title: MPFL reconstruction using a quadriceps tendon graft: part 1: biomechanical properties of quadriceps tendon MPFL reconstruction in comparison to the Intact MPFL. A human cadaveric study.
abstract: BACKGROUND
  The aim of this study was to analyze the structural properties of the original MPFL and to compare it to a MPFL-reconstruction-technique using a strip of quadriceps tendon.
  
  
  METHODS
  In 13 human cadaver knees the MPFLs were dissected protecting their insertion at the patellar border. The MPFL was loaded to failure after preconditioning with 10 cycles in a uniaxial testing machine evaluating stiffness, yield load and maximum load to failure. In the second part Quadriceps-MPFL-reconstruction was performed and tested in a uniaxial testing machine. Following preconditioning, the constructs were cyclically loaded 1000 times between 5 and 50 N measuring the maximum elongation. After cyclic testing, the constructs have been loaded to failure measuring stiffness, yield load and maximum load. For statistical analysis a repeated measures (RM) one-way ANOVA for multiple comparisons was used. The significance was set at P<0.05.
  
  
  RESULTS
  During the load to failure tests of the original MPFL the following results were measured: stiffness 29.4 N/mm (+9.8), yield load 167.8 N (+80) and maximum load to failure 190.7 N (+82.8). The results in the QT-technique group were as follows: maximum elongation after 1000 cycles 2.1 mm (+0.8), stiffness 33.6 N/mm (+6.8), yield load 147.1 N (+65.1) and maximum load to failure 205 N (+77.8). There were no significant differences in all tested parameters.
  
  
  CONCLUSIONS
  In a human cadaveric model using a strip of quadriceps-tendon 10 mm wide and 3mm deep, the biomechanical properties match those of the original MPFL when tested as a reconstruction.
  
  
  CONCLUSIONS
  The tested QT-technique shows sufficient primary stability with comparable biomechanical parameters to the intact MPFL.
authors.affiliation: Department of Trauma-, Hand- and Reconstructive Surgery, Westfaelian-Wilhelms University of Muenster, Muenster, Germany. Electronic address: Mirco.Herbort@gmail.com.
authors.forename: Mirco
authors.initials: M
authors.lastname: Herbort
authors.affiliation: Sportsclinic Austria, Innsbruck, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Hoser
authors.affiliation: Department of Trauma-, Hand- and Reconstructive Surgery, Westfaelian-Wilhelms University of Muenster, Muenster, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Domnick
authors.affiliation: Department of Trauma-, Hand- and Reconstructive Surgery, Westfaelian-Wilhelms University of Muenster, Muenster, Germany.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Raschke
authors.affiliation: Department of Trauma-, Hand- and Reconstructive Surgery, Westfaelian-Wilhelms University of Muenster, Muenster, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Lenschow
authors.affiliation: Department of Trauma-, Hand- and Reconstructive Surgery, Westfaelian-Wilhelms University of Muenster, Muenster, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Weimann
authors.affiliation: Department of Trauma-, Hand- and Reconstructive Surgery, Westfaelian-Wilhelms University of Muenster, Muenster, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Kösters
authors.affiliation: Sportsclinic Austria, Innsbruck, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
mesh_terms: D000368:Aged; D001178:Arthroplasty / Q000379:methods*; D002102:Cadaver; D004210:Dissection; D006801:Humans; D007593:Joint Instability / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008023:Ligaments, Articular / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D008875:Middle Aged; D057071:Patellofemoral Joint / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D052097:Quadriceps Muscle; D016059:Range of Motion, Articular; D013710:Tendons / Q000637:transplantation*; D016474:Weight-Bearing
keywords: Biomechanics; Knee; MPFL; Quadriceps tendon reconstruction; Stiffness