title: The effects of different hinge positions on posterior tibial slope in medial open-wedge high tibial osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to determine the standard hinge position to minimize effects from medial open-wedge high tibial osteotomy (HTO) on the posterior tibial slope.
  
  
  METHODS
  Sixteen cadaveric knees underwent medial open-wedge osteotomy using either the standard or the low hinge position. To define the standard hinge position, a line 3 cm inferior to the medial tibial plateau towards the fibular head and located its intersection with a longitudinal line 1 cm medial to the fibular shaft was drawn. Low hinge position was defined as the point 1 cm inferior to the standard position. After tibial osteotomy, computed tomography scans of each knee were taken and three-dimensional models were constructed to characterize hinge position orientation and measure the osteotomy site effects on posterior tibial slope, medial proximal tibial angle, and gap ratio (the ratio of the anterior to posterior gap in the opened wedge).
  
  
  RESULTS
  In two low hinge position specimens, the tibial lateral cortex hinge fracture occurred. Osteotomy through the low hinge position resulted in significantly greater posterior tibial slope compared to the standard hinge position (mean ± standard deviation) (11.2 ± 3.0° and 5.6 ± 2.5°, respectively; p < 0.001). Medial proximal tibial angle was also significantly greater for low compared to standard hinge position (95.4 ± 3.5° and 88.0 ± 3.5°, respectively; p < 0.001). Gap ratio was not significantly different between the two groups.
  
  
  CONCLUSIONS
  Hinge position significantly affects the posterior tibial slope and medial proximal tibial angle following medial open-wedge HTO. Accurate hinge position is crucial to prevent complications from changes in posterior tibial slope and medial proximal tibial angle after surgery.
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Ho-Seung
authors.initials: HS
authors.lastname: Jo
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Jin-Sung
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Oral and Maxillofacial Surgery, Gyeongsang National University School of Medicine and Gyeongsang National University, Jinju, Republic of Korea.
authors.forename: June-Ho
authors.initials: JH
authors.lastname: Byun
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Young-Bok
authors.initials: YB
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Young-Lac
authors.initials: YL
authors.lastname: Choi
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Seong-Hee
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Moon
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea.
authors.forename: Sang-Hyuk
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, 90 Chilamdong, Jinju, 660-702, Republic of Korea. hscspine@hanmail.net.
authors.forename: Sun-Chul
authors.initials: SC
authors.lastname: Hwang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000601:surgery; D010027:Osteotomy / Q000009:adverse effects* / Q000379:methods; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D013978:Tibial Fractures / Q000000981:diagnostic imaging* / Q000209:etiology; D014057:Tomography, X-Ray Computed
keywords: Hinge position; Medial open-wedge HTO; Osteoarthritis; Osteotomy