title: A cadaveric study of the anterolateral ligament: re-introducing the lateral capsular ligament.
abstract: OBJECTIVE
  The purpose of this study was to verify and characterize the anatomical properties of the anterolateral capsule, with the aim of establishing a more accurate anatomical description of the anterolateral ligament (ALL). Furthermore, microscopic analysis of the tissue was performed to determine whether the ALL can morphologically be classified as ligamentous tissue, as well as reveal any potential functional characteristics.
  
  
  METHODS
  Three different modalities were used to validate the existence of the ALL: magnetic resonance imagining (MRI), anatomical dissection, and histological analysis. Ten fresh-frozen cadaveric knee specimens underwent MRI, followed by anatomical dissection which allowed comparison of MRI to gross anatomy. Nine additional fresh-frozen cadaveric knees (19 total) were dissected for a further anatomical description. Four specimens underwent H&E staining to look at morphological characteristics, and one specimen was analysed using immunohistochemistry to locate peripheral nervous innervation.
  
  
  RESULTS
  The ALL was found in all ten knees undergoing MRI and all nineteen knees undergoing anatomical dissection, with MRI being able to predict its corresponding anatomical dissection. The ALL was found to have bone-to-bone attachment points from the lateral femoral epicondyle to the lateral tibia, in addition to a prominent meniscal attachment. Histological sectioning showed ALL morphology to be characteristic of ligamentous tissue, having dense, regularly organized collagenous bundles. Immunohistochemistry revealed a large network of peripheral nervous innervation, indicating a potential proprioceptive role.
  
  
  CONCLUSIONS
  From this study, the ALL is an independent structure in the anterolateral compartment of the knee and may serve a proprioceptive role in knee mechanics.
authors.affiliation: Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.|Fowler Kennedy Sport Medicine Clinic, 3M Centre, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Caterine
authors.affiliation: Fowler Kennedy Sport Medicine Clinic, 3M Centre, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Litchfield
authors.affiliation: Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Johnson
authors.affiliation: Department of Physics and Astronomy, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.
authors.forename: Blaine
authors.initials: B
authors.lastname: Chronik
authors.affiliation: Fowler Kennedy Sport Medicine Clinic, 3M Centre, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada. alan.getgood@uwo.ca.
authors.forename: Alan
authors.initials: A
authors.lastname: Getgood
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D017885:Collateral Ligaments / Q000033:anatomy & histology* / Q000502:physiology; D004210:Dissection; D005260:Female; D006801:Humans; D017746:Joint Capsule / Q000033:anatomy & histology* / Q000502:physiology; D007719:Knee Joint / Q000033:anatomy & histology* / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011434:Proprioception; D013977:Tibia / Q000033:anatomy & histology
keywords: ACL; Anterolateral ligament (ALL); Histology; Immunohistochemistry; Lateral capsular ligament; MRI