title: Changes of knee joint and ankle joint orientations after high tibial osteotomy.
abstract: OBJECTIVE
  We sought to determine (1) whether change in the tibial plateau inclination (TPI) after high tibial osteotomy (HTO) is different from change in the knee joint line orientation (KJLO) relative to the ground; (2) whether, in varus knee OA patients before and after HTO, these radiographic measures are different from those in normal control; and (3) whether the postoperative values of the TPI and KJLO relative to the ground are associated with short term clinical outcome scores after HTO.
  
  
  METHODS
  Fifty patients who underwent HTO and 75 normal controls were assessed with four radiographic measures. We compared the measures before HTO with those after HTO and with those of the normal controls, then examined associations between the postoperative radiographic measures and clinical outcome scores 1-year after HTO.
  
  
  RESULTS
  After HTO, TPI increased 9.0°, whereas KJLO relative to the ground only increased 4.1°, with a compensatory change of the ankle joint line orientation. However, the postoperative KJLO relative to the ground in the HTO group was significantly different from that of the normal controls (mean difference, 4.9°; P < 0.001). In the multiple regression analyses, the postoperative radiographic measures were not associated with outcome clinical scores 1 year after HTO.
  
  
  CONCLUSIONS
  After HTO the relative KJLO changed significantly less than did the anatomical geometry of the proximal tibia. Although the KJLO after the HTO was still significantly different from that of normal knees, its value did not adversely affect clinical outcome scores 1 year after HTO.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea.
authors.forename: K M
authors.initials: KM
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, SMG-SNU Boramae Medical Center, Seoul, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea. Electronic address: drchuc@chol.com.
authors.forename: C B
authors.initials: CB
authors.lastname: Chang
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea.
authors.forename: M S
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Orthopaedic Surgery, SMG-SNU Boramae Medical Center, Seoul, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea.
authors.forename: S-B
authors.initials: SB
authors.lastname: Kang
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea.
authors.forename: T K
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea.
authors.forename: C Y
authors.initials: CY
authors.lastname: Chung
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010027:Osteotomy / Q000379:methods; D011184:Postoperative Period; D013977:Tibia / Q000601:surgery*
keywords: Ankle joint line orientation relative to the ground; High tibial osteotomy; Knee joint line orientation relative to the ground; Tibial plateau inclination