title: Medial Open-Wedge High Tibial Osteotomy May Adversely Affect the Patellofemoral Joint.
abstract: OBJECTIVE
  To evaluate 2-stage arthroscopic findings of the patellofemoral joint before and after medial open-wedge high tibial osteotomy (HTO) and verify whether the patellofemoral joint would be influenced by medial open-wedge HTO.
  
  
  METHODS
  We prospectively reviewed 114 cases of medial open-wedge HTO for the treatment of osteoarthritis with a varus knee. First-look arthroscopy was performed during HTO. The mean age at the time of HTO was 56.34 ± 5.4 years (range, 40-69 years). Second-look arthroscopy was performed concomitantly with plate removal at an average of 26.1 ± 6.0 months (range, 21.6-32.0 months) after HTO. We assessed the patellofemoral joint using the International Cartilage Repair Society (ICRS) grading system by first- and second-look arthroscopy and compared it before and after HTO. Postoperative anterior knee pain was also evaluated.
  
  
  RESULTS
  Compared with first-look findings, second-look arthroscopic ICRS grading was changed as follows: In terms of the patella, 89 cases (78.1%) were not progressed whereas 25 cases (21.9%) were progressed. In terms of the femoral trochlea, 67 cases (58.8%) were not progressed whereas 47 cases (41.2%) were progressed. There was significant progression of the ICRS grade of the patella (P = .001) and femoral trochlea (P < .001) compared with first-look arthroscopic findings. The incidence of postoperative anterior knee pain was 11.4% (13 cases), and it was related to the ICRS grade of the patellofemoral joint at the time of second-look arthroscopy (P < .001 for patella and P < .001 for trochlea).
  
  
  CONCLUSIONS
  This study showed that the patellofemoral joint might be adversely affected by medial open-wedge HTO. Although the incidence of postoperative anterior knee pain was low, it was clinically correlated with patellofemoral arthritis.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Department of Orthopaedic Surgery, Center for Joint Diseases and Rheumatism, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea; Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Kang-Il
authors.initials: KI
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Center for Joint Diseases and Rheumatism, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea. Electronic address: coco9713@naver.com.
authors.forename: Dong-Kyoon
authors.initials: DK
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Sang-Jun
authors.initials: SJ
authors.lastname: Song
authors.affiliation: Department of Orthopaedic Surgery, Center for Joint Diseases and Rheumatism, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea; Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Sang-Hak
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, College of Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Dae-Kyung
authors.initials: DK
authors.lastname: Bae
mesh_terms: D000328:Adult; D000368:Aged; D001182:Arthroscopy / Q000379:methods; D001860:Bone Plates; D020878:Device Removal; D018450:Disease Progression; D005260:Female; D005269:Femur / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000601:surgery*; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods*; D010149:Postoperative Pain / Q000209:etiology; D010329:Patella / Q000473:pathology; D057071:Patellofemoral Joint / Q000473:pathology*; D011446:Prospective Studies; D024162:Second-Look Surgery; D013977:Tibia / Q000601:surgery*