title: Radiostereometric analysis of early anatomical changes following medial opening wedge high tibial osteotomy.
abstract: BACKGROUND
  The objective of this study was to use radiostereometric analysis (RSA) to evaluate the anatomical changes that occur in the tibia immediately after surgical correction with medial opening wedge high tibial osteotomy (HTO), and the changes that occur over the course of the first twelveweeks of osseous union.
  
  
  METHODS
  Patients included nine males and one female, with a mean age of 49.0 ± 5.5 years and mean BMI of 28.4 ± 3.8 kg/m(2). The patients underwent HTO using a non-locking plate. RSA marker beads were inserted in the tibia, femur, and patella. RSA exams were first obtained intra-operatively prior to the osteotomy, and subsequently at one, two, four, six, and twelveweeks postoperatively.
  
  
  RESULTS
  Patients were corrected from a mean alignment preoperatively of 8.6 ± 2.5° to 0.3 ± 1.9° postoperatively, with a mean osteotomy of 12.5 ± 3.6mm. Immediate tibia changes surrounding the osteotomy site included 9.2 ± 2.4° of valgus rotation and 6.2 ± 2.0mm of distal translation. Secondary motions included 2.5 ± 2.4° of internal rotation of the distal tibia, 1.8 ± 1.4mm of posterior movement of the femur, and 8.5 ± 3.4mm of patella baja. Micromotion between the proximal and distal tibial segments decreased over time.
  
  
  CONCLUSIONS
  The results suggest that subtle changes to the anatomy occur, beyond what is intended with the procedure, but partial corrections of these phenomena occurred over the twelveweeks. Micromotion surrounding the osteotomy site decreased with osseous union.
authors.affiliation: Department of Surgery, University of Western Ontario, London, ON, Canada. Electronic address: matthew.teeter@lhsc.on.ca.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Teeter
authors.affiliation: Wolf Orthopaedic Biomechanics Laboratory, Fowler Kennedy Sport Medicine Clinic, University of Western Ontario, London, ON, Canada.
authors.forename: Kristyn M
authors.initials: KM
authors.lastname: Leitch
authors.affiliation: Department of Orthopaedic Surgery, Centre Hospitalier de Luxembourg, Luxembourg.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Pape
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.
authors.forename: Xunhua
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Wolf Orthopaedic Biomechanics Laboratory, Fowler Kennedy Sport Medicine Clinic, University of Western Ontario, London, ON, Canada; School of Physical Therapy, Faculty of Health Sciences, University of Western Ontario, London, ON, Canada.
authors.forename: Trevor B
authors.initials: TB
authors.lastname: Birmingham
authors.affiliation: Department of Surgery, University of Western Ontario, London, ON, Canada; Wolf Orthopaedic Biomechanics Laboratory, Fowler Kennedy Sport Medicine Clinic, University of Western Ontario, London, ON, Canada.
authors.forename: J Robert
authors.initials: JR
authors.lastname: Giffin
mesh_terms: D000328:Adult; D000368:Aged; D001860:Bone Plates; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010027:Osteotomy / Q000379:methods; D059869:Radiostereometric Analysis / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D014182:Transplantation, Autologous
keywords: High tibial osteotomy; Radiostereometric analysis