Lateral Extra-articular Procedures Research Articles

SEX, PATELLAR TENDON GRAFT, AND EARLY MOTION DEFICITS PREDICT ARTHROFIBROSIS AFTER PEDIATRIC ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Background:Arthrofibrosis remains a concerning early complication after anterior cruciate ligament reconstruction (ACLR) in children and adolescents. Previous studies suggest that those receiving patellar tendon (PT) autograft may be at higher risk than hamstrings tendon (HT), but there is little data regarding this complication in patients receiving quadriceps tendon (QT) autograft.Purpose:The purpose of this study is to identify risk factors for arthrofibrosis following pediatric ACLR with attention to graft type.Methods:The medical records of patients that underwent primary ACLR at a single tertiary children’s hospital were reviewed for this retrospective cohort study. Those with multiligament reconstructions, lateral extra-articular tenodesis procedures, or a modified MacIntosh reconstruction were excluded. Arthrofibrosis was defined as a deficit of 10 degrees of extension and/or 20 degrees of flexion at 3 months after ACLR. Demographic data, intra-operative findings and techniques, and post-operative motion and complications were recorded. Univariate analysis was followed by purposeful entry logistic regression to control for confounding factors.Results:A total of 378 patients were included in the analysis, of which there were 180 PT, 103 HT, and 95 QT grafts. The mean age was 15.9±1.7 years and 188 (49.7%) were female. In univariate analysis, the rate of arthrofibrosis was 1.9% for HT, 6.3% for QT, and 10.0% for PT (p=0.04). Females developed arthrofibrosis more frequently than males (10.6% vs. 3.2%, p=0.004). Additionally, those that ultimately experienced this complication had lower median flexion at 6 weeks after ACLR (88 vs. 110 degrees, p<0.001). After controlling for covariates in a multivariate model, PT graft raised the odds of arthrofibrosis 6.2 times compared to HT (95% CI 1.4-27.6, p=0.02), but there were no significant differences between QT and other graft types. Females were at 4.2 times higher odds than males (95% CI 1.6-10.8; p=0.003). Patients that were unable to attain 90 degrees of flexion 6 weeks after ACLR had 14.7 times higher odds of eventually developing arthrofibrosis (95% CI 5.4-39.8; p<0.001). Finally, those with an extension deficit of ≥5 degrees 6 weeks after ACLR had 4.7 times higher odds of experiencing this complication (95% CI 1.8-12.2, p=0.001).Conclusion:After adjusting for multiple covariates, PT autograft, female sex, and motion deficits at 6 weeks after ACLR (<90 degrees of flexion or extension deficit ≥5 degrees) were predictive of arthrofibrosis in children and adolescents. Quadriceps tendon autograft did not increase the risk of this complication.

Predictors of Arthrofibrosis After Pediatric Anterior Cruciate Ligament Reconstruction: What Is the Impact of Quadriceps Autograft?

Recent literature on arthrofibrosis after anterior cruciate ligament reconstruction (ACLR) in children and adolescents is limited, especially with regards to quadriceps tendon (QT) autograft. The purpose of this study was to identify predictors of arthrofibrosis after ACLR, with attention to the impact of graft type. Patients that underwent primary ACLR at a tertiary children's hospital were reviewed for this retrospective case-control study. Those with multiligament reconstructions, lateral extra-articular tenodesis procedures, allografts, or a modified MacIntosh reconstruction were excluded. Arthrofibrosis was defined as a deficit of 10 degrees of extension and/or 20 degrees of flexion at 3 months after ACLR. Univariate analysis was followed by purposeful entry logistic regression to adjust for confounding factors. A total of 378 patients (mean age 15.9±1.7 y, 49.7% female) were included in the analysis, of which there were 180 patellar tendon (PT), 103 hamstrings tendon (HT), and 95 QT grafts. The rate of arthrofibrosis was 1.9% for HT, 6.3% for QT, and 10.0% for PT (P=0.04). Females developed arthrofibrosis more frequently than males (10.6% vs. 3.2%, P=0.004). Those that ultimately experienced this complication had lower median flexion at 6 weeks after ACLR (88 vs. 110 degrees, P<0.001). In multivariate analysis, PT graft raised the odds of arthrofibrosis 6.2 times compared to HT [95% confidence interval (CI): 1.4-27.6, P=0.02], but there were no significant differences between QT and other grafts. Females were at 4.2 times higher odds than males (95% CI: 1.6-10.8; P=0.003). Patients that were unable to attain 90 degrees of flexion 6 weeks after ACLR had 14.7 times higher odds of eventually developing arthrofibrosis (95% CI: 5.4-39.8; P<0.001). Finally, those with an extension deficit of ≥5 degrees 6 weeks after ACLR had 4.7 times higher odds of experiencing this complication (95% CI: 1.8-12.2, P=0.001). The rate of arthrofibrosis with QT autograft is 6.3% after pediatric ACLR. PT autograft, female sex, and motion deficits at 6 weeks after ACLR were predictive of arthrofibrosis in children and adolescents. Level III-prognostic study.

L’ajout d’une ténodèse extra-articulaire au facia lata permet un meilleur contrôle de la stabilité rotatoire par rapport à une plastie isolée aux ischio-jambiers prélevés sur le genou controlatéral pour la chirurgie de révision des ruptures du ligament croisé antérieur

BackgroundRecent years have seen a resurgence of interest about lateral extra-articular procedures performed in association with anterior cruciate ligament (ACL) surgery, as they can reduce the positivity to pivot shift test by acting on rotational instability. The purpose of the present study is to compare the postoperative functional outcomes of ACL revision surgery using contralateral hamstring tendon autografts with or without extra-articular tenodesis. HypothesisThe hypothesis is that combined extra-articular tenodesis gives better rotational stability with revision ACL surgery. Patients and methodsTwenty-four patients who underwent ACL revision surgery were retrospectively reviewed at an average follow-up of 4.5 years; 12 underwent contralateral hamstring tendon autografts reconstruction (group A) while in 12 extra-articular tenodesis was associated (group B). Assessment included Lysholm score, International Knee Documentation Committee (IKDC) Subjective Knee Form, Tegner activity level and objective evaluation (range of motion, Lachman test, pivot-shift test and KT-1000 instrumented laxity testing). ResultsFollow-up examination showed that there were no statistically significant differences in Lysholm, IKDC and Tegner scores between the groups (p=n.s.). Similarly, no differences concerning anterior tibial translation as measured with KT-1000 arthrometer were reported between the groups (p=n.s.); the percentage of positivity to pivot shift test was significantly higher in patients in group A (p<0.05). ConclusionsThe association of extra-articular tenodesis restores rotational stability more effectively compared to contralateral hamstring tendon autografts ACL revision surgery alone. Level of evidenceIII.

The association of extra-articular tenodesis restores rotational stability more effectively compared to contralateral hamstring tendon autografts ACL reconstruction alone in patients undergoing ACL revision surgery

BackgroundRecent years have seen a resurgence of interest about lateral extra-articular procedures performed in association with anterior cruciate ligament (ACL) surgery, as they can reduce the positivity to pivot shift test by acting on rotational instability. The purpose of the present study is to compare the postoperative functional outcomes of ACL revision surgery using contralateral hamstring tendon autografts with or without extra-articular tenodesis. HypothesisThe hypothesis is that combined extra-articular tenodesis gives better rotational stability following revision ACL surgery. Patients and methodsTwenty-four patients who underwent ACL revision surgery were retrospectively reviewed at an average follow-up of 4.5 years; 12 underwent contralateral hamstring tendon autografts reconstruction (group A) while in 12 extra-articular tenodesis was associated (group B). Assessment included Lysholm score, International Knee Documentation Committee (IKDC) Subjective Knee Form, Tegner activity level and objective evaluation (range of motion, Lachman test, pivot-shift test and KT-1000 instrumented laxity testing). ResultsFollow-up examination showed that there were no statistically significant differences in Lysholm, IKDC and Tegner scores between the groups (p=n.s.). Similarly, no differences concerning anterior tibial translation as measured with KT-1000 arthrometer were reported between the groups (p=n.s.); the percentage of positivity to pivot shift test was significantly higher in patients in group A (p<0.05). ConclusionsThe association of extra-articular tenodesis restores rotational stability more effectively compared to contralateral hamstring tendon autografts ACL revision surgery alone. Level of evidenceIII.

Lateral extra-articular tenodesis in patients with revision anterior cruciate ligament (ACL) reconstruction and high-grade anterior knee instability

BackgroundAdditional lateral extra-articular procedures can reduce the risk of failure of primary anterior cruciate ligament reconstruction (ACLR). There is limited evidence on the effect of lateral extra-articular procedures in revision ACL surgery. The purpose of this study was to evaluate the clinical outcome of patients with lateral extra-articular tenodesis (LET) in combination with revision ACLR for combined ACL graft failure and high-grade anterior knee instability. MethodsBetween 2016 and 2018, 75 patients with graft failure after primary ACLR and high-grade anterior knee instability who received revision ACLR were included in the retrospective study. High-grade anterior knee instability was defined as high-grade pivot-shift or side-to-side difference of more than six millimeters in Rolimeter®-testing. An additional modified Lemaire tenodesis was performed in 59 patients during revision ACLR. Seventy-three patients were clinically examined with a minimum of two years after revision surgery. ResultsFailure of the revision ACLR occurred in 8.2% (n = 6) of the cases. LET lead to significant decreased failure rates (five percent vs. 21%, p = .045) and decreased incidence of a positive pivot-shift in patients with revision ACLR and high-grade anterior knee instability in comparison to patients without LET. Also, postoperative functional scores were significantly increased in the group of additional LET. ConclusionsAdditional LET in patients with revision ACLR and high-grade anterior instability significantly reduces the risk of failure of revision ACLR, the incidence of pivot-shift and increases postoperative functional outcome.

Cabaud Memorial Award: Lateral Extra-articular Tenodesis Alters Regional Distribution of Contact Stress in the Lateral Knee Compartment under Simulated Pivoting Loads: An In Vitro Study

Objectives:Residual laxity after ACL reconstruction (ACLR) may adversely impact patient outcomes and function and has led to the increasing utilization of lateral extra-articular augmentation procedures in conjunction with ACLR and specifically, Lateral Extra-articular Tenodesis (LET). However, concerns of overconstraining the lateral compartment and subsequent increased lateral compartment contact stress and accelerated degenerative changes have been suggested with LET procedures. Therefore, the purpose of this work was to assess the impact of a LET on contact mechanics of the lateral compartment in response to multiplanar torques representing pivoting maneuvers.Methods:Nine cadaveric knees (4 male, 37.4 ± 11.6 years old) were mounted to a robotic manipulator equipped with a six-axis force-torque sensor. The robot applied multiplanar torques simulating two types of pivot shift (PS) maneuvers, subluxing the lateral compartment, at 30° of knee flexion. The following loading combinations were applied: (PS1) 8 Nm of valgus and 4 Nm of internal rotation torques; (PS2) 100 N compression force, 8 Nm valgus torque, 2 Nm internal rotation torque, and 30 N anterior force. Kinematics were recorded in the following states: ACL intact, sectioned, reconstructed and, finally, after sectioning the anterolateral ligament (ALL) and kaplan fibers and performing a LET. ACLR was performed utilizing a bone-patellar tendon-bone autograft, via medial parapatellar arthrotomy. LET was performed using a modified lemaire technique with a metal staple femoral fixation at 60° of flexion in neutral rotation. A contact stress transducer was then sutured to the tibial plateau beneath the menisci and the previously-determined kinematics were replayed, while recording the lateral compartment contact stress. At the peak applied loads, the following measures were determined in the lateral compartment: contact force, contact area, the anterior-posterior (AP) location of the center of contact stress (CCS), the mean contact stress, and the peak contact stress and its AP location. Statistical differences were assessed via one-way repeated measures ANOVA with Student-Neumen-Keuls post hoc test (p< 0.05).Results:Under combined valgus and internal rotation torques (PS1), the addition of a LET to ACLR increased lateral compartment contact force compared to the native knee by 51 ± 51 N (p = 0.035) on average. Contact area also increased by 60 ± 56 mm2 and 61 ± 58 mm2 relative to the ACL intact and ACL reconstructed knee (p ≤ 0.002), respectively. LET also shifted anteriorly the CCS by 4.6 ± 3.6 mm and 5.7 ± 3.1 mm on average relative to the ACL intact and ACL reconstructed knees (p < 0.001) (Fig. 1). No differences were detected for the mean and peak lateral compartment contact stress with the addition of LET compared to the ACL intact or ACL reconstructed knee (p> 0.854). The location of peak contact stress, however, shifted anteriorly compared to the ACL intact and ACL reconstructed knees by 6.2 ± 5.7 mm and 7.6 ± 5.4 mm (p < 0.001). (Fig.1). Similar results were observed under multiplanar torques with compression (PS2) for all outcome measures.Conclusion:In response to multiplanar torques representing pivoting maneuvers, the addition of a LET to ACLR, in the presence of compromised anterolateral tissues, did not increase lateral compartment contact stress. As contact force increased with the addition of LET, so did the contact area, likely mitigating changes in the level of contact stress. LET shifted the contact location anteriorly thereby altering regional loading of the lateral articular cartilage. Further study of the impact of changes in regional loading patterns in the lateral compartment on cartilage degeneration is warranted.Figure 1.

Combined ACL and Anterolateral Reconstruction Is Not Associated With a Higher Risk of Adverse Outcomes: Preliminary Results From the SANTI Randomized Controlled Trial.

Background:The widespread historical abandonment of lateral extra-articular procedures in anterior cruciate ligament (ACL) injuries occurred as a result of concerns about high rates of adverse events. Recently, the popularity of lateral extra-articular procedures has resurged, warranting an urgent evaluation of their safety profile.Purpose/Hypothesis:The aim of this study was to perform an interim analysis of the ongoing SANTI randomized controlled trial to determine whether combined ACL and anterolateral ligament reconstruction (ACL + ALLR) is associated with an increased rate of adverse outcomes when compared with isolated ACL reconstruction (ACLR). The hypothesis was that there would be no significant difference between groups at a minimum follow-up of 1 year.Study Design:Randomized controlled trial; Level of evidence, 1.Methods:Recruitment commenced in November 2016. Patients scheduled for ACLR were randomized to either isolated ACLR (with bone–patellar tendon–bone [BPTB] autograft) or combined ACL + ALLR (with hamstring tendon autograft). All patients with a minimum follow-up of 1 year by March 2019 were included. The evaluated parameters included complications and reoperations, knee laxity parameters, range of motion, and scores on the Tegner, Lysholm, International Knee Documentation Committee (IKDC), and Knee injury and Osteoarthritis Outcome Score (KOOS) instruments.Results:A total of 224 patients (112 in each group) with a mean ± SD follow-up of 12.3 ± 1.9 months (range, 12-19 months) formed the study population. A significantly higher rate of reoperation for cyclops syndrome was noted in the isolated ACLR group compared with the combined ACL + ALLR group (8.9% vs 0%, respectively; P = .0012). No significant differences were found in frequency of graft rupture (ACLR, 5.4%; ACL + ALLR, 0.9%; P = .1191), range of motion deficits, pain, or reoperation for meniscectomy between groups. No cases of postoperative infection, venous thromboembolism, or arthrofibrosis were seen. Subjective IKDC (81.2 vs 86.8; P = .0048), Lysholm (88 vs 92; P = .0131), and some components of the KOOS were significantly better in the combined ACL + ALLR group.Conclusion:This study demonstrates no evidence of an increased risk of short-term adverse events after combined ACL + ALLR compared with isolated ACLR with BPTB graft.Registration:NCT03740022 (ClinicalTrials.gov Identifier)

Tactile techniques are associated with a high variability of tunnel positions in lateral extra-articular tenodesis procedures.

The purpose of this study was to determine the variability of femoral tunnel positions applying two different lateral extra-articular tenodesis (LET) techniques, guiding on the tactile identification (1) of the lateral epicondyle (Lemaire procedure) and (2) of the Kaplan fibre attachments on the distal femur (MacIntosh procedure) and to analyse whether one of these procedures is more suitable for reliable femoral tunnel positioning in LET procedures. Two experienced knee surgeons determined femoral tunnel positions in ten fresh-frozen cadaveric knee specimens according to the modified Lemaire and MacIntosh techniques. Tunnel positions were measured on true lateral radiographs as absolute distances from the posterior cortex line (anterior-posterior direction) and from a perpendicular line intersecting the contact of the posterior femoral condyle (proximal-distal direction), respectively. Further, tunnel positions were measured relatively to the femur height. An independent F test was used to compare variances between Lemaire and MacIntosh tunnel positions and between anterior-posterior and proximal-distal directions. The mean Lemaire and MacIntosh positions were found 2.7 ± 5.5mm and 3.6 ± 3.4mm anterior to the posterior cortex line, and 7.5 ± 5.0mm and 17.3 ± 6.9mm proximal to the perpendicular line intersecting the contact of the posterior femoral condyle, respectively. Mean Lemaire and MacIntosh positions, relative to the femur height, were found at 8.8% and 10.9% (anterior-posterior) and 22.2% and 50.8% (proximal-distal), respectively. Variability in tunnel positioning was observed for both techniques, showing no significant differences in the variance (p > 0.05) and partially overlapping tunnel positions of both techniques. The overall variance of tunnel positions, however, was significantly greater in proximal-distal than in anterior-posterior direction (F = 2.673, p < 0.038). Femoral tunnel positions in LET procedures have a high degree of variability and inaccuracy. Palpating anatomic landmarks appears to be insufficient to generate reproducible tunnel positions. Radiographic landmarks may enable more reproducible identification of isometric femoral tunnel positions and reduce malpositioning.

La reconstruction combinée du LCA et du ligament antérolatéral est-elle associée à un risque plus important de complications ? Résultats préliminaires d’une étude prospective randomisée

Background The widespread historical abandonment of lateral extra-articular procedures in ACL-injured knees occurred due to concerns about high rates of adverse events. Recently there has been a resurgence in popularity of lateral extra-articular procedures and this warrants an urgent evaluation of their safety profile. Hypothesis/Purpose The aim of this study was to perform an interim analysis of the ongoing (blinded for journal review) randomized controlled trial in order to determine whether combined ACL and anterolateral ligament reconstruction (ACL + ALLR) is associated with an increased rate of adverse outcomes when compared to isolated ACL reconstruction (ACLR). The hypothesis was that there would be no significant difference between groups at a minimum follow-up of one year. Study Design Randomized Controlled Trial Methods Recruitment was commenced in November 2016. Patients scheduled for ACL reconstruction were randomized to either isolated ACL reconstruction (bone-patella tendon-bone autograft) or combined ACL + ALLR (hamstring tendon autograft). All patients with a minimum follow-up of one year, in March 2019 were included. Complications and re-operations, knee laxity parameters, range of motion, Tegner, Lysholm, IKDC and KOOS scores were evaluated. Results Deux cent vingt quatre patients (112 in each group) with a mean follow-up 12.3 ± 1.9 (range 12 to 19) months formed the study population. There was a significantly higher rate of re-operation for cyclops syndrome in the isolated ACL group (B-PT-B 8.9 %, ACL + ALLR 0 %, p = 0.0012). There was no significant difference in the frequency of graft rupture (B-PT-B 5.4 %, ACL + ALLR 0.9 %, p = 0.1191), range of motion deficits, pain, or re-operation for meniscectomy between groups. There were no cases of post-operative infection, venous thromboembolism, or arthrofibrosis. Subjective IKDC (81.2 vs. 86.8, p = 0.0048), Lysholm (88 vs. 92, p = 0.0131) and some components of KOOS were significantly better in the ACL + ALL group. Conclusion This study demonstrates no evidence of an increased risk of adverse events after combined ACL + ALL reconstruction when compared to isolated ACL reconstruction with a B-PT-B graft. The trend towards a reduced graft rupture rate and significantly better subjective IKDC, Lysholm and KOOS scores with the combined procedure is consistent with the previous literature and expected to be more pronounced at the end of the overall study period.

Radiographic Landmarks for Femoral Tunnel Positioning in Lateral Extra-articular Tenodesis Procedures

Background: Lateral extra-articular tenodesis (LET) is being increasingly performed as an additional procedure in both primary and revision anterior cruciate ligament reconstruction in patients with excessive anterolateral rotatory instability. Consistent guidelines for femoral tunnel placement would aid in intraoperative reproducible graft placement and postoperative evaluation of LET procedures. Purpose: To determine radiographic landmarks of a recently described isometric femoral attachment area in LET procedures with reference to consistent radiographic reference lines. Study Design: Descriptive laboratory study. Methods: Ten fresh-frozen cadaveric knees were dissected. The footprints of the lateral femoral epicondyle (LFE) apex and the deep aspects of the iliotibial tract, with its Kaplan fiber attachments (KFAs) on the distal femur, were marked with a 2.5-mm steel ball. True lateral radiographic images were taken. Mean absolute LFE and KFA distances were measured from the posterior cortex line (anterior-posterior direction) and from the perpendicular line intersecting the contact of the posterior femoral condyle (proximal-distal direction), respectively. Furthermore, positions were measured relative to the femur width. Finally, radiographic descriptions of an isometric femoral attachment area were developed. Results: The mean LFE and KFA positions were found to be 4 ± 4 mm posterior and 4 ± 3 mm anterior to the posterior cortex line, and 6 ± 4 mm distal and 20 ± 5 mm proximal to the perpendicular line intersecting the posterior femoral condyle, respectively. The mean LFE and KFA locations, relative to the femur width, were found at –12% and 11% (anterior-posterior) and –17% and 59% (proximal-distal), respectively. Femoral tunnel placement on or posterior to the femoral cortex line and proximal to the posterior femoral condyle within a 10-mm distance ensures that the tunnel remains safely located in the isometric zone. Conclusion: Radiographic landmarks for an isometric femoral tunnel placement in LET procedures were described. Clinical Relevance: These findings may help to intraoperatively guide surgeons for an accurate, reproducible femoral tunnel placement and to reduce the potential risk of tunnel misplacement, as well as to aid in the postoperative evaluation of LET procedures in patients with residual complaints.

Good mid-term outcomes and low rates of residual rotatory laxity, complications and failures after revision anterior cruciate ligament reconstruction (ACL) and lateral extra-articular tenodesis (LET).

Residual rotational instability remains a controversial factor when analysing failure rates of anterior cruciate ligament (ACL) reconstruction. Anatomical and biomechanical studies have demonstrated a very important role of anterolateral structures for rotational control. Revision ACL is considered one of the main indications for a lateral extra-articular tenodesis (LET). Yet, few series evaluating these procedures are published. To perform a systematic review of studies that assessed outcomes in patients treated with revision ACL surgery associated with a lateral extra-articular procedure. Systematic review. A comprehensive literature search was performed in February 2018 using PubMed, Scopus, Web of Search and Cochrane. Inclusion criteria were series of ACL revision reconstructions associated with lateral extra-articular procedures. Clinical outcomes (Lysholm, subjective IKDC, KOOS, Cincinnati and WOMAC), joint stability measures (Lachman test, pivot-shift, arthrometer assessment and navigation assessment), graft type, reported chondral and meniscal injury, radiographic outcomes, complications and failures were recorded. Articles were assessed for level of evidence and methodology using a modification of the ACL Methodology Score (AMS) system. Twelve studies met the inclusion criteria out of the 231 abstracts; 9 retrospective evaluations, two prospective cohorts and one combination of two populations (a retrospective and prospective series). A total of 851 patients evaluated with a mean age of 28.8years (range 16-68years) and a weighted mean follow-up of 4.9years (range 1-10years). The mean time from primary ACL reconstruction to revision was 5.3years (reported in 7 studies, including 710 patients). The Lysholm, IKDC, and KOOS scores indicated favorable results in studies that reported these outcomes. Objective evaluations reported 86% objective A and B IKDC results, 2.6mm mean side-to-side arthrometric difference and 80% negative pivot-shift. About 74% of patients returned to their previous sport (evaluated in six studies). Few studies reported radiological evaluation. Fifty-nine complications (8.0%) and 24 failures (3.6%) were reported. The mean modified ACL Methodology Score was 55.5 (range 32-72). Good mid-term results were obtained for combined revision ACL reconstruction and lateral extra-articular procedures. Despite the fact that in clinical practice LET are a common indication associated with revision ACL, there are no high-level studies supporting this technique. IV.

Anatomic Study and Reanalysis of the Nomenclature of the Anterolateral Complex of the Knee Focusing on the Distal Iliotibial Band: Identification and Description of the Condylar Strap.

Background:The capsulo-osseous layer (COL), short lateral ligament, mid–third lateral capsular ligament, lateral capsular ligament, and anterolateral ligament (ALL) are terms that have been used interchangeably to describe what is probably the same structure. This has resulted in confusion regarding the anatomy and function of the anterolateral complex of the knee and its relation to the distal iliotibial band (ITB).Purpose:To characterize the macroscopic anatomy of the anterolateral complex of the knee, in particular the femoral condylar attachment of the distal ITB. We identified a specific and consistent anatomic structure that has not been accurately described previously; it connects the deep surface of the ITB to the condylar area and is distinct from the ALL, COL, and Kaplan fibers.Study Design:Descriptive laboratory study.Methods:Sixteen fresh-frozen human cadaveric knees were used to study the anterolateral complex of the knee. Standardized dissections were performed that included qualitative and quantitative assessments of the anatomy through both anterior (n = 5) and posterior (n = 11) approaches.Results:The femoral condylar attachment of the distal ITB was not reliably identified by anterior dissection but was in all posterior dissections. A distinct anatomic structure, hereafter termed the “condylar strap” (CS), was identified between the femur and the lateral gastrocnemius on one side and the deep surface of the ITB on the other, in all posteriorly dissected specimens. The structure had a mean thickness of 0.88 mm, and its femoral insertion was located between the distal Kaplan fibers and the epicondyle. The proximal femoral attachment of the structure had a mean width of 15.82 mm, and the width of the distal insertion of the structure on the ITB was 13.27 mm. The mean length of the structure was 26.33 mm on its distal border and 21.88 mm on its proximal border. The qualitative evaluation of behavior in internal rotation revealed that this anatomic structure became tensioned and created a tenodesis effect on the ITB.Conclusion:There is a consistent structure that attaches to the deep ITB and the femoral epicondylar area. The orientation of fibers suggests that it may have a role in anterolateral knee stability.Clinical Relevance:This new anatomic description may help surgeons to optimize technical aspects of lateral extra-articular procedures in cases of anterolateral knee laxity.

Anatomic and Histological Study of the Anterolateral Aspect of the Knee: A SANTI Group Investigation.

Background:The structure and function of the anterolateral aspect of the knee have been significantly debated, with renewed interest in this topic since the description of the anterolateral ligament (ALL).Purpose:To define and describe the distinct structures of the lateral knee and to correlate the macroscopic and histologic anatomic features.Study Design:Descriptive laboratory study.Methods:Twelve fresh-frozen human cadavers were used for anatomic analysis. In the left knee, a layer-by-layer dissection and macroscopic analysis were performed. In the right knee, an en bloc specimen was obtained encompassing an area from the Gerdy tubercle to the posterior fibular head and extending proximally from the anterior aspect to the posterior aspect of the lateral femoral epicondyle. The en bloc resection was then frozen, sliced at the level of the joint line, and reviewed by a musculoskeletal pathologist.Results:Macroscopically, the lateral knee has 4 main layers overlying the capsule of the knee: the aponeurotic layer, the superficial layer including the iliotibial band (ITB), the deep fascial layer, and the ALL. Histologically, 8 of 12 specimens demonstrated 4 consistent, distinct structures: the ITB, the ALL, the lateral collateral ligament, and the meniscus.Conclusion:The lateral knee has a complex orientation of layers and fibers. The ALL is a distinct structure from the ITB and is synonymous to the previously described capsulo-osseous layer of the ITB.Clinical Relevance:Increasingly, lateral extra-articular procedures are performed at the time of anterior cruciate ligament reconstruction. Understanding the anatomic features of the anterolateral aspect of the knee is necessary to understand the biomechanics and function of the structures present and allows surgeons to attempt to replicate those anatomic characteristics when performing extra-articular reconstruction.

The anterolateral complex of the knee: results from the International ALC Consensus Group Meeting

The structure and function of the anterolateral complex (ALC) of the knee has created much controversy since the 're-discovery' of the anterolateral ligament (ALL) and its proposed role in aiding control of anterolateral rotatory laxity in the anterior cruciate ligament (ACL) injured knee. A group of surgeons and researchers prominent in the field gathered to produce consensus as to the anatomy and biomechanical properties of the ALC. The evidence for and against utilisation of ALC reconstruction was also discussed, generating a number of consensus statements by following a modified Delphi process. Key points include that the ALC consists of the superficial and deep aspects of the iliotibial tract with its Kaplan fibre attachments on the distal femur, along with the ALL, a capsular structure within the anterolateral capsule. A number of structures attach to the area of the Segond fracture including the capsule-osseous layer of the iliotibial band, the ALL and the anterior arm of the short head of biceps, and hence it is not clear which is responsible for this lesion. The ALC functions to provide anterolateral rotatory stability as a secondary stabiliser to the ACL. Whilst biomechanical studies have shown that these structures play an important role in controlling stability at the time of ACL reconstruction, the optimal surgical procedure has not yet been defined clinically. Concern remains that these procedures may cause constraint of motion, yet no clinical studies have demonstrated an increased risk of osteoarthritis development. Furthermore, clinical evidence is currently lacking to support clear indications for lateral extra-articular procedures as an augmentation to ACL reconstruction. The resulting statements and scientific rationale aim to inform readers on the most current thinking and identify areas of needed basic science and clinical research to help improve patient outcomes following ACL injury and subsequent reconstruction.Level of evidence V.

The Anterolateral Complex of the Knee

Aims and Objectives: The objective of this study was to clarify the layer-by-layer anatomy of the anterolateral complex of the knee. Materials and Methods: Twenty fresh-frozen human cadaveric knees (age range 38 - 56 yrs.) without any history of knee injury or surgery were used for this dissection study. After skin and subcutaneous tissue removal, the ITB was incised in its most anterior part and reflected posteriorly followed by blunt dissection of its deeper layers. Subsequently, an incision was made between the ITB and the short head of the biceps muscle with consecutive evaluation of the insertion site of the biceps tendon and its extensions. Once the deep layers of the ITB were identified, the connections to the lateral intermuscular septum and Kaplan fibers were cut. The superficial ITB was then reflected distally in order to assess the geographical relationship between the superficial and deep ITB as well as the distal anteromedial aspect of the biceps muscle. Finally, the anterolateral capsule was incised to evaluate its connections to the surrounding anatomic structures. Results: The anterolateral aspect of the knee consists of three distinct layers. Superficially, the ITB with its insertion to Gerdy’s tubercle and extensions to the patella (iliopatellar band) was appreciated. Posterior reflection of the superficial ITB revealed a firm distinct connection of Kaplan fibers to the distal femoral metaphysis. The deep layer of the ITB runs from the Kaplan fibers in a distal direction and forms a functional arc. This arc is reinforced by the capsulo-osseous layer of the ITB, which originates from an area distal to the Kaplan fibers, the fascia of the lateral gastrocnemius and plantaris muscles. The distal half of the capsulo-osseous layer merges posteriorly with the fascia of the biceps muscle. The three layers of the ITB become confluent distally. Its insertion spanned from Gerdy’s tubercle to an area just posteriorly, with the capsulo-osseous layer forming the posterior part. The biceps muscle has fascial and aporoneurotical extensions, which insert to the proximal tibia together with the capsulo-osseous layer of the ITB. Layer 3 consists of the anterolateral capsule. In 7/20 (35%) specimens the mid-third capsular ligament was observed as a thickening within, but not separate from the anterolateral capsule. Conclusion: The anterolateral complex of the knee consists of the ITB with its three layers, the functional arc formed by the fibers between the distal femoral metaphysis and Gerdy’s tubercle, and the anterolateral capsule. In 35% of specimens a capsular thickening (mid-third capsular ligament) was identified. Surgeons should consider the complex anatomy of this functional unit, i.e. the anterolateral complex, when considering lateral extra-articular procedures.

Combined ACL and Anterolateral Ligament Reconstruction.

Clinical results of combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction have demonstrated a significant reduction in ACL graft rupture rates and improved rates of return to sports compared with isolated ACL reconstruction1. This finding is supported by laboratory studies that have demonstrated that combined ACL reconstruction and lateral extra-articular tenodesis procedures protect the ACL graft by load-sharing with it and by more reliably restoring normal knee kinematics compared with isolated ACL reconstruction. The ACL graft is formed from a tripled semitendinosus tendon and a single strand of gracilis tendon. The femoral tunnel is drilled to provide an anatomic location intra-articularly and to exit the femur just posterior and proximal to the lateral epicondyle. The additional length of gracilis therefore exits the femoral tunnel at the anatomic origin of the ALL and is then routed (under the iliotibial band [ITB]) through a tibial tunnel, and back to the femoral origin, to reconstruct the ALL. Many different types of nonanatomic lateral extra-articular tenodesis procedures have been reported. The most frequently performed were the Lemaire and MacIntosh procedures; however, these, and others, were widely abandoned after poor results were reported in the 1980s. ALL reconstruction differs from other lateral extra-articular tenodesis-type procedures because the procedure is anatomically based and can be percutaneously performed. Nonanatomic procedures (typically with a strand of ITB passed under the lateral collateral ligament [LCL]) have been reported to be associated with overconstraint, early arthritis, and an increased risk of infection2-5. In contrast, ALL reconstruction has been shown to restore normal knee kinematics and to avoid overconstraint when correctly fixed in full extension and neutral rotation6. The main concern with any type of lateral extra-articular tenodesis is based on historical reports of poor outcomes2,3. However, a recent study has demonstrated that combined ACL and ALL reconstruction is associated with a reoperation rate that is comparable with the rate seen after isolated ACL reconstruction, and it has a very low rate of complications7. This makes a compelling argument for anatomic ALL and ACL reconstruction being the procedure of choice when considering an extra-articular procedure. This is further supported by the fact that, even though previous studies have demonstrated a trend toward reduced ACL graft rupture with nonanatomic lateral extra-articular tenodesis procedures, they have not shown a significant improvement in outcomes8. Combined ACL and ALL reconstruction is currently the only type of lateral extra-articular procedure that has been demonstrated to significantly reduce the risk of ACL graft rupture and improve the rate of return to sports1.

Clinical Results of Lateral Extra-Articular Tenodesis.

In the anterior cruciate ligament (ACL) deficient knee, excellent outcomes are achieved in many patients with an isolated, intra-articular ACL reconstruction. Some patients, however, have ongoing instability or suffer graft rupture. Failure after ACL reconstruction is multifactorial, but residual anterolateral rotatory laxity is 1 potential contributing factor. Lateral extra-articular procedures are a heterogenous group of operations that were initially described as isolated treatments for the ACL deficient knee, and subsequently used in combination with intra-articular reconstructions. Initial observational studies were encouraging, however, comparative studies were less flattering and lead to a general abandonment of these procedures. With improved understanding of the anatomy and biomechanics of the anterolateral capsuloligamentous complex there has been a renewed interest in these procedures. Recent systematic reviews suggest efficacy of these procedures in improving rotational control, though data showing improved patient reported outcomes or reduced graft rupture rates are lacking. Preliminary results from ongoing clinical trials are supportive for lateral extra-articular tenodesis when used as an augment to modern, intra-articular ACL reconstructions in targeted, high-risk patients.

Role of the anterolateral complex in rotatory instability of the anterior cruciate ligament deficient knee

The anterolateral complex (ALC) of the knee plays an important role in rotatory knee stability, especially in anterior cruciate ligament (ACL)-deficient patients. There is considerable awareness of anterolateral rotatory instability secondary to reported high failure rates after ACL reconstruction. As such, there has been a renewed interest in lateral extra-articular reconstruction procedures to stabilize the ALC. The concept of lateral extra-articular tenodesis (EAT) as the sole treatment of ACL injuries was popular in the 1970s, but fell out of favor due to unacceptably poor long-term outcomes. However, as greater understanding of rotatory knee instability has evolved, lateral stabilization procedures similar to those described in the 1970s have emerged to augment ACL reconstruction. These additional soft tissue techniques are not without risk, as many studies have demonstrated knee over-constraint after these procedures. Therefore, it is prudent to take an individualized approach to ACL reconstruction and to assess the value of additional soft tissue procedures in the face of persistent rotatory laxity. This review will address the role of the ALC in rotatory knee injury, the difficulty in diagnosing these injuries, and provide an objective review of additional stabilizing procedures after ACL reconstruction.

Historical Overview of Lateral Tenodeses Procedures and State of the Art in 2016

Since the original descriptions of the lateral capsuloligamentous complex of the knee, this structure (also known as the anterolateral ligament [ALL]) has been known to be commonly injured at the time of anterior cruciate ligament (ACL) injury. Surgeons have sought to reconstruct the ALL in ACL-deficient knees with the goal of restoring normal kinematics. Numerous surgical procedures have been developed over the last 50 years to correct the pathologic anterior and rotatory laxity seen with ACL tears. Initially, isolated lateral extra-articular tenodesis procedures were used. These procedures corrected the pathologic internal rotation laxity but their inability to adequately control anterior tibial translation led to a high rate of failure. Therefore, isolated lateral tenodesis procedures have fallen out of favor. With the advent of arthroscopy, isolated intra-articular ACL reconstructions became more popular. Some surgeons performed an additional lateral tenodesis procedure in conjunction with an intra-articular ACL reconstruction. Although these combined procedures have been abandoned by many surgeons, long-term results of these reconstructions have been encouraging. Because of the persistence of a pivot shift in some patients after isolated intra-articular ACL reconstruction, there has been a renewed interest in the anatomy and biomechanics of the ALL. Most recently, several authors have described an anatomic ALL reconstruction. Although early clinical results of these ALL reconstructions are encouraging, ongoing studies are still needed to better understand the biomechanical effects of these procedures on knee kinematics and on the intra-articular graft. The specific indications for lateral tenodeses and the ideal technique have yet to be determined.

The anterolateral ligament of the knee: anatomy, biomechanics, and clinical implications

A detailed anatomic description of the anterolateral ligament published in 2013 has led to a renewed interest in the anatomy of the anterolateral structures of the knee and lateral extraarticular reconstruction procedures. It was hypothesized that the anterolateral ligament may represent an important stabilizer to anterolateral rotational instability, and injury to this structure may be involved in the pathogenesis of a high-grade pivot shift. Hence, several authors have suggested reconstruction of this ligament in conjunction with intraarticular reconstruction of the anterior cruciate ligament to improve postoperative knee stability. This article provides a comprehensive review about the historical and contemporary literature related to the anterolateral ligament. The anatomic descriptions of the anterolateral ligament vary considerably with regard to the femoral insertion site, and it remains controversial whether the anterolateral ligament represents a distinct extracapsular ligament or a part of the anterolateral capsule. Based on currently available biomechanical data, the anterolateral ligament can be considered a stabilizer against internal tibial rotation. Preliminary data after combined reconstruction of the anterior cruciate ligament and anterolateral ligament are promising; however, the value of this combined procedure over isolated anterior cruciate ligament reconstruction has yet to be determined.