Anatomy of the anterolateral ligament of the knee joint

Despite remarkable improvements in clinical outcomes after anterior cruciate ligament reconstruction,the residual rotational instability of knee joints remains a major concern.The anterolateral ligament(ALL)has recently gained attention as a distinct ligamentous structure on the anterolateral aspect of the knee joint.Numerous studies investigated the anatomy,function,and biomechanics of ALL to establish its potential role as a stabilizer for anterolateral rotational instability.However,controversies regarding its existence,prevalence,and femoral and tibial insertions need to be addressed.According to a recent consensus,ALL exists as a distinct ligamentous structure on the anterolateral aspect of the knee joint,with some anatomic variations.The aim of this article was to review the updated anatomy of ALL and present the most accepted findings among the existing controversies.Generally,ALL originates slightly proximal and posterior to the lateral epicondyle of the distal femur and has an anteroinferior course toward the tibial insertion between the tip of the fibular head and Gerdy’s tubercle below the lateral tibial plateau.

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.

Clinical and mechanical outcomes in isolated anterior cruciate ligament reconstruction vs additional lateral extra-articular tenodesis or anterolateral ligament reconstruction

BACKGROUND Anterior cruciate ligament(ACL) reconstruction has been a successful treatment for ACL rupture.However ongoing rotational instability can be an issue.Several surgical techniques have been recommended to overcome this including lateral extra-articular tenodesis(LET) and more recently anterolateral ligament reconstruction(ALLR).AIM To compare the clinical outcomes following ACL reconstruction(ACLR) alone or ACLR with either LET or ALLR.METHODS A systematic review was conducted by means of four databases(MEDLINE,EMBASE,Cochrane and Clinical.Trials.Gov),and the Reference Citaion Analysis(https://www.referencecitationanalysis.com/) to identify all studies investigating either or both of LET and ALLR.The Critical Appraisal Skills Programme checklist for cohort studies was employed for critical appraisal and evaluation of all twenty-four studies which met the inclusion criteria.RESULTS Pooled meta-analyses illustrated that ACLR with additional LET or ALLR results in improved pivot shift test scores,compared to isolated ACLR.There was no statistically significant difference in International Knee Documentation Committee(IKDC) clinical scores with addition of either LET or ALLR.ACL re-rupture rates were compared between LET and ALLR techniques.There was a statistically significant difference between techniques,with a 1.14% rupture rate in ACLR +ALLR,and 4.03% rupture rate in ACLR + LET.Isolated ACLR re-rupture rates were 12.59%,significantly higher than when augmented with either ALLR or LET(P < 0.0001 for both groups).There were no statistical differences in pivot shift test or IKDC scores between LET and ALLR techniques.CONCLUSION This meta-analysis has found that use of either LET or ALLR in addition to ACLR results in improved mechanical outcomes suggesting surgeons should consider augmenting ACLR with an extra-articular procedure in patients with rotatory instability.Furthermore,both anterolateral extra articular procedures in addition to ACLR lead to reduced ACL re-rupture rates compared to isolated ACLR.Moreover,ALLR results in reduced ACL re-rupture rates,compared to LET.More research is needed to compare the two respective extra-articular procedures.

Overview of the anterolateral complex of the knee

In the last few years,much more information on the anterolateral complex of the knee has become available.It has now been demonstrated how it works in conjunction with the anterior cruciate ligament(ACL)controlling anterolateral rotatory laxity.Biomechanical studies have shown that the anterolateral complex(ALC)has a role as a secondary stabilizer to the ACL in opposing anterior tibial translation and internal tibial rotation.It is of utmost importance that surgeons comprehend the intricate anatomy of the entire anterolateral aspect of the knee.Although most studies have only focused on the anterolateral ligament(ALL),the ALC of the knee consists of a functional unit formed by the layers of the iliotibial band combined with the anterolateral joint capsule.Considerable interest has also been given to imaging evaluation using magnetic resonance and several studies have targeted the evaluation of the ALC in the setting of ACL injury.Results are inconsistent with a lack of association between magnetic resonance imaging evidence of injury and clinical findings.Isolated ACL reconstruction may not always reestablish knee rotatory stability in patients with associated ALC injury.In such cases,additional procedures,such as anterolateral reconstruction or lateral tenodesis,may be indicated.There are several techniques available for ALL reconstruction.Graft options include the iliotibial band,gracilis or semitendinosus tendon autograft,or allograft.