Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (854 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
A strong ligament of the knee that originates from the posteromedial portion of the lateral condyle of the femur, passes anteriorly and inferiorly between the condyles, and attaches to the depression in front of the intercondylar eminence of the tibia.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Cruciate Ligament, Anterior; Anterior Cruciate Ligaments; Cruciate Ligaments, Anterior; Ligament, Anterior Cruciate; Ligaments, Anterior Cruciate; Anterior Cranial Cruciate Ligament; Cranial Cruciate Ligament; Cranial Cruciate Ligaments.
Where it fits in the MeSH classification
- Broader topics
- Ligaments, Articular
- See also
- Posterior Cruciate Ligament; Medial Collateral Ligament, Knee
Research landscape
PubMed indexes 13,295 records tagged with the MeSH heading “Anterior Cruciate Ligament” (counts retrieved 2026-10-31). 2,463 of them (18.5%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 4,906 records.
Reviews account for 1,401 records (10.5%) and meta-analyses for 163. Randomized controlled trials number 671 (5.0%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 2,088 |
| 2000-2009 | 3,838 |
| 2010-2019 | 4,906 |
| 2020 onward | 2,463 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,401 | 10.5% |
| Meta-analyses | 163 | 1.2% |
| Randomized controlled trials | 671 | 5.0% |
Method: PubMed query "Anterior Cruciate Ligament"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in anatomy and physiology
Anatomy describes how body structures are built and physiology describes how they normally work, so most findings here are descriptive or mechanistic rather than evidence about treatment. Much of what is known comes from dissection, imaging, tissue studies and experiments in animals, and measurements in healthy volunteers can differ from those in people with disease or at different ages. Normal ranges vary between individuals and populations. Check whether a result was measured in people or in another species, the age and health of the participants, and the method used.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture | 2019 | Review article Design not recorded in structured metadata | 271 | cc by PMID 31431274 · DOI · PMC6723618 |
| Muscle Force Contributions to Anterior Cruciate Ligament Loading | 2022 | Review article Design not recorded in structured metadata | 103 | cc by PMID 35437711 · DOI · PMC9325827 |
| Intraarticular Ligament Degeneration Is Interrelated with Cartilage and Bone Destruction in Osteoarthritis | 2019 | Review article Design not recorded in structured metadata | 77 | cc by PMID 31462003 · DOI · PMC6769780 |
| Interobserver variability in assessing anterior cruciate ligament anatomy: comparing gross and microanatomical observations | 2026 | Research article Design not recorded in structured metadata | 0 | cc by PMID 41649559 · DOI · PMC12881017 |
Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Anterior cruciate ligament (ACL) rupture occurs most commonly in young and active individuals and can have negative long-term physical and psychological impacts.
- Closing excerpt
- Finally, we define evidence-based rehabilitation and present phase-specific rehabilitation recommendations and criteria to inform return to sport decisions.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (150 words)
Anterior cruciate ligament (ACL) rupture occurs most commonly in young and active individuals and can have negative long-term physical and psychological impacts. The diagnosis is made with a combination of patient's history, clinical examination, and, if appropriate, magnetic resonance imaging. The objectives of management are to restore knee function, address psychological barriers to activity participation, prevent further injury and osteoarthritis, and optimize long-term quality of life. The three main treatment options for ACL rupture are (1) rehabilitation as first-line treatment (followed by ACL reconstruction (ACLR) in patients, who develop functional instability), (2) ACLR and post-operative rehabilitation as the first-line treatment, and (3) pre-operative rehabilitation followed by ACLR and post-operative rehabilitation. We provide practical recommendations for informing and discussing management options with patients, and describe patient-related factors associated with a worse ACL-rupture outcome. Finally, we define evidence-based rehabilitation and present phase-specific rehabilitation recommendations and criteria to inform return to sport decisions.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 31431274 · DOI · PMC6723618
Muscle Force Contributions to Anterior Cruciate Ligament Loading [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Anterior cruciate ligament (ACL) injuries are one of the most common knee pathologies sustained during athletic participation and are characterised by long convalescence periods and associated financial burden.
- Closing excerpt
- It is recommended that interventions aiming to reduce the risk of ACL injury consider specifically targeting the function of the hamstrings, soleus and gluteus medius.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (254 words)
Anterior cruciate ligament (ACL) injuries are one of the most common knee pathologies sustained during athletic participation and are characterised by long convalescence periods and associated financial burden. Muscles have the ability to increase or decrease the mechanical loads on the ACL, and thus are viable targets for preventative interventions. However, the relationship between muscle forces and ACL loading has been investigated by many different studies, often with differing methods and conclusions. Subsequently, this review aimed to summarise the evidence of the relationship between muscle force and ACL loading. A range of studies were found that investigated muscle and ACL loading during controlled knee flexion, as well as a range of weightbearing tasks such as walking, lunging, sidestep cutting, landing and jumping. The quadriceps and the gastrocnemius were found to increase load on the ACL by inducing anterior shear forces at the tibia, particularly when the knee is extended. The hamstrings and soleus appeared to unload the ACL by generating posterior tibial shear force; however, for the hamstrings, this effect was contingent on the knee being flexed greater than ~ 20° to 30°. The gluteus medius was consistently shown to oppose the knee valgus moment (thus unloading the ACL) to a magnitude greater than any other muscle. Very little evidence was found for other muscle groups with respect to their contribution to the loading or unloading of the ACL. It is recommended that interventions aiming to reduce the risk of ACL injury consider specifically targeting the function of the hamstrings, soleus and gluteus medius.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 35437711 · DOI · PMC9325827
Intraarticular Ligament Degeneration Is Interrelated with Cartilage and Bone Destruction in Osteoarthritis [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Osteoarthritis (OA) induces inflammation and degeneration of all joint components including cartilage, joint capsule, bone and bone marrow, and ligaments.
- Closing excerpt
- Facilitation of OA progression by changed biomechanics of degenerated ligaments should be addressed in more detail in the future.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (202 words)
Osteoarthritis (OA) induces inflammation and degeneration of all joint components including cartilage, joint capsule, bone and bone marrow, and ligaments. Particularly intraarticular ligaments, which connect the articulating bones such as the anterior cruciate ligament (ACL) and meniscotibial ligaments, fixing the fibrocartilaginous menisci to the tibial bone, are prone to the inflamed joint milieu in OA. However, the pathogenesis of ligament degeneration on the cellular level, most likely triggered by OA associated inflammation, remains poorly understood. Hence, this review sheds light into the intimate interrelation between ligament degeneration, synovitis, joint cartilage degradation, and dysbalanced subchondral bone remodeling. Various features of ligament degeneration accompanying joint cartilage degradation have been reported including chondroid metaplasia, cyst formation, heterotopic ossification, and mucoid and fatty degenerations. The entheses of ligaments, fixing ligaments to the subchondral bone, possibly influence the localization of subchondral bone lesions. The transforming growth factor (TGF)β/bone morphogenetic (BMP) pathway could present a link between degeneration of the osteochondral unit and ligaments with misrouted stem cell differentiation as one likely reason for ligament degeneration, but less studied pathways such as complement activation could also contribute to inflammation. Facilitation of OA progression by changed biomechanics of degenerated ligaments should be addressed in more detail in the future.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 31462003 · DOI · PMC6769780
Interobserver variability in assessing anterior cruciate ligament anatomy: comparing gross and microanatomical observations [4]
Abstract reading summary — source excerpts
- Opening excerpt
- PURPOSE: Most commonly, the ACL is described as having two distinct anatomical bundles: anteromedial and posterolateral.
- Closing excerpt
- This is, to our knowledge, the first study that has directly compared gross and microscopic observations of ACL bundle number.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (248 words)
PURPOSE: Most commonly, the ACL is described as having two distinct anatomical bundles: anteromedial and posterolateral. These bundles have been observed in a gross anatomical setting, but not as closely observed histologically. Here, we sought to compare observations of ACL bundle number when observed anatomically versus histologically to determine if the double bundle ACL is a reliably observed structure. METHODS: Nineteen knees were dissected to expose the intracapsular ligaments. Bundle number was assessed in three ways: Via gross anatomical observation, histological observation, and via the presence of a connective tissue septum when observed histologically. Inter-rater agreements were calculated for each of the three modes. Cronbach’s alpha was calculated to assess the consistency of double-bundle observations across all three modes of observation. RESULTS: Prevalence of a double-bundle ACL under gross observation was 68.4%. Inter-rater agreement was fair (Fleiss’s kappa = 0.202). Under histological observation, prevalence of a double-bundle ACL was 47.4%, with only 26.4% demonstrating a connective tissue septum that could be said to divide the ligament. CONCLUSION: These results suggest that the human ACL may exhibit more anatomical variation than has been previously appreciated in human cadaveric studies. Inter-rater agreement was fair, indicating that the demarcation of ACL bundles is not an obvious feature, even under gross observation. Additionally, our histological observations support the idea that ACL bundles exhibit substantial variation in terms of degree of distinct separation. This is, to our knowledge, the first study that has directly compared gross and microscopic observations of ACL bundle number.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41649559 · DOI · PMC12881017
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Arthroscopic anterior cruciate ligament reconstruction: a metaanalysis comparing patellar tendon and hamstring tendon autografts [5]
- Research article Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Outcomes for Quadriceps Tendon Autograft Versus Bone-Patellar Tendon-Bone and Hamstring-Tendon Autografts [6]
- Research article Hamstring Autograft versus Patellar Tendon Autograft for ACL Reconstruction: Is There a Difference in Graft Failure Rate? A Meta-analysis of 47,613 Patients [7]
- Research article Anatomy of the anterior cruciate ligament [8]
- Research article Osteoarthritis prevalence following anterior cruciate ligament reconstruction: a systematic review and numbers-needed-to-treat analysis [9]
- Research article Evidence-based rehabilitation following anterior cruciate ligament reconstruction [10]
References
- Filbay SR, Grindem H. Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture. . 2019. PMID 31431274 · DOI · PMC6723618
- Maniar N, Cole MH, Bryant AL, Opar DA. Muscle Force Contributions to Anterior Cruciate Ligament Loading. . 2022. PMID 35437711 · DOI · PMC9325827
- Schulze-Tanzil G. Intraarticular Ligament Degeneration Is Interrelated with Cartilage and Bone Destruction in Osteoarthritis. . 2019. PMID 31462003 · DOI · PMC6769780
- Reschenberg E, Ruth AA. Interobserver variability in assessing anterior cruciate ligament anatomy: comparing gross and microanatomical observations. . 2026. PMID 41649559 · DOI · PMC12881017
- Freedman KB, D'Amato MJ, Nedeff DD, Kaz A, Bach BR. Arthroscopic anterior cruciate ligament reconstruction: a metaanalysis comparing patellar tendon and hamstring tendon autografts. Am J Sports Med. 2003. PMID 12531750 · DOI
- Mouarbes D, Menetrey J, Marot V, Courtot L, Berard E, Cavaignac E. Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Outcomes for Quadriceps Tendon Autograft Versus Bone-Patellar Tendon-Bone and Hamstring-Tendon Autografts. Am J Sports Med. 2019. PMID 30790526 · DOI
- Samuelsen BT, Webster KE, Johnson NR, Hewett TE, Krych AJ. Hamstring Autograft versus Patellar Tendon Autograft for ACL Reconstruction: Is There a Difference in Graft Failure Rate? A Meta-analysis of 47,613 Patients. Clin Orthop Relat Res. 2017. PMID 28205075 · DOI · PMC5599382
- Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee Surg Sports Traumatol Arthrosc. 2006. PMID 16235056 · DOI
- Luc B, Gribble PA, Pietrosimone BG. Osteoarthritis prevalence following anterior cruciate ligament reconstruction: a systematic review and numbers-needed-to-treat analysis. J Athl Train. 2014. PMID 25232663 · DOI · PMC4264654
- van Grinsven S, van Cingel RE, Holla CJ, van Loon CJ. Evidence-based rehabilitation following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2010. PMID 20069277 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.