title: The Anatomic Midpoint of the Attachment of the Medial Patellofemoral Complex.
abstract: BACKGROUND
  The medial patellofemoral ligament varies in attachment of its fibers to the patella and vastus intermedius tendon. Our aim was to identify and describe its anatomic midpoint. To account for the variability of the attachment site, we refer to it as the medial patellofemoral complex.
  
  
  METHODS
  Using AutoCAD software, we identified the midpoint of the medial patellofemoral complex attachment on photographs of 31 cadaveric knee dissections. The midpoint was referenced relative to the superior articular surface of the patella (P1) and was described in terms of the percentage of the patellar articular length distal to this point. A second point, at the junction of the medial border of the vastus intermedius tendon with the superior articular border of the patella, was identified (P2). The distances of the midpoint to P1 and P2 were calculated and were compared using paired t tests.
  
  
  RESULTS
  Twenty-five images had appropriate quality and landmarks for digital analysis. The midpoint of the medial patellofemoral complex was located a mean (and standard deviation) of 2.3% ± 15.8% of the patellar articular length distal to the superior pole and was at or proximal to P1 in 12 knees. In all knees, the midpoint was at or proximal to P2. After exclusion of 2 knees with vastus intermedius tendon attachments only, the medial patellofemoral complex midpoint was closer to P2 (5.3% ± 8.6% of the patellar articular length) than to P1 (9.3% ± 8.5% of the patellar articular length) (p = 0.06).
  
  
  CONCLUSIONS
  The midpoint of the medial patellofemoral complex was 2.3% of the articular length distal to the superior pole of the patella. Additionally, we describe an anatomic landmark at the junction of the medial border of the vastus intermedius tendon and the articular border of the patella that approximates the midpoint of this complex.
  
  
  CONCLUSIONS
  Our study shows that the anatomic midpoint of the attachment of the medial patellofemoral complex is proximal to the junction of the medial vastus intermedius tendon and the articular border of the patella, suggesting that graft placement may be more anatomic on the vastus intermedius tendon rather than on the patella.
authors.affiliation: Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland Mtanaka4@jhmi.edu.
authors.forename: Miho J
authors.initials: MJ
authors.lastname: Tanaka
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut Department of Orthopaedic Sports Medicine, Technical University, Munich, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Voss
authors.affiliation: Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut Orthopedic Associates of Hartford, Farmington, Connecticut.
authors.forename: John P
authors.initials: JP
authors.lastname: Fulkerson
mesh_terms: D006801:Humans; D008023:Ligaments, Articular / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D010329:Patella / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D057071:Patellofemoral Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D012984:Software