title: Anterior laxity and MR signals of the knee after exercise. A comparison of 9 normal knees and 6 anterior cruciate ligament reconstructed knees.
abstract: 9 healthy volunteers and 6 patients with anterior cruciate ligament (ACL) grafts underwent anterior knee laxity measurements and MRI examinations of their knees before and after intensive physical exercise. In the volunteer group, anterior displacement of the knee at 89 and 133 newtons of loading, measured with a KT-2000 knee arthrometer, increased after exercise, compared to before it. In addition, anterior terminal stiffness decreased at 133 newtons of anterior loading. In the ACL group, anterior displacement at 89 and 133 newtons of loading also increased, while no difference was found in anterior terminal stiffness before versus after exercise. On MRI, the signal intensity of normal ACLs after exercise was higher than before it. In contrast, the signals from the grafts showed no differences before versus after exercise. Our findings suggest that the ACL grafts are biomechanically and biochemically different from normal ACLs, even 15 months after ACL reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, Hiroshima University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sumen
authors.forename: M
authors.initials: M
authors.lastname: Ochi
authors.forename: N
authors.initials: N
authors.lastname: Adachi
authors.forename: Y
authors.initials: Y
authors.lastname: Urabe
authors.forename: Y
authors.initials: Y
authors.lastname: Ikuta
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D004548:Elasticity; D005081:Exercise Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009129:Muscle Tonus; D016059:Range of Motion, Articular; D013710:Tendons / Q000637:transplantation*; D013997:Time Factors; D014182:Transplantation, Autologous