Anatomical Risk Factors for Rupture of the Anterior Cruciate Ligament:Magnetic Resonance Imaging Based Knee Joint Assessment

Anterior cruciate ligament (ACL) rupture is one of the most frequently encountered traumatic ligamentous lesions of the knee. Several intrinsic and extrinsic factors are linked to this lesion. Anatomical factors increase the anterior translation of the knee and thus promote the stretching and rupture of the anterior cruciate ligament. Objectives: To determine the anatomical risk factors favouring ACL rupture by comparing morphometric parameters of patients with knee ACL rupture to patients without ACL rupture, as well as the intercondylar notch index and the tibial slopes of the two groups and describing the ruptured ACLs and associated signs. Materials and Methods: We conducted a case-control descriptive analytical study in imaging centres of the General Henri Mondor of Aurillac Hospital Centre in France (CHM) and the Jordan Medical Centre of Yaoundé in Cameroon (CMJ). MRI exam protocols included T1 SE, T2 SE, proton density and Fat Sat sequences, with slices in all three planes. Morphometry knee variables measured in our study were: intercondylar notch index and the tibial slopes. These measurements were obtained from images stored in DICOM format and post processing software OsiriX MD®for CMJ patients and Explore®for CHM patients. Results: The study included 92 individuals, 38 in the case group and 54 in the control group. The mean age was 36.6 years for both groups;35.5 years for the cases and 37.4 years for the controls. The sex ratio was 1.87 men for 1 woman in both groups;2.16 men for 1 woman for the case group. 53% of ACL ruptures are partial, with the predominant direct sign being morphologic and signal abnormalities of the ACL. The most significant indirect sign of ACL rupture was mirror-image bone contusion that was observed in 47.3% of cases. In the case group, the mean lateral tibial slope was 4.003°, whereas it was 2.92°in the control group. The comparison of means was estimated at approximately 0.039 (p Conclusion: The increase in the lateral tibial slope was a risk factor for anterior cruciate ligament rupture in our study population. Intercondylar notch index and medial tibial slope did not show any statistical significant difference.

Biomechanics of the anterior cruciate ligament:Physiology,rupture and reconstruction techniques

The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.

Effect of suspension training on neuromuscular function, postural control, and knee kinematics in anterior cruciate ligament reconstruction patients

BACKGROUND Suspension training(SET)is a method of neuromuscular training that enables the body to carry out active training under unstable support through a suspension therapy system.However,there have been few reports in the literature on the application of SET to anterior cruciate ligament reconstruction(ACLR)patients.It is not clear what aspects of the patient's function are improved after SET.AIM To investigate the effect of SET on the neuromuscular function,postural control,and knee kinematics of patients after ACLR surgery.METHODS Forty participants were randomized to an SET group or a control group.The SET group subjects participated in a SET protocol over 6 wk.The control group subjects participated in a traditional training protocol over 6 wk.Isokinetic muscle strength of the quadriceps and hamstrings,static and dynamic posture stability test,and relative translation of the injured knee were assessed before and after training.RESULTS The relative peak torque of the quadriceps and hamstrings in both groups increased significantly(P<0.001),and the SET group increased by a higher percentage than those in the control group(quadriceps:P=0.004;hamstrings:P=0.011).After training,both groups showed significant improvements in static and dynamic posture stability(P<0.01),and the SET group had a greater change than the control group(P<0.05).No significant improvement on the relative translation of the injured knee was observed after training in either group(P>0.05).CONCLUSION Our findings show that SET promotes great responses in quadriceps and hamstring muscle strength and balance function in ACLR patients.

Patient reported outcome measures in anterior cruciate ligament rupture and reconstruction:The significance of outcome score prediction

BACKGROUND Numerous anterior cruciate ligament(ACL) clinical outcome measures exist.However,the result of one score does not equate to the findings of another even when evaluating the same patient group.AIM To investigate if statistically derived formulae can be used to predict the outcome of one knee scoring system when the result of another is known in patients with ACL rupture before and after reconstruction.METHODS Fifty patients with ACL rupture were evaluated using nine clinical outcome measures.These included Tegner Activity Score,Lysholm Knee Score,Cincinnati Knee Score,International Knee Documentation Committee(IKDC) Objective Knee Score,Tapper and Hoover Meniscal Grading Score,IKDC Subjective Knee Score,Knee Outcome Survey-Activities of Daily Living Scale(KOS-ADLS),Short Form-12 Item Health Survey and Knee Injury and Osteoarthritis Outcome Score.Thirtyfour patients underwent an ACL reconstruction and were reassessed post-operatively.RESULTS The mean total of each of the nine outcome scores appreciably differed from each other.Significant correlations and regressions were found between most of the outcome scores and were stronger post-operatively.The strongest correlation was found between Cincinnati and KOS-ADLS (r=0.91,P<0.001).The strongest regression formula was also found between Cincinnati and KOS-ADLS (R~2=0.84,P<0.001).CONCLUSION The formulae produced from this study can be used to predict the outcome of one knee score when the results of the other are known.These formulae could facilitate the conduct of systematic reviews and meta-analysis in studies relating to ACL injuries by allowing the pooling of substantially more data.

Five Strand Hamstring Tendon Autograft for Anterior Cruciate Ligament Reconstruction Provides No Benefit over the Gold Standard Four Strand Repair for Anterior Stability of the Knee: A Prospective Cohort Study

The Four-Strand Hamstring Tendon Autograft has been long established as the gold standard for surgical reconstruction of the Anterior Cruciate Ligament. Some studies have suggested wider grafts, such as a Five-Strand hamstring graft, may provide greater strength and a larger scaffold for incorporation of the graft into the bone tunnels, leading to greater postoperative anterior stability of the knee. 28 (n = 18 Four-Strand and n = 10 Five-Strand) patients with planned ACL reconstructive surgery by a single surgeon were recruited for this study. The KT-1000 Arthrometer (MED metric, CA, USA) was used to quantify AP translation in the subjects’ knees before (T0) and after surgery at 6 (T1) and 12 (T2) weeks. At 12 weeks there was significantly higher (p = 0.01) mean anterior laxity on Maximum Manual Test in the Five- Strand group (9.1 ± 1.7 mm) than the Four Strand Group (6.9 ± 2.3 mm). Further, there were significantly higher mean side-to-side differences (p = 0.01) on Maximum Manual Test in the Five-Strand cohort (5.1 ± 3.5 mm) compared to the Four-Strand cohort (1.9 ± 2.2 mm). A significantly larger positive mean change in anterior laxity (p = 0.02) from 6 - 12 weeks was evident in the Five-Strand group (1.4 ± 0.9) than the Four-Strand group (-0.3 ± 1.9 mm). No significant correlations were seen between graft widths and measures of anterior stability on KT-1000. This study illustrated that there was no benefit to using a Five-Strand Hamstring Tendon Autograft when compared to the gold standard Four-Strand Repair specifically with regards to anterior stability of the knee.

Lateral femoral tunnel preparation and graft fixation for anterior cruciate ligament reconstruction–A discussion

This article provides a discussion and commentary around the recent advances in arthroscopic anterior cruciate ligament reconstruction(ACLR),with a focus on the aspects of lateral femoral tunnel preparation and graft fixation techniques.The paper explores and comments on a recently published review by Dai et al,titled"Research progress on preparation of lateral femoral tunnel and graft fixation in ACLR",while providing insight into its relevance within the field of ACLR,and recommendations for future research.

Cyclops syndrome following anterior cruciate ligament reconstruction: Can relapse occur after surgery?

Symptomatic cyclops lesions are complications that can be seen at rates of up to approximately 10%after anterior cruciate ligament reconstruction.However,recurrent cyclops lesions have rarely been documented.There are case rare series in the literature regarding the treatment of recurrent cyclops lesion.Future large studies are needed to investigate factors contributing to the development of cyclops lesions and syndrome and treatment options.

Current practice variations in the management of anterior cruciate ligament injuries in Croatia

AIM: To investigate current preferences and opinions on the diagnosis, treatment and rehabilitation of patients with anterior cruciate ligament(ACL) injury in Croatia. METHODS: The survey was conducted using a questionnaire which was sent by e-mail to all 189 members of the Croatian Orthopaedic and Traumatology Association. Only respondents who had performed at least one ACL reconstruction during 2011 were asked to fill out the questionnaire. RESULTS: Thirty nine surgeons responded to the survey. Nearly all participants(95%) used semitendinosus/gracilis tendon autograft for reconstruction and only 5% used bone-patellar tendon-bone autograft. No other graft type had been used. The accessory anteromedial portal was preferred over the transtibial approach(67% vs 33%). Suspensory fixation was the most common graft fixation method(62%) for the femoral side, followed by the cross-pin(33%) and bioabsorbable interference screw(5%). Almost all respondents(97%) used a bioabsorbable interference screw for tibial side graft fixation. CONCLUSION: The results show that ACL reconstruction surgery in Croatia is in step with the recommendations from latest world literature.

Imaging of the anterior cruciate ligament

The anterior cruciate ligament(ACL)is an important structure in maintaining the normal biomechanics of the knee and is the most commonly injured knee ligament.However,the oblique course of the ACL within the intercondylar fossa limits the visualization and assessment of the pathology of the ligament.This pictorial essay provides a comprehensive and illustrative review of the anatomy and biomechanics as well as updated information on different modalities of radiological investigation of ACL,particularly magnetic resonance imaging.

The 45-Degree Arthroscope Improves Visualization of the Femoral Attachment of the Anterior Cruciate Ligament

Background: Exposure of the insertion site of the anterior cruciate ligament (ACL) is important for appropriate tunnel placement in ACL reconstruction surgery. However, observing the femoral ACL insertion site via the standard anterolateral portal is sometimes difficult. In this study, we compared views of the femoral ACL insertion site between 30-degree and the 45-degree arthroscopes. Methods: We first inserted the 30-degree and the 45-degree arthroscope into the anterolateral portal of a knee simulator in which we had drawn a lattice pattern on the lateral intercondylar notch based on the quadrant method. Next, we compared the arthroscopic views provided by the 30-degree and 45-degree arthroscopes during ACL reconstruction surgery by measuring the area of the lateral intercondylar notch visible through each of the arthroscopes. Results: In the knee simulator, the 45-degree arthroscope showed the entire area of the lateral intercondylar notch, whereas the 30-degree arthroscope had to be introduced more deeply to show the most superior and posterior quadrant, where the attachment of the anteromedial bundle of ACL is located. During the ACL reconstruction, the area of the lateral intercondylar notch in the field of view was larger through the 45-degree arthroscope than through the 30-degree arthroscope. Conclusion: The 45-degree arthroscope provides a better view of the femoral ACL insertion site via the anterolateral portal, which may be helpful during ACL reconstruction.

Osteoarthritis action alliance consensus opinion-best practice features of anterior cruciate ligament and lower limb injury prevention programs

AIM To identify best practice features of an anterior cruciate ligament(ACL) and lower limb injury prevention programs(IPPs) to reduce osteoarthritis(OA).METHODS This consensus statement started with us performing a systematic literature search for all relevant articles from 1960 through January 2017 in PubM ed, Web of Science and CINAHL. The search strategy combined the Medical Subject Heading(Me SH) and keywords for terms:(1) ACL OR "knee injury" OR "anterior cruciate ligament";(2) "prevention and control" OR "risk reduction" OR "injury prevention" OR "neuromuscular training"; and(3) meta-analysis OR "systematic review" OR "cohort study" OR randomized. We found 166 different titles. The abstracts were reviewed for pertinent papers. The papers were reviewed by at least two authors and consensus of best practice for IPP to prevent OA was obtained by conference calls and e-mail discussions. All authors participated in the discussion.RESULTS The best practice features of an IPP have the following six components:(1) lower extremity and core strengthening;(2) plyometrics;(3) continual feedback to athletes regarding proper technique;(4) sufficient dosage;(5) minimal-to-no additional equipment; and(6) balance training to help prevent injuries. Exercises focused on preventing ankle sprains, hamstring injuries and lateral trunk movements are important. Plyometric exercises should focus on correcting knee valgus movement.Exercises should focus on optimizing the hamstring to quadriceps strength ratio. In order for IPP to be successful, there should be increased education and verbal feedback along with increased athletic compliance. Additional equipment is not necessary. Balance training alone does not significantly reduce injuries, but is beneficial with other exercises. Not enough evidence to recommend stretching and agility exercises, with no ill effects identified. Therefore, we suggest making these optional features.CONCLUSION Best practice features for ACL and lower limb IPPs to help prevent OA contain six key components along with two optional.

Estimates of voluntary activation in individuals with anterior cruciate ligament reconstruction:Effects of type of stimulator,number of stimuli,and quantification technique

Background:Accurate quantification of voluntary activation is important for understanding the extent of quadriceps dysfunction in individuals with anterior cruciate ligament reconstruction(ACLR).Voluntary activation has been quantified using both percent activation derived from the interpolated twitch technique and central activation ratio(CAR)derived from the burst superimposition technique,as well as by using different types of electrical stimulators and pulse train conditions.However,it is unclear how these parameters affect voluntary activation estimates in individuals with ACLR.This study was performed to fill this important knowledge gap in the anterior cruciate ligament literature.Methods:Quadriceps strength and voluntary activation were examined in 18 ACLR participants(12 quadriceps/patellartendon graft,6 hamstring tendon graft;time since ACLR:1.06±0.82 years,mean±SD)at 90°of knee flexion using 2 stimulators(Digitimer and Grass)and pulse train conditions(3-pulse and 10-pulse).Voluntary activation was quantified by calculating both CAR and percent activation.Results:Results indicated that voluntary activation was significantly overestimated by CAR when compared with percent activation(p<0.001).Voluntary activation estimates were not affected by pulse train conditions when using percent activation;however,3-pulse stimuli resulted in greater overestimation than 10-pulse stimuli when using CAR(p=0.003).Voluntary activation did not differ between stimulators(p>0.05);however,the Digitimer evoked greater torque at rest than the Grass(p<0.001).Conclusion:These results indicate that percent activation derived from the interpolated twitch technique provides superior estimates of voluntary activation than CAR derived from burst superimposition and is less affected by pulse train conditions or stimulators in individuals with ACLR.

Demographic characteristics of patients who underwent anterior cruciate ligament reconstruction at a tertiary care hospital in India

BACKGROUND Anterior cruciate ligament(ACL)tears are common sports-related injuries.Their incidence is not the same either for all the sports or for the same sport across various nations.This information is maintained by many sports leagues in their registries.However,very few nationwide registries exist for such injuries.This study is carried out to know the demographic characteristics of patients who underwent ACL reconstruction at our hospital in India.AIM To know the demographic characteristics of patients who underwent ACL reconstruction at a tertiary care hospital in India.METHODS All the patients who underwent ACL reconstruction from January 2020 to December 2021 were retrospectively studied.Patients with multi-ligament injuries or a history of previous knee surgery were excluded.The patients’history was obtained from the hospital records,they were interviewed telephonically,and online questionnaires were given.Their demographic data was analyzed and compared to the existing literature.RESULTS A total of 124 patients were operated on for ACL reconstruction during this period.The mean age of the patients was 27.97 years.One hundred and thirteen patients(91.1%)were male and 11(8.9%)were female.The majority of the patients(47.6%)sustained this injury by road traffic accidents(RTA)followed by sportsrelated injuries(39.5%).The commonest presenting complaint was giving way of the knee in 118 patients(95.2%).The mean duration from the injury to the first hospital visit among the patients was 290.1 d.The mean duration from the injury to surgery was 421.8 d.CONCLUSION ACL patients’demography is different in developing nations as compared to the developed world.RTA are the leading cause of ACL injuries and are followed by recreational sports as a cause.There is delayed access to healthcare leading to delayed diagnosis as well as even greater time to surgery.This,in turn,leads to poorer prognosis and longer rehabilitation.National registries for developing nations are the need of the hour due to the different demographics of ACL injuries in developing countries.

Potential Association between Anterior Cruciate Ligament Tear and “Bi-Collateral” Ligamentous Rupture: A Retrospective Study

Background: Anterior cruciate ligament (ACL) tears are common complications of knee trauma. This entity can be reliably diagnosed by Magnetic Resonance Imaging. There is a lack of data on the epidemiology of ACL tears in Sub-Saharan Africa. The aim of this study is to describe the radiological aspects of post traumatic ACL tears in a black African setting (Yaounde Teaching Hospital). Methods: ninety six (96) MR studies of the knee were retrospectively reviewed. They were realized on a low field device (0.2T) from July 2012 to December 2013. All the examinations were indicated for knee trauma. Ligamentous, meniscal, bony and joint lesions were sought on coronal and sagittal sections. Results: the sample consists of 70% (68/96) of men. The mean age is 35.36 ± 11.86 years. The prevalence of ACL tears is 45.8% (44/96) of which 36 (81.81%, 36/44) are total tears. 23 (24%) have associated meniscal lesion and 8 (8.3%) have a simultaneous damage of the collateral ligaments. The most frequently injured part of the meniscus is its posterior horn (12/23 cases). Meniscal and “bi-collateral” ligament injuries are independently associated to ACL tears. Conclusion: The prevalence of ACL tears at the Yaounde Teaching Hospital is 45.8%. It is independently associated to meniscal tears and concomitant injury of the tibial and fibular collateral ligaments.

Consensus Delphi study on guidelines for the assessment of anterior cruciate ligament injuries in children

Background:Knee examination guidelines in minors are intended to aid decisionmaking in the management of knee instability.Clinical question:A Delphi study was conducted with a formal consensus process using a validated methodology with sufficient scientific evidence.A group consensus meeting was held to develop recommendations and practical guidelines for use in the assessment of instability injuries in children.Key findings:there is a lack of evidence to analyse anterior cruciate ligament injuries in children and their subsequent surgical management if necessary.Diagnostic guidelines and clinical assessment of the patient based on a thorough examination of the knee are performed and a guide to anterior cruciate ligament exploration in children is developed.Clinical application:In the absence of a strong evidence base,these established guidelines are intended to assist in that decision-making process to help the clinician decide on the most optimal treatment with the aim of benefiting the patient as much as possible.Following this expert consensus,surgical treatment is advised when the patient has a subjective sensation of instability accompanied by a pivot shift test++,and may include an anterior drawer test+and a Lachman test+.If these conditions are not present,the conservative approach should be chosen,as the anatomical and functional development of children,together with a physiotherapy programme,may improve the evolution of the injury.

Biomechanical Risk Assessment of Non-Contact Anterior Cruciate Ligament Injury in Taekwondo Athletes

Non-contact anterior cruciate ligament(ACL)injury can occur in many sports.It is interrelated with gender,anatomy,biomechanics,and neuromuscular control.Taekwondo athletes have a higher incidence of ACL injury than athletes from other sports.Objective:This study aimed to determine the biomechanical gender differences and mechanism of taekwondo athletes with ACL injury.Methods:A total of 28 taekwondo athletes(aged 14–19 years)were randomly selected and grouped by gender.Feet high floor,one foot high floor,and single leg squat were analyzed by a Vicon motion analysis system and Kistler 3D force platform for action.The knee joint angle and ground force were evaluated.Results:Results demonstrated biomechanical differences in knee joint between male and female athletes.Conclusion:ACL injury in taekwondo female athletes indicated the biomechanical mechanism of the knee joint,and it can be prevented by neuromuscular control training.

Mesenchymal stem cells and collagen patches for anterior cruciate ligament repair

AIM: To investigate collagen patches seeded with mesenchymal stem cells(MSCs) and/or tenocytes(TCs) with regards to their suitability for anterior cruciate ligament(ACL) repair. METHODS: Dynamic intraligamentary stabilization utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide?(CG) and Novocart?(NC). Cells were seeded onto the scaffolds and cultured for 7 d either as a pure populations or as "premix" containing a 1:1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts(0.4 μm). We analyzed the patches by real time polymerase chain reaction, glycosaminoglycan(GAG), DNA and hydroxyproline(HYP) content. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e., confocal laser scanning microscopy(c LSM) and scanning electron microscopy(SEM), were applied.RESULTS: CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and c LSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitativepolymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 d.CONCLUSION: CG and NC are both cyto-compatible with primary MSCs and TCs; TCs seemed to perform better on these collagen patches than MSCs.

Anterior cruciate ligament reconstruction using a double bundle hamstring autograft configuration in patients under 30 years

BACKGROUND Anterior cruciate ligament reconstruction(ACLR)has a high incidence of re-tear in younger patients.Despite comparable functional outcomes,the incidence of retear using single and double bundle ACLR methods has not been well reported.AIM To hypothesize that double bundle hamstring ACLR has a lower graft rupture rate compared with single bundle hamstring ACLR grafts in young patients.METHODS One hundred and twelve patients<30 years of age at the time of primary double bundle ACLR were eligible for study participation.91(81.3%)could be contacted,with a mean age of 20.4 years(range 13-29)and mean post-operative follow-up time of 59 mo(range 25-107).Telephone questionnaires evaluated the incidence(and timing)of subsequent re-tear and contralateral ACL tear,further surgeries,incidence and time to return to sport,and patient satisfaction.RESULTS Of the 91 patients,there were 6(6.6%,95%CI:1.4-11.7)ACL graft re-ruptures,with a mean time to re-rupture of 28 mo(range 12-84).Fourteen patients(15.4%)experienced a contralateral ACL rupture and 14 patients(15.4%)required further surgery to their ipsilateral knee.fifty patients(54.9%)returned to pre-injury level of sport.Of those<20 years(n=45),4 patients(8.9%,95%CI:0.4-17.3)experienced a re-rupture,with mean time to re-injury 15 mo(range 12-24).Comparative analysis with existing literature and revealed a non-significant Chisquared statistic of 2.348(P=0.125).CONCLUSION A trend existed toward lower graft rupture rates in young patients undergoing double bundle ACLR utilizing a hamstring autograft,compared with rates reported after single bundle ACLR.

Recurrent cyclops lesion after primary anterior cruciate ligament reconstruction using bone tendon bone allograft:A case report

BACKGROUND Cyclops lesions are a known complication of anterior cruciate ligament(ACL)reconstruction,with symptomatic cyclops syndrome occurring in up to 11%of surgeries.Recurrent cyclops lesions have been rarely documented;this case study documents the successful treatment of a recurrent cyclops lesion.CASE SUMMARY A 28-year-old female presented following a non-contact injury to the right knee.Workup and clinical exam revealed an ACL tear,and arthroscopic reconstruction was performed.Two years later a cyclops lesion was discovered and removed via arthroscopic synovectomy.Seven months postoperatively,the patient presented with pain,stiffness,and difficulty achieving terminal extension.A smaller recurrent cyclops lesion was diagnosed,and a repeat synovectomy was performed.The patient recovered fully.CONCLUSION To the best of our knowledge,this is the first documented case of recurrent cyclops lesion after bone-patellar tendon-bone allograft ACL reconstruction presenting as cyclops syndrome.

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.