title: Influence of lateral meniscal posterior root avulsions and the meniscofemoral ligaments on tibiofemoral contact mechanics.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of lateral meniscal posterior root avulsions combined with intact meniscofemoral ligaments (MFLs), deficient MFLs, anterior cruciate ligament (ACL) tears and reconstructions, and root repairs using an established tibiofemoral contact mechanics testing protocol.
  
  
  METHODS
  Ten fresh-frozen cadaveric knees were tested with six knee conditions (1: intact; 2: lateral meniscal posterior root avulsion; 3: root avulsion and deficient MFLs; 4: condition 3 with ACL tear; 5: condition 4 with ACL reconstruction; 6: ACL reconstruction with root repair) at five flexion angles (0°, 30°, 45°, 60°, and 90°), under a 1000-N axial load. Contact area and pressure were measured with Tekscan sensors.
  
  
  RESULTS
  Compared to the intact state, condition 2 did not significantly change lateral compartment contact area or pressure. Changes in contact mechanics were greater at increased flexion angles; for condition 3 at 0° and 90°, contact area decreased 37 and 52 % [95 % CI (21-53) and (39-66), respectively] and mean contact pressure increased 55 and 87 % [95 % CI (33-76) and (59-114), respectively]. Root repair with ACL reconstruction was not significantly different from the intact state.
  
  
  CONCLUSIONS
  The MFLs protect the lateral compartment from changes in contact mechanics in the setting of a lateral meniscal posterior root avulsion, whereas a combination of lateral meniscal root avulsion and deficient MFLs leads to significant changes. Concurrent ACL reconstruction and lateral meniscal root repair restore mean contact pressure and area to the intact state and are recommended in this combined injury to prevent or slow the development of lateral compartment arthritis.
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA.|Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, USA.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Geeslin
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: David
authors.initials: D
authors.lastname: Civitarese
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Travis Lee
authors.initials: TL
authors.lastname: Turnbull
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Grant J
authors.initials: GJ
authors.lastname: Dornan
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Fuso
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA. drlaprade@sprivail.org.|The Steadman Clinic, 181 West Meadow Drive, Suite 400, Vail, CO, 81657, USA. drlaprade@sprivail.org.
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction; D001696:Biomechanical Phenomena; D002102:Cadaver; D005269:Femur / Q000503:physiopathology*; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology; D007719:Knee Joint / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000503:physiopathology*; D008297:Male; D008592:Menisci, Tibial / Q000503:physiopathology*; D008875:Middle Aged; D011312:Pressure; D016059:Range of Motion, Articular; D012421:Rupture; D013977:Tibia / Q000503:physiopathology*; D000070600:Tibial Meniscus Injuries / Q000503:physiopathology*
keywords: Contact area; Contact pressure; Lateral meniscal root tear; Meniscofemoral ligaments; Root repair; Tekscan pressure sensors