Objective:To investigate the effect of early high-sucrose diet (eHSD) on cognitive function and its regulatory mechanism in 3×Tg-AD mice.Methods:(1) Eighteen specific-pathogen-free (SPF)-grade 2-month-old wide-type (WT) mice were randomly divided into a WT+normal chow diet (NCD) group and a WT+eHSD group, with 9 mice in each group; and 18 SPF-grade 2-month-old 3×Tg-AD mice were randomly divided into a 3×Tg-AD+NCD group and a 3×Tg-AD+eHSD group, with 9 mice in each group. At 2-5 months old, mice in the 4 groups received standard laboratory food+purified water or 30% sucrose water, followed by standard feed for all groups. At 8 months old, cognitive function was assessed by Morris water maze test; fluorescent intensity of AT8 (phosphorylated [p]-tau) and T22 (tau oligomers) in the hippocampal tissues was detected by immunofluorescent staining; concentrations of β-amyloid protein (Aβ) 42 and Aβ 40 were detected by enzyme-linked immunosorbent assay (ELISA); protein expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1), p-TBK1, and CCAAT/enhancer-binding protein β (C/EBPβ) were detected by Western blotting; activity of C/EBPβ transcription factor was detected by activity assay; mitochondrial DNA (mtDNA) content in the cytoplasm of cell was detected by real-time quantitative PCR (qPCR). (2) Eighteen SPF-grade 2-month-old 3×Tg-AD mice were randomized into a 3×Tg-AD+eHSD+H-151 group and a 3×Tg-AD+eHSD+dimethyl sulfoxide (DMSO) group, with 9 mice in each group. Mice at 2-5 months old were given standard laboratory food+30% sucrose water; they were, respectively, injected intraperitoneally with STING pathway inhibitor H-151 or DMSO at 5 months old, and continually injected until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, Western blotting and C/EBPβ transcription factor activity experiments were repeated as before. (3) After crossing C/EBPβ heterozygous knockout (C/EBPβ +/-) mice with 3×Tg-AD mice, 3×Tg-AD/C/EBPβ +/- mice were obtained, and 3×Tg-AD mice were used as controls; they were named 3×Tg-AD/C/EBPβ +/-+eHSD group and 3×Tg-AD+eHSD group, with 9 mice in each group. Both groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old, followed by standard feed until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. (4) C/EBPβ transgenic mice (C/EBPβTg) were crossed with 3×Tg-AD mice to obtain C/EBPβTg/3×Tg-AD mice, and Non-Tg/3×Tg-AD mice were used as controls; they were, respectively, named as C/EBPβTg/3×Tg-AD+eHSD+H-151 group, Non-Tg/3×Tg-AD+eHSD+H-151 group, and Non-Tg/3×Tg-AD+eHSD+DMSO group, with 9 mice in each group. All 3 groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old; at 5-8 months old, mice in the C/EBPβTg/3×Tg-AD+eHSD+H-151 group and Non-Tg/3×Tg-AD+eHSD+H-151 group were intraperitoneally injected with H-151, while mice in the Non-Tg/3×Tg-AD+eHSD+DMSO group were injected with DMSO; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. Results:(1) Compared with those in the WT+NCD group and WT+eHSD group, area under the latency curve of 3×Tg-AD+eHSD mice was significantly increased, and proportion of time spending in the targeted quadrant of mice in the 3×Tg-AD+NCD group and 3×Tg-AD+eHSD group was significantly decreased ( P<0.05); compared with that in the 3×Tg-AD+NCD group, proportion of time spending in the targeted quadrant in mice of the 3×Tg-AD+eHSD group was significantly reduced ( P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.076 vs. 2.902±0.399; T22 fluorescent intensity: 1.000±0.145 vs. 2.495±0.273; Aβ 42: 1.000±0.167 vs.1.956±0.132; Aβ 40: 1.000±0.226 vs.1.900±0.116), significantly increased C/EBPβ protein expression and C/EBPβ transcription factor activity (1.000±0.164 vs. 1.804±0.112; 1.000±0.216 vs. 2.743±0.301), and statistically increased mtDNA level detected by D-loop1 and D-loop3 (1.000±0.234 vs. 2.800±0.210; 1.000±0.155 vs. 2.952±0.078; P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.192 vs. 2.093±0.081; p-TBK1/TBK1: 1.000±0.148 vs. 1.561±0.112, P<0.05). (2) Compared with the 3×Tg-AD+eHSD+DMSO group, the 3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers expressions, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.142 vs. 0.538±0.057; T22 fluorescent intensity: 1.000±0.104 vs. 0.665±0.088; Aβ 42: 1.000±0.084 vs. 0.600±0.007; Aβ 40: 1.000±0.138 vs. 0.476±0.083), significantly decreased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.054 vs. 0.468±0.111; p-TBK1/TBK1: 1.000±0.057 vs. 0.598±0.090), and significantly decreased C/EBPβ transcription factor activity (1.000±0.097 vs. 0.445±0.106; P<0.05). (3) Compared with the 3×Tg-AD+eHSD group, the 3×Tg-AD/C/EBPβ +/-+eHSD group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.160 vs. 0.506±0.065; T22 fluorescent intensity: 1.000±0.127 vs. 0.346±0.048; Aβ 42: 1.000±0.017 vs. 0.510±0.101; Aβ 40: 1.000±0.098 vs. 0.586±0.153), and significantly decreased C/EBPβ protein expression (1.000±0.101 vs. 0.568±0.094; P<0.05). (4) Compared with the Non-Tg/3×Tg-AD+eHSD+DMSO group, the Non-Tg/3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, and significantly decreased p-tau and tau oligomers expressions, Aβ 40 concentration in the hippocampus, and the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly decreased STING protein expression and p-TBK1/TBK1 ratio in the hippocampus ( P<0.05). Compared with the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly increased area under the latency curve, significantly decreased proportion of time spending in the targeted quadrant, and significantly increased p-tau and tau oligomers expressions, Aβ 40 and Aβ 42 concentration in the hippocampus ( P<0.05). Conclusion:The eHSD aggravates cognitive impairment in 3×Tg-AD mice through activating cGAS-STING-C/EBPβ pathway.

Objective:To investigate the effect of early high-sucrose diet (eHSD) on cognitive function and its regulatory mechanism in 3×Tg-AD mice.Methods:(1) Eighteen specific-pathogen-free (SPF)-grade 2-month-old wide-type (WT) mice were randomly divided into a WT+normal chow diet (NCD) group and a WT+eHSD group, with 9 mice in each group; and 18 SPF-grade 2-month-old 3×Tg-AD mice were randomly divided into a 3×Tg-AD+NCD group and a 3×Tg-AD+eHSD group, with 9 mice in each group. At 2-5 months old, mice in the 4 groups received standard laboratory food+purified water or 30% sucrose water, followed by standard feed for all groups. At 8 months old, cognitive function was assessed by Morris water maze test; fluorescent intensity of AT8 (phosphorylated [p]-tau) and T22 (tau oligomers) in the hippocampal tissues was detected by immunofluorescent staining; concentrations of β-amyloid protein (Aβ) 42 and Aβ 40 were detected by enzyme-linked immunosorbent assay (ELISA); protein expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1), p-TBK1, and CCAAT/enhancer-binding protein β (C/EBPβ) were detected by Western blotting; activity of C/EBPβ transcription factor was detected by activity assay; mitochondrial DNA (mtDNA) content in the cytoplasm of cell was detected by real-time quantitative PCR (qPCR). (2) Eighteen SPF-grade 2-month-old 3×Tg-AD mice were randomized into a 3×Tg-AD+eHSD+H-151 group and a 3×Tg-AD+eHSD+dimethyl sulfoxide (DMSO) group, with 9 mice in each group. Mice at 2-5 months old were given standard laboratory food+30% sucrose water; they were, respectively, injected intraperitoneally with STING pathway inhibitor H-151 or DMSO at 5 months old, and continually injected until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, Western blotting and C/EBPβ transcription factor activity experiments were repeated as before. (3) After crossing C/EBPβ heterozygous knockout (C/EBPβ +/-) mice with 3×Tg-AD mice, 3×Tg-AD/C/EBPβ +/- mice were obtained, and 3×Tg-AD mice were used as controls; they were named 3×Tg-AD/C/EBPβ +/-+eHSD group and 3×Tg-AD+eHSD group, with 9 mice in each group. Both groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old, followed by standard feed until 8 months old; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. (4) C/EBPβ transgenic mice (C/EBPβTg) were crossed with 3×Tg-AD mice to obtain C/EBPβTg/3×Tg-AD mice, and Non-Tg/3×Tg-AD mice were used as controls; they were, respectively, named as C/EBPβTg/3×Tg-AD+eHSD+H-151 group, Non-Tg/3×Tg-AD+eHSD+H-151 group, and Non-Tg/3×Tg-AD+eHSD+DMSO group, with 9 mice in each group. All 3 groups of mice were given standard laboratory food+30% sucrose water at 2-5 months old; at 5-8 months old, mice in the C/EBPβTg/3×Tg-AD+eHSD+H-151 group and Non-Tg/3×Tg-AD+eHSD+H-151 group were intraperitoneally injected with H-151, while mice in the Non-Tg/3×Tg-AD+eHSD+DMSO group were injected with DMSO; and then, the behavioral testing, immunofluorescent staining, ELISA, and Western blotting experiments were repeated as before. Results:(1) Compared with those in the WT+NCD group and WT+eHSD group, area under the latency curve of 3×Tg-AD+eHSD mice was significantly increased, and proportion of time spending in the targeted quadrant of mice in the 3×Tg-AD+NCD group and 3×Tg-AD+eHSD group was significantly decreased ( P<0.05); compared with that in the 3×Tg-AD+NCD group, proportion of time spending in the targeted quadrant in mice of the 3×Tg-AD+eHSD group was significantly reduced ( P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.076 vs. 2.902±0.399; T22 fluorescent intensity: 1.000±0.145 vs. 2.495±0.273; Aβ 42: 1.000±0.167 vs.1.956±0.132; Aβ 40: 1.000±0.226 vs.1.900±0.116), significantly increased C/EBPβ protein expression and C/EBPβ transcription factor activity (1.000±0.164 vs. 1.804±0.112; 1.000±0.216 vs. 2.743±0.301), and statistically increased mtDNA level detected by D-loop1 and D-loop3 (1.000±0.234 vs. 2.800±0.210; 1.000±0.155 vs. 2.952±0.078; P<0.05). Compared with the 3×Tg-AD+NCD group, the 3×Tg-AD+eHSD group had significantly increased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.192 vs. 2.093±0.081; p-TBK1/TBK1: 1.000±0.148 vs. 1.561±0.112, P<0.05). (2) Compared with the 3×Tg-AD+eHSD+DMSO group, the 3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers expressions, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.142 vs. 0.538±0.057; T22 fluorescent intensity: 1.000±0.104 vs. 0.665±0.088; Aβ 42: 1.000±0.084 vs. 0.600±0.007; Aβ 40: 1.000±0.138 vs. 0.476±0.083), significantly decreased STING protein expression and p-TBK1/TBK1 ratio (STING: 1.000±0.054 vs. 0.468±0.111; p-TBK1/TBK1: 1.000±0.057 vs. 0.598±0.090), and significantly decreased C/EBPβ transcription factor activity (1.000±0.097 vs. 0.445±0.106; P<0.05). (3) Compared with the 3×Tg-AD+eHSD group, the 3×Tg-AD/C/EBPβ +/-+eHSD group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, significantly decreased p-tau and tau oligomers, Aβ 42 and Aβ 40 concentrations in the hippocampus (AT8 fluorescent intensity: 1.000±0.160 vs. 0.506±0.065; T22 fluorescent intensity: 1.000±0.127 vs. 0.346±0.048; Aβ 42: 1.000±0.017 vs. 0.510±0.101; Aβ 40: 1.000±0.098 vs. 0.586±0.153), and significantly decreased C/EBPβ protein expression (1.000±0.101 vs. 0.568±0.094; P<0.05). (4) Compared with the Non-Tg/3×Tg-AD+eHSD+DMSO group, the Non-Tg/3×Tg-AD+eHSD+H-151 group had significantly decreased area under the latency curve, significantly increased proportion of time spending in the targeted quadrant, and significantly decreased p-tau and tau oligomers expressions, Aβ 40 concentration in the hippocampus, and the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly decreased STING protein expression and p-TBK1/TBK1 ratio in the hippocampus ( P<0.05). Compared with the Non-Tg/3×Tg-AD+eHSD+H-151 group, the C/EBPβTg/3×Tg-AD+eHSD+H-151 group had significantly increased area under the latency curve, significantly decreased proportion of time spending in the targeted quadrant, and significantly increased p-tau and tau oligomers expressions, Aβ 40 and Aβ 42 concentration in the hippocampus ( P<0.05). Conclusion:The eHSD aggravates cognitive impairment in 3×Tg-AD mice through activating cGAS-STING-C/EBPβ pathway.

Anterior cruciate ligament (ACL) reconstruction is a standard treatment for ACL injuries, but it has drawbacks of a low rate of return to sports and a high incidence of osteoarthritis. In recent years, research has found that the proximal ACL tissue has a healing potential after injury. For patients who meet the indications for surgical repair, primary repair of ACL can achieve therapeutic effects comparable to ACL reconstruction, showing advantages of smaller trauma and preservation of the original ligament. Therefore, this surgical approach has received renewed attention and adoption, becoming an important supplement to ACL reconstruction. This article reviews the factors leading to the failure of previous open primary repair, and analyzes the current popularity of arthroscopic ACL primary repair. Moreover, it summarizes the surgical indications, repair procedures, rehabilitation, and return to sports of ACL primary repair, hoping to promote the clinical application of this surgical approach.

Objective:To compare the arthroscopic primary repair versus reconstruction for proximal anterior cruciate ligament (ACL) tears by a meta analysis.Methods:A comprehensive computer search was performed in China National Knowledge Infrastructure, WanFang Data, Pubmed, Web of Since, The Cochrane Library for studies comparing primary ACL repair and ACL reconstruction published before August, 2023. A meta-analysis was performed using RevMan 5.4 software to compare the surgical failure rate in repair of proximal ACL tears, International Knee Documentation Committee (IKDC) score, Lysholm score, patient satisfaction score of visual analogue scale (VAS), positive rate of Lachman test, and side-to-side difference in anterior tibial translation.Results:Included in this meta analysis were 8 articles (4 randomized controlled trials and 4 cohort studies) involving 217 eligible patients undergoing primary ACL repair and 187 eligible patients undergoing ACL reconstruction. The follow-up duration for the cases in the literature ranged from 12 to 28 months. The meta analysis showed that the short-term side-to-side difference in anterior tibial translation in the primary ACL repair group was significantly larger than that in the ACL reconstruction group ( MD=0.75, 95% CI: 0.33 to 1.16, P<0.001). However, there were no significant differences between the 2 groups in IKDC score, Lysholm score, positive rate in the Lachman test, VAS patient satisfaction score, or surgical failure rate ( P>0.05). Conclusions:Compared with ACL reconstruction, arthroscopic primary ACL repair may lead to similar functional recovery and clinical outcomes in the early postoperative period (12 to 28 months). However, caution should be exercised against primary ACL repair because it is related to greater asymptomatic knee laxity.

For patients with anterior cruciate ligament (ACL) injuries, arthroscopic anterior cruciate ligament reconstruction (ACLR) is the primary method to restore function. The positioning and creation of bone tunnels, graft selection, and fixation methods are crucial to the effectiveness of ACLR. Improper graft fixation can lead to bone tunnel enlargement, graft laxity, and ultimately, ACL reconstruction failure and revision. Thus, the graft fixation method is pivotal for ACLR. Over the past 40 years, significant progress has been made in ACLR under arthroscopy, leading to a more consistent surgical philosophy and more standardized surgical techniques. The most commonly used graft fixation methods are interference screws (IS) and adjustable-length loops (ALP). IS involves compression fixation within the bone tunnel, while ALP is a widely used cortical suspensory fixation method. Compared to IS, ALP offers advantages such as more secure fixation, higher strength, no graft damage, and promotion of tendon-bone healing. It also reduces the inflammatory response, minimizes bone tunnel enlargement, cortical bone membrane damage, and postoperative pain. Consequently, ALP has gained increasing attention and adoption in clinical practice. Currently, the fixation method on the femoral side has been generally unified, while the optimal fixation method on the tibial side remains controversial. Domestic guidelines suggest that both IS and ALP fixation are acceptable. However, surgeons should have a comprehensive understanding of each fixation method. This article systematically compares the clinical applications and research progress of IS and ALP fixation, providing clinicians with a more suitable choice for fixation method.

OBJECTIVE: To review the research progress of meniscus repair in recent years, in order to provide help for the clinical decision-making of meniscus injury treatment. METHODS: The domestic and foreign literature related to meniscal repair in recent years was extensively reviewed to summarize the reasons for the prevalence of meniscal repair, surgical indications, various repair methods and long-term effectiveness, the need to deal with mechanical structural abnormalities, biological enhancement repair technology, rehabilitation treatment, and so on. RESULTS: In order to delay the occurrence of osteoarthritis, the best treatment of meniscus has undergone an important change from partial meniscectomy to meniscal repair, and the indications for meniscal repair have been expanding. The mid- and long-term effectiveness of different meniscal repair methods are ideal. During meniscus repair, the abnormality of lower limb force line and meniscus protrusion should be corrected at the same time. There are controversies about the biological enhancement technology to promote meniscus healing and rehabilitation programs, which need further study. CONCLUSION Meniscal repair can restore the normal mechanical conduction of lower limbs and reduce the incidence of traumatic osteoarthritis, but the poor blood supply and healing ability of meniscal tissue bring difficulties to meniscal repair. Further development of new biological enhanced repair technology and individualized rehabilitation program and verification of its effectiveness will be an important research direction.
Humans ; Menisci, Tibial/surgery* ; Knee Joint/surgery* ; Meniscectomy/methods* ; Lower Extremity ; Osteoarthritis

Anterior cruciate ligament (ACL) injury is a common sports injury of the knee joint, which can lead to knee instability, dyskinesia and secondary traumatic osteoarthritis, which seriously affects the quality of life of patients. As it is difficult to self-heal after ACL injury, arthroscopic ACL reconstruction is commonly used as a clinical treatment to restore knee stability and motion function. However, more and more studies have found that bone tunnel enlargement is common after ACL reconstruction. A variety of biological (such as immunological rejection, local inflammation) and mechanical (such as offset bone tunnel positioning, improper graft fixation, and aggressive rehabilitation) factors are considered to be important causes of bone tunnel enlargement. It is still controversial whether the enlargement of bone tunnels affects clinical outcomes, but most researchers believe that the enlargement of bone tunnels is detrimental to the creation of bone tunnels and the fixation of grafts in revision surgery. Therefore, minimizing postoperative bone tunnel enlargement has positive clinical implications. The existing methods mainly include the selection of autografts, the use of independent bone tunnel positioning technology, modified bone tunnel drilling method, the use of remnant preservation technique and all-inside technique, the development of progressive individualized rehabilitation programs, and biological methods such as platelet-rich plasma and autogenous periosteum wrapping graft to enhance graft tendon-bone healing. This article reviews the causes and countermeasures of bone tunnel enlargement after ACL reconstruction to provide theoretical basis and help reduce or avoid bone tunnel enlargement after ACL reconstruction.

The anterior cruciate ligament (ACL) is one of the most crucial components to maintain knee joint stability and also the most vulnerable structure during knee-related sports activities. ACL injuries often cause knee instability, difficulty in returning to sports, and secondary degenerative knee disease. Although using autograft to reconstruct the ACL is currently a popular choice in clinical settings, it has drawbacks such as limited autograft source, donor site morbidity and delayed return to sports. Ligament advanced reinforcement system (LARS) artificial ligament possesses unique advantages such as wide availability, no donor-site morbidity, and early recovery, avoiding the problems associated with autograft reconstruction of ACL, and it has drawn increasing attention in recent years. In this paper, the authors reviewed the characteristics of LARS artificial ligament and its application in ACL reconstruction, so as to provide reference for clinical treatment of ACL injuries.

The anterior cruciate ligament (ACL) injury is a common sports injury, which can lead to the knee unstable, make it difficult for the patient to return to sports, and cause post-traumatic osteoarthritis. The difficulty of its clinical diagnosis and treatment has always been the focus of sports medicine research. In August 2022, the American Association of Orthopaedic Surgeons updated and published "evidence-based clinical practice guideline on management of ACL injuries (2022 version)" based on the "evidence-based clinical practice guideline on management of ACL injuries (2014 version)". In the prevention, diagnosis and treatment of ACL injuries, the new guideline offers 8 recommendations and 7 options according to different evidence strength. To assist clinicians in the diagnosis and treatment of ACL injuries, this article provides an interpretation of the new guideline. In comparison to the 2014 version, the new guideline does not recommend allografts any more, shortens the time for reconstruction after ACL injury from 5 months to 3 months, adds advice that ACL reconstruction can be combined with anterolateral ligament reconstruction or lateral extra-articular tenodesis, and does not recommend ACL repair. The new guideline also shares many similarities with the domestic "clinical evidence-based guideline for the diagnosis and treatment of anterior cruciate ligament injury (2022 version)", both of which advocate history and physical examination at diagnosis, early reconstruction, the use of autologous bone-patellar tendon-bone or hamstring tendon, and either single-bundle or double-bundle ACL reconstruction. The new ACL guidelines of the American Association of Orthopaedic Surgeons lack specific recommendations on artificial ligaments, techniques for bone tunnel creation, and rehabilitation programs, all of which are of concern to domestic physicians because they are based on evidence-based research from abroad. Therefore, in order to improve the diagnosis and treatment of ACL injuries in China, clinicians should not only follow the new ACL guidelines of the American Association of Orthopaedic Surgeons, but also combine the characteristics of Chinese patients, clinical practice, and pertinent domestic guidelines when diagnosing and treating ACL injuries.

Rupture of the anterior cruciate ligament (ACL) is one of the most frequent forms of knee sports injuries. Nowadays, ACL reconstruction is commonly performed to help patients restore their rotational stability. However, in patients with high risk factors, the risk of ACL reconstruction failure remains high, primarily because of continuous postoperative anterolateral rotational instability. This rotational instability after ACL reconstruction has prompted researchers to focus on the anterolateral complex of the knee, such as iliotibial tract and anterolateral ligament (ALL). Among them, ALL has remained largely unappreciated for more than a century since its discovery in 1879. Even though it is still controversial, most studies in recent years have supported the anterolateral ligament as an independent ligament and a crucial anatomical component for preserving the rotational stability of the knee joint. Although augmentation of the anterolateral complex has experienced twists and turns, the anatomic ALL reconstruction, which can be performed minimally invasively and has a low risk of complications and minimal injury, is reappearing as a key strategy to address this problem. Currently, the majority of scholars believe that the need for combined ALL reconstruction during ACL reconstruction should be taken into account when there is severe rotational instability present, such as high-grade pivot shift test preoperatively, ACL revision surgery, and high requirements for rotational stability, such as age less than 25 years and the need to participate in pivoting sports. The corresponding suggested criteria are also put forth in the authoritative consensus of both domestic and foreign sources. However, the surgical indications chosen by different experts based on their individual experiences are not all consistent. Due to conflicting reports on the actual impact of ALL reconstruction on improving rotational stability and whether it will excessively restrict knee's internal rotation function, there is still much debate among researchers regarding whether ALL reconstruction and ACL reconstruction should be combined. Currently, there are two main reconstruction techniques: ALL single bundle reconstruction and Y-construct ALL double bundle reconstruction. Y-construct ALL double bundle reconstruction has a better ability to restore the original anatomy and is recommended in the consensus, but there is still a lack of randomized controlled trials between the two techniques. Therefore, the combination of ALL reconstruction at the time of ACL reconstruction has been clinically started in recent years for patients who are susceptible to failure after ACL reconstruction, which also raises many controversies.