title: Comparison of the change in patellar height between opening and closed wedge high tibial osteotomy: measurement with a new method.
abstract: OBJECTIVE
  The purposes of this study were to examine patellar height at preoperation and postoperation, and compare the change of patellar height between opening wedge high tibial osteotomy (HTO) and closed wedge HTO by using Insall-Salvati (IS) ratio and our original method.
  
  
  METHODS
  Twenty patients (26 knees) were included. There were 6 males (6 knees) and 14 females (20 knees). Sixteen knees underwent closed method and 10 knees underwent opening method. Patellar height was measured at preoperation, immediately after the operation (postoperation) and 1 year after the operation according to IS ratio and modified Blumensaat (MB) ratio. We defined MB ratio as the ratio of distance from Blumensaat line to the midpoint of patellofemoral joint of patella against the length of Blumensaat line.
  
  
  RESULTS
  In opening wedge HTO, though IS ratio significantly increased postoperatively compared with preoperative IS ratio, IS ratio at 1 year after operation was not significantly different from preoperative values. MB ratio at postoperation and that at 1 year after the operation significantly decreased compared with preoperative MB ratio. In closed wedge HTO, there was no difference between preoperative and postoperative values of both IS ratio and MB ratio.
  
  
  CONCLUSIONS
  In the postoperative period after opening wedge HTO, IS ratio was significantly increased, whereas MB ratio was decreased. We recommend that patients with low preoperative MB ratio must be treated with closed wedge HTO.
authors: Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan, mitsuruhanada@gmail.com.
authors: Mitsuru
authors: M
authors: Hanada
authors: Masaaki
authors: M
authors: Takahashi
authors: Hiroshi
authors: H
authors: Koyama
authors: Yukihiro
authors: Y
authors: Matsuyama
mesh_terms: D000328:Adult; D000368:Aged; D059925:Anatomic Landmarks; D001175:Arthrography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D010329:Patella / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D017847:Patellar Ligament / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D057071:Patellofemoral Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D018579:Patient Selection; D011184:Postoperative Period; D057234:Preoperative Period; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*
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