title: Corrective osteotomy of the distal femur with fixator assistance: A novel technique of minimally invasive osteosynthesis.
abstract: OBJECTIVE
  Varus or valgus deformity of the distal femur may progress into knee osteoarthritis. To delay or prevent this, various types of corrective osteotomy techniques have been used to shift the mechanical axis from the diseased compartment to the healthy one. We introduced a new, minimally invasive osteotomy of the distal femur with the assistance of temporary external fixation.
  
  
  METHODS
  We retrospectively studied 25 legs that underwent open-wedge osteotomy of the distal femur, involving insertion of a Schanz pin at the medial femoral condyle and another pin at the distal diaphysis of the femur. At the meta-diaphyseal junction, osteotomy was performed. After achieving angular correction, two pins were locked for temporary external fixation and a locking plate was fixed at the lateral side of the femur submuscularly. Radiological and functional outcomes were evaluated, including mechanical lateral distal femoral angle (m-LDFA), mechanical axis deviation, tibiofemoral angle, osseous union, and knee joint motion.
  
  
  RESULTS
  The minimum follow-up was 12 months (mean, 39 months; range, 12-88 months). Bone healing occurred in all legs, with an average of 16.6 weeks. The m-LDFA was corrected from 77.7° (18 valgus) and 104.6° (7 varus) to 88.1° after surgery, with an average correction of 12.9°. At the final follow-up, the mechanical axis deviation averaged 7.6 mm and the tibia-femoral angle averaged 5.6°. Most of legs (88%) achieved acceptable m-LDFA (87° ± 3°).
  
  
  CONCLUSIONS
  A new, minimally invasive osteotomy of the distal femur offers excellent bone healing with few complications, attributable to preserved blood supply.
authors.affiliation: Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Kyeong-Hyeon
authors.initials: KH
authors.lastname: Park
authors.affiliation: Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Joon-Woo
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Hee-June
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Hee-Soo
authors.initials: HS
authors.lastname: Kyung
authors.affiliation: Department of Orthopedic Surgery, Korea University Guro Hospital, Seoul, Republic of Korea.
authors.forename: Jong-Keon
authors.initials: JK
authors.lastname: Oh
authors.affiliation: Department of Orthopedic Surgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Tae-Joon
authors.initials: TJ
authors.lastname: Cho
authors.affiliation: Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Il
authors.initials: I
authors.lastname: Seo
authors.affiliation: Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea. Electronic address: cwoh@knu.ac.kr.
authors.forename: Chang-Wug
authors.initials: CW
authors.lastname: Oh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016267:External Fixators / Q000009:adverse effects; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects; D016916:Joint Deformities, Acquired / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects*; D009984:Orthopedic Fixation Devices / Q000009:adverse effects*; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D010027:Osteotomy / Q000379:methods*; D011183:Postoperative Complications; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult