title: Radiologic Outcomes According to Varus Deformity in Minimally Invasive Surgery Total Knee Arthroplasty.
abstract: OBJECTIVE
  To identify the accuracy of postoperative implant alignment in minimally invasive surgery total knee arthroplasty (MIS-TKA), based on the degree of varus deformity.
  
  
  METHODS
  The research examined 627 cases of MIS-TKA from November 2005 to December 2007. The cases were categorized according to the preoperative degree of varus deformity in the knee joint in order to compare the postoperative alignment of the implant: less than 5° varus (Group 1, 351 cases), 5° to less than 10° varus (Group 2, 189 cases), 10° to less than 15° varus (Group 3, 59 cases), and 15° varus or more (Group 4, 28 cases).
  
  
  RESULTS
  On average, the alignment of the tibial implant was 0.2±1.4°, 0.1±1.3°, 0.1±1.6°, and 0.3±1.7° varus, and the tibiofemoral alignment was 5.2±1.9degrees, 4.7±1.9°, 4.9±1.9°, and 5.1±2.0° valgus for Groups 1, 2, 3, and 4, respectively, in the preoperative stage, indicating no difference between the groups (p>0.05). With respect to the accuracy of the tibial implant alignment, 98.1%, 97.6%, 87.5%, and 86.7% of Groups 1, 2, 3, and 4, respectively, had 0±3° varus angulation, demonstrating a reduced level of accuracy in Groups 3 and 4 (p<0.0001). There was no difference in terms of tibiofemoral alignment, with 83.9%, 82.9%, 85.4%, and 86.7% of each group, respectively, showing 6±3° valgus angulation (p>0.05).
  
  
  CONCLUSIONS
  Satisfactory component alignment was achieved in minimally invasive surgery in total knee arthroplasty, regardless of the degree of varus deformity.
authors.affiliation: Department of Orthopedic Surgery, National Health Insurance Service, Ilsan Hospital, Goyang, Korea.
authors.forename: Ju Hyung
authors.initials: JH
authors.lastname: Yoo
authors.affiliation: Department of Orthopedic Surgery, National Health Insurance Service, Ilsan Hospital, Goyang, Korea. orthomania@gmail.com.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Orthopedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chang Dong
authors.initials: CD
authors.lastname: Han
authors.affiliation: Department of Orthopedic Surgery, National Health Insurance Service, Ilsan Hospital, Goyang, Korea.
authors.forename: Hyun Cheol
authors.initials: HC
authors.lastname: Oh
authors.affiliation: Department of Orthopedic Surgery, National Health Insurance Service, Ilsan Hospital, Goyang, Korea.
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Orthopedic Surgery, National Health Insurance Service, Ilsan Hospital, Goyang, Korea.
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Choi
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D060750:Bone Anteversion / Q000150:complications / Q000000981:diagnostic imaging*; D017760:Bone Malalignment / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D016916:Joint Deformities, Acquired / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D011184:Postoperative Period; D057234:Preoperative Period; D011859:Radiography; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery; D016896:Treatment Outcome
keywords: Minimally invasive total knee arthroplasty; lower limb alignment; varus deformity