >6 mm.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Retrospective analysis was peformed on 626 consecutive patients who underwent primary anatomic ACLR between October 2016 and November 2017. Anterior subluxation of the lateral and medial compartments in extension relative to the femoral condyles was measured on preoperative magnetic resonance imaging scans. Among patients who demonstrated significant PATS (>6 mm) in the lateral compartment, 54 who underwent DB-ACLR (study group) were matched to 54 who underwent SB-ACLR (control group). PATS, stability (pivot-shift test and KT-2000 arthrometer), the Lysholm score, and the International Knee Documentation Committee (IKDC) grade were investigated preoperatively and at 3- to 4-year follow-up.

RESULTS

The preoperative mean PATS values in the lateral and medial compartments were not significantly different between groups (control vs study: lateral compartment, 8.1 ± 1.8 vs 8.5 ± 2.1 mm; medial compartment, 5.2 ± 1.9 vs 5.4 ± 1.9 mm; P > .05). Postoperatively, mean PATS values in the lateral and medial compartments of the study group were significantly improved as compared with the control group (control vs study: lateral compartment, 5.9 ± 2.8 vs 3.2 ± 4.1 mm; medial compartment, 3.7 ± 2.9 vs 1.4 ± 2.3 mm; P < .05). Significantly superior results were found for knee stability in the study group regarding the Lachman test (grade 0/1/2/3, study vs control: 29/22/3/0 vs 16/28/10/0; P = .031), pivot-shift test (grade 0/1/2/3, study vs control: 44/9/1/0 vs 30/19/5/0; P = .023), and KT-2000 arthrometer (study vs control: 2.5 ± 1.5 vs 3.9 ± 1.4 mm; P < .001). Clinical scores showed significantly better results in the study group in terms of IKDC score (study vs control: 87.9 ± 8.7 vs 81.2 ± 15.0; P = .01), Tegner activity score (study vs control: 6.0 ± 1.4 vs 4.9 ± 1.5; P < .001), and Lysholm score (study vs control: 91.7 ± 7.0 vs 86.3 ± 11.4; P = .004).

CONCLUSION

DB-ACLR achieved better knee stability and clinical outcomes when compared with SB-ACLR in patients with PATS >6 mm at 3- to 4-year follow-up.

Surgical Timing Does Not Interfere on Clinical Outcomes in Combined Reconstruction of the Anterior Cruciate Ligament and Anterolateral Ligament: A Comparative Study With Minimum 2-Year Follow-Up

PURPOSE

To compare the functional outcomes, knee stability, failure rate and complication rates of combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction with hamstrings grafts between acute and chronic cases.

METHODS

Consecutive patients who underwent combined ACL and ALL reconstruction with hamstrings grafts were evaluated. Patients operated on less than 8 weeks after injury were allocated to group 1, and the others were allocated to group 2. Demographic data, knee stability, and functional outcomes of the 2 groups were evaluated.

RESULTS

Thirty-four patients in the acute group and 96 in the chronic group were evaluated. The follow-up time was similar between the groups (28.7 ± 5.2 [24-43] months vs 29.4 ± 7.2 [24-58] months; P = 0.696). No differences were found between the groups in age, sex, trauma mechanism, presence of knee hyperextension, graft diameter, and meniscal injuries. There was no difference between the groups in the postoperative KT-1000 and in the pre- or postoperative pivot shift. The preoperative KT-1000 was higher in group 2 (7.9 ± 1.1 vs 7.4 ± 1.2; P = 0.031). There were no differences in the International Knee Documentation Committee or Lysholm. Three (2.3%) patients developed failure, 1 (2.9%) in group 1 and 2 (2.1%) in group 2. The total complication rate was 10% and did not differ between the groups.

CONCLUSIONS

Combined ACL and ALL reconstruction has similar outcomes in patients undergoing surgery in the acute and chronic phases. Patients with chronic injury have similar knee stability, functional scores, and failure rates as acute-injury patients, and patients with acute injury have no more complications than chronic patients.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Ramp lesion of the medial meniscus

Ramp lesion of the medial meniscus used to be completely disregarded in the past.

Ramp lesion has been now put under the spotlight by orthopaedic and sport medicine surgeons and requires attention.

It is closely associated with anterior cruciate ligament injury. Major risk factors include chronic laxity, lateral meniscal lesion, anterior cruciate ligament reconstruction revision, anterolateral ligament tear concomitant with anterior cruciate ligament injury, time from injury, pre-operative side-to-side laxity > 6 mm, age < 30 years old, male sex, etc.

Radiologists attempt to create diagnostic criteria for ramp lesion using magnetic resonance imaging. However, the only definite method to diagnose ramp lesion is still arthroscopy. Various techniques exist, among which posteromedial approach is the most highly recommended.

Various treatment options are available. The success rate of ramp repair is very high. Major complications are uncommon.

Cite this article: EFORT Open Rev 2021;6:372-379. DOI: 10.1302/2058-5241.6.200126

Editorial Commentary: Lateral Extra-Articular Tenodesis Results in Better Stability After Anterior Cruciate Ligament Reconstruction for Patients With High-Grade Pivot Shifts

Magnetic resonance imaging of the torn anterior lateral ligament (ALL) is inconsistent and subject to significant intra- and interobserver variability. Like that of an anterior cruciate ligament (ACL), an ALL tear can vary in degree (first, second, or third) and location (tibial or femoral side). These variations may impact the appropriate surgical intervention. Relevant biomechanical data indicate that the deep iliotibial band fibers are more important than the ALL in controlling pivot shift. Lateral compartment overconstraint after ALL reconstruction does not appear to be a biomechanical or clinical issue. An ALL reconstruction creates a nonisometric construct (tight in extension and lax in flexion), allowing physiologic internal tibial rotation at 90° flexion, whereas lateral extra-articular tenodesis (LET) is more isometric, limiting physiologic internal tibial rotation at 90° flexion. The indications for a combined ACL/ALL reconstruction are evolving, but a Segond fracture and ligamentous hyperlaxity of ≥5 using the modified Beighton system seem reasonable. An ACL/LET reconstruction results in better stability for patients with high-grade pivot shifts.

Editorial Commentary: Another Take on the Anterolateral Ligament: High-Grade Are Worse Than Low-Grade Injuries, But the Categorization Is Problematic

The anatomy, function, and existence of the anterolateral ligament (ALL) is still hotly debated and a controversial topic. Currently both basic biomechanical and clinical studies are not providing sufficient and strong evidence to either support or refute that the ALL plays an important role for knee stability. One could argue that stability is provided by the anterolateral complex, including the iliotibial band, Kaplan fibers, and the anterolateral capsule, which may contain a structure called the ALL. Magnetic resonance imaging (MRI) is routinely performed in patients with anterior cruciate ligament (ACL) injury, but unfortunately ALL injuries cannot be reliably diagnosed in patients with concomitant ACL tears. When dividing ALL injuries into high and low grade using preoperative MRI and investigating clinical outcomes after double-bundle ACL reconstruction, patients with high-grade injuries have inferior outcomes and a significantly greater revision rates. However, the limitations of this research reduce the validity of these conclusions: high rate of loss to follow-up above accepted standard, unequal size of their study groups, fragility index of zero, the inaccuracy of diagnosing ALL injuries in the presence of ACL tears on MRI, and the dilemma with randomly classifying high- and low-grade ALL injury based on MRI.