title: A dynamic study of the anterior cruciate ligament of the knee using an open MRI.
abstract: Recent anatomical and radiological studies of the anterior cruciate ligament (ACL) suggest the ACL length and orientation change during knee flexion, and an open MRI sequencing during knee flexion enables a dynamic ACL analysis. This study's goal is to describe a normal ACL using a 1T open MRI and, in particular, variations in length and insertion angles at different degrees of flexion. Twenty-one volunteers with clinically healthy knees received a dynamic MRI with their knees in hyperextension, neutral position, and flexed at 45° and 90° angles. For each position, two radiologists measured the ACL lengths and angles of the proximal insertion between the ACL's anterior edge and the roof of the inter-condylar notch. Additionally, we measured the ACL's and the tibial plateau's distal angle insertion between their anterior edges and then compared these with the nonparametric Wilcoxon test. The ACL had a significant extension between the 90° flexion and all other positions (hyperextension: 31.75 ± 2.5 mm, neutral position: 32.5 ± 2.6 mm, 45°: 35.6 ± 1.6 mm, 90°: 35.6 ± 1.6 mm). There was also a significant increase of the angle insertion between the proximal 90° flexion and all other positions, as well as between hyperextension and bending to 45° (hyperextension: 2.45° ± 3.7°, neutral: 13.4° ± 9.7°, 45°: 33 25 ± 9.3, 90: 51.85° ± 9.3°). Additionally, there is a significant increase in the distal angle insertion for all positions (hyperextension: 133.2° ± 5.4°, neutral position: 134.95° ± 4.4°, 45°: 138.35° ± 5.9°, 90°: 149.15° ± 8.6°). Our study is the first to exhibit that a dynamic MRI has a significant ACL extension in vivo during bending. This concept opens the way for further studies to improve the diagnosis of traumatic ACL injuries using a dynamic MRI.
authors: Department of Radiology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France. Daphne.guenoun@ap-hm.fr.
authors: Daphne
authors: D
authors: Guenoun
authors: Department of Radiology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France.
authors: Julien
authors: J
authors: Vaccaro
authors: Department of Radiology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France.
authors: Thomas
authors: T
authors: Le Corroller
authors: Department of Radiology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France.
authors: Pierre-Antoine
authors: PA
authors: Barral
authors: Department of Anatomy, Aix Marseille Université, 13005, Marseille, France.
authors: Aude
authors: A
authors: Lagier
authors: Unité de Recherche EA3279, Santé Publique et Maladies Chroniques: Qualité de vie Concepts, Usages et Limites, Déterminants, Aix Marseille Université, 13005, Marseille, France.
authors: Vanessa
authors: V
authors: Pauly
authors: Department of Radiology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France.
authors: Benjamin
authors: B
authors: Coquart
authors: Department of Rheumatology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France.
authors: Joel
authors: J
authors: Coste
authors: Department of Radiology, Sainte-Marguerite Hospital, Institute for Locomotion, APHM, 13009, Marseille, France.
authors: Pierre
authors: P
authors: Champsaur
mesh_terms: D000328:Adult; D063405:Anatomic Variation; D016118:Anterior Cruciate Ligament / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D000070598:Anterior Cruciate Ligament Injuries / Q000000981:diagnostic imaging*; D001696:Biomechanical Phenomena; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D013977:Tibia / Q000033:anatomy & histology*; D055815:Young Adult
keywords: Anatomy; Anterior cruciate ligament; Dynamic MRI; Knee; Open field