Anterolateral Complex Reconstruction: Another Fad or Method to Improve ACL Outcomes?

ACL reconstruction combined with anterolateral structures reconstruction for treating ACL rupture and knee injuries: a finite element analysis

Introduction: The biomechanical indication for combining anterolateral structures reconstruction (ASLR) with ACL reconstruction (ACLR) to reduce pivot shift in the knee remains unclear. This study aims to investigate knee functionality after ACL rupture with different combinations of injuries, and to compare the effectiveness of ALSR with ACLR for treating these injuries. Methods: A validated finite element model of a human cadaveric knee was used to simulate pivot shift tests on the joint in different states, including 1) an intact knee; 2) after isolated ACL rupture; 3) after ACL rupture combined with different knee injuries or defect, including a posterior tibial slope (PTS) of 20°, an injury to the anterolateral structures (ALS) and an injury to the posterior meniscotibial ligament of the lateral meniscus (LP); 4) after treating the different injuries using isolated ACLR; v. after treating the different injuries using ACLR with ALSR. The knee kinematics, maximum von Mises stress (Max.S) on the tibial articular cartilage (TC) and force in the ACL graft were compared among the different simulation groups. Results and discussion: Comparing with isolated ACL rupture, combined injury to the ALS caused the largest knee laxity, when a combined PTS of 20° induced the largest Max.S on the TC. The joint stability and Max.S on the TC in the knee with an isolated ACL rupture or a combined rupture of ACL and LP were restored to the intact level after being treated with isolated ACLR. The knee biomechanics after a combined rupture of ACL and ALS were restored to the intact level only when being treated with a combination of ACLR and ALSR using a large graft diameter (6 mm) for ALSR. However, for the knee after ACL rupture combined with a PTS of 20°, the ATT and Max.S on the TC were still greater than the intact knee even after being treated with a combination of ACLR and ALSR. The finite element analysis showed that ACLR should include ALSR when treating ACL ruptures accompanied by ALS rupture. However, pivot shift in knees with a PTS of 20° was not eliminated even after a combined ACLR and ALSR.

Anterior Cruciate Ligament Reconstruction Plus Lateral Extra-articular Tenodesis Has a Similar Return-to-Sport Rate to Anterior Cruciate Ligament Reconstruction Alone but a Lower Failure Rate

PURPOSE

To determine whether the addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament reconstruction (ACLR) would improve return-to-sport (RTS) rates in young, active patients who play high-risk sports.

METHODS

This multicenter randomized controlled trial compared standard hamstring tendon ACLR with combined ACLR and LET using a strip of the iliotibial band (modified Lemaire technique). Patients aged 25 years or younger with an anterior cruciate ligament-deficient knee were included. Patients also had to meet 2 of the following criteria: (1) pivot-shift grade 2 or greater, (2) participation in a high-risk or pivoting sport, and (3) generalized ligamentous laxity. Time to return and level of RTS were determined via administration of a questionnaire at 24 months postoperatively.

RESULTS

We randomized 618 patients in this study, 553 of whom played high-risk sports preoperatively. The proportion of patients who did not RTS was similar between the ACLR (11%) and ACLR-LET (14%) groups; however, the graft rupture rate was significantly different (11.2% in ACLR group vs 4.1% in ACLR-LET group, P = .004). The most cited reason for no RTS was lack of confidence and/or fear of reinjury. A stable knee was associated with nearly 2 times greater odds of returning to a high-level high-risk sport postoperatively (odds ratio, 1.92; 95% confidence interval, 1.11-3.35; P = .02). There were no significant differences in patient-reported functional outcomes or hop test results between groups (P > .05). Patients who returned to high-risk sports had better hamstring symmetry than those who did not RTS (P = .001).

CONCLUSIONS

At 24 months postoperatively, patients who underwent ACLR plus LET had a similar RTS rate to those who underwent ACLR alone. Although the subgroup analysis did not show a statistically significant increase in RTS with the addition of LET, on returning, the addition of LET kept subjects playing longer by reducing graft failure rates.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Reconstruction for Chronic ACL Tears with or without Anterolateral Structure Augmentation in Patients at High Risk for Clinical Failure: A Randomized Clinical Trial

BACKGROUND

The purpose of this trial was to determine whether anterior cruciate ligament reconstruction (ACLR) with anterolateral structure augmentation (ALSA) would result in better clinical outcomes in patients with a high risk of clinical failure.

METHODS

From February 2017 to June 2018, 120 young, active adults with chronic anterior cruciate ligament injury and high risk of clinical failure were randomized. The patients were followed for >2 years, with 5 being lost to follow-up and 1 being withdrawn from the study. Clinical characteristics, operative findings, and postoperative clinical outcomes were analyzed.

RESULTS

The analysis included data from 114 patients, including 95 men and 19 women with a mean age (and standard deviation) of 30.1 ± 6.7 years in the ACLR group and 30.1 ± 6.4 years in the ALSA group. The rate of clinical failure was 20.4% (11 of 54 patients) and 3.3% (2 of 60 patients) in the ACLR and ALSA groups, respectively (difference, 17.1%; 95% confidence interval [CI], 5.3% to 29.8%; p = 0.007). Significantly higher rates of return to the preinjury level of sports (48.3% versus 27.8%; difference, 20.5%; 95% CI, 2.7% to 36.6%; p = 0.024) and to a competitive level of play (63.3% versus 42.6%; difference, 22.3%; 95% CI, 4.1% to 38.8%; p = 0.027) was found in the ALSA group.

CONCLUSIONS

Compared with isolated ACLR, combined ACLR and ALSA resulted in a reduction in persistent rotatory laxity and higher rates of return to preinjury and competitive levels of play at 2 years of follow-up in the population studied. Our study suggests that patients with high risk of clinical failure appear to be candidates for the ALSA approach.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Increased Rotatory Laxity after Anterolateral Ligament Lesion in Anterior Cruciate Ligament- (ACL-) Deficient Knees: A Cadaveric Study with Noninvasive Inertial Sensors

The anterolateral ligament (ALL) has been suggested as an important secondary knee restrain on the dynamic laxity in anterior cruciate ligament- (ACL-) deficient knees. Nevertheless, its kinematical contribution to the pivot-shift (PS) phenomenon has not been clearly and objectively defined, and noninvasive sensor technology could give a crucial contribution in this direction. The aim of the present study was to quantify in vitro the PS phenomenon in order to investigate the differences between an ACL-deficient knee and an ACL+ALL-deficient knee. Ten fresh-frozen paired human cadaveric knees (n = 20) were included in this controlled laboratory study. Intact, ACL-deficient, and ACL+ALL-deficient knees were subjected to a manual PS test quantified by a noninvasive triaxial accelerometer (KiRA, OrthoKey). Kinematic data (i.e., posterior acceleration of the tibial lateral compartment) were recorded and compared among the three statuses. Pairwise Student's t-test was used to compare the single groups (p < 0.05). Intact knees, ACL-deficient knees, and ACL+ALL-deficient knees showed an acceleration of 5.3 ± 2.1 m/s², 6.3 ± 2.3 m/s², and 7.8 ± 2.1 m/s², respectively. Combined sectioning of ACL and ALL resulted in a statistically significant acceleration increase compared to both the intact state (p < 0.01) and the ACL-deficient state (p < 0.01). The acceleration increase determined by isolated ACL resection compared to the intact state was not statistically significant (p > 0.05). The ALL sectioning increased the rotatory laxity during the PS after ACL sectioning as measured through a user-friendly, noninvasive triaxial accelerometer.

Effects of Anterolateral Structure Augmentation on the In Vivo Kinematics of Anterior Cruciate Ligament-Reconstructed Knees

BACKGROUND

Double-bundle anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-known treatment that restores the stability of ACL-deficient knees. However, some isolated ACL-reconstructed knees ultimately show rotatory laxity and develop osteoarthritis. Whether combined ACLR with anterolateral structure (ALS) augmentation (ALSA) can provide better improvement in the in vivo knee rotational kinematics remains unknown.

HYPOTHESIS

When compared with isolated double-bundle ACLR, combined double-bundle ACLR with ALSA can improve knee in vivo rotational kinematics and provide better restoration of knee kinematics.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen patients with unilateral ACL injury were randomly divided into 2 groups to receive either combined double-bundle ACLR and ALSA (ALSA group) or isolated double-bundle ACLR (ACLR group). All patients performed a single-leg lunge using the operative and nonoperative/contralateral legs under dual-fluoroscopic imaging system surveillance during a hospital visit at a minimum 1 year (12-13 months) of follow-up to assess the 6 degrees of freedom knee kinematics. Functional evaluation using the Lysholm and Marx rating scales and clinical examinations were also performed.

RESULTS

From full extension to approximately 90° of knee flexion at 5° intervals, the mean ± SD internal rotation of the reconstructed knees in the ALSA group (1.5°± 0.9°) was significantly smaller than that of the contralateral knees (8.2°± 1.9°; P = .008). The ALSA group knees also showed significantly (P = .045) more medial translation than the contralateral knees. In the ACLR group, the mean internal rotation of the reconstructed knee (6.0°± 2.1°) was significantly smaller than that of the contralateral knees (8.9°± 0.6°; P < .001). At full extension, the tibia was significantly more externally rotated than that of the contralateral legs (0.5°± 7.4° vs 7.6°± 3.4°, P = .049).

CONCLUSION

When compared with isolated double-bundle ACLR, double-bundle ACLR augmented with ALS reconstruction resulted in anterolateral rotatory overconstraint during the lunge motion.

CLINICAL RELEVANCE

Additional ALSA of double-bundle ACL-reconstructed knees overconstrained rotatory stability. Therefore, the use of ALSA for ACL-reconstructed knees should be considered with caution for patients with ACL deficiency and anterolateral rotatory instability. Longer-term follow-up to evaluate long-term outcomes and altered kinematics over time is recommended.

Lateral Extra-articular Tenodesis Reduces Failure of Hamstring Tendon Autograft Anterior Cruciate Ligament Reconstruction: 2-Year Outcomes From the STABILITY Study Randomized Clinical Trial

BACKGROUND

Persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been correlated with poor clinical outcomes and graft failure.

HYPOTHESIS

We hypothesized that a single-bundle, hamstring ACLR in combination with a lateral extra-articular tenodesis (LET) would reduce the risk of ACLR failure in young, active individuals.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This is a multicenter, prospective, randomized clinical trial comparing a single-bundle, hamstring tendon ACLR with or without LET performed using a strip of iliotibial band. Patients 25 years or younger with an ACL-deficient knee were included and also had to meet at least 2 of the following 3 criteria: (1) grade 2 pivot shift or greater, (2) a desire to return to high-risk/pivoting sports, (3) and generalized ligamentous laxity (GLL). The primary outcome was ACLR clinical failure, a composite measure of rotatory laxity or a graft rupture. Secondary outcome measures included the P4 pain scale, Marx Activity Rating Scale, Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee score, and ACL Quality of Life Questionnaire. Patients were reviewed at 3, 6, 12, and 24 months postoperatively.

RESULTS

A total of 618 patients (297 males; 48%) with a mean age of 18.9 years (range, 14-25 years) were randomized. A total of 436 (87.9%) patients presented preoperatively with high-grade rotatory laxity (grade 2 pivot shift or greater), and 215 (42.1%) were diagnosed as having GLL. There were 18 patients lost to follow-up and 11 who withdrew (~5%). In the ACLR group, 120/298 (40%) patients sustained the primary outcome of clinical failure, compared with 72/291 (25%) in the ACLR+LET group (relative risk reduction [RRR], 0.38; 95% CI, 0.21-0.52; P < .0001). A total of 45 patients experienced graft rupture, 34/298 (11%) in the ACLR group compared with 11/291 (4%) in the ACL+LET group (RRR, 0.67; 95% CI, 0.36-0.83; P < .001). The number needed to treat with LET to prevent 1 patient from graft rupture was 14.3 over the first 2 postoperative years. At 3 months, patients in the ACLR group had less pain as measured by the P4 (P = .003) and KOOS (P = .007), with KOOS pain persisting in favor of the ACLR group to 6 months (P = .02). No clinically important differences in patient-reported outcome measures were found between groups at other time points. The level of sports activity was similar between groups at 2 years after surgery, as measured by the Marx Activity Rating Scale (P = .11).

CONCLUSION

The addition of LET to a single-bundle hamstring tendon autograft ACLR in young patients at high risk of failure results in a statistically significant, clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after surgery.

REGISTRATION

NCT02018354 ( ClinicalTrials.gov identifier).