title: Clinical and radiographic outcomes of minimally invasive total knee arthroplasty through a lateral approach.
abstract: OBJECTIVE
  With increasing confidence and surgical experience, minimally invasive surgery (MIS) in total knee arthroplasty (TKA) is now being applied to more complicated cases. The present study assessed the feasibility of MIS-TKA using a lateral approach for valgus knees.
  
  
  METHODS
  Subjects comprised 26 patients with valgus knees who underwent MIS-TKA using a lateral subvastus approach. Five cases required a 1-cm snip of vastus lateralis obliquus, to shift the patella medially without eversion. Clinical scores and radiographic parameters of lateral MIS-TKA were examined and compared with those of 26 medial MIS-TKAs matched for preoperative patient characteristics.
  
  
  RESULTS
  The lateral MIS-TKA group showed slightly longer operative time and larger skin incision than the medial MIS-TKA group. Nevertheless, myoglobin index and pain on a visual analog scale on postoperative day 7 were significantly lower in the lateral MIS-TKA group than in the medial MIS-TKA group. Postoperative improvement of clinical scores was quite comparable between lateral and medial MIS-TKA groups. Radiographic assessment revealed that tibiofemoral mechanical axis aligned within ±3° from ideal in 24 of 26 patients after lateral MIS-TKA. MIS technique-related complications occurred in only 1 patient presenting with subsidence of the tibial component, due to malpositioning of the tibial component.
  
  
  CONCLUSIONS
  From the perspectives of postoperative pain, clinical scores, radiographic accuracy, and postoperative complication rate, lateral MIS-TKA achieved comparable or superior results to medial MIS-TKA. This technique may offer a promising technical option that can be utilized for most patients with valgus knee deformity.
authors.affiliation: Department of Orthopaedic Surgery, Keio University, 35, Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. y.niki@lib.bekkoame.ne.jp
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Niki
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hakozaki
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kanagawa
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Suda
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000601:surgery*; D010147:Pain Measurement; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000503:physiopathology / Q000601:surgery; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D016896:Treatment Outcome