title: Hand-held navigation may improve accuracy in minimally invasive total knee arthroplasty: a prospective randomized controlled trial.
abstract: BACKGROUND
  A novel hand-held navigation combines gyroscopes, accelerometers and a secure local wireless channel to guide the distal femoral and proximal tibial cutting positions by displaying to the surgeon directly on the pods within the surgical field. No previous study has reported on its accuracy.
  
  
  METHODS
  A prospective randomized controlled trial was performed to compare radiographic outcomes in minimally invasive surgery total knee arthroplasty (MIS-TKA) with (40 patients, 40 knees) and without (40 patients, 40 knees) the novel hand-held navigation.
  
  
  RESULTS
  The use of hand-held navigation resulted in fewer outliers (> ± 3° malalignment) in all frontal alignment: the hip-knee-ankle, the femoral component, and the tibial component. Tibial slope was also better achieved with the navigation. Femoral component flexion was not significantly different. Operation time and bone cutting time with the navigation were not longer than those without. Blood loss from drainage was not significantly different.
  
  
  CONCLUSIONS
  The hand-held navigation improves accuracy for mechanical alignment and positioning of the prosthesis without additional surgical time.
authors.affiliation: Department of Orthopaedics, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, 681 Samsen Rd, Dusit, Bangkok, 10300, Thailand. satitthh@hotmail.com.
authors.forename: Satit
authors.initials: S
authors.lastname: Thiengwittayaporn
authors.affiliation: Department of Physical Medicine and Rehabilitation, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, 681 Samsen Rd, Dusit, Bangkok, 10300, Thailand.
authors.forename: Yupadee
authors.initials: Y
authors.lastname: Fusakul
authors.affiliation: Center of Calcium and Bone Research (COCAB), and Department of Physiology, Faculty of Science, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok, 10400, Thailand.
authors.forename: Nunnapat
authors.initials: N
authors.lastname: Kangkano
authors.affiliation: Department of Orthopaedics, Faculty of Medicine Vajira Hospital, Navamindradhiraj University, 681 Samsen Rd, Dusit, Bangkok, 10300, Thailand.
authors.forename: Chanintorn
authors.initials: C
authors.lastname: Jarupongprapa
authors.affiliation: Center of Calcium and Bone Research (COCAB), and Department of Physiology, Faculty of Science, Mahidol University, 272 Rama VI Road, Ratchathewi District, Bangkok, 10400, Thailand.
authors.forename: Narattaphol
authors.initials: N
authors.lastname: Charoenphandhu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013977:Tibia / Q000601:surgery
keywords: Accelerometers; Gyroscopes; Hand-held navigation; Minimally invasive surgery; Total knee arthroplasty