title: Kinematics and laxity of the knee joint after anterior cruciate ligament reconstruction: pre- and postoperative radiostereometric studies.
abstract: BACKGROUND
  Injury of the anterior cruciate ligament changes the kinematics of the knee joint. In studies of cadaveric knees, investigators have examined the effect of anterior cruciate ligament reconstruction on knee kinematics, but the effect on dynamic knee motion is not known.
  
  
  OBJECTIVE
  Reconstruction of the anterior cruciate ligament restores knee kinematics to normal.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Nine patients were examined preoperatively and 1 year after reconstruction. Continuous radiostereometric exposures were performed at a speed of two to four exposures per second while the patients ascended an 8-cm high platform. Tibial rotation and tibial and femoral translation were measured with radiostereometric analysis.
  
  
  RESULTS
  Tibial rotation and tibial and femoral translation were not significantly different after anterior cruciate ligament reconstruction compared with preoperative measurements. A radiostereometric evaluation of anterior knee laxity revealed restoration to within 1 mm of that on the uninjured side. Further evaluation of knee function using the Lysholm score, the Tegner activity level score, the International Knee Documentation Committee evaluation system score, and measurements of laxity using the KT-1000 arthrometer revealed significant improvements after reconstruction.
  
  
  CONCLUSIONS
  Kinematics of the anterior cruciate ligament injured knee did not change significantly after ligament reconstruction, but the functional results were satisfactory and knee laxity was diminished.
authors.affiliation: Department of Orthopaedics, Sahlgrenska University Hospital, SE-416 85 Göteborg, Sweden.
authors.forename: Sveinbjörn
authors.initials: S
authors.lastname: Brandsson
authors.forename: Jon
authors.initials: J
authors.lastname: Karlsson
authors.forename: Leif
authors.initials: L
authors.lastname: Swärd
authors.forename: Jüri
authors.initials: J
authors.lastname: Kartus
authors.forename: Bengt I
authors.initials: BI
authors.lastname: Eriksson
authors.forename: Johan
authors.initials: J
authors.lastname: Kärrholm
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D015331:Cohort Studies; D005260:Female; D005269:Femur / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*; D007718:Knee Injuries / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D010780:Photogrammetry; D011446:Prospective Studies; D016059:Range of Motion, Articular; D012421:Rupture; D013977:Tibia / Q000503:physiopathology; D016896:Treatment Outcome