title: The influence of tibial morphology on the design of an anatomical tibial baseplate for TKA.
abstract: BACKGROUND
  Finding the right balance between tibial coverage and minimal implant overhang is an important factor in TKA. Another significant cause of failure is component malrotation.
  
  
  METHODS
  An average master shape of the proximal tibia at TKA resection level was calculated using fine slice computed tomographies of 117 cadaveric knees. To find out whether alternate implant contours would be necessary depending on the patient's body size, we established five subgroups to compare. CAD-Analysis was performed to simulate the overhang produced after ±4°/±7°/±10° rotation.
  
  
  RESULTS
  A master shape for the tibial resection cut (with a 5° posterior slope, 7 mm under lateral joint line) could be determined. Neither left vs. right knee joint, nor male vs. female nor the size subdivision appears to alter the calculated master shape significantly. The optimized shape allowing for ±4° of rotational freedom was found to be the best variant.
  
  
  CONCLUSIONS
  Valid methods have been obtained to design a two-dimensional average shape of the tibial plateau. The modifications described in this study might come in useful, when designing future implant designs.
  
  
  CONCLUSIONS
  An optimized fit at the tibial plateau and lower rates of component malrotation may result in better outcomes after TKA.
authors: Department of Trauma, Hand, and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Germany. Electronic address: mh@maxhartel.de.
authors: Maximilian J
authors: MJ
authors: Hartel
authors: Dr. h.c. Robert Mathys Foundation, Bettlach, Switzerland.
authors: Yannick
authors: Y
authors: Loosli
authors: Mathys Ltd, Bettlach, Switzerland.
authors: Daniel
authors: D
authors: Delfosse
authors: Department of Orthopedic Surgery, Inselspital, Bern University Hospital, Switzerland.
authors: Peter
authors: P
authors: Diel
authors: Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Switzerland.
authors: Michael
authors: M
authors: Thali
authors: Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Switzerland.
authors: Steffen
authors: S
authors: Ross
authors: Department of Orthopedic Surgery, Inselspital, Bern University Hospital, Switzerland.
authors: Sandro
authors: S
authors: Kohl
authors: Sonnenhof Orthopaedic Clinic, Swiss Leading Hospitals, Berne, Switzerland.
authors: Stefan
authors: S
authors: Eggli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D002102:Cadaver; D017076:Computer-Aided Design; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012399:Rotation; D013977:Tibia / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055815:Young Adult
keywords: Prosthesis design; Tibial component; Tibial plateau; Total knee arthroplasty (TKA)