title: A historical perspective of PCL bracing.
abstract: OBJECTIVE
  Currently there are many functional knee braces but very few designed to treat the posterior cruciate ligament (PCL). No PCL braces have been biomechanically validated to demonstrate that they provide stability with proper force distribution to the PCL-deficient knee. The purpose of this review was to evaluate the history and current state of PCL bracing and to identify areas where further progress is required to improve patient outcomes and treatment options.
  
  
  METHODS
  A PubMed search was conducted with the terms "posterior cruciate ligament", "rehabilitation", "history", "knee", and "brace", and the relevant articles from 1967 to 2011 were analysed. A review of the current available PCL knee bracing options was performed.
  
  
  RESULTS
  Little evidence exists from the eight relevant articles to support the biomechanical efficacy of nonoperative and postoperative PCL bracing protocols. Clinical outcomes reported improvements in reducing PCL laxity with anterior directed forces to the tibia during healing following PCL tears. Biomechanics research demonstrates that during knee flexion, the PCL experiences variable tensile forces. One knee brace has been specifically designed and clinically validated to improve stability in PCL-deficient knees during rehabilitation. While available PCL braces demonstrate beneficial patient outcomes, they lack evidence validating their biomechanical effectiveness.
  
  
  CONCLUSIONS
  There is limited information evaluating the specific effectiveness of PCL knee braces. A properly designed PCL brace should apply correct anatomic joint forces that vary with the knee flexion angle and also provide adjustability to satisfy the demands of various activities. No braces are currently available with biomechanical evidence that satisfies these requirements.
  
  
  METHODS
  IV.
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Kyle S
authors.initials: KS
authors.lastname: Jansson
authors.forename: Kerry E
authors.initials: KE
authors.lastname: Costello
authors.forename: Luke
authors.initials: L
authors.lastname: O'Brien
authors.forename: Coen A
authors.initials: CA
authors.lastname: Wijdicks
authors.forename: Robert F
authors.initials: RF
authors.lastname: Laprade
mesh_terms: D001696:Biomechanical Phenomena; D001915:Braces; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000628:therapy*; D007718:Knee Injuries / Q000503:physiopathology / Q000628:therapy*; D007719:Knee Joint / Q000601:surgery; D016119:Posterior Cruciate Ligament / Q000293:injuries / Q000503:physiopathology* / Q000601:surgery