title: Development of a pneumatic tensioning device for gap measurement during total knee arthroplasty.
abstract: BACKGROUND
  Despite the importance of soft tissue balancing during total knee arthroplasty (TKA), all estimating techniques are dependent on a surgeon's manual distraction force or subjective feeling based on experience. We developed a new device for dynamic gap balancing, which can offer constant load to the gap between the femur and tibia, using pneumatic pressure during range of motion.
  
  
  METHODS
  To determine the amount of distraction force for the new device, 3 experienced surgeons' manual distraction force was measured using a conventional spreader. A new device called the consistent load pneumatic tensor was developed on the basis of the biomechanical tests. Reliability testing for the new device was performed using 5 cadaveric knees by the same surgeons. Intraclass correlation coefficients (ICCs) were calculated.
  
  
  RESULTS
  The distraction force applied to the new pneumatic tensioning device was determined to be 150 N. The interobserver reliability was very good for the newly tested spreader device with ICCs between 0.828 and 0.881.
  
  
  CONCLUSIONS
  The new pneumatic tensioning device can enable us to properly evaluate the soft tissue balance throughout the range of motion during TKA with acceptable reproducibility.
authors.affiliation: Department of Anatomy, Catholic Institute for Applied Anatomy, The Catholic University of Korea School of Medicine, Seoul, Korea.
authors.forename: Dai-Soon
authors.initials: DS
authors.lastname: Kwak
authors.forename: Chae-Gwan
authors.initials: CG
authors.lastname: Kong
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Han
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
authors.forename: Yong
authors.initials: Y
authors.lastname: In
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena; D004867:Equipment Design; D005269:Femur / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000601:surgery*; D055595:Mechanical Phenomena; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D013977:Tibia / Q000601:surgery