The Anterolateral Ligament of the Knee: An Updated Systematic Review of Anatomy, Biomechanics, and Clinical Outcomes

Evaluation of anterolateral ligament healing in patients with anterior cruciate ligament injury without anterior cruciate ligament reconstruction and its relationship with clinical examination tests

PURPOSE

This study radiologically investigated the potential of preoperative recovery of the anterolateral ligament (ALL) in patients who did not undergo anterior cruciate ligament reconstruction (ACLR) surgery in the early stages despite surgical indication. The secondary aim was to investigate the relationship between ALL injuries in magnetic resonance imaging (MRI) and the results of Lachman and pivot shift tests performed preoperatively and postoperatively under anaesthesia among patients who underwent ACLR in acute and chronic stages.

METHODS

The study examined 100 patients aged 19-51 years who underwent anatomic single bundle ACLR using hamstring autografts for the ACL. Based on the time between the injury and ACLR, they were divided into acute (≤6 months) and chronic (>6 months) groups. The chronic group had three subgroups of ACLR times: 7-12, 13-24 and >24 months. Complete recovery was defined as a change from grade B or C upon injury to grade A before surgery according to the Muramatsu MRI classification. The relationship between preoperative and postoperative Lachman grades and pivot shifting test results and the degree of ALL injury was evaluated.

RESULTS

In the chronic group, 19/61 patients (31.1%) had preoperative grade A, and 4/61 patients (6.5%) had grade A at the time of injury. In the acute group, 22/29 patients with grades B and C (76%) had grade 3 preoperative pivot shifting. In the acute group, grades 1 and 2 were more common in patients with grades B and C (10/29, 35%) than grade A (0/10, 0.0%).

CONCLUSION

The improvement rate was 24.6% among patients who did not receive ACLR in the acute phase and underwent ACLR in the chronic phase. In the acute group, the degree of ALL damage was related to the pivot shift results. However, the results in the chronic phase were not associated with the degree of injury.

LEVEL OF EVIDENCE

Level IV.

The Anterolateral Ligament of the Knee Is a Nonisometric Thin Ligament With High Prevalence and Almost Constant Attachment to the Lateral Meniscus: A Systematic Review With Meta-analysis

PURPOSE

To provide comprehensive information about the anterolateral ligament (ALL) prevalence, morphometry, isometry, insertions, histology, and its relationship with the lateral meniscus (LM).

METHODS

The study was performed, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Eligible cadaveric studies investigating the frequency of the ALL presence, and anatomical features were identified through an online search of the PubMed, Scopus, and Cochrane Central databases from inception to June 2022. Statistical analysis was conducted with the open-source R programming language using the "meta" package. The Higgins I2 statistic was used for quantifying heterogeneity.

RESULTS

Thirty-three studies (1,478 cadaveric knees) were included. The ALL had a 79% prevalence. It was attached to the LM periphery in 97% of studies. Most studies reported a femoral insertion of the ALL, just proximal and posterior to the lateral epicondyle. Tibial attachment is constant at the midpoint between Gerdy's tubercle and fibular head. The mean ALL thickness at the joint line was 1.6 [1.2; 2.0] mm. The ALL length was found to significantly change across the knee flexion (P < .01). It was increased from 0° to 60° and decreased after 60° flexion. Seven histological studies demonstrated a typical ligamentous microstructure.

CONCLUSION

The ALL is a thin ligament, distinct to the knee capsule, which may be found in 79% of the knees having an almost constant attachment to the LM. The ALL is not isometric. It becomes tense during internal rotation and between 30° and 60° knee flexion. Pooled results should be interpreted with caution due to the high heterogeneity among the included studies.

CLINICAL RELEVANCE

This study sheds light on controversial issues and provides comprehensive and accurate information about the essential anatomical knowledge on ALL, which may contribute to optimizing ALL reconstruction surgical techniques and biomechanical settings.

Outcomes of "Over the Top" Anterior Cruciate Ligament Reconstruction Associated with a Lateral Extra-Articular Tenodesis in Children

(1) Purpose: The incidence of anterior cruciate ligament (ACL) ruptures in children and adolescents has considerably increased during the last decades due to higher levels of competitive athletic activity, and early sport specialization and professionalization. Contemporary ACL reconstruction techniques have recently been subject to renewed interest in this population. The objective of this study is to report the short- and mid-term results of our physis-sparing ACL reconstruction technique using an "over the top" technique associated with a modified Lemaire procedure. (2) Methods: A retrospective series of 12 junior soccer players who presented to our clinic with a torn ACL between January 2019 and September 2021 was reviewed. The inclusion criteria were patients under 15 years with open tibial and femoral physes, with a stable contralateral knee, a minimum follow-up of 6 months, and a time frame from injury to surgery of <3 months. Patients with previous knee surgery, structural concomitant injuries, muscular, neurological, or vascular abnormalities, or hypersensitivity to metal alloys were excluded. The functional evaluation was performed using the International Knee Documentation Committee (IKDC) rating, Lysholm score, and Tegner activity level. Moreover, clinical and radiological assessments were also performed, including KT-1000 and knee X-rays. (3) Results: We identified 1 female and 11 male patients with ACL tears, with a mean age of 13.17 ± 0.9 months. Concomitant injuries include isolated vertical and bucket-handle tears of the medial meniscus, lateral meniscus tears, bilateral tear of both menisci. The mean follow-up time was 26 ± 12.6 months. The average IKDC, Lysholm and Tegner scores were 93.29 ± 11.04, 95.08 ± 13.2 and 9 ± 0.0 points, respectively. The average KT-1000 score of the participants was 0.96 ± 1.6 points. None of the included patients reported post-surgical complications or required additional surgeries. (4) Conclusions: Our novel ACL reconstruction with LET technique is a safe procedure that resulted in good clinical outcomes, lower failure rate and return to sports in skeletally immature patients.

Study on the use of 3D printed guides in the individualized reconstruction of the anterior cruciate ligament

OBJECTIVE

Evaluation of the accuracy and effectiveness of 3D printed guides to assist femoral tunnel preparation in individualised reconstruction of the anterior cruciate ligament.

METHODS

Sixty patients who attended the Affiliated Hospital of Binzhou Medical College for autologous hamstring single bundle reconstruction of the anterior cruciate ligament from October 2018 to October 2020 were selected and randomly divided into two groups, including 31 cases in the 3D printing group (14 males and 17 females, mean age 41.94 ± 10.15 years) and 29 cases in the control group (13 males and 16 females, mean age 37.76 ± 10.34 years). Patients in both groups were assessed for intraoperative femoral tunnel accuracy, the number of intraoperative positioning and the time taken to prepare the femoral tunnel, the length of the anteromedial approach incision, the pre-planned bone tunnel length and intraoperative bone tunnel length in the 3D printed group, IKDC score and Lysholm score preoperatively and at 3, 6 and 12 months postoperatively, the Lachman、pivot-shift test preoperatively and at 6 months postoperatively, gait analysis to assess internal and external rotation in flexion of the knee at 12 months postoperatively and postoperative complications in both groups.

RESULTS

There was no statistical difference in functional knee scores and anteromedial approach incision length between the 3D printed and control groups (p > 0.05), while there was a statistical difference in the accuracy of tunnel positioning, the time taken to prepare the femoral bone tunnel and the degree of external rotation of the knee in flexion between the two groups (p < 0.05). There was no statistical difference between the preoperative planning of the bone tunnel length and the intraoperative bone tunnel length (p > 0.05).

COMPLICATIONS

One case in the 3D printing group developed intermuscular vein thrombosis in the affected lower limb after surgery, which disappeared after treatment, while three cases in the control group developed intermuscular vein thrombosis in the affected lower limb. No complications such as bone tunnel rupture, deep vein thrombosis in the lower limb and infection occurred in either group.

CONCLUSION

3D printed guides assisted with individualized ACL reconstruction may improve the accuracy of femoral tunnel positioning, which is safe and effective, while reducing the operative time and the number of intraoperative positioning, without increasing the length of incision, and may obtain higher functional scores and rotational stability of the knee joint, which is in line with the concept of individualized ACL reconstruction.

Does combined anterior cruciate ligament and anterolateral ligament reconstruction improve return to sport?

PURPOSE

Only 50-65% of patients return to their previous sporting level after ACL rupture. The literature reports a reduced rate of graft rupture when an anterolateral ligament reconstruction (ALLR) is associated with ACL reconstruction. ACL reconstruction combined with ALL allows a higher return to sport at pre-injury level than isolated reconstruction in patients playing pivot-contact sports.

METHODS

A retrospective, single-centre study between 2012 and 2020 comparing reconstruction by hamstring tendon technique, isolated ACLR vs ACL with ALLR. An isokinetic test was performed at 6 months post-operatively and patients were re-contacted at a minimum 2-year follow-up to assess their level and delay to return to sport, graft rupture rate and functional evaluation.

RESULTS

83 patients were included, 42 in ACLR group and 41 in ACL + ALLR group. Four patients were lost to follow-up and 79 patients were analysed. No significant difference was found on the level of return to sport (28.2% vs. 42.5%; p = 0.18), return to competition (43% vs. 60%; p = 0.18), delay to sports return, isokinetic assessment, functional scores, but a significant difference was found on graft rupture rate in favour of ALLR (12.8% vs. 0%; p = 0.02).

CONCLUSION

In our study, the addition of an ALL to ACL reconstruction did not improve pre-injury sports recovery or return to competition.

STUDY DESIGN

Cohort study, level of evidence 4.

Anatomic Double-Bundle and Single-Bundle Reconstructions Yield Similar Outcomes Following Anterior Cruciate Ligament Rupture: A Systematic Review and Meta-analysis

PURPOSE

To evaluate outcomes of arthroscopic single-bundle (SB) versus anatomic double-bundle (ADB) anterior cruciate ligament reconstruction (ACLR) in adults through a synthesis of randomized controlled trials (RCTs). We hypothesized that SB and ADB methods would lead to similar outcomes after reconstruction of ACL rupture.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist guided our reporting. To identify RCTs that compared SB and ADB reconstructions, a thorough literature search was conducted of PubMed, Embase, Cochrane library, and Web of Science. The methodologic quality of each included study was independently assessed by 2 authors using the Cochrane Collaboration's risk of bias tool. The Anatomic ACL Reconstruction Scoring Checklist (AARSC) was used to screen the eligibility of each study's operative approaches. Twelve clinical outcomes were investigated through pooled analyses conducted using Review Manager 5.3.

RESULTS

This meta-analysis synthesized 13 RCTs comparing postoperative outcomes between ADB and SB reconstructions of ACLs. After a minimum follow-up of 12 months, ADB and SB technique resulted in similar subjective clinical outcomes, including the International Knee Documentation Committee subjective score, Lysholm score, Tegner activity score, and Knee injury and Osteoarthritis Outcome Score sports subscale. Similarly, no statistically significant outcomes were found for objective outcomes such as International Knee Documentation Committee objective grade, pivot-shift test, Lachman test, side-to-side difference, extension deficit, flexion deficit, and osteoarthritis change. However, patients who underwent SB reconstruction had significantly greater complication rates than those that underwent ADB reconstruction.

CONCLUSIONS

When an ACLR approach meets a minimal total AARSC score of 8, ADB and SB techniques may result in similar subjective and objective outcomes, but the ADB technique may lead to lower complication rates following surgery. We recommend that surgeons favor ADB ACLR, as guided by the AARSC.

LEVEL OF EVIDENCE

Level I, systematic review and meta-analysis of Level I randomized controlled trials.

Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction Decreases Passive Anterior Tibial Subluxation Compared With Isolated Anterior Cruciate Ligament Reconstruction Despite Similar Rotational Stability and Clinical Outcomes

PURPOSE

To analyze the effect of augmenting a hamstring autograft anterior cruciate ligament reconstruction (ACLR) with an anterolateral ligament reconstruction (ALLR) on a primary outcome of passive anterior tibial subluxation (PATS) and a secondary outcome of the clinical outcomes.

METHODS

ACL-injured patients who underwent primary ACLR between March 2014 and February 2020 at our center were enrolled. Patients who underwent combined procedures (ACLR + ALLR) were matched in a 1:1 propensity ratio to patients who underwent ACLR only. We evaluated PATS, knee stability (side-to-side laxity difference, pivot-shift test), and patient-reported outcome measures (PROMs) after the procedure and documented complications.

RESULTS

From an initial cohort of 252 patients with a minimum follow-up period of 2 years (48.4 ± 16.6 months), 35 matched pairs were included, and 17 patients (48.6%) in each group underwent second-look arthroscopy. The combined ACLR + ALLR group showed significantly better improvement of PATS in the lateral compartments than the isolated ACLR group (P = .034). There were no significant differences between the groups regarding knee stability (side-to-side laxity difference, pivot-shift test), PROMs, complications, and second-look arthroscopic findings (all P > .05). Moreover, the proportions of patients who achieved the minimal clinically important difference in PROMs were not different between groups.

CONCLUSIONS

The combined ACLR + ALLR procedure was associated with a mean improvement in anterior tibial subluxation for the lateral compartment that was 1.2 mm better than an isolated ACLR procedure, despite its lack of clinical significance.

LEVEL OF EVIDENCE

Level III, cohort study.

Digital measurement of anterolateral knee laxity using strain sensors

PURPOSE

The ambition of the research group was to develop a sensor-based system that allowed the transfer of results with strain sensors applied to the knee joint. This system was to be validated in comparison to the current static mechanical measurement system. For this purpose, the internal rotation laxity of the knee joint was measured, as it is relevant for anterolateral knee laxity and anterior cruciate ligament (ACL) injury.

METHODS

This is a noninvasive measurement method using strain sensors which are applied to the skin in the course of the anterolateral ligament. The subjects were placed in supine position. First the left and then the right leg were clinically examined sequentially and documented by means of an examination form. 11 subjects aged 21 to 45 years, 5 women and 6 men were examined. Internal rotation of the lower leg was performed with a torque of 2 Nm at a knee flexion angle of 30°.

RESULTS

Comparison of correlation between length change and internal knee rotation angle showed a strong positive correlation (r = 1, p < 0.01). Whereas females showed a significant higher laxity vs. males (p = 0.003).

CONCLUSIONS

The present study showed that the capacitive strain sensors can be used for reproducible measurement of anterolateral knee laxity. In contrast to the previous static systems, a dynamic measurement will be possible by this method in the future.

Is antero-lateral complex of knee joint of critical importance in restoring rotational instability in patients with anterior cruciate ligament tear?

Antero-lateral ligament complex (ALC) is a vital structure for maintaining rotational stability of the knee. Evaluation of ALC radiologically (MRI) is still unpopular in setting of anterior cruciate ligament injury. A dire necessity exists for the orthopedic surgeons in outdoor patient department settings to rule out involvement of ALC. So, that it can be addressed during operating for Anterior Cruciate Ligament injury. The authors have formulated an algorithm on a personal level and have implemented this screening program and initiated screening of young to middle aged patients reporting with rotational knee instability for ALC involvement before recommending final operative plan. This screening program which uses specifically devised physical tests have significantly reduced the number of underdiagnosed Antero Lateral Ligament tear.

The Principles of Knee Joint Preservation: Operative Treatment Strategies

➤ Joint alignment, meniscal status, and ligament stability are codependent factors involved in knee joint preservation, and any injury or imbalance can impact the knee articular cartilage status and can result in adverse clinical outcomes.➤ Cartilage preservation procedures in the knee will not result in optimal outcomes if there is joint malalignment, meniscal deficiency, or ligamentous instability.➤ Lower-extremity varus or valgus malalignment is a risk factor for the failure of an anterior cruciate ligament (ACL) reconstruction. It represents an indication for a high tibial osteotomy or distal femoral osteotomy in the setting of failed ACL reconstruction, and may even be considered in patients who have an initial ACL injury and severe malalignment.➤ An elevated posterior tibial slope increases the risk of failure of ACL reconstruction, whereas a decreased posterior tibial slope increases the risk of failure of posterior cruciate ligament reconstruction.

Comparison of ACL and Anterolateral Ligament Reconstruction With Isolated ACL Reconstruction Using Hamstring Autograft: Outcomes in Young Female Patients With High-Grade Pivot Shift

Background

Inferior return to sports (RTS) and functional outcomes have been reported in women after anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis

The purpose was to evaluate the results of combined ACLR and anterolateral ligament reconstruction (ALLR) in young women with a high-grade pivot shift (grade ≥2). It was hypothesized that combined ACLR and ALLR would result in better RTS and rotational stability than isolated ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Two groups were retrospectively evaluated and compared. Group I (n = 39; mean age, 31.1 ± 5.7 years) underwent isolated ACLR using hamstring autografts; group C (n = 39; mean age, 30.4 ± 6.1 years) underwent combined ACLR and ALLR. Subjective outcome measures included the International Knee Documentation Committee subjective form, Lysholm, Tegner, and ACL-Return to Sport after Injury (ACL-RSI). Objective tests included a KT-2000 arthrometer stress test, a pivot-shift test, an isokinetic strength test, a Y-balance test, and a single-leg hop test. A postoperative questionnaire was administered to determine the rates and types of RTS, quality of sports performance, and reinjury and satisfaction rates. Subjective scores and clinical tests were performed at 2 years. Magnetic resonance imaging and second-look arthroscopy were conducted during the 1- and 2-year follow-ups, respectively.

Results

The mean follow-up for groups I and C were 30.4 ± 3.9 and 29.3 ± 3.5 months, respectively (P = .194). Patients in group C had better anteroposterior (P = .001) and rotational (P = .005) stability and higher ACL-RSI scores (P = .025) than those in group I. Group C had higher composite and posteromedial reach scores on the Y-balance test than group I (P = .014 and P = .010, respectively). A total of 26 (66.7%) patients in group C and 17 (43.6%) in group I returned to their prior level of sports (P = .040). Rerupture of the ACL graft and contralateral ACL rupture occurred in 2 (5.1%) and 2 (5.1%) patients in group I, respectively, compared with no rerupture or contralateral ACL rupture in group C.

Conclusion

Combined ACLR and ALLR in young women with a high-grade pivot shift was associated with better knee stability parameters, dynamic postural stability, and psychological readiness to RTS than isolated ACLR.

Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction With Pedicular Hamstrings Tendon Graft, Single-Strand Gracilis for ALL and Single Blind Femoral Tunnel

Combined anterior cruciate ligament and anterolateral ligament reconstruction (ACL+ALL r) is a common procedure to treat rotational instability and to prevent ACL graft failure. Recent studies have described numerous combined reconstruction techniques to obtain the most anatomical procedure with the least graft donor site morbidity and the best clinical results. Hamstring (HG) grafts are the most popular graft in literature. Leaving pedicle HG can preserve enough blood supply to improve tendon-bone healing with additional mechanical fixation of the graft on the tibial side. A single femoral tunnel reduces bone loss and prevents convergence of 2 femoral tunnels. We describe an original ACL and ALL reconstruction technique that preserves hamstring tibial insertion with a single blind femoral tunnel.

Combined Anterolateral Ligament and Anterior Cruciate Ligament Injury Is Associated With Increased Lateral Femoral Condyle Ratio

PURPOSE

to investigate the association between the lateral femoral condylar ratio (LFCR), the posterior tibial slope (PTS), and injury of the anterolateral ligament (ALL).

METHODS

Inclusion criteria were patients with acute anterior cruciate ligament (ACL) tear after noncontact injury during sports from October 1997 to May 2021. The LFCR and PTS were measured, and injury of the ALL was evaluated. Patients were divided into 2 groups: isolated ACL tear (isolated group) and combined ACL with ALL tear (combined group). The LFCR and PTS were compared between the isolated and combined groups. For each risk factor, the receiver operating characteristic curve, the area under the curve (AUC), and its 95% confidence interval (CI) were calculated to determine the cutoff for detecting increased risk of ALL injury.

RESULTS

There were 83 patients in the isolated group and 176 patients in the combined group. Demographics of the 2 groups did not differ significantly. The LFCR was significantly larger in the combined group than in the isolated group (P = .000). The PTS did not differ between the two groups (P = .405). The LFCR (odds ratio [OR] = 1.58; P = .000) was a significant factor. Age, body mass index, and PTS were not associated with an ALL injury. The AUC (0.79; 95% CI, 0.74-0.85) for the LFCR had a sensitivity of 73% and specificity of 76% to predict an ALL rupture. The calculated cutoff of 64.5 was associated with an increased risk for ALL rupture (OR = 8.65; 95% CI, 4.73-15.81) when compared with the isolated group.

CONCLUSIONS

An increased LFCR was associated with the ALL injury. However, increased PTS was not associated with ALL injury. These findings need to be considered for clinicians in treating ACL tear patients at risk for an ALL injury.

LEVEL OF EVIDENCE

III, retrospective comparative prognostic trial.

"Over-the-Top" Anterior Cruciate Ligament Reconstruction Associated With a Lateral Extra-Articular Tenodesis in Children

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.

Combined Lateral Extra-Articular Tenodesis or Combined Anterolateral Ligament Reconstruction and Anterior Cruciate Ligament Reconstruction Improves Outcomes Compared to Isolated Reconstruction for Anterior Cruciate Ligament Tear: A Network Meta-analysis of Randomized Controlled Trials

PURPOSE

To conduct a network meta-analysis (NMA) comparing the results of randomized controlled trials (RCTs) among patients who underwent either isolated anterior cruciate ligament (ACL) reconstruction or combined lateral extra-articular tenodesis (LET) or anterolateral ligament reconstruction (ALLR).

METHODS

RCTs that compared isolated ACL reconstruction and combined LET or ALLR were included with minimum 12 months follow-up. Studies that used the double-bundle technique were excluded. Outcome assessment included the number of positive pivot shifts, amount of anterior tibial translation, and International Knee Documentation Committee (IKDC) subjective, Tegner, and Lysholm scores. Bayesian NMA and the surface under the cumulative ranking area (SUCRA) were evaluated.

RESULTS

A total of 1,077 patients from 11 RCTs were enrolled in this study. In NMA, the odds ratios (ORs) of positive pivot shift were significantly lower in ACL + ALLR (OR: 0.17; 95% CI: 0.027-0.67) than isolated ACL reconstruction, but no difference between ACL + ALLR and ACL + LET. There were no significant differences in anterior tibial translation among the techniques, but the IKDC subjective and Lysholm scores of ACL + ALLR and ACL + LET were significantly higher than isolated ACL reconstruction. ACL + ALLR were the most preferred in terms of residual pivot shift, anterior tibial translation, and IKDC subjective scores (SUCRA = 88.2%, 86.4%, and 93.1%, respectively). Additional lateral procedures resulted in significantly lower risk of graft failure (OR: 0.27; 95% CI: 0.1-0.71) than isolated ACL reconstruction.

CONCLUSIONS

ACL + ALLR were found to have significantly better outcomes in terms of knee rotational stability and graft failure rate than isolated ACL reconstructions, but the clinical outcomes were uncertain after a minimum 12 months follow-up. Considering the greatest probability of obtaining better knee rotational stability in this NMA, ACL + ALLR was found to be the most preferred technique for patients with ACL injury.

LEVEL OF EVIDENCE

Level II, network meta-analysis and systematic review of Level I and II studies.

The anterolateral capsule is infrequently damaged as evaluated arthroscopically in patients undergoing anatomic ACL reconstruction

OBJECTIVES

Concomitant anterolateral complex (ALC) injury may contribute to persistent rotatory knee instability following anterior cruciate ligament (ACL) reconstruction. There is no consensus on how to best identify concomitant ALC injury preoperatively, nor how well ALC injury identified on imaging modalities correlates with clinical examination of knee instability. The purpose of this retrospective study was to determine the incidence of concomitant ALC injury in ACL-injured knees, as determined by arthroscopy to preoperative radiography, ultrasound, and MRI.

METHODS

A total of 117 patients with a unilateral primary ACL injury who underwent individualized anatomic ACLR between June 2016 and May 2019 were enrolled. Preoperative imaging modalities, including X-ray, ultrasound, and MRI, were evaluated for concomitant ALC injury. Clinical examination under anesthesia, including the anterior drawer, Lachman, and pivot shift tests were performed. Anterolateral capsule injury, as defined by hemorrhage and/or capsular tearing on diagnostic arthroscopy, was also determined. Correlative analyses of ALC injury incidence and severity were performed across imaging modalities and against clinical examination grades.

RESULTS

ALC injury incidence across imaging modalities was as follows: X-ray (3%), arthroscopy (19%), MRI (53%), and US (63%). The ALC injury rate on arthroscopy was significantly less than MRI (p < 0.001) or ultrasound (p < 0.001). ALC injury incidence and severity were significantly correlated between MRI and US grading scales (p = 0.02), but no correlations among other imaging modalities were found. Similarly, no imaging modality meaningfully correlated with physical examination maneuvers.

CONCLUSION

The incidence of ALC injury varies across imaging modalities, with lower injury rates found on arthroscopy (19%) compared to MRI (53%) and US (63%). Increasing ALC injury severity grades on imaging does not predict increasing anterolateral knee laxity on clinical examination.

LEVEL OF EVIDENCE

V, retrospective case series.

Combining Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Procedures in Skeletally Immature Patients Is Safe and Associated With a Low Failure Rate

Purpose

To analyze the rates of graft ruptures and growth disorders, the level of return to sport, and the clinical results of 2 lateral extra-articular procedures in growing children.

Methods

This study was a retrospective, single-center study of patients undergoing anterior cruciate ligament (ACL) surgery combined with 2 different lateral extra-articular procedures (anatomic reconstruction with a gracilis graft or modified Lemaire technique with a strip of fascia lata). The measurements of side-to-side anterior laxity and pivot shift were performed preoperatively and at the last follow-up. The sports level and the complications rate were assessed. The minimal clinically important differences (MCID) and patient acceptable symptoms state threshold scores were calculated.

Results

Thirty-nine patients (40 ACLs) were included (20 anatomic and 20 modified Lemaire) at an average follow-up of 57 months ± 10 [42-74]. One patient (2.5%) was lost to follow-up. The mean age at surgery was 13.8 ± 1.4 years old [9.8; 16.5]. One graft failure was reported (2.6% [0.06-13.5]) at 35.6 months after surgery. Two cases (5.4%) of femoral overgrowth were observed, and one of them required distal femoral epiphysiodesis. Ninety-two percent of the patients returned to sports. At the final follow-up, side-to-side anterior laxity was significantly improved, and no residual pivot shift was recorded in 95% of patients. Eighty-nine percent of the patients presented a Pedi-International Knee Documentation Committee score greater than the MCID postoperatively, and 77% presented a Lysholm score greater than the MCID.

Conclusions

This series of ACL reconstructions combined with 2 different lateral extra-articular procedures in skeletally immature patients demonstrated promising findings. The low rate of observed complications, including graft rupture and growth disturbance, is encouraging, but the small study population and lack of comparative group precludes reliable conclusions.

Level of Evidence

IV, therapeutic case series.

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

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

Preoperative excessive lateral anterior tibial subluxation is related to posterior tibial tunnel insertion with worse sagittal alignment after anterior cruciate ligament reconstructions

Objective

To investigate whether preoperative lateral anterior tibial subluxation (LATS) measured from magnetic resonance imaging (MRI) can influence tibial insertion and postoperative sagittal alignment after anterior cruciate ligament reconstructions (ACLRs).

Methods

84 patients who underwent single-bundle ACLRs were retrospectively investigated. Among them, 39 patients (LATS of <6 mm) 23 patients (LATS of ≥6 mm and <10 mm) and 22 patients (excessive LATS of ≥10 mm) were defined as group 1, 2 and 3, respectively. LATS, the position of graft insertion into tibia as ratio of anterior-posterior width (AP ratio) and the sagittal graft angle (SGA) were postoperatively assessed from MRI at 2-year follow-up. Following linear regression analyses were employed.

Results

The group 3 exhibited the largest preoperative LATS and remained the most postoperative LATS. Moreover, the group 3 possessed the most posteriorly located tunnel insertion with the largest AP ratio and the most vertical graft orientation. Of all included patients, a moderate correlation was demonstrated between pre- and postoperative LATS (r = 0.635). A low correlation was observed between preoperative LATS and AP ratio (r = 0.300) and a moderate correlation was displayed between AP ratio and SGA (r = 0.656).

Conclusion

For ACL injuries with excessive LATS (≥10 mm), most posteriorly located tibial insertion was found out, and worse sagittal alignment containing high residual LATS was associated with more vertical graft orientation following ACLRs.

Graft choices for anterolateral ligament knee reconstruction surgery: Current concepts

The anterolateral ligament (ALL) is a primary structure of the anterolateral complex of the knee that contributes to internal rotational stability of the joint. Injury of the ALL is commonly associated with rupture of the anterior cruciate ligament. If left untreated, ALL lesions may lead to residual anterolateral rotational instability of the knee after anterior cruciate ligament reconstruction, which is a common cause of anterior cruciate ligament graft failure. The function of the ALL can be restored by lateral extraarticular tenodesis or anterolateral ligament reconstruction (ALLR). In the lateral extraarticular tenodesis procedure, a strip of the iliotibial band is placed in a non-anatomical position to restrain the internal rotation of the tibia, while in ALLR, a free graft is fixed at the insertion points of the native ALL. Gracilis and semitendinosus grafts have mainly been utilized for ALLR, but other autografts have also been suggested. Furthermore, allografts and synthetic grafts have been applied to minimize donor-site morbidity and maximize the size and strength of the graft. Nevertheless, there has been no strong evidence to fully support one method over another thus far. The present review presents a detailed description of the graft choices for ALLR and the current literature available in regard to the effectiveness and outcomes of published surgical techniques.

Superior rotational stability and lower re-ruptures rate after combined anterolateral and anterior cruciate ligament reconstruction compared to isolated anterior cruciate ligament reconstruction: a 2-year prospective randomized clinical trial

PURPOSE

The purpose of the current prospective randomized clinical trial (RCT) was to compare the clinical outcomes of combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction with those of isolated ACL reconstruction and evaluate the re-rupture rate between the two study groups.

METHODS

This prospective RCT included 58 patients (43 men and 15 women) who underwent ACL reconstruction, either isolated (Group I: 26 patients) or combined with the ALL reconstruction (Group II: 32 patients). Preoperatively, the two groups differed in age and rate of medial meniscal injuries. The patients were evaluated preoperatively and postoperatively during the time points corresponding to 6 (T₁) weeks, 12 (T₂) weeks, 6 (T₃) months, 12 (T₄) months, and 24 (T₅) months. The evaluation included the clinical examination (comprising Lachman test, Pivot Shift test, Range of Motion, and Rolimeter differential anterior laxity), the objective clinical score (Objective IKDC [The International Knee Documentation Committee] score), and the subjective clinical scores (comprising Subjective IKDC score, Lysholm score, and Tegner activity score). The postoperative complications of all the patients were recorded.

RESULTS

Both the groups reported a significant improvement in clinical scores during the final follow-up as compared to the preoperative value (p < 0.05). The only differences between the two groups were observed with respect to the pivot shift test during each follow-up, wherein more patients from group I reported a pivot shift test grade I as compared to group II (p < 0.05). Three patients from group I reported a re-rupture of the operated knee, whereas no patients from group II reported new ruptures (p = 0.041).

CONCLUSIONS

Combined ACL and ALL reconstruction has proven to be more effective in obtaining a high grade of rotational knee stability during mid-term follow-up as compared to isolated ACL reconstruction along with a significantly lower rate of re-ruptures.

LEVEL OF EVIDENCE

Level I: Randomized Clinical Trial.

REGISTRATION

researchregistry5873: www.researchregistry.com.

Return to sports after ACL injury 5 years from now: 10 things we must do

Background

The outcome after ACL reconstruction (ACLR) is in general disappointing with unacceptable number of athletes that do not return to pre-injury level of sports, high re-injury rates, early development of osteoarthritis and shorter careers. Athletes after ACLR have high expectation to return to sports which is in contrast with the current outcomes. The aim of this manuscript is to present an overview of factors that are needed to be incorporated and to personalize the rehabilitation process for an athlete who has undergone an ACLR.

Level of evidence

4.

Anatomy, Biomechanics, and Reconstruction of the Anterolateral Ligament of the Knee Joint

Despite remarkable advances in the clinical outcomes after anterior cruciate ligament reconstructions (ACLRs), residual rotational instability of the knee joint remains a major concern. Since the anterolateral ligament (ALL) on the knee joint has been “rediscovered”, the role of anterolateral structures, including ALL and deep iliotibial band, as secondary stabilizers of anterolateral rotatory instability has gained interest. This interest has led to the resurgence of anterolateral procedures combined with ACLRs to restore rotational stability in patients with anterior cruciate ligament (ACL) deficiencies. However, the difference in concepts between anterolateral ligament reconstructions (ALLRs) as anatomical reconstruction and lateral extra-articular tenodesis (LETs) as non-anatomical reinforcement has been conflicting in present literature. This study aimed to review the anatomy and biomechanics of anterolateral structures, surgical techniques, and the clinical outcomes of anterolateral procedures, including LET and ALLR, in patients with ACL deficiencies.

Risk of Graft Rupture After Adding a Lateral Extra-articular Procedure at the Time of ACL Reconstruction: A Retrospective Comparative Study of Elite Alpine Skiers From the French National Team

BACKGROUND

Elite alpine skiing is associated with a particularly high risk of anterior cruciate ligament (ACL) injuries, including graft ruptures. Despite a considerable focus on prevention, a reduction in injury rates has not been observed since the 1980s.

PURPOSE

To determine whether elite alpine skiers undergoing ACL reconstruction (ACLR) with a lateral extra-articular procedure (LEAP) had a lower rate of ACL graft rupture when compared with those who underwent isolated ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Elite skiers from the French ski team who had undergone ACLR, with or without a LEAP, and had a minimum follow-up of 2 years were identified from the national ski team database. Rates of secondary ACL injury were determined via interrogation of the database, review of medical notes, and a final telemedicine interview. A multivariable analysis using the penalized Cox model was performed to explore the relationship among graft rupture, surgical procedure type, and any potential explanatory variables.

RESULTS

Among 81 ACLR procedures analyzed, 50 were isolated and 31 were combined with a LEAP, which was performed using modified Lemaire or anterolateral ligament reconstruction. Graft rupture rates were 34.0% in the isolated ACLR group and 6.5% in the ACLR + LEAP group. Multivariable analysis demonstrated that adding a LEAP was associated with a significant reduction in risk of ACL graft rupture when compared with isolated ACLR (hazard ratio [HR], 5.286 [95% CI, 1.068-26.149]; P = .0412). Age (HR, 1.114; P = .1157), sex (HR, 1.573; P = .3743), and ACL graft type (HR, 1.417; P = .5394) were not significant risk factors.

CONCLUSION

Combined ACLR and LEAP were associated with a significant reduction in the rate of ACL graft rupture in elite alpine ski athletes. Those treated with isolated ACLR remain at extremely high risk of a second ACL injury.

Anterolateral Structure Reconstruction Similarly Improves the Stability and Causes Less Overconstraint in Anterior Cruciate Ligament-Reconstructed Knees Compared With Modified Lemaire Lateral Extra-articular Tenodesis: A Biomechanical Study

PURPOSE

To compare the kinematics of anterolateral structure (ALS) reconstruction (ALSR) and lateral extra-articular tenodesis (LET) in ACL-ALS-deficient knees with anterior cruciate ligament (ACL) reconstruction.

METHODS

Ten fresh-frozen cadaveric knees with the following conditions were tested: (1) intact, (2) ACL-ALS deficiency, (3) ACL reconstruction (ACLR), (4) ACLR combined with ALSR (ACL-ALSR) or LET (ACLR+LET). Anterior translation and tibial internal rotation were measured with 90-N anterior load and 5 N·m internal torque at 0°, 30°, 60°, and 90°. The anterolateral translation and internal rotation were also measured during a simulated pivot-shift test at 0°, 15°, 30°, and 45°. The knee kinematic changes in all reconstructions were compared with each other, with intact knees as the baseline.

RESULTS

Isolated ACLR failed to restore native knee kinematics in ACL-ALS-deficient knees. Both ACL-ALSR and ACLR+LET procedures decreased the anterior instability of the ACLR. However, ACLR+LET caused overconstraints in internal rotation at 30° (-3.73° ± 2.60°, P = .023), 60° (-4.96° ± 2.22°, P = .001) and 90° (-6.14° ± 1.60°, P < .001). ACL-ALSR also overconstrained the knee at 60° (-3.65° ± 1.90°, P < .001) and 90° (-3.18° ± 2.53°, P < .001). For a simulated pivot-shift test, both combined procedures significantly reduced the ACLR instability, with anterolateral translation and internal rotation being overconstrained in ACLR+LET at 30° (-3.32 mm ± 3.89 mm, P = .005; -2.58° ± 1.61°, P < .001) and 45° (-3.02 mm ± 3.95 mm, P = .012; -3.44° ± 2.86°, P < .001). However, the ACL-ALSR overconstrained only the anterolateral translation at 30° (-1.51 mm ± 2.39 mm, P = .046) and internal rotation at 45° (-2.09° ± 1.70°, P < .001). There were no significant differences between the two combined procedures at most testing degrees in each testing state, except for the internal rotation at 30° (P = .007) and 90° (P = .032) in internal rotation torque.

CONCLUSION

ACL reconstruction alone did not restore intact knee kinematics in knees with concurrent ACL tears and severe ALS injury (ACL-ALS-deficient status). Both ACL-ALSR and ACLR+LET procedures restored knee stability at some flexion degrees, with less overconstraints in internal rotation resulting from ACL-ALSR.

CLINICAL RELEVANCE

For patients with combined ACL tears and severe ALS deficiency, isolated ACLR probably results in residual rotational and pivot-shift instability. Both ACL-ALSR and ACLR+LET show promise for the improvement of knee stability, whereas ACL-ALSR has less propensity for knee overconstraint.

Editorial Commentary: Anterior Cruciate Ligament Reconstruction Alone Is Not Sufficient in Anterolateral Complex Injury: Extra-Articular Augmentation (Lateral Extra-Articular Tenodesis [LET] or Anterolateral Ligament [ALL] Reconstruction) Allows Surgeons to Indicate Tight (LET) or Just Right (ALL) on a Case-by-Case Basis

Extra-articular augmentation has become an essential consideration in contemporary anterior cruciate ligament reconstruction (ACL) surgery. The verdict is still out on the extra-articular augmentation procedure of choice to accompany ACL surgery in the treatment of anterolateral rotatory instability. Anterolateral ligament reconstruction and lateral extra-articular tenodesis) are 2 common methods with clinical outcome data to support their use. Both procedures have demonstrated clinical effectiveness in reducing the rate of recurrent ACL tear/recurrent knee instability. Biomechanics studies to date have reached varied conclusions; however, a growing body of research including the study discussed here suggests both procedures enhance stability in the setting of surgical treatment of anterolateral rotatory instability, whereas ACL reconstruction alone is not sufficient in the setting of anterolateral complex injury. I suggest surgeons carefully consider when to augment ACL surgery with an extra-articular procedure and feel there is a place for both procedures. When extra constraint is indicated, I recommend lateral extra-articular tenodesis. When patient athletic demands may be lesser and a less-invasive procedure is indicated, anterolateral ligament augmentation of ACL reconstruction is my preference.

Lateral-extra articular tenodesis vs. anterolateral ligament reconstruction in skeletally immature patients undergoing anterior cruciate ligament reconstruction

PURPOSE OF REVIEW

The aim of this study was to review the most recent available evidence about lateral-extra articular tenodesis (LET) and anterolateral ligament (ALL) reconstruction in young patients treated for anterior cruciate ligament (ACL) injury.

RECENT FINDINGS

The ALL of the knee acts as a secondary stabilizer of the knee preventing anterior translation and internal rotation. In vitro and in vivo biomechanical studies as well as prospective clinical trials have shown the importance of the ALL in knee biomechanics. The ALL injury has a synergetic impact on the knee stability in patients with acute ACL injury. ALL augmentation of ACL provides reduction of knee instability and graft failure and higher return to sport rates in high-risk patients. It has not been demonstrated that extra-articular procedures increase the risk of knee osteoarthritis secondary to knee over-constriction. Both Iliotibial band (ITB) ALL reconstruction and modified Lemaire LET have been shown safe and effective. Minimal biomechanical or clinical differences have been found between the two reconstruction methods.

SUMMARY

Young patients with ACL tears and risk factors such as laxity or pivot shift willing to return to sports may benefit from ALL augmentation. Therefore, it is essential to identify these high-risk patients to individualize treatment.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Editorial Commentary: Timing of the Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction: Still a Debatable Issue

Anterior cruciate ligament (ACL) injuries frequently occur as the results of twisting injury of the knee. Accompanying damages to other structures at the time of injury determine the severity of the injury, subsequent surgical procedures, and hence, clinical outcomes. Anterolateral ligament (ALL) seems to act as a side-bar of the ACL rather than a major ligament that should be reconstructed separately. We should also consider the pros and cons of the adding ALL reconstruction procedures. There is insufficient evidence that can either support or refute that ALL plays an important role for knee stability. Determining the timing of the combined reconstruction is still a debatable issue, just like the efficacy of combined ACL and ALL reconstruction.

Editorial Commentary: This Is the Way: Extra-Articular Augmentation Is an Essential Consideration in Contemporary Anterior Cruciate Ligament Surgery

Since the rediscovery of the anterolateral ligament, extra-articular augmentation (EA) has evolved from controversial to an essential consideration in contemporary anterior cruciate ligament reconstruction surgery. Anterolateral ligament (ALL) reconstruction and lateral extra-articular tenodesis are 2 common methods. Indications among early adopters pioneering anterolateral ligament reconstruction at anterior cruciate ligament surgery included revision anterior cruciate ligament (ACL) case, chronic ACL tear, high-grade pivot shift, and patients with hyperlax, hypermobile knees. Newer indications include young patient age, pivoting sport/high-demand/high-risk athlete, and concurrent medial meniscus repair. Questions remain regarding best practices as indications continue to evolve regarding technique, graft choice, angle/position of reconstruction fixation, and whether EA should be reconstructed routinely. This fast-moving surgical evolution serves as a reminder of 2 key concepts; first, that anterior cruciate ligament tears occur more fundamentally in the setting of anterolateral rotatory instability, in which concurrent soft tissue injuries are common, and, second, that even our best "anatomic" reconstructions do not fully recapitulate the native ACL, both of which give impetus to reconstructing the ALL.