title: Cartilage health in high tibial osteotomy using dGEMRIC: Relationships with joint kinematics.
abstract: OBJECTIVE
  The aims of this study are to determine how opening-wedge high tibial osteotomy (HTO) affects cartilage health in the tibiofemoral (TF) joint and patella, and to explore relationships between TF and patellofemoral (PF) joint kinematics and cartilage health in HTO.
  
  
  METHODS
  14 knees (13 subjects) with medial TF osteoarthritis (OA) were examined before HTO and 6 and 12 months after HTO using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) to evaluate cartilage health at the TF joint and patella. They were also examined using a validated 3D MR knee kinematics measurement to obtain 11 rotations and translations at both TF and PF joints.
  
  
  RESULTS
  No statistically significant differences in overall TF or patellar dGEMRIC score were found at 6 or 12 months after HTO. However three subjects had large decreases (mean 105 ms) in TF dGEMRIC at 6 months that recovered at 12 months. Kinematics for these subjects were compared to subjects who did not have decreases in TF dGEMRIC at 6 months (n=5). Differences were observed between groups with HTO in anterior and proximal tibial translation (mean differences 3.05 mm and 1.35 mm), and patellar flexion (mean difference 3.65°). These changes were consistent between 6 and 12 months, despite recovery of TF dGEMRIC values.
  
  
  CONCLUSIONS
  We did not find significant differences in TF or patellar dGEMRIC before and after HTO with all subjects, however there were differences in kinematics between subjects who had a decrease in TF dGEMRIC at 6 months and those who did not. This suggests a link between joint kinematics and cartilage health in HTO.
  
  
  CONCLUSIONS
  The effect of opening-wedge high tibial osteotomy on cartilage GAG concentration may be linked to specific changes in knee kinematics following surgery.
authors.affiliation: Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4, Canada; Centre for Hip Health and Mobility, University of British Columbia, Robert H. N. Ho Research Centre, 2635 Laurel Street, Vancouver, BC V5Z 1M9, Canada; Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: agnes.dentremont@mech.ubc.ca.
authors.forename: Agnes G
authors.initials: AG
authors.lastname: d'Entremont
authors.affiliation: Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: robert.mcccormack@ubc.ca.
authors.forename: Robert G
authors.initials: RG
authors.lastname: McCormack
authors.affiliation: Department of Mechanical Engineering, University of British Columbia, 2054-6250 Applied Science Lane, Vancouver, BC V6T 1Z4, Canada; Centre for Hip Health and Mobility, University of British Columbia, Robert H. N. Ho Research Centre, 2635 Laurel Street, Vancouver, BC V5Z 1M9, Canada. Electronic address: kenard.agbanlog@gmail.com.
authors.forename: Kenard
authors.initials: K
authors.lastname: Agbanlog
authors.affiliation: Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: shorlick@vbjc.ca.
authors.forename: Simon G D
authors.initials: SG
authors.lastname: Horlick
authors.affiliation: Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: trevorbstone@hotmail.com.
authors.forename: Trevor B
authors.initials: TB
authors.lastname: Stone
authors.affiliation: Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: mojieb@gmail.com.
authors.forename: Mojieb M
authors.initials: MM
authors.lastname: Manzary
authors.affiliation: Centre for Hip Health and Mobility, University of British Columbia, Robert H. N. Ho Research Centre, 2635 Laurel Street, Vancouver, BC V5Z 1M9, Canada; Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada. Electronic address: david.wilson@ubc.ca.
authors.forename: David R
authors.initials: DR
authors.lastname: Wilson
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D057071:Patellofemoral Joint / Q000503:physiopathology / Q000601:surgery*; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery*
keywords: High tibial osteotomy; Joint kinematics; Knee; Osteoarthritis; dGEMRIC