To perform an updated systematic review of the biomechanical characteristics investigating the contributions of the anterolateral ligament complex to rotational and anterior knee stability in ACL-intact, ACL-deficient, and ACL-reconstructed knees.

Medline, Embase, Scopus, and Google Scholar were screened for studies from 2012 to 2024. Biomechanical laboratory cadaver studies were included if they described biomechanical characteristics in ACL-intact (ACLI), ACL-deficient (ACLD), ACL-reconstructed with (ALLR) or without ALL-reconstruction (ALLD). Studies examining other anatomical structures, such as the iliotibial band and Kaplan fibers, and alternative reconstruction techniques, such as lateral extra-articular tenodesis, were excluded. CASP (Critical Appraisal Skills Programme) checklist for qualitative research and the BOBQAT (Biomechanics Objective, Basic Science Quality Assessment Tool) scale, were used for study quality assessment. Heterogeneity within and between studies was evaluated using the I2 statistic. Publication bias was examined using funnel plots and Egger's test.

Twenty-two studies were included in the analysis. CASP assessment deemed 21 of these studies to be valuable. BOBQAT evaluated, 9 studies were as moderate quality, 8 as fair quality, and 5 as poor quality. The mean load to failure varied between 49 N and 319.8 N, with a pooled mean of 171.9 N. Stiffness values ranged from 2.6 to 41.9 N/mm, yielding a pooled mean of 21.46 N/mm. Comparisons of load displacement did not reveal significant differences across the following groups for both anterior tibial translation (ATT) and internal rotation (IR) for all comparisons.

This systematic review did not find conclusive evidence that the ALL plays a significant role in limiting anterior tibial translation or internal rotation stability in either ACLI or ACLR knees at point zero during biomechanical testing of cadaver specimens.

Biomechanical laboratory studies conducted at time zero suggest that the added benefit of combining ALLR with ACLR reconstruction remains uncertain. When ACLR sufficiently restores knee stability, additional procedures may not always be necessary.

A preoperative high-grade pivot-shift phenomenon (2+ and 3+) is often a predictor of inferior knee rotational stability and excessive anterior tibial translation of the lateral compartment (L-ATT) after an anterior cruciate ligament (ACL) injury. Lateral extra-articular tenodesis (LET) has been reported to reduce failure rates and improve knee stability in patients with an ACL injury. However, the effect of LET on knee rotational stability and L-ATT is still not entirely clear in patients with an ACL injury and a high-grade pivot-shift phenomenon.

To explore the effect of LET on knee rotational stability and L-ATT in patients with an ACL injury and a high-grade pivot-shift phenomenon.

Cohort study; Level of evidence, 3.

A total of 254 patients who underwent ACL reconstruction (ACLR) between January 2019 and December 2020 were retrospectively reviewed, and 71 patients (43 male and 28 female) with a preoperative high-grade pivot-shift phenomenon were included. Of these, 24 patients who underwent ACLR combined with LET and 47 patients who underwent ACLR alone were categorized as the study and control groups, respectively. Knee stability was evaluated by the KT-1000 arthrometer side-to-side difference and the pivot-shift test, and L-ATT was measured on magnetic resonance imaging. Baseline patient characteristics, preoperative and postoperative knee stability, and preoperative and postoperative L-ATT were compared between the 2 groups. Moreover, the relative risk of a residual pivot-shift phenomenon after ACLR combined with LET versus ACLR alone was calculated.

The mean time from injury to surgery in the study group was significantly longer than that in the control group (29.9 ± 54.7 vs 10.1 ± 23.1 months, respectively; P = .035). Other baseline patient characteristics, preoperative knee stability, and preoperative L-ATT showed no significant differences between the groups. At the final follow-up (26.4 ± 4.7 and 28.1 ± 11.0 months for study and control groups, respectively), knee rotational stability (residual pivot-shift phenomenon: 2/24 vs 16/47, respectively; P = .018) and L-ATT (4.6 ± 2.6 vs 6.3 ± 2.6 mm, respectively; P = .010) were superior in the study group compared with the control group. Furthermore, the relative risk of a residual pivot-shift phenomenon was significantly lower in the study group (0.176 [95% CI, 0.037-0.845]; P = .030).

ACLR combined with LET was an effective treatment strategy for ACL injuries with a high-grade pivot-shift phenomenon, associated with satisfactory clinical outcomes, significantly improved rotational stability, and reduced L-ATT.

This study aimed to determine the trends and indications for anterolateral complex augmentation during anterior cruciate ligament reconstruction (ACL-R) among international orthopedic sports surgeons.

An electronically distributed survey was sent out to international surgeons with high-volume experience in complex ligament reconstructions and revision surgery attending the 2024 Freddie Fu Panther Sports Medicine Symposium. The survey was sent prior to the meeting with questions related to the use of lateral extra-articular tenodesis (LET) or anterolateral ligament reconstruction (ALL-R) during ACL-R. Sessions pertaining to anterolateral complex augmentation were held during the symposium to inform about current clinical practices among attendees.

A total of 49 surgeons were identified from 5 different geographic regions prior to the meeting date and were sent an electronic survey, of which 48 responded (98% response rate). Among the surgeons who reported performing anterolateral complex augmentation procedures (n = 45), a total of 39 (87%) respondents reported using only the LET technique, 2 (4%) reported using only the ALL-R technique, and 4 (9%) reported using both techniques during ACL-R. The most common indication for anterolateral complex augmentation was a high-grade pivot shift, which 39 of 43 (91%) respondents ranked in their top 3 indications. In the setting of primary ACL-R, respondents added LET when using hamstring tendon autograft in 38% of cases on average compared with 34% of cases when using either bone-patellar tendon-bone autograft or quadriceps tendon autograft. In the setting of revision ACL-R, LET was added in an average of 68% of cases for a first-time revision ACL-R and in 84% of cases for a multiple-revision ACL-R.

The most common indication for ACL-R with anterolateral complex augmentation was a high-grade pivot shift and most respondents preferred LET over ALL-R. Respondents performed LET in a comparable percentage of cases of primary ACL-R using hamstring tendon, bone-patellar tendon-bone, and quadriceps tendon autografts, and this number increased with the number of revision ACL-Rs. Based on the results of this survey, surgeons may consider adding LET in cases of revision ACL-R or in patients with a high-grade pivot shift.

Level V.

To analyze a large, cross-sectional sample of patients from an administrative database for trends in the yearly utilization of either isolated anterior cruciate ligament (ACL) reconstruction or concomitant ACL reconstruction with lateral extra-articular tenodesis (ACLR/LET) for the treatment of ACL injury and to compare the cumulative incidence of 5-year reoperations and 90-day emergency visits for each treatment modality.

International Classification of Diseases, Tenth Revision and Current Procedural Terminology codes were used to query the PearlDiver database between October 2015 and October 2022 to identify patients with a diagnosis of ACL injury undergoing either isolated ACLR or ACLR/LET. Propensity score matching was performed on the basis of age, sex, Charlson Comorbidity Index, overweight or obesity (body mass index >25.0), and tobacco use. Kaplan-Meier survival analysis was used to estimate the 5-year cumulative incidence of reoperations (revision ACLR, meniscus debridement/repair, adhesion lysis, knee joint manipulation, total knee arthroplasty) for each group.

In total, 1,022 patients underwent ACLR/LET, and 64,504 patients underwent ACLR for a diagnosis of ACL injury; following 1:1 propensity matching, 1,022 patients remained in each group. Patient counts for ACLR/LET increased yearly during the study period for every year except 2020, with greater than 20% increases annually after 2017. Kaplan-Meier analysis of revision ACLR in propensity-matched groups showed a 5-year cumulative incidence of 2.6% for patients undergoing ACLR/LET and 4.9% for ACLR (hazard ratio, 0.37; 95% confidence interval, 0.18-0.74; P = .005). There were no significant differences between groups and any other secondary event or postoperative complications.

ACLR/LET is increasingly utilized to treat patients with ACL tears and shows a decreased risk for revision ACLR without an increased risk for complications compared to patients treated with isolated ACLR.

Level III, retrospective matched comparative series.

The addition of an extra-articular reinforcement, such as the anterolateral ligament (ALL) or a Lemaire's procedure, in anterior cruciate ligament reconstructions has shown good clinical results, with greater graft protection and a lower rerupture rate. Despite being a reproducible procedure, its application in cases of large, muscled knees or in obese patients can be challenging. This Technical Note describes the "Open-ALL" technique, using a mini-open approach for a combined anterior cruciate ligament and ALL reconstruction.

Anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) has been used more frequently in conjunction with anterior cruciate ligament reconstruction (ACLR) in recent years. However, there are still concerns that these procedures may lead to complications such as overconstraint of the lateral compartment, stiffness, infections, tunnel convergence, and other intra- and postoperative complications because of increased surgical time and the need for additional procedures.

The lateral extra-articular procedure will reduce the failure rate of reconstructed ACLs without increasing the number of complications. The purpose was to compare the complication and graft reinjury rates of 2 main anterolateral complex procedure categories described in the literature-LET and ALLR with isolated ACLR.

Systematic review and meta-analysis of randomized controlled trials (RTCs); Level of evidence, 2.

The methodology followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The PubMed, Embase, and Cochrane Library databases were searched on March 15, 2024, to identify RTCs comparing isolated ACLR with ACLR + LET or ALLR. The methodological index for nonrandomized studies was employed for the quality evaluation. Complications and graft reinjury rates were recorded and meta-analyzed from all included studies.

The initial search yielded 1411 articles. Seventeen studies that included the complication rates (5 in the ALLR group and 12 in the LET group) were included in the review. No significant differences were found in the incidence of complications between the ACLR and ACLR + ALLR groups (Mantel-Haenszel [M-H], 1.20 [95% CI, 0.05-29.30]; P = .91) or between the ACLR and ACLR + LET groups (M-H, 0.39 [95% CI, 0.05-2.98]; P = .36). Significant differences were observed in the failure rate between the ACLR + ALLR group (M-H, 6.78 [95% CI, 1.98-23.22]; P = .002) and the ACLR + LET group (M-H, 3.14 [95% CI, 1.96- 5.04]; P < .00001).

Adding a lateral extra-articular procedure, regardless of the surgical technique, can reduce the failure rate without increasing the number of complications at the mid-term follow-up.

PROSPERO (CRD42023458354).

Knee ligament injury is among the most common sports injuries and is associated with long recovery periods and low return-to-sport rates. Unfortunately, the mechanics of ligament injury are difficult to study in vivo, and computational studies provide limited insight. The objective of this study was to implement and validate a robotic system capable of reproducing natural six degree-of-freedom clamped-kinematic trajectories on human cadaver knees (meaning that positions and orientations are rigidly controlled and resultant loads are measured). To accomplish this, we leveraged the field's recent access to high-fidelity bone kinematics from dynamic biplanar radiography (DBR), and implemented these kinematics in a coordinate frame built around the knee's natural flexion-extension axis. We assessed our system's capabilities in the context of ACL injury, by moving seven cadaveric knee specimens through kinematics derived from walking, running, drop jump, and ACL injury. We then used robotically simulated clinical stability tests to evaluate the hypothesis that knee stability would be only reduced by the motions intended to injure the knee. Our results show that the structural integrity of the knee was not compromised by non-injurious motions, while the injury motion produced a clinically relevant ACL injury with characteristic anterior and valgus instability. We also demonstrated that our robotic system can provide direct measurements of reaction loads during a variety of motions, and facilitate gross evaluation of ligament failure mechanisms. Clamped-kinematic robotic evaluation of cadaver knees has the potential to deepen understanding of the mechanics of knee ligament injury.

The anatomy of the antero-lateral corner (ALC) has been the topic of recent interest, as evidenced by the increasing number of publications. Knowledge needs to be improved amongst clinicians regarding the anatomy and biomechanical function of this vital structure and its implications on the rotational stability of the knee. There has yet to be a consensus on the role of surgical procedures and their indications for addressing the instability associated with the injury to these structures. Through this article, the authors have tried to outline the existing literature regarding Anterolateral knee instability, the associated structures, and the management of its injuries, emphasising the role of the anterolateral capsule and reconstructive procedures in combined ligamentous knee injuries.

Despite advancements in surgical techniques for anterior cruciate ligament reconstruction, some patients still experience rotational instability after surgery. Anterior cruciate ligament and anterolateral ligament reconstruction have been described using hamstring tendon autograft while preserving the insertion of the semitendinosus tendon. This article describes a combined anterior cruciate ligament and anterolateral ligament reconstruction using a hamstring tendon autograft with a suspensory button fixation.

Recent anterior cruciate ligament (ACL) research focuses on risk factors for ACL graft failure and techniques and augmentations to limit failure. One of the most recognized risk factors is sagittal malalignment in the form of high posterior tibial slope (PTS), especially PTS ≥12°, which leads to increased force through the ACL and ACL graft. To reduce the risk associated with increased PTS, lateral augmentation techniques, typically either a lateral extra-articular tenodesis or an anterolateral ligament reconstruction, improve clinical outcomes, and the authors preferred graft choice, particularly in such cases, is bone-patellar tendon-bone autograft. Furthermore, in revision cases, there exists a strong argument to perform a slope reducing osteotomy to correct bony malalignment which, if left untreated, could lead to ACL graft failure. Slope-reducing osteotomies are reported to significantly decrease anterior tibial translation and forces on the ACL graft. Coronal malalignment is also a risk factor for ACL failure (although not as extensively studied as sagittal alignment). Both varus and valgus alignment of the knee can lead to increased forces through the ACL or ACL graft compared with knees in neutral alignment, and workup requires proper lateral and long-leg anteroposterior radiographs to determine sagittal and coronal alignment and guide treatment algorithms. Recent research shows that decreased medial proximal tibial angle of the knee (increasing varus alignment of the tibia) may delay graft maturation. However, there is yet to be a consensus about what exactly contributes to ACL graft failure in the coronal plane and what is the best treatment option, especially in the primary setting when an osteotomy is not indicated. Again, we recommend bone-patellar tendon-bone autograft as our preferred graft choice unless contraindicated by skeletal immaturity.

Anterior cruciate ligament (ACL) injuries and subsequent surgical reconstruction are exceedingly common orthopaedic procedures. Surgical technique and graft preparation techniques continue to evolve as surgeons seek to increase surgical outcomes and decrease recovery time. As such, there is significant interest in identifying tools and techniques that may enhance the surgical process for patients undergoing an ACL reconstruction. Recently, there has been significant interest in evaluating biologic scaffolds that may augment graft healing. This Technical Note describes our technique for the preparation of a bone-patellar tendon-bone ACL graft with a BioBrace biocomposite scaffold augmentation.

When performing lateral extra-articular procedures (LEAPs) at the time of anterior cruciate ligament (ACL) reconstruction, it is essential to be aware of the possibility of tunnel collision and understand strategies to avoid it. The risk of tunnel collision is high, especially if an anteromedial portal ACL femoral tunnel is drilled. Tunnel collision can be avoided by using a single femoral tunnel for both procedures, outside-in femoral tunnel drilling to place the ACL tunnel a safe distance away from the LEAP, and cortical fixation techniques. Other strategies that have been explored have included anteromedial portal drilling in low degrees of flexion, anterior angulation of LEAP tunnels, and the use of an "anterior Lemaire" position. These alternative strategies are not preferred because they are associated with an increased risk of iatrogenic injuries to important posterolateral structures, penetration of trochlea articular cartilage, and overconstraint, respectively.

To determine the most common indications for lateral extra-articular tenodesis (LET) augmentation of anterior cruciate ligament reconstruction (ACLR).

A systematic review of the literature was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed, Embase, Web of Science, and Cochrane Database of Systematic Reviews from 2000 to the present (June 2022). Studies that met the following criteria were included: patients of any age who underwent LET in addition to ACLR, studies reporting at least 1 indication for LET, and observational/randomized controlled trial study designs including prevalence of indications. Publications had to be reported in English and peer reviewed and to have originated in the United States or countries offering identical protocols and procedures.

A total of 463 studies were identified from the initial search, 23 of which met inclusion criteria and were included in the review. Eight of the 23 studies (34.8%) used a modified Lemaire technique, seven (30.4%) used a MacIntosh modified by Arnold-Coker, and eight (34.8%) used other techniques to perform LET. A total of 2,125 patients (53% female, 47% male [3 studies did not report sex]) underwent ACLR augmented with LET. The indications along with prevalence were as follows: positive pivot shift test (grade ≥2) (19 of 23, 82.6%), revision ACLR (12 of 23, 52.2%), ligamentous laxity (11 of 23, 47.8%), general sports participation (11 of 23, 47.8%), age less than 25 years (8 of 23, 34.8%), high risk of graft failure (5 of 23, 21.7%), and positive Lachman test (4 of 23, 17.4%).

Pivot shift grade ≥2 was the most common reason orthopaedic surgeons chose to add LET to ACLR, with revision ACLR, patient age <25, and general sports participation following closely behind.

Level IV, systematic review of Level I-IV studies.

To investigate tibiofemoral knee kinematics when shifting the femoral insertion point of the modified Lemaire lateral extra-articular tenodesis (LET) anterior to the lateral epicondyle.

Six fresh-frozen human knee joints were tested on a test bench in the following states: (1) native, (2) anterolateral insufficient, (3) original Lemaire (oLET; insertion point: 4 mm posterior and 8 mm proximal to the epicondyle), (4) anterior Lemaire (aLET; insertion point: 5 mm anterior and 5 mm proximal to the epicondyle). Internal tibial rotation was statically investigated under an internal tibial torque of 5 Nm in 0°, 30°, 60°, and 90° of flexion. Anterior translation was statically investigated during a simulated Lachman test with an anterior translational force of 98 N. Additionally, the range of internal tibial rotation and anterior translation were dynamically investigated by a simulated pivot-shift test. Tibiofemoral kinematics were measured using an optical 3D motion analysis system.

The aLET showed an internal tibial rotation comparable to the native state for all tested flexion angles except 90° (0°: P = .201; 30°: P = .118; 60°: P = .126; 90°: P = .026). The oLET showed an internal tibial rotation below the values of the native state for all tested flexion angles indicating an overconstraint (0°: P = .003; 30°: P = .009; 60°: P = .029; 90°: P = .029). Direct comparisons between aLET and oLET showed a significantly decreased overconstraint at 0° and 30° of flexion (P = .001 and P = .003, respectively) when using the aLET. No differences in anterior translation and internal tibial rotation were found between the oLET and aLET during simulated Lachman and pivot-shift test (P > .05), approximating the native state.

An anteriorly shifted LET insertion point restored internal tibial rotation after anterolateral insufficiency to the native state while decreasing the overconstraint of internal tibial rotation induced by an LET using the originally described insertion point for small flexion angles ≤30°.

Using an LET insertion point anterior to the epicondyle was recently reported to lower the risk of tunnel interference and has now been shown to restore internal tibial rotation effectively in vitro in the course of the present study. Concerns of overconstraining internal tibial rotation are not diminished by this technique, but using an anterior insertion point helps to decrease overconstraint.

» The rate of primary anterior cruciate ligament reconstruction (ACLR) failure in at-risk populations remains unacceptably high and necessitates thorough evaluation of native alignment and concomitant injuries.» Posterior tibial slope of >12° is a substantial risk factor of ACLR failure and should be corrected through anterior closing wedge osteotomy.» Varus malalignment of >5° exacerbates stress on the ACL graft, increases ACLR failure risks, and should be considered for correction through high tibial osteotomy at the time of revision ACLR.» Injuries to the anterolateral ligamentous complex are prevalent in ACL ruptures, and high-risk patients have shown benefit from anterolateral ligament reconstruction or lateral extra-articular tenodesis in the revision setting.» Addressing posterolateral corner, collateral ligament, and meniscal injuries, during revision ACLR, is vital to mitigate increased graft forces and optimize knee stability and functional outcomes.

The treatment of rotational instability has been an intriguing challenge since the era of modern anterior cruciate ligament (ACL) surgery. Lateral extra-articular procedures (LEAPs) have emerged as a solution to this problem, particularly in high-risk populations. Several studies have shown significant benefits of combining LEAPs with ACL reconstruction, including reduced graft failure rates, improved knee stability, improved rotational stability, and higher return-to-play rates. These findings have led to an in-depth evaluation of LEAPs as lateral extra-articular tenodesis and anterolateral ligament reconstruction and their potential role in improving outcomes after ACL reconstruction.

The purpose of this study was to investigate the effect of anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) fixation at low versus high flexion angles during anterior cruciate ligament reconstruction (ACLR) on rotation or translational knee stability.

The inclusion criteria for this study were (1) cadaveric study, (2) cadaveric specimens underwent ACLR, (3) cadaveric specimen underwent ALLR or LET and (4) specimen preparation technique described the knee flexion angle at the time of ALLR or LET tensioning and fixation. A priori, 'low flexion' was defined as 0-30° and 'high flexion' was defined as 60-90° at graft fixation. Main outcomes of interest included internal rotation and anterior translation.

Data from 92 cadaveric knees (from 9 studies) were extracted and included in the meta-analysis. The mean pooled value for internal rotation was 10.1° (95% confidence interval [CI], 5.7-14.5°) for the low flexion group and 11.5° (95% CI, 7.4-15.7°) for the high flexion group (n.s.). The mean pooled value for anterior translation was 4.3 mm (95% CI, 0.5-8.1 mm) for the low flexion group and 3.0 mm (95% CI, 1.1-5.0 mm) for the high flexion group (n.s.).

This meta-analysis of existing biomechanical research found that the rotational and translational stability of the knee were not significantly different between scenarios in which ALLR or LET fixation was performed at low knee flexion angles (0-30°) versus high knee flexion angles (60-90°).

Level IV.

We describe a surgical technique for ACL reconstruction combined with anterolateral structure reinforcement and report early clinical follow-up results.

The semitendinosus and gracilis tendons are braided into 5 strands and the ACL femoral tunnel and tibial tunnel are created. The graft is passed through the tunnel with the use of a traction suture and the tibial end is fixed with absorbable interference screws at 30° of knee flexion. The ACL graft traction suture is used as an anterolateral reconstruction structure to pass through the proximal exit of the ACL femoral tunnel and then through the depth of the iliotibial bundle to the anterior to Gerdy's tubercle, a bony tunnel is created from the anterior to Gerdy's tubercle to the goose foot, and the traction suture is passed through this bony tunnel to form a Loop structure at 20° of knee flexion. Between March 2021 and May 2022 IKDC score, Lysholm score, and Tegner score were performed preoperatively and 6-12 months postoperatively in 24 consecutive patients who met the indications for this procedure and underwent surgery. The patient's maximum flexion angle, the circumference of the thigh, and the stress X-ray between the operated and healthy knee were measured.

Patients showed significant improvement in IKDC score, Lysholm score and Tegner score at a mean follow-up of 7 months postoperatively compared to preoperatively. No significant increase in anterior tibial displacement was found between the patient's operated side and the healthy side.

The Loop technique ACLR combined with ALSA can be used in patients with an ACL tear combined with a high degree of positive pivot shift. The patient's subjective perception was significantly improved from the preoperative period and knee stability was restored.

IV, therapeutic study.

Anterior cruciate ligament reconstructions (ACLRs) are performed to restore knee biomechanics, increase knee stability, and slow the progression of osteoarthritis. After ACLRs, many patients still have residual anterolateral instability which is a risk factor for ACL graft failure. An anterolateral ligament reconstruction (ALLR) attempts to restore the native function of the anterolateral complex to augment the ACL. Performing an ALLR with an ACLR has been reported to reduce symptoms of instability and improve clinical outcomes.

While no definitive indication for an ALLR has been set, current considerations include high posterior tibial slope >12°, revision ACLR, high-grade pivot shift, skeletally immature patients, hyperlaxity, and patients in high-level sports.

The preoperative assessment includes a thorough physical examination with special attention paid to rotational laxity assessed via the pivot-shift examination. Imaging should include standard radiographic series (anteroposterior, posteroanterior flexion, lateral, and sunrise views), long-leg mechanical axis views to assess coronal plane alignment and standing lateral ACL stress radiographs to assess sagittal alignment and objective instability. The iliotibial band ALLR graft is harvested first. An 8-cm long by 1-cm wide strip of the inferior iliotibial band is harvested in a standard fashion, leaving the distal aspect attached to Gerdy's tubercle. An anchor is placed centered upon the native ALL distal tibial insertion. The native ALL femoral origin is identified at 4.7 mm posterior and proximal to the fibular collateral ligament, and a second suture anchor is placed at this point. Final fixation is performed after the final fixation of the ACLR graft.

A study by Pioger et al reported that patients with ACLR and ALLR had significantly less reoperation rate than patients with isolated ACLR, 8.9% versus 20.5% respectively. Lee et al found that a revision ACLR in combination with an ALLR was effective in reducing rotational laxity, which was assessed by the pivot-shift test.

We describe a technique for a new anatomic ALLR using the iliotibial band that attempts to restore the native ALL anatomy. This surgical technique effectively restores rotational laxity and improves knee stability.

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Anterior cruciate ligament (ACL) tears are one of the most common knee injuries experienced by active individuals engaging in cutting sports. Despite improved surgical techniques and rehabilitation, the return to sport rate and re-tear rates remain unsatisfactory. Lateral extra-articular tenodesis (LET) is a procedure that has been growing in interest when performed in conjunction with ACL reconstruction. The benefits of adding an LET procedure to an ACL surgery may include greater rotational stability, decreased re-tear rates, and improved return to play. Level of evidence: V.

Concerns have arisen that anterior cruciate ligament reconstruction (ACLR) with lateral extra-articular tenodesis (LET) may accelerate the development of posttraumatic osteoarthritis in the lateral compartment of the knee.

The purpose of this study was to evaluate whether the augmentation of ACLR with LET affects the quality of lateral compartment articular cartilage on magnetic resonance imaging (MRI) at 2 years postoperatively. We hypothesized that there would be no difference in T1rho and T2 relaxation times when comparing ACLR alone with ACLR + LET.

Randomized controlled trial; Level of evidence, 1.

A consecutive subgroup of patients at the Fowler Kennedy Sport Medicine Clinic participating in the STABILITY 1 Study underwent bilateral 3-T MRI at 2 years after surgery. The primary outcome was T1rho and T2 relaxation times. Articular cartilage in the lateral compartment was manually segmented into 3 regions of the tibia (lateral tibia [LT]-1 to LT-3) and 5 regions of the femur (lateral femoral condyle [LFC]-1 to LFC-5). Analysis of covariance was used to compare relaxation times between groups, adjusted for lateral meniscal tears and treatment, cartilage and bone marrow lesions, contralateral relaxation times, and time since surgery. Semiquantitative MRI scores according to the Anterior Cruciate Ligament OsteoArthritis Score were compared between groups. Correlations were used to determine the association between secondary outcomes (including results of the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Lower Extremity Functional Scale, 4-Item Pain Intensity Measure, hop tests, and isokinetic quadriceps and hamstring strength tests) and cartilage relaxation.

A total of 95 participants (44 ACLR alone, 51 ACLR + LET) with a mean age of 18.8 years (61.1% female [58/95]) underwent 2-year MRI (range, 20-36 months). T1rho relaxation times were significantly elevated for the ACLR + LET group in LT-1 (37.3 ± 0.7 ms vs 34.1 ± 0.8 ms, respectively; P = .005) and LFC-2 (43.9 ± 0.9 ms vs 40.2 ± 1.0 ms, respectively; P = .008) compared with the ACLR alone group. T2 relaxation times were significantly elevated for the ACLR + LET group in LFC-1 (51.2 ± 0.7 ms vs 49.1 ± 0.7 ms, respectively; P = .03) and LFC-4 (45.9 ± 0.5 ms vs 44.2 ± 0.6 ms, respectively; P = .04) compared with the ACLR alone group. All effect sizes were small to medium. There was no difference in Anterior Cruciate Ligament OsteoArthritis Scores between groups (P = .99). Weak negative associations (rs = -0.27 to -0.22; P < .05) were found between relaxation times and quadriceps and hamstring strength in the anterolateral knee, while all other correlations were nonsignificant (P > .05).

Increased relaxation times demonstrating small to medium effect sizes suggested early biochemical changes in articular cartilage of the anterolateral compartment in the ACLR + LET group compared with the ACLR alone group. Further evidence and long-term follow-up are needed to better understand the association between these results and the potential risk of the development of osteoarthritis in our patient cohort.

The aims of this study were to describe a lateral extra-articular tenodesis (LET) using no additional hardware and compare the tibiofemoral kinematics of anterior cruciate ligament (ACL) reconstruction augmented with either the LET or a standard anatomic anterolateral ligament (ALL) reconstruction using intra-tunnel fixation.

Ten cadaveric knees were mounted on a robotic testing system and underwent a kinematic assessment of anterior tibial translation and internal tibial rotation under a simulated pivot-shift in the following states: ACL-intact, ACL-sectioned, ACL-sectioned/anterolateral complex (ALC)-sectioned, ACL-reconstructed/ALC-sectioned, ACL-reconstructed/ALL-reconstructed, and ACL-reconstructed/LET. For the LET, an iliotibial autograft was passed under the fibular collateral ligament and secured to the femur with the pull sutures of the ACL reconstruction femoral cortical suspensory fixation device, positioned at the distal ridge of Kaplan's fibers.

Anterior tibial translation was restored to normal by ACL reconstruction without meaningful benefit of augmentation with LET or ALL. ACL reconstruction restored internal tibial rotation close to normal between 0° and 30°, but increased internal tibial rotation persisted between 45° and 90°. Augmentation of ACL reconstruction with the LET reduced internal rotation close to normal between 45° and 90°, whereas increased internal rotation persisted after ALL reconstruction.

ACL reconstruction and LET are complementary in controlling tibiofemoral kinematics of knees with a combined ACL and ALC injury: ACL reconstruction restored native tibiofemoral kinematics except for internal rotation at flexion greater than 30°. The increased internal rotation at flexion greater than 30° was restored to normal with an LET, but not with an ALL reconstruction.

The association of ALL and KF injuries in anterior cruciate ligament (ACL)-deficient knees remain topics of conflicting research despite improved magnetic resonance imaging (MRI). We aimed to evaluate the rate of the anterolateral ligament (ALL) and Kaplan fibers (KF) injuries in adults with acute ACL injuries using MRI.

We retrospectively reviewed 64 patients with clinical and MRI diagnoses of acute ACL tears. Two radiologists analyzed and categorized the status of the ALL and KF in all patients as intact, partially injured, or completely injured. Interobserver agreement was assessed. Injuries to the collateral ligaments, ITB and posterior cruciate ligament (PCL) were also evaluated.

The mean age of the patients was 33 years. ALL injuries were observed in 46 (71%) patients, among whom 33 (71%) had partial and 13 (28%) had complete injuries. KF injuries were identified in 32 (50%) patients, with 28 (87.5%) of them having partial and 4 (12.5%) having complete injuries. Combined injuries of both ALL and KF were found in 25 (32.4%) patients (p-value of 0.266). The agreement between the examiners ranged from moderate to substantial (Kappa between 0.55 and 0.75), with the highest agreement observed in cases of KF injuries (Kappa = 0.75).

ALL and KF injuries were prevalent in acute ACL-injured knees with rates of injury of 71% and 50%, respectively. ALL injuries were more frequent and more frequently severe compared to KF injuries.

To obtain a comprehensive overview of comparative biomechanical cadaveric studies investigating the effect of both the iliotibial band (ITB) and anterolateral ligament (ALL) on anterolateral rotatory instability (ALRI) in anterior cruciate ligament (ACL)-injured knees, and the effect of lateral extra-articular tenodesis (LET) versus ALL reconstruction (ALLR) in ACL-reconstructed knees.

An electronic search was performed in the Embase and MEDLINE databases for the period between January 1, 2010, and October 1, 2022. All sectioning studies comparing the role of both the ITB and ALL on ALRI and all studies comparing the effect of both LET and ALLR were included. Articles were assessed for methodological quality according to the Quality Appraisal for Cadaveric Studies scale.

Data of 15 studies were included, representing the mean values of biomechanical data collected from 203 cadaveric specimens, with sample sizes ranging from 10 to 20 specimens. All 6 sectioning studies reported that the ITB acts as a secondary stabilizer to the ACL and helps resist internal knee rotation, whereas in only 2 of 6 sectioning studies the ALL contributed significantly to tibial internal rotation (IR). Most reconstruction studies reported that both a modified Lemaire tenodesis and an ALLR could significantly reduce the residual ALRI in isolated ACL-reconstructed knees and were able to restore IR stability/IR stability during the pivot shift.

The ITB acts as the main secondary stabilizer to the ACL in resisting IR/IR during pivot shift and an anterolateral corner (ALC) reconstruction with either a modified Lemaire tenodesis and ALLR can improve residual knee rotatory laxity in ACL reconstructed knees.

This systematic review provides insight in the biomechanical function of the ITB and ALL and emphasizes the importance of adding an ALC reconstruction to ACL reconstruction.

The way in which force increases in the anterolateral tissues and the lateral extra-articular tenodesis (LET) tissue to resist internal rotation (IR) of the tibia after anterior cruciate ligament (ACL) reconstruction in isolation and after LET augmentation, respectively, is not well understood.

(1) To compare in a cadaveric model how force increases (ie, engages) in the anterolateral tissues with IR of the tibia after isolated ACL reconstruction and in the LET tissue after augmentation of the ACL reconstruction with LET and (2) to determine whether IR of the tibia is related to engagement of the LET tissue.

Controlled laboratory study.

IR moments were applied to 9 human cadaveric knees at 0°, 30°, 60°, and 90° of flexion using a robotic manipulator. Each knee was tested in 2 states: (1) after isolated ACL reconstruction with intact anterolateral tissues and (2) after LET was performed using a modified Lemaire technique with the LET tissue fixed at 60° of flexion under 44 N of tension. Resultant forces carried by the anterolateral tissues and the LET tissue were determined via superposition. The way force increased in these tissues was characterized via parameters of tissue engagement, namely in situ slack, in situ stiffness, and tissue force at peak applied IR moment, and then compared (α < .05). IR was related to parameters of engagement of the LET tissue via simple linear regression (α < .05).

The LET tissue exhibited less in situ slack than the anterolateral tissues at 30°, 60°, and 90° of flexion (P≤ .04) and greater in situ stiffness at 30° and 90° of flexion (P≤ .043). The LET tissue carried greater force at the peak applied IR moment at 0° and 30° of flexion (P≤ .01). IR was related to the in situ slack of the LET tissue (R2≥ 0.88; P≤ .0003).

LET increased restraint to IR of the tibia compared with the anterolateral tissue, particularly at 30°, 60°, and 90° of flexion. IR of the tibia was positively associated with in situ slack of the LET tissue.

Fixing the LET at 60° of flexion still provided IR restraint in the more functionally relevant flexion angle of 30°. Surgeons should pay close attention to the angle of internal and/or external tibial rotation when fixing the LET tissue intraoperatively because this surgical parameter is related to in situ slack of the LET tissue and, therefore, the amount of IR of the tibia.

Quadriceps tendon autograft (QTA) has recently gained popularity in the treatment of anterior cruciate ligament (ACL) ruptures in pediatric patients. The addition of lateral extra-articular tenodesis (LET) to an ACL reconstruction (ACLR) has been found to reduce the risk of ACL retear in high-risk patients.

To (1) compare ACL graft maturity using signal intensity ratios (SIRs) on magnetic resonance imaging (MRI) scans in skeletally immature patients undergoing ACLR with QTA either with or without concomitant LET and (2) evaluate LET safety by calculating the physeal disturbance-related reoperation rate in the ACLR+LET group.

Cohort study; Level of evidence, 3.

The records of patients aged ≤18 years who underwent ACLR between 2015 and 2021 were reviewed retrospectively. Patients undergoing ACLR with QTA who had open distal femoral and proximal tibial physes on MRI scans and a minimum 2-year follow-up data were included. SIR values were measured on sagittal MRI scans by averaging the signal at 3 regions of interest along the ACL graft and dividing by the signal of the posterior cruciate ligament at its insertion. Statistical analysis was performed to evaluate differences in SIR values at 6 months, 1 year, and 2 years postoperatively in patients who underwent ACLR alone versus ACLR+LET.

Overall, 29 patients were included in the study: 16 patients in the ACLR+LET group and 13 patients in the ACLR-only group. There were no significant differences in SIR values between groups at the 6-month or 1-year postoperative timepoints. At 2 years postoperatively, the median SIR of the ACLR+LET group was significantly lower than that of the ACLR-only group on both univariate (1.33 vs 1.86, respectively, P = .0012) and multivariate regression analyses adjusting for both sex and surgical technique (β = -0.49 [95% CI, -0.91 to -0.05]; P = .029). There were no cases of reoperation for physeal disturbance in patients who underwent ACLR+LET.

The addition of LET to an ACLR with QTA was associated with lower average SIR values and thus improved graft maturity at 2 years postoperatively compared with ACLR alone in skeletally immature patients. The addition of LET to an ACLR was found to be safe in skeletally immature patients.

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.

This study aimed to compare the short-term outcomes of ACL reconstruction (ACLR) alone, ACLR with lateral tenodesis, and ACL and ALL reconstruction.

A retrospective cohort of prospectively collected data on all ACL procedures was performed at Aspetar Specialized Orthopaedic and Sports Medicine Hospital between January 2020 and January 2021. Patients were treated with ACLR alone, ACLR with lateral tenodesis, or ACLR with ALL reconstruction. The primary outcome was the subjective International Knee Documentation Committee (sIKDC) score. The secondary outcomes were the ACL Return to Sport after Injury (ACL-RSI) scores, pivot shift grade, subjective knee stability, and subjective pain on activity.

A total of 100 cases were included. The most common technique was ACLR with lateral tenodesis (42%), followed by ACLR alone (38%) and ACL with ALL reconstruction (20%). The mean age was 28.15 years (15-60), and 94% of the patients were males. Meniscal procedures were more frequent in the ACLR alone group (65.8%). There was no association between subjective stability, sIKDC, ACL-RSI, and pivot shift grade and the three ACLR techniques while adjusting for age, sex, and concomitant meniscus procedures at six weeks, 12 weeks, six months, and nine months. However, there was a significant decrease in postoperative flexion in the ACL and ALL reconstruction group by a mean of 22° (95% CI - 40.7 - 3.4; P = 0.02) at 6 weeks compared to ACLR alone, which was not evident on later follow-ups.

ACLR with/without lateral augmentation procedures yields similar subjective IKDC, ACL-RSI, pivot shift grade, and subjective knee instability at short-term follow-up. Therefore, lateral extra-articular augmentation procedures are safe to be performed.

The purpose of the present study was to assess the internal rotation of the tibia on Magnetic Resonance Imaging (MRI) in a series of consecutive athletes with Anterior cruciate Ligament (ACL) tears.

Retrospective analysis of prospectively collected data was performed to include all consecutive patients who had undergone primary ACL reconstruction between January 2022 and June 2022. The angle between surgical epicondylar axes (SEA) of the knee and posterior tibial condyles (PTC) was measured. A negative value was defined as internal torsion. KFs and ALL injuries were reported. Analysis of covariance (ANCOVA) was performed to examine the independent associations between SEA-PTC angle and injuries of KFs and ALL adjusted for physical variables (age, gender and body mass index [BMI]). Statistical significance was set at a p-value of < 0.05.

A total of 83 eligible patients were included. The result of multiple linear regression analysis showed that internal tibial rotation was associated with KFs and ALL injuries. The estimated average of SEA-PTC angle in relation to ALL injuries controlling the other variables was -5.49 [95%CI -6.79 - (-4.18)] versus -2.99 [95%CI -4.55 - (-1.44)] without ALL injuries. On the other hand, the estimated average of SEA-PTC angle in relation to KFs lesions controlling the other variables was -5.73 [95%CI -7.04 - (-4.43)] versus -2.75 [95%CI -4.31 - (-1.18)] without KFs injuries.

KFs and ALL injuries were associated with an increased intra-articular internal tibial rotation in ACL-deficient knees. The measurement of femorotibial rotation on axial MRI could be useful to detect indirect signs of anterolateral complex (ALC) injuries.

It is essential to obtain rotational stability of the knee after anterior cruciate ligament reconstruction (ACL-R) and it is suggested that a supplementary reconstruction of the antero-lateral ligament (ALL-R) may supports this. Theoretically, ALL-R may be particularly advantageous to support revision of failed ACL-Rs. It was hypothesized that ACL revision combined with ALL-R will result in superior outcome compared to isolated ACL revision.

The study was designed as a randomized controlled trial. Patients eligible for first time ACL revision were randomized to either isolated ACL revision (- ALL group) or ACL revision combined with a single-stranded allograft ALL-reconstruction (+ ALL group). Patient reported outcomes and function were evaluated at two-year follow-up by KNEES-ACL, KOOS, and Tegner activity scale. Objective knee laxity was evaluated at one-year follow-up using an instrumented Rolimeter test, the pivot shift test, and a manual Lachman test.

A total of 103 patients were enrolled with 49 patients randomized to the + ALL group and 54 patients in the - ALL group. There were no differences at baseline between groups regarding age, gender, body mass index, preoperative patient reported outcome scores and concomitant meniscus or cartilage injury. The ACL revision was performed with an allograft in 10 patients (20%) in the + ALL group and 8 patients (15%) in the -ALL group. At follow-up there was no significant difference between the groups in patient reported outcome scores and clinical knee laxity.

Supplementary ALL-R does not improve subjective outcome of first time ACL revision at two-years and clinical knee stability at one-year follow-up compared to isolated ACL revision.

Level I.

Appreciation of persistent anterolateral rotatory instability and graft failure after anterior cruciate ligament (ACL) reconstruction procedures has led surgeons to adopt the addition of lateral extra-articular tenodesis (LET) in both the revision and primary setting. Multiple techniques have been shown to eliminate anterolateral rotatory instability and reduce forces on the ACL graft, which has translated to lower re-rupture rates and improved patient outcomes. The risk of ACL/LET tunnel convergence can potentially compromise the fixation of one or both graft reconstructions. This article describes a technique for LET fixation which minimizes the depth of the LET femoral bone socket and utilizes low-profile implants thus mitigating this risk.

Many studies have confirmed the existence of ligament structures in the anterolateral region of the knee that maintain rotational stability of the knee joint, namely, the anterolateral ligament (ALL). Most scholars believe that knee joint reconstruction should be considered during revision surgery and a high level of pivot displacement test (stage 2 or 3). During ALL reconstruction, the choice of ligament reconstruction sites affects the success rate and prognosis of the operation. Therefore, the choice of ligament reconstruction sites is particularly important. There is little research on the lateral ALL tibia insertion point, and most clinicians use the midpoint Gerdy's tubercle and fibular head as insertion points. However, the reconstruction effect is not ideal.

This study aims to measure the position of the Segond fracture bed on CT images to determine the ALL position of the tibia.

To determine the position of the Segond fracture bone bed, the CT AM Volume Share 2 system was used to manually measure the position of bone fragments in 23 Segond fracture patients. Using the highest point of Gerdy's tubercle in the CT axial slices and the outermost point of the fibular head in the CT axial slices as reference points, the direction and angle of the CT slices were adjusted to ensure that the highest point of the Gerdy tubercle, the outermost point of the fibular head, and the center of Segond fracture bed were in the same sagittal slice. A CT sagittal slice measures the vertical distance from the center of the Segond fracture bed to the Gerdy-fibular line segment (G-F line segment), which is the line connecting the highest point of the segment to the outermost point of the fibula. The distance from the vertical point at the center of the Segond fracture bed of the G-F line to the highest point of the Gerdy tubercle was measured. All measurements were performed using the same measurement standard and were expressed as a percentage of the length of the G-F line. The measured results were statistically analyzed using SPSS 25.0 descriptive statistical research methods.

The average length of the G-F segment measured on CT images was 39.6 ± 2.0 mm, and the average vertical length from the center of the Segond fracture bed to the G-F segment was 13.1 ± 1.1 mm, accounting for 33.2% ± 2.1% of the length of the G-F segment. The length from the vertical point of the fracture bed on the G-F line segment to the highest point of the Gerdy tubercle was 14.7 ± 1.3 mm, accounting for 37.1% ± 2.9% of the length of the G-F segment.

Through the study of the CT measurement of the Segond fracture location, we obtained the location of the functional tibial insertion of ALL, which is different from the anatomical insertion of ALL and is more inclined to the Gerdy tubercle and above, which has reference value for the treatment of recovering the function of anterolateral ligament after reconstruction.

To investigate whether anterolateral ligament (ALL) sectioning (sALL) in the anterior cruciate ligament (ACL)-sectioned (sACL) knee increases the anterior tibial translation (ATT) or internal rotation (IR) of the knee from previous cadaveric biomechanical studies.

Multiple comprehensive literature databases, including PubMed (MEDLINE), EMBASE, and Cochrane Library, were searched for studies evaluating the in vitro biomechanical function of ALL. This meta-analysis compared the increased ATT and IR between the sACL and sACL + sALL knees at 30°, 60°, and 90° of knee flexion. Thresholds of 2 mm for the difference in ATT and 2° for the difference in IR were considered to be clinically significant.

Thirteen cadaveric biomechanical studies were included. All 13 studies satisfied the threshold for a satisfactory methodological quality (Quality Appraisal for Cadaveric Studies score >75%). At 30° of knee flexion, the meta-analysis showed a greater increase in ATT in the sACL + sALL knees than in the sACL knees by 1.23 mm (95% confidence interval [CI], 0.62-1.84; P < .0001). However, the mean difference was less than the minimal clinically significant difference (<2 mm). The meta-analysis also showed a greater increase in IR in the sACL + sALL knees than in the sACL knees at 30° (mean difference [MD]: 2.24°; 95% CI: 1.39-3.09; P < .00001), 60° (MD: 2.77°; 95% CI: 1.88-3.67; P < .00001), and 90° (MD: 2.29°; 95% CI: 1.42-3.15; P < .00001) of knee flexion. The differences in IR at 30°, 60°, and 90° of knee flexion were clinically relevant (>2°).

Despite the different experimental setups and protocols between studies, the meta-analysis of biomechanical cadaveric studies showed that sectioning of the ALL in sACL knees increased IR at 30°, 60°, and 90° of knee flexion.

The results of this systematic review and meta-analysis suggest that ALL contributes to IR in ACL-deficient knees at 30°, 60°, and 90° of flexion.

Many surgeons performing anterior cruciate ligament (ACL) reconstruction have encountered the problem of harvesting small hamstring grafts. For this situation, several options are available such as harvesting contralateral hamstring tendons, reinforce the ACL graft with allografts, take a bone-patellar tendon-bone or quadriceps graft or add an anterolateral ligament reconstruction or lateral extra-articular tenodesis. Recent studies have shown that the presence of a lateral extra-articular procedure might be more important than the thickness of an isolated ACL graft, which is reassuring news. Current evidence suggests that both anterolateral ligament reconstruction and modified Lemaire tenodesis are similar biomechanically and clinically and could solve the problem of small-diameter hamstring ACL autografts.

The addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament (ACL) reconstruction (ACLR) has become increasingly popular to address residual rotatory knee instability. The purpose of this article is to review the anatomy and biomechanics of the anterolateral complex (ALC) of the knee, outline different LET techniques, and provide biomechanical and clinical evidence for its use as an augmentation procedure with ACLR.

Rotatory knee instability has been identified as a common contributor to ACL rupture in both the primary and revision settings. Several biomechanical studies have shown that LET reduces strain on the ACL by decreasing excess tibial translation and rotation. Additionally, in vivo studies have demonstrated restoration of side-to-side differences in anterior-posterior knee translation, higher rates of return to play, and overall increased patient satisfaction following combined ACLR and LET. As a result, various LET techniques have been developed to help offload the ACL graft and lateral compartment of the knee. However, conclusions are limited by a lack of concrete indications and contraindications for use of LET in the clinical setting. Recent studies have shown that rotatory knee instability contributes to native ACL and ACL graft rupture and LET may provide further stability to reduce rates of failure. Further investigation is needed to establish concrete indications and contraindications to determine which patients would most benefit from added stability of the ALC.

Anterior cruciate ligament (ACL) tears are one of the most frequent injuries in growing children, and they are often associated with other injuries such as meniscal and chondral injuries. In the past, treatment of ACL tears in growing patients relied on activity modification and bracing. However, surgical treatment has prevailed over conservative treatment in recent years. A surgical technique is presented for ACL reconstruction using an "over-the-top" technique associated with a lateral extra-articular tenodesis procedure in children. An extra-articular lateral tenodesis is done first. The gracilis and semitendinous tendons are then extracted using a tenotome without releasing their distal desinsertions. The tibial guide is then centered over the ACL tibial footprint under arthroscopic vision and an image intensifier, proximal to the physis. Then, a Kocher-type forceps is used to pass a suture "over the top" from the posterolateral window to the tibial tunnel. The double-bundle graft and iliotibial tract graft are fixed within the tunnel in full extension and neutral rotation with an interference screw.

Persistent instability of the knee is reported in up to 30% of patients after anterior cruciate ligament (ACL) reconstruction. Based on anatomic findings showing that ACL is a flat ribbon-like structure that twists during knee flexion, a new surgical ACL reconstruction technique using a ribbon-like graft has been developed. However the effect of this surgical technique on knee kinematics has not yet been evaluated.

To compare the anteroposterior and rotational stability of the knee after ACL reconstruction using single-bundle (SB) round and ribbon-like grafts in anterolateral-intact/deficient knees.

Controlled laboratory study.

Twelve human fresh-frozen cadaveric knees were tested with a 6 degrees of freedom robotic system. Internal rotation and anterior translation of the knee were recorded from 0° to 90° of flexion. A full kinematic assessment was performed in each of the following conditions: (1) intact knee, (2) after sectioning of the ACL, (3) after ACL reconstruction using a SB hamstring tendon graft in a round configuration and a ribbon-like configuration, and (4) after sectioning of the anterolateral structures. One-way analysis of variance and post hoc Tukey tests were used for statistical analyses.

When compared with the intact knee, the ACL-deficient knee demonstrated a mean ± SD increase in anterior translation and internal rotation of 6.3 ± 2.5 mm (P < .01) and 5.8°± 2.3° (P < .01), respectively. After ACL reconstruction using a SB ribbon-like graft, the mean difference in anterior translation and internal rotation as compared with the intact knee was -0.1 ± 1.5 mm (P = .842) and 0.0°± 1.1° (P = .999). These differences from the intact knee were also not significant after ACL reconstruction using a round graft (-0.1 ± 1.3 mm, P = .999; -0.5°± 1.5°, P = .401). In the ACL-reconstructed knee using either a ribbon-like or round graft, sectioning of the anterolateral structures did not induce a significant increase of anterior translation and internal rotation of the knee.

ACL reconstruction using a SB ribbon-like or round graft restored the kinematics of the intact knee at time zero. Secondary sectioning of the anterolateral structures in the ACL-reconstructed knee using both types of graft did not significantly affect the anterior translation and internal rotation of the knee.

This is the first biomechanical study on the new ACL reconstruction technique using a ribbon-like graft.

The incidence of anterior cruciate ligament (ACL) reconstruction (ACLR) in children and adolescents has increased significantly, and many such patients are at increased risk for ACL retear. Lateral extra-articular tenodesis (LET) may be performed in conjunction with ACLR to reduce the risk of ACL retear.

To evaluate the 2-year clinical outcomes of ACLR with soft tissue quadriceps tendon (QUAD) autograft performed with a concomitant LET using a modified Lemaire technique in skeletally immature patients.

Case series; Level of evidence, 4.

A consecutive series of adolescent patients who underwent QUAD autograft ACLR and LET with a minimum of 2 years of follow-up data were analyzed retrospectively. ACLR techniques, including all-epiphyseal and complete transphyseal, were indicated based on skeletal age. Outcome measures included return to sports, concomitant or subsequent surgical procedures, and multiple patient-reported outcome measures, including Single Assessment Numeric Evaluation (SANE), Pediatric International Knee Documentation Committee (Pedi-IKDC), and Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) scores.

The final cohort included 49 consecutive adolescent patients aged 11 to 16 years (mean, 14.2 ± 1 years) with a minimum follow-up of 2 years. One patient was lost to follow-up. Of the patients included in the study (N = 48; 27 male, 21 female), 98% participated in high-risk competitive sports. Two (4%) patients were undergoing revision ACLR. Thirty-eight (79%) patients underwent complete transphyseal, and 10 (21%) patients underwent all-epiphyseal ACLR. Sixteen (33%) patients had subsequent surgical procedures, including 5 contralateral ACLR, 4 meniscal surgery, 4 QUAD autograft scar revision, 4 irrigation and debridement (2 patients, 2 each), and 3 hardware removal (2 for hemi-epiphysiodesis and 1 tibial socket button removal) procedures. The rate of graft rupture was 0%. At a mean follow-up of 3.4 ± 1.2 years (range, 2-7 range), the mean SANE score was 93, the mean Pedi-IKDC score was 89, and the mean HSS Pedi-FABS score was 23. The return-to-sports rate was 100%.

An LET performed concomitantly with an ACLR is safe and should be considered as a concomitant procedure for adolescent patients with nonmodifiable risk factors who are at high risk of retear.

In young patients, anterior cruciate ligament (ACL) reconstruction often results in graft failure. This may be due, in part, to concomitant injury to anterolateral complex (ALC) of the knee leading to rotatory laxity. The modified Lemaire lateral extra-articular tenodesis (LET) technique is intended to address the anterolateral rotatory instability due to injury to the ALC and to protect the ACL graft and meniscus.

The International Anterolateral Complex Consensus Group Meeting identified 4 appropriate indications for the modified Lemaire LET procedure: revision ACL, high-grade pivot shift, generalized ligamentous laxity/genu recurvatum, and young patients returning to pivoting activities.

The technique consists of harvesting an 8-cm long by 1-cm wide graft from the iliotibial band. The graft is released proximally and remains attached distally to Gerdy's tubercle. The graft is then passed deep to the lateral collateral ligament (LCL) from distal to proximal. The graft is then affixed to a point proximal and posterior to the lateral femoral epicondyle with an all-suture button. The graft is then tensioned with knee at 30° of flexion and neutral rotation, and then secured in place.

With the modified Lemaire LET, there was previously concern for overconstraint and lateral compartment degeneration. However, recent studies have shown that there is no increased risk for these complications with the LET procedure. The STABILITY trial found that the addition of LET to ACL reconstruction significantly reduces re-rupture and residual laxity when compared with ACL reconstruction alone. Moreover, the addition of LET to ACL reconstruction can restore native knee kinematics.

The addition of the modified Lemaire LET technique to traditional ACL reconstruction is a safe and effective adjunct that reduces the occurrence of graft rupture, addresses residual rotational laxity, and can restore native knee kinematics in appropriately indicated patient populations.

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

To compare patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring grafts 7 mm or less in diameter combined with anterolateral ligament (ALL) reconstruction versus isolated ACL reconstruction with grafts greater than 7 mm in diameter.

We retrospectively evaluated the descriptive data and clinical outcomes of patients who underwent primary ACL reconstruction with hamstring grafts from June 2013 to January 2020 and had a minimum follow-up period of 2 years. Patients with quadrupled or quintupled semitendinosus and gracilis autograft 7 mm or less in diameter combined with single-strand ALL reconstruction (ACL-ALL group) were matched in a 1:2 propensity ratio to patients who underwent isolated single-bundle ACL reconstruction with hamstring grafts greater than 7 mm (ACL group).

We identified 30 patients in our database who met the criteria for the ACL-ALL group. The patients in this group were matched to 60 patients comprising the ACL group. Both groups were similar regarding all preoperative matched and unmatched variables. The mean ACL graft diameter was 6.8 ± 0.4 mm in the ACL-ALL group and 8.6 ± 0.6 mm in the ACL group (P < .001). The ACL-ALL group presented 1 failure (3.3%), and the ACL group presented 3 failures (5%) (P = .717). Postoperative KT-1000 measurements were similar between the groups (2.1 ± 1.1 mm vs 1.9 ± 1.2 mm, P = .114), as were postoperative pivot-shift grades (P = .652). Subjective International Knee Documentation Committee scores and Lysholm scores did not present any differences between the groups (P = .058 and P = .280, respectively).

Patients who undergo combined ACL-ALL reconstruction with an ACL graft diameter of 7 mm or less can achieve similar results to patients who undergo isolated ACL reconstruction with a graft diameter greater than 7 mm. An associated ALL reconstruction can be performed to increase knee stability in patients with small-diameter hamstring grafts.

Level III, retrospective, comparative therapeutic trial.

Anterior cruciate ligament (ACL) injuries are among the most common lesions in orthopaedics practice, but still today, rates up to 24% of unsatisfactory results are reported. Unaddressed anterolateral complex (ALC) injuries have been claimed to be responsible for residual anterolateral rotatory instability (ALRI) after isolate ACL reconstruction and have demonstrated to increase graft failure. In this article, we present our technique for reconstruction of the ACL and anterolateral (ALL) ligament combining the advantages of the anatomical position and the intraosseous femoral fixation to ensure anteroposterior and anterolateral rotational stability.

Anterolateral rotatory instability (ALRI) may result from isolated ruptures of the anterior cruciate ligament (ACL) or combined lesions with the anterolateral ligament (ALL). Biomechanical studies have demonstrated that the ALL contributes to the overall rotational stability of the knee. The purpose of this study was to investigate the biomechanical function of anatomic ALL reconstruction (ALL_rec) in the setting of a combined ACL and ALL injury and reconstruction. The hypothesis was that combined ACL reconstruction (ACL_rec) and ALL_rec (ACL/ALL_rec) significantly reduces internal rotation and shows load sharing between both reconstructions compared with isolated ACL_rec.

Eight fresh-frozen cadaveric knees were evaluated using a six degrees of freedom knee simulator. Continuous passive motion and external loads were tested. Kinematic differences between ACL_rec and combined ACL/ALL_rec were compared. Additionally, ACL graft tension and ALL graft strain were measured continuously throughout the testing protocol.

Combined anatomic ACL/ALL_rec significantly improved the internal rotatory stability compared with isolated ACL_rec at 30°-90° under an internal rotation moment. During a static pivot-shift test, additional ALL_rec showed no significant reduction of ap-translation. ALL_rec resulted in an increase in ACL graft tension during continuous passive motion and with additional internal rotation moment.

In the case of a combined ACL and ALL deficiency, concurrent ACL_rec and ALL_rec significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL at flexion angles ≥ 30°. Nevertheless, additional ALL_rec with fixation at 60° and with low tension could not restore extension-near rotatory stability. For that reason, ALL_rec with fixation at 60° flexion cannot be recommended in clinical application.

To compare the failure rate in patients who underwent revision anterior cruciate ligament (ACL) reconstruction alone or associated with an extra-articular procedure. Secondary objectives were to compare ACL laxity, patient-reported outcome measures, and complication rates in these patients and, subsequently, to compare the outcomes of patients who underwent revision ACL reconstruction associated with anatomical anterolateral ligament (ALL) reconstruction or lateral extra-articular tenodesis (LET).

This was a retrospective comparative study. Patients were classified into 2 groups, according to whether (group 2) or not (group 1) an extra-articular reconstruction was performed. Patients who underwent an extra-articular procedure were further divided into ALL reconstruction (group 2A) and LET (group 2B). Baseline demographic variables, operative data and postoperative data were evaluated.

The groups with (86 patients) and without (88 patients) an associated extra-articular reconstruction had similar preoperative data. Group 2 had a lower failure rate (4.6% vs 14.7%; P = .038), better KT-1000, better pivot-shift, and better Lysholm. There was no difference regarding complications, except more lateral pain in group 2. Regarding the groups who underwent ALL reconstruction (41 patients) and LET (46 patients), group 2A showed better Lysholm scores. Both groups had similar failure rates and complications.

Patients who underwent revision ACL reconstruction with a laterally based augmentation procedure had a lower failure rate than patients who underwent isolated revision ACL reconstruction. KT-1000 and pivot-shift examination were also significantly better when a lateral augmentation was performed. Complications were similar except for an increase in lateral pain in the augmented group. No clinically important differences were found when comparing the LET group to the ALL group other than a statistical improvement in the Lysholm functional scale, likely not clinically meaningful, favoring the ALL group and an increased duration of post-operative lateral pain in the LET group.

III, retrospective comparative therapeutic trial.

To compare the biomechanical effects of femoral cortical surface fixation and intra-tunnel fixation in modified Lemaire tenodesis on the restoration of native kinematics in anterolateral structure-deficient knees.

Eight fresh-frozen cadaveric knees were mounted in a knee-customized jig to evaluate anterior translation in anterior load and internal rotation degree in internal rotation torque at 0°, 30°, 60°, and 90°, as well as anterolateral translation (ALT) in a simulated pivot-shift test at 0°, 15°, 30°, and 45°. Kinematic tests were performed in the following states: intact; anterolateral knee lesion (AL-Les); modified Lemaire lateral extra-articular tenodesis (LET) with the femoral iliotibial band (ITB) strip fixed on the cortical surface (cortical fixation), deep to the lateral collateral ligament (LCL) (deep LET-C); and LET with the femoral ITB strip fixed into a tunnel (intra-tunnel fixation), deep to the LCL (deep LET-IT) or superficial to the LCL (superficial LET-IT). The knee kinematic changes in the AL-Les state and the 3 LET states were compared with each other, with the intact state as the baseline.

In the AL-Les state, the increased anterior translation instabilities were significantly mitigated by the 3 LETs at 30°, 60°, and 90° (all P < .001), with overconstraint observed in both the deep LET-IT and superficial LET-IT states at 60° (P = .047 and P < .001, respectively) and 90° (both P < .001). Similarly, the 3 LETs significantly reduced the internal rotation instabilities in the AL-Les state at all flexion angles. The superficial LET-IT state overconstrained the knee at 60° (P = .009) and 90° (P < .001) during internal rotation torque, and the deep LET-IT state did so at 60° (P = .012). Furthermore, the ALT instabilities found in the AL-Les state were significantly reduced by the 3 LETs during the simulated pivot-shift test. At 30° and 45°, these LET states resulted in overconstraint when compared with the intact state, but the superficial LET-IT state (P < .001) or deep LET-IT state (P = .016) presented a larger overconstraint than that in the deep LET-C at 45°, respectively.

The 3 Lemaire LET procedures evaluated reduced the anterior, internal rotational, and ALT laxities in AL-Les knees and restored these parameters to the native baseline of the intact state at most flexion angles. However, in deep flexion, some overconstraint occurred in all LETs when compared with the intact state, of which the deep LET-C state resulted in less overconstraint in anterior translation and internal rotation than the deep LET-IT and superficial LET-IT states.

This biomechanical study supports using the femoral cortical fixation technique to fix the ITB strip in the modified Lemaire LET, which similarly improves knee kinematic stability and causes less overconstraint compared with conventional intra-tunnel fixation. These findings need more verification in clinical scenarios.

Lateral extra-articular procedures (LEAPs) performed concomitant to anterior cruciate ligament reconstruction improve clinical outcomes and can restore normal knee kinematics. However, some LEAPs may result in overconstraint depending on technique. When using an iliotibial band based technique, passing the graft deep to the lateral collateral ligament and fixing it on the lateral cortex (rather than in a tunnel with an interference screw) minimizes the risk of tunnel collision and may also reduce the risk of overconstraint. Although several laboratory studies report overconstraint with iliotibial band based procedures, clinical reports of overconstraint are rare. This may be due to lack of a clear definition of clinical overconstraint and resultant underdiagnosis. However, long term randomised controlled study has demonstrated significantly higher rates of osteoarthritis when a modified Lemaire is added to an anterior cruciate ligament reconstruction. There is clearly a need for further study and in the meantime clinical efficacy must be balanced with the risk of kinematic restriction.

The increase in anterior cruciate ligament (ACL) injuries in pediatric patients and the high failure rate reported in the literature in this population are driving surgeons to search for specific techniques to better restore knee stability. Recent literature has reported that the combination of lateral extra-articular tenodesis (LET) and ACL reconstruction improves outcomes in high-risk patients. However, such advantages in pediatric patients have been infrequently evaluated.

To assess whether adding LET to ACL reconstruction can significantly improve knee stability, clinical outcomes, and failure rates in pediatric patients.

Cohort study; Level of evidence, 3.

A multicentric study involving 3 orthopaedic teaching centers was conducted to evaluate pediatric patients aged between 12 and 16 years who had undergone primary ACL reconstruction using a physeal-sparing femoral tunnel drilling technique. A minimum 2-year follow-up evaluation was required. Based on the surgical technique performed, the patients were divided into 2 group. The patients in group 1 underwent an isolated arthroscopic ACL reconstruction, while the patients in group 2 had an arthroscopic ACL reconstruction in combination with a modified Lemaire LET procedure. Group 1 was a historical control cohort of patients, whereas group 2 was prospectively enrolled. All the patients included in the present study were clinically evaluated using the Pediatric International Knee Documentation Committee (Pedi-IKDC) subjective score and the Pediatric Functional Activity Brief Scale (Pedi-FABS) score. Anteroposterior knee stability was measured using the KT-1000 knee ligament arthrometer, and the objective pivot-shift evaluation was documented using a triaxial accelerometer (Kinematic Rapid Assessment [KiRA]). The included patients also underwent a standardized radiological protocol to evaluate leg-length discrepancies, axial deviation, and degenerative signs preoperatively and at last follow-up.

This study included 66 pediatric patients with an anatomic hybrid ACL reconstruction using an autologous 4-strand hamstring graft. In group 1, there were 34 patients (mean age, 13.5 ± 1.2 years), while 32 patients (mean age, 13.8 ± 1.4 years) were included in group 2. The clinical outcome scores showed no difference between the 2 groups (Pedi-IKDC, P = .072; Pedi-FABS, P = .180). Nevertheless, the patients in group 2 had better anteroposterior stability measured using a KT-1000 arthrometer (1.9 ± 1.1 mm in group 1 vs 0.8 ± 0.8 mm in group 2; P = .031), as well as better rotational stability measured using the KiRA (-0.59 ± 1.05 m/s² in group 2 vs 0.98 ± 1.12 m/s² in group 1; P = .012). The patients in group 1 returned to sports at the same competitive level at a rate of 82.4%, while patients included in group 2 returned at the same competitive level in 90.6% of the cases without a significant difference between the 2 groups (P = .059). No leg-length discrepancies were found between the 2 groups at last follow-up (P = .881). Two patients displayed an increased valgus deformity of 3° on the operated limb at last follow-up (1 patient in group 1 and 1 patient in group 2). Group 1 had a significatively higher cumulative failure rate (14.7% vs 6.3%; P = .021). No intra- or postoperative complications was observed between the 2 groups.

Performing a modified Lemaire LET along with an ACL reconstruction with hamstring graft in pediatric patients reduced the cumulative failure rate and improved objective stability with no increase in intra- or postoperative complications. No significant difference was found between the 2 groups in terms of patient-reported outcomes or in the return-to-sports activity.

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.

Conventional adult anterior cruciate ligament reconstruction techniques are controversial in skeletally immature patients due to the risk of iatrogenic physeal damage and potential growth disturbance. The physeal-sparing, combined intra- and extra-articular anterior cruciate ligament reconstruction using an autogenous iliotibial band was developed to mitigate this risk in prepubescent, skeletally immature patients, with excellent functional outcomes and a low revision rate. This article describes the surgical details of this reproducible reconstruction technique.