Anatomic Anterolateral Ligament Reconstruction Research Articles

New Anatomic Anterolateral Ligament Reconstruction Used in a Complex Revision ACL Reconstruction

Background: 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. Indications: 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. Technique Description: 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. Results: 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. Discussion: 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. Patient Consent Disclosure Statement: 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.

A lateral extra-articular tenodesis without additional hardware: Surgical technique and biomechanical comparison with an anatomic anterolateral ligament reconstruction in the augmentation of anterior cruciate ligament reconstruction

BackgroundThe 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. MethodsTen 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. ResultsAnterior 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. ConclusionACL 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.

Characterizing the viscoelastic properties of the anterolateral ligament and grafts commonly used in its reconstruction

BackgroundCurrent anatomic anterolateral ligament reconstruction is typically performed using either a gracilis tendon or an iliotibial band graft based on their quasi-static behavior. However, there is limited knowledge about their viscoelastic behaviors. This study aimed to characterize the viscoelastic properties of the anterolateral ligament, distal iliotibial band, distal gracilis tendon and proximal gracilis tendon for graft material choice in anterolateral ligament reconstruction. MethodsAll the tissues were harvested from thirteen fresh-frozen cadaveric knees and subjected to preconditioning (3-6 MPa), sinusoidal cycle (1.2-12 MPa), dwell at constant load (12 MPa), and load to failure (3%/s). The quasi-static and viscoelastic properties of the soft tissues were computed and compared using a linear mixed model (p < 0.05). FindingsThe hysteresis of anterolateral ligament (mean:0.4 Nm) was comparable with gracilis halves (p > 0.85) but iliotibial band (6 Nm) was significantly higher (p < 0.001,ES = 6.5). In contrast, the dynamic creep of anterolateral ligament (0.5 mm) was similar to iliotibial band (0.7 mm, p > 0.82) whereas both gracilis halves were significantly lower (p < 0.007,ES > 1.4). The elastic modulus of anterolateral ligament (181.4 MPa, p < 0.001,ES > 2.1) was the lowest compared to the grafts materials (distal gracilis tendon:835 MPa, distal gracilis tendon:726 MPa, iliotibial band:910 MPa). Additionally, the failure load of the anterolateral ligament (124.5 N, p < 0.001,ES > 2.9) was also the lowest. InterpretationThe mechanical properties of the gracilis halves and iliotibial band were significantly different from anterolateral ligament, except for hysteresis and dynamic creep, respectively. Our findings showed that the gracilis halves may be a more appropriate graft choice for anterolateral ligament reconstruction due to its low energy dissipation and permanent deformation under dynamic loads.

Function and strain of the anterolateral ligament part II: reconstruction.

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 (ALLrec) in the setting of a combined ACL and ALL injury and reconstruction. The hypothesis was that combined ACL reconstruction (ACLrec) and ALLrec (ACL/ALLrec) significantly reduces internal rotation and shows load sharing between both reconstructions compared with isolated ACLrec. 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 ACLrec and combined ACL/ALLrec were compared. Additionally, ACL graft tension and ALL graft strain were measured continuously throughout the testing protocol. Combined anatomic ACL/ALLrec significantly improved the internal rotatory stability compared with isolated ACLrec at 30°-90° under an internal rotation moment. During a static pivot-shift test, additional ALLrec showed no significant reduction of ap-translation. ALLrec 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 ACLrec and ALLrec significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL at flexion angles ≥ 30°. Nevertheless, additional ALLrec with fixation at 60° and with low tension could not restore extension-near rotatory stability. For that reason, ALLrec with fixation at 60° flexion cannot be recommended in clinical application.

A biomechanical study after combined reconstruction of the anterior cruciate and anterolateral ligaments: Comparison between anatomic anterolateral ligament reconstruction and lateral tenodesis using the modified Lemaire technique

Objectives:To determine the stabilizing role of the anterolateral ligament reconstruction (ALLR) and the modified Lemaire lateral extraarticular tenodesis (LET) performed in combination with anterior cruciate ligament reconstruction (ACLR) and to determine if one of these two procedures was superior to the other.Methods:Six non paired cadaveric knees were tested with a 6 degrees of freedom robotic system (KUKA Robotics). Internal rotation and anterior tibial translation were measured between 0 and 90° knee flexion after applying 5 N-m Torque and a 134-N anterior load, respectively. A full kinematics assessment was performed in each following conditions: intact knee, after section of the anterior cruciate ligament (ACL), after section of the ACL and anterolateral ligament (ALL) and Kaplan fibers, after isolated ACLR, after combined ACLR+LET and ACLR+ALLR. ALLR was performed using Gracilis tendon while central strip of the ilio-tibial band was used for the modified Lemaire procedure.These different states were compared using a Tukey paired comparison test.Results:In combined ACL and anterolateral deficient knee, anterior translation and internal rotation remained significantly increased after isolated ACLR compared to intact knee (+2.33 ± 1.44 mm and +1.98 ± 1.06°; p > 0.01). On the other hand, the addition of an ALLR or a modified Lemaire LET to the ACLR allowed to restore anterior translation and internal rotation to values similar to the intact knee. Finally, the two anterolateral procedures had not significantly different values in both tests. This difference was 0.67 ± 1.46 mm for anterior translation (p=0.79) and 0.11 ± 1.11° for internal rotation (p=0.99).Conclusion:In ACL and anterolateral deficient knee, combined ACLR and anterolateral reconstruction allowed restoration of native stability of the knee in anterior translation and internal rotation contrary to isolated ACLR.Additionally, both types of extra-articular reconstruction, ALLR or modified Lemaire procedure, were similar in terms of restoring knee kinematics and neither overconstrained the knee.

Clinical Outcomes of Isolated Revision Anterior Cruciate Ligament Reconstruction or in Combination With Anatomic Anterolateral Ligament Reconstruction

Background: Although the cause of rotational instability after revision anterior cruciate ligament reconstruction (ACLR) is multifactorial, the rationale of adding an extra-articular procedure is based on its ability to restrict rotational instability. Purpose: To assess the effect of anterolateral ligament (ALL) reconstruction on revision ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 87 patients who underwent revision ACLR between March 2011 and July 2014 with a follow-up of more than 3 years were included in this retrospective study. Patients were divided into the isolated revision ACLR group (group I, n = 45, from March 2011 to January 2013) or the revision ACLR in combination with ALL reconstruction group (group C, n = 42, from February 2013 to July 2014). Subjective knee assessments including the subjective International Knee Documentation Committee (IKDC) form, Lysholm score, Tegner activity scale, and Anterior Cruciate Ligament–Return to Sport after Injury (ACL-RSI) scale were used. Clinical and functional tests were performed before surgery and at ≥6 months after surgery. All tests were usually completed at 36 months of follow-up. Results: The mean follow-up duration for groups I and C were 41.5 ± 8.2 and 38.2 ± 6.9 months, respectively (P = .451). The subjective IKDC score, Tegner score, and ACL-RSI score were significantly better in group C compared with those in group I at the last follow-up (84.3 ± 18.5 vs 75.9 ± 19.2, 7.0 ± 0.8 vs 6.3 ± 0.7, and 69.5 ± 25.4 vs 51.9 ± 23.1, respectively), although they were not significantly different between the 2 groups at 12 months after surgery (79.2 ± 18.8 vs 76.7 ± 17.2, 6.7 ± 0.7 vs 6.5 ± 0.9, and 50.2 ± 24.6 vs 49.9 ± 25.1, respectively). There were no significant differences in KT-2000 arthrometer, isokinetic extensor strength, single-legged hop for distance, co-contraction test, or carioca test results between the 2 groups at the last follow-up (P = .304, .068, .125, .056, and .066, respectively). Preoperatively, 43 (95.6%) patients in group I and 40 (95.2%) patients in group C had a grade 2 or 3 pivot shift (P = .387). Postoperatively, 23 (53.5%) patients in group I and 38 (90.5%) patients in group C had a negative pivot shift (P < .001). Group C showed a higher rate of return to the same level of sports activity than group I (57.1% vs 25.6%, respectively; P = .008), although there was no significant difference in the rate of return to any sports activity at the last follow-up (88.4% in group I vs 88.1% in group C; P = .713). Conclusion: Revision ACLR in combination with ALL reconstruction significantly reduced rotational laxity and showed a higher rate of return to the same level of sports activity than revision ACLR alone, although there were no significant differences in anterior laxity or functional test results between the 2 groups.

An Overview of Clinically Relevant Biomechanics of the Anterolateral Structures of the Knee.

Residual anterolateral rotatory laxity following injury and reconstruction of the anterior cruciate ligament (ACL) has become a popular topic and has generated interest in characterizing the relative contribution from the anterolateral structures of the knee. Studies have reported on the anatomic and biomechanical features of the anterolateral ligament (ALL), revealing a role in restraining internal tibial rotation in both ACL-intact and ACL-deficient knees. The Kaplan fibers of the iliotibial band have also been reported to provide significant restraint to internal tibial rotation. The ACL is the primary restraint to anterior tibial translation, and both the proximal and distal bundles of the iliotibial band, with a divergent orientation, also provide significant static restraint against internal tibial rotation, and each bundle may have a distinct individual role. In the setting of ACL deficiency, subsequent sectioning of the ALL and Kaplan fibers led to further increases in anterior tibial translation. Residual rotatory laxity that may be seen clinically following ACL reconstruction may be attributable to an associated anterolateral structure injury even in the setting of an anatomic ACLR, leading to consideration for a concomitant anterolateral structure reconstruction. Studies evaluating the kinematic influence of anatomic ALL reconstruction or lateral extra-articular tenodesis have focused on internal rotation, axial plane translation, and anterior tibial translation, with variable results having been reported. Further, despite the long history of anterolateral structure reconstruction, most commonly with a lateral extra-articular tenodesis, the clinical use of these combined techniques is still in its relative infancy, and long-term patient outcomes have yet to be published for relative comparisons.

In Vivo Anterolateral Ligament Length Change in the Healthy Knee During Functional Activities—A Combined Magnetic Resonance and Dual Fluoroscopic Imaging Analysis

To measure the invivo anterolateral ligament (ALL) length change in healthy knees during step-up and sit-to-stand motions. Eighteen healthy knees were imaged using magnetic resonance and dual fluoroscopic imaging techniques during a step-up and sit-to-stand motion. The ALL length change was measured using the shortest three-dimensional wrapping path, with its femoral attachment located slightly anterior-distal (ALL-Claes) or posterior-proximal (ALL-Kennedy) to the fibular collateral ligament attachment. The ALL length measured from the extended knee position of the non-weight-bearing magnetic resonance scan was used as a reference to normalize the length change. During the step-up motion (approximately 55° flexion to full extension), both the ALL-Claes and ALL-Kennedy showed a significant decrease in length of 21.2% (95% confidence interval 18.0-24.4, P < .001) and 24.3% (20.6-28.1, P < .001), respectively. During the sit-to-stand motion (approximately 90° flexion to full extension), both the ALL-Claes and ALL-Kennedy showed a consistent, significant decrease in length of 35.2% (28.8-42.2, P < .001) and 39.2% (32.4-46.0, P < .001), respectively. From approximately 90° to 70° of flexion, a decrease in length of approximately 6% was seen; 70° of flexion to full extension resulted in an approximately 30% decrease in length. The ALL was found to be a nonisometric structure during the step-up and sit-to-stand motion. The length of the ALL was approximately 35% longer at approximately 90° of knee flexion when compared with full extension and showed decreasing length at lower flexion angles. Similar ALL length change patterns were found with its femoral attachment located slightly anterior-distal or posterior-proximal to the fibular collateral ligament attachment. These data suggest that, if performing anatomic ALL reconstruction, graft fixation may be performed beyond 70° flexion to reduce the chance of lateral compartment overconstraint. Anatomic ALL reconstruction may affect the knee kinematics more in high flexion than at low flexion angles.

Anatomic Anterolateral Ligament Reconstruction of the Knee Leads to Overconstraint at Any Fixation Angle

Background: Anterior cruciate ligament (ACL) tears are one of the most common injuries among athletes. However, the ability to fully restore rotational stability with ACL reconstruction (ACLR) remains a challenge, as evidenced by the persistence of rotational instability in up to 25% of patients after surgery. Advocacy for reconstruction of the anterolateral ligament (ALL) is rapidly increasing because some biomechanical studies have reported that the ALL is a significant contributor to internal rotational stability of the knee. Hypothesis/Purpose: The purpose of this study was to assess the effect of ALL reconstruction (ALLR) graft fixation angle on knee joint kinematics in the clinically relevant setting of a concomitant ACLR and to determine the optimal ALLR graft fixation angle. It was hypothesized that all fixation angles would significantly reduce rotational laxity compared with the sectioned ALL state. Study Design: Controlled laboratory study. Methods: Ten nonpaired fresh-frozen human cadaveric knees underwent a full kinematic assessment in each of the following states: (1) intact; (2) anatomic single-bundle (SB) ACLR with intact ALL; (3) anatomic SB ACLR with sectioned ALL; (4) anatomic SB ACLR with 7 anatomic ALLR states using graft fixation angles of 0°, 15°, 30°, 45°, 60°, 75°, and 90°; and (5) sectioned ACL and ALL. Internal rotation during a 5-N·m internal rotation torque and anterior translation during an 88-N anterior load were recorded at 15° flexion intervals between 0° and 120°. Axial plane translation and internal rotation during a simulated pivot-shift test (combined 5-N·m internal rotation and 10-N·m valgus torques) were recorded between 0° and 60°. Kinematic changes were measured and compared with the intact state for all reconstructed and sectioned states. Results: Anatomic ALLR at all graft fixation angles significantly overconstrained internal rotation of the knee joint beyond 30° of flexion and at 45° and 60° during the pivot-shift test. Furthermore, there were no significant knee kinematic differences between any tested graft fixation angles during anterior drawer, pivot-shift, and internal rotation tests. Conclusion: Anatomic ALLR in conjunction with an ACLR significantly reduced rotatory laxity of the knee beyond 30° of knee flexion. However, ALLR, regardless of fixation angle, resulted in significant overconstraint of the knee. Clinical Relevance: ALLR at any fixation angle overconstrained native joint kinematics and should be performed with careful consideration. Further investigation into the application and target population for ALLR is strongly recommended.

Anatomic Anterolateral Ligament Reconstruction of the Knee Leads to Overconstraint at any Fixation Angle

Objectives:Anterior cruciate ligament (ACL) tears are one of the most common injuries among athletes. However, the ability to fully restore rotational stability with ACL reconstruction (ACLR) remains a challenge because up to 25% of patients may present with a residual pivot shift following surgery. Advocacy for reconstruction of the anterolateral ligament (ALL) is rapidly increasing because biomechanical studies have reported that the ALL is a significant contributor to internal rotational stability of the knee. Although several graft fixation angles for the anatomic ALL reconstruction (ALLR) have been reported in literature, none have been biomechanically validated. Therefore, the purpose of this study was to assess the effect of ALLR graft fixation angle on knee joint kinematics in the clinically relevant setting of a concomitant ACLR. The goal was to find the optimal knee flexion angle for fixation of the ALLR graft that would most accurately restore native knee kinematics without introducing overconstraint to the knee. It was hypothesized that all fixation angles would significantly reduce rotational laxity compared to the sectioned ALL state and that fixation at 30° would best reproduce native joint kinematics.Methods:Eight non-paired fresh-frozen human cadaveric knees with no prior injury, surgical history, or gross anatomic abnormality were evaluated with a 6 degree-of-freedom robotic system. Each specimen underwent a full kinematic assessment in each of the following states: 1) intact, 2) anatomic single-bundle (SB) ACLR with intact ALL, 3) anatomic SB ACLR with sectioned ALL, 4) 7 anatomic SB ACLR and ALLR states utilizing ALL graft fixation knee flexion angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°, and 5) sectioned ACL and ALL. Internal rotation during a 5 N-m internal rotation torque and anterior displacement during an 88 N anterior load were recorded at 15° intervals between 0° and 120° of knee flexion. Axial plane displacement and internal rotation during a simulated pivot shift (combined 5 N-m internal rotation and 10 N-m valgus torques) were recorded between 0° and 60°. Kinematic changes were measured and compared to the native state for all reconstructed and sectioned states.Results:Anterolateral ligament reconstruction at all graft fixation angles significantly reduced internal rotation of the knee with respect to the ACLR with sectioned ALL state at all knee flexion angles beyond 30° (Figure 1). However, ALLR overconstrained the knee joint at each tested ALL graft fixation angle and through all tested knee flexion angles beyond 15° during simulated internal rotation torque and pivot shift tests (Figure 1). Furthermore, no significant difference was observed between the different graft fixation angles on the kinematics of the knee with respect to anterior drawer, pivot shift and internal rotation.Conclusion:Anatomic ALLR in conjunction with an ACLR overconstrained internal rotation of the knee joint at flexion angles beyond 15° regardless of graft fixation angle. The surgical technique and indications for this procedure should be investigated further and it is recommended that ALLR be used with caution.

Anterolateral Ligament Reconstruction Technique: An Anatomic-Based Approach

Restoration of anteroposterior laxity after an anterior cruciate ligament reconstruction has been predictable with traditional open and endoscopic techniques. However, anterolateral rotational stability has been difficult to achieve in a subset of patients, even with appropriate anatomic techniques. Therefore, differing techniques have attempted to address this rotational laxity by augmenting or reconstructing lateral-sided structures about the knee. In recent years, there has been a renewed interest in the anterolateral ligament as a potential contributor to residual anterolateral rotatory instability in anterior cruciate ligament–deficient patients. Numerous anatomic and biomechanical studies have been performed to further define the functional importance of the anterolateral ligament, highlighting the need for surgical techniques to address these injuries in the unstable knee. This article details our technique for an anatomic anterolateral ligament reconstruction using a semitendinosus tendon allograft.

An In Vitro Robotic Assessment of the Anterolateral Ligament, Part 2

Background: Recent biomechanical studies have demonstrated that an extra-articular lateral knee structure, most recently referred to as the anterolateral ligament (ALL), contributes to overall rotational stability of the knee. However, the effect of anatomic ALL reconstruction (ALLR) in the setting of anterior cruciate ligament (ACL) reconstruction (ACLR) has not been biomechanically investigated or validated. Purpose/Hypothesis: The purpose of this study was to investigate the biomechanical function of anatomic ALLR in the setting of a combined ACL and ALL injury. More specifically, this investigation focused on the effect of ALLR on resultant rotatory stability when performed in combination with concomitant ACLR. It was hypothesized that ALLR would significantly reduce internal rotation and axial plane translation laxity during a simulated pivot-shift test compared with isolated ACLR. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen cadaveric knees were evaluated with a 6 degrees of freedom robotic system. Knee kinematics were evaluated with simulated clinical examinations including a simulated pivot-shift test consisting of coupled 10-N·m valgus and 5-N·m internal rotation torques, a 5-N·m internal rotation torque, and an 88-N anterior tibial load. Kinematic differences between ACLR with an intact ALL, ACLR with ALLR, and ACLR with a deficient ALL were compared with the intact state. Single-bundle ACLR tunnels and ALLR tunnels were placed anatomically according to previous quantitative anatomic attachment descriptions. Results: Combined anatomic ALLR and ACLR significantly improved the rotatory stability of the knee compared with isolated ACLR in the face of a concurrent ALL deficiency. During a simulated pivot-shift test, ALLR significantly reduced internal rotation and axial plane tibial translation when compared with ACLR with an ALL deficiency. Isolated ACLR for the treatment of a combined ACL and ALL injury was not able to restore stability of the knee, resulting in a significant increase in residual internal rotation laxity. ALLR did not affect anterior tibial translation; no significant differences were observed between the varying ALL conditions with ACLR except between ACLR with an intact ALL and ACLR with a deficient ALL at 0° of flexion. Conclusion: In the face of a combined ACL and ALL deficiency, concurrent ACLR and ALLR significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL. Clinical Relevance: Significant increases in residual internal rotation and laxity during the pivot-shift test may exist in both acute and chronic settings of an ACL deficiency and in patients treated with isolated ACLR for a combined ACL and ALL deficiency. For this subset of patients, surgical treatment of the ALL, in addition to ACLR, should be considered to restore knee stability.