title: Planned Bone Resections Using an MRI-Based Custom Cutting Guide System Versus 3-Dimensional, Weight-Bearing Images in Total Knee Arthroplasty.
abstract: Potential sources of alignment variability not yet investigated with the use of custom cutting guides (CCG) in total knee arthroplasty (TKA) are weight-bearing and lower extremity rotation. This study compared the preoperative planned bone resections created using an MRI-based CCG system to those from 3-dimensional, weight-bearing, full-length lower extremity images in 53 patients undergoing TKA. The angular difference between the proposed resections of the two systems was greater than 2° in 30.2% of patients for the distal femur, and 52.8% for the proximal tibia. An increased preoperative varus alignment had a slight association with an increased angular difference for the tibial resection (r=0.4). This study demonstrates weight-bearing and lower extremity rotation to be potential sources of alignment variability when using MRI-based CCGs.
authors.affiliation: Washington University School of Medicine/Barnes-Jewish Hospital, Department of Orthopedic Surgery, St. Louis, Missouri.
authors.forename: Denis
authors.initials: D
authors.lastname: Nam
authors.affiliation: Washington University School of Medicine/Barnes-Jewish Hospital, Department of Orthopedic Surgery, St. Louis, Missouri.
authors.forename: Brandon
authors.initials: B
authors.lastname: Williams
authors.affiliation: Washington University School of Medicine/Barnes-Jewish Hospital, Department of Orthopedic Surgery, St. Louis, Missouri.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Hirsh
authors.affiliation: Washington University School of Medicine/Barnes-Jewish Hospital, Department of Orthopedic Surgery, St. Louis, Missouri.
authors.forename: Staci R
authors.initials: SR
authors.lastname: Johnson
authors.affiliation: Washington University School of Medicine/Barnes-Jewish Hospital, Department of Orthopedic Surgery, St. Louis, Missouri.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Nunley
authors.affiliation: Washington University School of Medicine/Barnes-Jewish Hospital, Department of Orthopedic Surgery, St. Louis, Missouri.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Barrack
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005269:Femur / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D035002:Lower Extremity / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012189:Retrospective Studies; D012399:Rotation; D012984:Software; D013977:Tibia / Q000473:pathology / Q000601:surgery*; D016474:Weight-Bearing
keywords: alignment; custom cutting guides; rotation; total knee arthroplasty; weight-bearing