title: Computer-assisted minimally invasive total knee arthroplasty compared with standard total knee arthroplasty. A prospective, randomized study.
abstract: BACKGROUND
  There is little information on the feasibility of computer navigation when using a minimally invasive approach for total knee arthroplasty, during which the anatomic landmarks for registration may be obscured. The purpose of the present study was to determine the radiographic accuracy of this technique and to compare the rate of functional recovery between patients who underwent computer-assisted minimally invasive arthroplasty and those who underwent conventional total knee arthroplasty.
  
  
  METHODS
  One hundred and eight consecutive patients were randomized to undergo computer-assisted minimally invasive total knee arthroplasty or conventional total knee arthroplasty. Perioperative pain management was standardized. The clinical parameters, long-leg radiographs, and functional assessment scores were evaluated for six months postoperatively.
  
  
  RESULTS
  Patients who underwent computer-assisted minimally invasive total knee arthroplasty had a significantly longer operative time (by a mean of twenty-four minutes) and a significantly shorter inpatient stay (3.3 compared with 4.5 days) in comparison with those who underwent conventional arthroplasty (p </= 0.001). Significantly more patients in the computer-assisted minimally invasive total knee arthroplasty group were able to walk independently for more than thirty minutes at one month (p = 0.04). The percentage of patients with a coronal tibiofemoral angle within +/-3 degrees of the ideal was 92% for the computer-assisted minimally invasive total knee arthroplasty group, compared with 68% for the conventional total knee arthroplasty group (p = 0.003).
  
  
  CONCLUSIONS
  Although specific clinical parameters reflect an early increased rate of functional recovery in association with computer-assisted minimally invasive total knee arthroplasty within the first postoperative month, the main advantage of this technique over conventional total knee arthroplasty is improved postoperative radiographic alignment without increased short-term complications.
authors.affiliation: Department of Orthopaedic Surgery, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074, Republic of Singapore. andrew_dutton@hotmail.com
authors.forename: Andrew Quoc
authors.initials: AQ
authors.lastname: Dutton
authors.forename: Seng-Jin
authors.initials: SJ
authors.lastname: Yeo
authors.forename: Kuang-Ying
authors.initials: KY
authors.lastname: Yang
authors.forename: Ngai-Nung
authors.initials: NN
authors.lastname: Lo
authors.forename: Kui-Un
authors.initials: KU
authors.lastname: Chia
authors.forename: Hwei-Chi
authors.initials: HC
authors.lastname: Chong
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000601:surgery*; D010149:Postoperative Pain / Q000503:physiopathology; D011336:Probability; D011446:Prospective Studies; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D025321:Surgery, Computer-Assisted / Q000379:methods*