title: The SPECT/CT Evaluation of Compartmental Changes after Open Wedge High Tibial Osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to evaluate compartmental changes using combined single-photon emission computerized tomography and conventional computerized tomography (SPECT/CT) after open wedge high tibial osteotomy (OWHTO) for providing clinical guidance for proper correction.
  
  
  METHODS
  Analysis was performed using SPECT/CT from around 1 year after surgery on 22 patients who underwent OWHTO. Postoperative mechanical axis was measured and classified into 3 groups: group I (varus), group II (0°-3° valgus), and group III (>3° valgus). Patella location was evaluated using Blackburne-Peel (BP) ratio. On SPECT/CT, the knee joint was divided into medial, lateral, and patellofemoral compartments and the brighter signal was marked as a positive signal.
  
  
  RESULTS
  Increased signal activity in the medial compartment was observed in 12 cases. No correlation was observed between postoperative mechanical axis and medial signal increase. Lateral increased signal activity was observed in 3 cases, and as valgus degree increased, lateral compartment's signal activity increased. Increased signal activity of the patellofemoral joint was observed in 7 cases, and significant correlation was observed between changes in BP ratio and increased signal activity.
  
  
  CONCLUSIONS
  For the treatment of medial osteoarthritis, OWHTO requires overcorrection that does not exceed 3 valgus. In addition, the possibility of a patellofemoral joint problem after OWHTO should be kept in mind.
authors.affiliation: Department of Orthopedic Surgery, Gacheon University Gil Medical Center, Incheon, Korea.
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Gacheon University Gil Medical Center, Incheon, Korea.
authors.forename: Byung Kag
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Gacheon University Gil Medical Center, Incheon, Korea.
authors.forename: Dong Whan
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Gacheon University Gil Medical Center, Incheon, Korea.
authors.forename: Jae Ang
authors.initials: JA
authors.lastname: Sim
authors.affiliation: Department of Orthopedic Surgery, The Armed Forces Capital Hospital, Seongnam, Korea.
authors.forename: Beom Koo
authors.initials: BK
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yong Seuk
authors.initials: YS
authors.lastname: Lee
keywords: Knee; Open wedge; Osteotomy; Single-photon emission computerized tomography