title: The patellar insertion of the medial patellofemoral ligament in children: a cadaveric study.
abstract: BACKGROUND
  The purpose of this study was to evaluate the medial patellofemoral ligament (MPFL) patellar insertion in skeletally immature anatomic specimens.
  
  
  METHODS
  Nine pediatric cadaveric knee specimens were examined through gross dissection. Metallic markers were placed at the MPFL patellar insertion footprint. Computed tomographic scans for each specimen were analyzed. The MPFL insertion footprint width, patellar height, and patellar width were measured. The distance from the MPFL insertion footprint center to the midline of the patella was assessed. The proportion of the patella that the MPFL footprint inserted upon was calculated.
  
  
  RESULTS
  The mean width of the MPFL patellar insertion footprint was 12 mm (range, 8 to 18 mm). The mean patellar height was 31 mm (range, 20 to 48 mm). The mean patellar width was 27 mm (range, 21 to 39 mm). The center of the MPFL insertion footprint was found to be a mean 4.7 mm (range, -2 to 10.5 mm) above the midline of the patella, with insertion centers occurring both above and below the midline. The MPFL insertion footprint spanned a mean 41% (24% to 63%) of the longitudinal width of the patella.
  
  
  CONCLUSIONS
  Most adult studies report the MPFL insertion on the upper 1/2 to 2/3 of the patella. This series of skeletally immature subjects demonstrated that the center of the MPFL insertion was above and below the midpoint of the patella. The MPFL insertions of some of the younger specimens did extend into the distal 1/3 of the patella. The insertion of the older specimens was found in the proximal 2/3 of the patella, a similar location to most previous adult anatomic studies.
  
  
  CONCLUSIONS
  This research suggests that the MPFL insertion on the patella may be at slightly different locations in some skeletally immature subjects compared with adults. The specimens dissected in the present study showed more variability than previously published reports, with some insertions extending into the distal 1/3 of the patella in the youngest subjects. These dissections may be useful to surgeons performing MPFL reconstructions in skeletally immature patients.
authors: *St. Luke's Sports Medicine, St. Luke's Children's Hospital Boise, ID †Rocky Mountain Youth Sports Medicine Institute, Rocky Mountain Hospital for Children Denver, CO ‡University of Utah School of Medicine, Salt Lake City, UT §Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine Philadelphia, PA ∥Department of Orthopedics, University of Utah ¶Department of Orthopaedic Surgery, Duke University Medical Center Durham, NC #Division of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center Cincinnati, OH.
authors: Kevin G
authors: KG
authors: Shea
authors: John D
authors: JD
authors: Polousky
authors: John C
authors: JC
authors: Jacobs
authors: Theodore J
authors: TJ
authors: Ganley
authors: Stephen K
authors: SK
authors: Aoki
authors: Nathan L
authors: NL
authors: Grimm
authors: Shital N
authors: SN
authors: Parikh
mesh_terms: D000718:Anatomy, Regional / Q000379:methods; D002102:Cadaver; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008023:Ligaments, Articular / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008297:Male; D009929:Organ Size; D010329:Patella / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D031222:Patellar Dislocation / Q000601:surgery; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed