title: Femoral radiographic landmarks for popliteus tendon reconstruction and repair: a new method of reference.
abstract: BACKGROUND
  Although the popliteus muscle-tendon complex is one of the most important structures in controlling posterolateral rotatory stability of the knee, not much literature has been reported concerning the use of femoral radiographic landmarks of the popliteus tendon in repair and reconstruction.
  
  
  OBJECTIVE
  By using standardized radiographic techniques, the femoral insertion of the popliteus tendon could be more precisely determined by the Blumensaat line than by the extension line of the posterior cortex.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Ten fresh-frozen human knees were dissected, and the popliteus tendon was exposed. After identification of the femoral insertion site of the popliteus tendon, the insertion's center was indicated with a radiographic marker. True lateral radiographs of the distal femur were taken, and the digital radiographic images were analyzed by 2 independent observers.
  
  
  RESULTS
  The femoral insertion site of the popliteus tendon was found to be a mean 47.5% ± 5.2% across the width of the femoral condyle, 60.7% ± 7.8% along the perpendicular bisector of the Blumensaat line, 0.3 ± 1.7 mm posterior to the extension line of the posterior femoral cortex, and 20.5 ± 3.8 mm distal to the perpendicular line at the Blumensaat point. The variance from the mean point by using the Blumensaat line as a reference was significantly smaller than by using the extension line of the posterior cortex (mean, 2.6 vs 3.6 mm; P = .044).
  
  
  CONCLUSIONS
  A reproducible anatomic and radiographic reference point for the femoral insertion of the popliteus tendon can be determined using standardized radiographic techniques and can be more precisely determined by the Blumensaat line compared with the extension line of the posterior femoral cortex.
  
  
  CONCLUSIONS
  This radiographic information provides an adjunctive tool for preoperative, intraoperative, and postoperative assessments of surgical repair and reconstruction of the popliteus tendon.
authors.affiliation: W.P. Yau, FHKCOS, Division of Sports and Arthroscopic Surgery, Department of Orthopaedics and Traumatology, The University of Hong Kong, Room 508A, 5/F Professorial Block, Queen Mary Hospital, No. 102, Pokfulam Road, Hong Kong. peterwpy@hkucc.hku.hk.
authors.forename: August W M
authors.initials: AW
authors.lastname: Fok
authors.forename: Guan Ming
authors.initials: GM
authors.lastname: Kuang
authors.forename: W P
authors.initials: WP
authors.lastname: Yau
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D002102:Cadaver; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging* / Q000601:surgery; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000601:surgery; D015588:Observer Variation; D019637:Orthopedic Procedures; D011859:Radiography; D013710:Tendons / Q000000981:diagnostic imaging* / Q000601:surgery
keywords: fluoroscopy; popliteus tendon; posterolateral corner; posterolateral rotatory instability