Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament - deficient knee

Surgical indications for anterior cruciate ligament reconstruction combined with extra-articular lateral tenodesis or anterolateral ligament reconstruction

Recently described in the medical literature, the anterolateral ligament of the knee is already considered an important stabilizer against the anterolateral tibial rotation, affecting the pivot shift in the failure of the anterior cruciate ligament and behaving as an important secondary rotational stabilizer. The mechanism of anterolateral ligament injury combined with anterior cruciate ligament injury is similar to the mechanism of anterior cruciate ligament injury alone. Thus, the main objective of the joint reconstruction of anterior cruciate ligament and anterolateral ligament would be increased rotational control and prevention of anterior cruciate ligament re-rupture. In view of this importance, the aim of the present study is to summarize the evidence on the main surgical indications described for anterior cruciate ligament reconstruction combined with lateral extra-articular tenodesis or anterolateral ligament reconstruction. A review of the literature was conducted in April 2017, through a search of the PubMed, MEDLINE, Cochrane, and Google Scholar databases, with no date limits. After reviewing the main articles in the subject, it was concluded that the main surgical indications described for anterior cruciate reconstruction combined with extra-articular lateral tenodesis or anterolateral ligament reconstruction are: anterior cruciate ligament revision, physical examination with pivotal shift grade 2 or 3, practice of sport with pivot mechanism and/or high level mechanism, ligament laxity and Segond fracture; Secondly, the following may also be indications: chronic anterior cruciate ligament injury, age less than 25 years old, and radiological sign of lateral femoral condyle depression. However, it is worth mentioning that more studies are still needed to prove these trends.

Magnetic resonance imaging assessment of the normal knee anterolateral ligament in children and adolescents

OBJECTIVE

To characterize the anterolateral ligament (ALL) in normal knees of pediatric patients by magnetic resonance imaging (MRI) and to establish the age at which it is possible to visualize its presence and whether there are differences between male and female populations.

MATERIALS AND METHODS

MRI scans of patients younger than 18 years were retrospectively evaluated. The exams were performed in 1.5-T scanners. The ALL was characterized dichotomously as visualized or not visualized based on the assessment criteria of this structure in adult patients. The characterization of the ALL was divided according to sex and age.

RESULTS

A total of 363 knee MRI scans were evaluated, 200 from male and 163 from female patients. The ALL was more frequently visualized in coronal sequences. The mean ALL visualization in pediatric patients was 69.4% and was lower in younger patients and higher in patients close to 18 years. It was not possible to visualize the ALL in female patients younger than 7 years or in male patients younger than 6 years. In patients between 17 and 18 years of age, the ALL was visualized in 100% of cases in both sexes.

CONCLUSIONS

Visualization of the ALL increased with age in both sexes. Only after age 13 in females and age 15 in males was visualization of the ALL close to 70%; thus, below these ages, we believe that the characterization of this structure with conventional protocols is still imprecise.

A novel test for assessment of anterolateral rotatory instability of the knee: the tibial internal rotation test (TIR test)

Background

Rotational instability of the knee may persist after anterior cruciate ligament (ACL) reconstruction, which may be due to insufficiency of anterolateral stabilizing structures. However, no reliable diagnostic tool or physical examination test is available for identifying patients with anterolateral rotatory instability (ALRI). As shown in cadaveric studies, static internal rotation of the knee is increased in higher flexion angles of the knee after severing the anterolateral structures. This might also be the case in patients with an ACL-deficient knee and concomitant damage to the anterolateral structures. The objective of this study is to assess anterolateral rotatory instability of the knee during physical examination with a tibial internal rotation test.

Methods

ACL-injured knees of 52 patients were examined by two examiners and side-to-side differences were compared. Both lower legs were internally rotated by applying manual internal rotation torque to both feet in prone position with the knees in 30°, 60° and 90° of flexion. For quantification of the amount of rotation in degrees, a torque adapter on a booth was used. Intra-rater, inter-rater and rater-device agreement were determined by calculating kappa (κ) for the tibial internal rotation test.

Results

Tibial internal rotation is increased in 19.2% of the patients with ACL injury according to the tibial internal rotation test. Good intra-rater agreement was found for the tibial internal rotation test, κ_C = 0.63 (95%CI -0.02-1.28), p = 0.015. Fair inter-rater agreement was found, κ_F = 0.29 (95%CI 0.02–0.57), p = 0.038. Good rater-device agreement was found, κ_C = 0.62 (95%CI 0.15–1.10), p = 0.001.

Conclusion

The tibial internal rotation test shows increased tibial internal rotation in a small amount of patients with ACL injury. Even though no gold standard for assessment of increased tibial internal rotation of the knee is available yet, the test can be of additional value. It can be used for assessment of internal rotatory laxity of the knee as part of ALRI in addition to the pivot shift test. No clinical implications should yet be based on this test alone.

Electronic supplementary material

The online version of this article (10.1186/s40634-018-0141-9) contains supplementary material, which is available to authorized users.

Combined ACL reconstruction and Segond fracture fixation fails to abolish anterolateral rotatory instability

The Segond fracture (SF) is considered pathognomonic of an anterior cruciate ligament (ACL) tear. However, the anatomy of the soft-tissue attachments responsible for the avulsion of SFs has been a cause of controversy. A 31-year-old male patient presented with an injury to his right knee that resulted in ACL tear and a SF. Open SF fixation and arthroscopic ACL reconstruction were performed. The anatomical dissection demonstrated that the avulsion of SFs had occurred because of the tibial attachment of the anterolateral ligament (ALL) with an intact Iliotibial band. At 1-year postoperative follow-up, the ACL graft had restored anterior tibial translation to within normal limits. However, residual rotational knee laxity was observed. This finding highlights that patients with SF may be at increased risk of persistent instability after ACL reconstruction. Consideration should be given to recession of the fixation or augmentation of the ALL when dealing with this injury pattern.

Clinical Outcomes After Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction

Background

Graft rupture rate, return to sport and persistent rotational instability remain a concern postoperatively following anterior cruciate ligament (ACL) reconstruction. The anterolateral ligament (ALL) has recently been shown to act as a lateral knee stabilizer that helps improve rotational stability. To improve functional and clinical outcomes, a combined ACL reconstruction with an associated ALL reconstruction has been proposed.

Purpose

The main purpose of this study was to evaluate the clinical outcomes of the combined ACL and ALL reconstruction.

Methods

A literature search in PubMed was performed and papers reporting on clinical outcomes after combined ACL and ALL reconstruction were identified. The inclusion criteria was a minimum 2-year follow-up.

Results

Five studies were included in the review. The overall graft failure rate in patients with ACL and ALL reconstruction was <3% at 2 years minimum after surgery. Comparison analysis in a high-risk population demonstrated that the graft failure rate in combined ACL and ALL reconstruction was 2.5 times lower than with isolated bone-patella tendon-bone graft and 3.1 times lower than with isolated hamstring graft. The medial meniscal repair failure rate was also 2 times lower in the combined ACL and ALL reconstruction group compared with isolated ACL reconstruction. Return to sport and functional outcomes did not show any significant difference between the groups. The rate of reoperations was not increased in patients with combined ACL and ALL reconstruction.

Conclusions

Overall, combined ACL and ALL reconstruction provides promising results that may improve graft rupture rates and meniscal repair failure rates, while maintaining excellent functional outcomes.

Anterolateral Ligament (ALL) — Myth or Reality?

Although the anterolateral ligament (ALL) was described a long time ago, recent research shows a lot of interest regarding this structure. There is a high variability concerning its anatomy, especially its capsular/extracapsular situation and insertion sites. There is also some controversy about its ligamentous structure. It seems that it has a biomechanical role in restricting anterior tibial translation and internal rotation. The ALL complex seems to have a clinical significance, and a relationship with the pivot shift has been described. Although there are promising results recently, the surgical techniques of ALL reconstruction, in addition to anterior cruciate ligament reconstruction, have to be further investigated. A precise indication algorithm and patient selection criteria need to be established.