title: Biomechanical evaluation of a novel dynamic posterior cruciate ligament brace.
abstract: BACKGROUND
  Use of a rigid brace or cast immobilization is recommended in conservative treatment or postoperative rehabilitation after a posterior cruciate ligament injury. To prevent the loss of knee joint function and muscle activity often associated with this, a flexible knee brace has been developed that allows an adjustable anteriorly directed force to be applied to the calf in order to prevent posterior tibial translation. The purpose of this biomechanical study was to evaluate the impact of this novel dynamic brace on posterior tibial translation after posterior cruciate ligament injury and reconstruction.
  
  
  METHODS
  A Telos stress device was used to provoke posterior tibial translation in seven human lower limb specimens, and stress radiographs were taken at 90° of knee flexion. Posterior tibial translation was measured in the native knees with an intact posterior cruciate ligament; after arthroscopic posterior cruciate ligament dissection with and without a brace; and after posterior cruciate ligament reconstruction with and without a brace. The force applied with the brace was measured using a pressure sensor.
  
  
  RESULTS
  Posterior tibial translation was significantly reduced (P=0.032) after application of the brace with an anteriorly directed force of 50N to the knees with the dissected posterior cruciate ligament. The brace also significantly reduced posterior tibial translation after posterior cruciate ligament reconstruction in comparison with reconstructed knees without a brace (P=0.005).
  
  
  CONCLUSIONS
  Posterior tibial translation was reduced to physiological values using this dynamic brace system that allows an anteriorly directed force to be applied to the calf.
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: christian.heinrichs@i-med.ac.at.
authors.forename: Christian H
authors.initials: CH
authors.lastname: Heinrichs
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: werner.schmoelz@tirol-kliniken.at.
authors.forename: Werner
authors.initials: W
authors.lastname: Schmoelz
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: raul.mayr@tirol-kliniken.at.
authors.forename: Raul
authors.initials: R
authors.lastname: Mayr
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: alexander.keiler@tirol-kliniken.at.
authors.forename: Alexander
authors.initials: A
authors.lastname: Keiler
authors.affiliation: Department of Orthopaedic and Trauma Surgery, Isar Medical Center, Sonnenstrasse 24, 80331 Munich, Germany. Electronic address: p_schoettle@web.de.
authors.forename: Philip B
authors.initials: PB
authors.lastname: Schöttle
authors.affiliation: Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria. Electronic address: rene.attal@tirol-kliniken.at.
authors.forename: René
authors.initials: R
authors.lastname: Attal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059549:Anterior Cruciate Ligament Reconstruction / Q000534:rehabilitation*; D001696:Biomechanical Phenomena; D001915:Braces; D005260:Female; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007866:Leg / Q000503:physiopathology; D008875:Middle Aged; D016119:Posterior Cruciate Ligament / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery*; D013977:Tibia / Q000503:physiopathology
keywords: Brace; Orthopedic biomechanics; PCL reconstruction; Posterior cruciate ligament; Posterior tibial translation; Stress radiographs