title: Which Tibial Tray Design Achieves Maximum Coverage and Ideal Rotation: Anatomic, Symmetric, or Asymmetric? An MRI-based study.
abstract: Two goals of tibial tray placement in TKA are to maximize coverage and establish proper rotation. Our purpose was to utilize MRI information obtained as part of PSI planning to determine the impact of tibial tray design on the relationship between coverage and rotation. MR images for 100 consecutive knees were uploaded into PSI software. Preoperative planning software was used to evaluate 3 different tray designs: anatomic, symmetric, and asymmetric. Approximately equally good coverage was achieved with all three trays. However, the anatomic compared to symmetric/asymmetric trays required less malrotation (0.3° vs 3.0/2.4°; P < 0.001), with a higher proportion of cases within 5° of neutral (97% vs 73/77%; P < 0.001). In this study, the anatomic tibia optimized the relationship between coverage and rotation.
authors.affiliation: Northwestern Feinberg School of Medicine, Department of Orthopaedic Surgery, Chicago, Illinois; Northshore Orthopaedics, Chicago, Illinois.
authors.forename: S David
authors.initials: SD
authors.lastname: Stulberg
authors.affiliation: Northwestern Feinberg School of Medicine, Department of Orthopaedic Surgery, Chicago, Illinois.
authors.forename: Nitin
authors.initials: N
authors.lastname: Goyal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena / Q000502:physiology; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D007720:Knee Prosthesis; D007866:Leg / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012399:Rotation; D012984:Software; D013977:Tibia / Q000473:pathology* / Q000601:surgery*
keywords: coverage; implant design; rotation; tibial tray; total knee arthroplasty