title: Comparison of five patellar height measurement methods in 90° knee flexion.
abstract: OBJECTIVE
  The aim of this prospective study was to evaluate the patellar height in 90° knee flexion.
  
  
  METHODS
  A total of 85 patients with 95 knee joints were included in the study. Patellar height was measured according to the Blackburne-Peel, Labelle-Laurin, Insall-Salvati, Linclau, and Caton-Deschamps methods in the whole group and in subgroups based on age, gender, and side.
  
  
  RESULTS
  The BP-ratio showed a patella norma in 45 cases, and in 25 cases a patella alta and infera, respectively. The Labelle-Laurin method determined a patella norma in eight knees, in 35 a patella alta and in 52 a patella infera. The IS-ratio revealed a patella norma in 52 patients, a patella alta in six and in 37 a patella infera. The Linclau method demonstrated in 52 cases a patella norma, in 17 a patella alta and in 26 a patella infera. The CD-ratio showed the highest values of a patella norma among all tested methods in 67 knees, whereas a patella alta was evident in 13 and a patella infera in 15 cases. In the subgroups, discrepancies depended on the subgroup and method used.
  
  
  CONCLUSIONS
  Our results demonstrate a method-dependent discrepancy in the measurement of patellar height. A future study should evaluate this effect in a direct comparison between 30° and 90° knee flexion.
authors.affiliation: Department of Orthopaedics and Orthopaedic Surgery, University of Saarland, Homburg/Saar, Germany. k.anagnostakos@web.de
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Anagnostakos
authors.forename: Olaf
authors.initials: O
authors.lastname: Lorbach
authors.forename: Sarah
authors.initials: S
authors.lastname: Reiter
authors.forename: Dieter
authors.initials: D
authors.lastname: Kohn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000886:Anthropometry / Q000379:methods*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010329:Patella / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D011859:Radiography / Q000379:methods; D016059:Range of Motion, Articular; D055815:Young Adult