title: The effect of tibial tuberosity realignment procedures on the patellofemoral pressure distribution.
abstract: OBJECTIVE
  The study was performed to characterize the influence of tibial tuberosity realignment on the pressure applied to cartilage on the patella in the intact condition and with lesions on the lateral and medial facets.
  
  
  METHODS
  Ten knees were loaded in vitro through the quadriceps (586 N) and hamstrings (200 N) at 40°, 60°, and 80° of flexion while measuring patellofemoral contact pressures with a pressure sensor. The tibial tuberosity was positioned 5 mm lateral of the normal position to represent lateral malalignment, 5 mm medial of the normal position to represent tuberosity medialization, and 10 mm anterior of the medial position to represent tuberosity anteromedialization. The knees were tested with intact cartilage, with a 12-mm-diameter lesion created within the lateral patellar cartilage, and with the lateral lesion repaired with silicone combined with a medial lesion. A repeated measures ANOVA and post hoc tests were used to identify significant (P < 0.05) differences in the maximum lateral and medial pressure between the tuberosity positions.
  
  
  RESULTS
  Tuberosity medialization and anteromedialization significantly decreased the maximum lateral pressure by approximately 15% at 60° and 80° for intact cartilage and cartilage with a lateral lesion. Tuberosity medialization significantly increased the maximum medial pressure for intact cartilage at 80°, but the maximum medial pressure did not exceed the maximum lateral pressure for any testing condition.
  
  
  CONCLUSIONS
  The results indicate that medializing the tibial tuberosity by 10 mm reduces the pressure applied to lateral patellar cartilage for intact cartilage and cartilage with lateral lesions, but does not overload medial cartilage.
authors: Department of Orthopaedic Surgery, Calhoun Research Laboratory, Akron General Medical Center, 400 Wabash Avenue, Akron, OH, 44307, USA.
authors: Archana
authors: A
authors: Saranathan
authors: Marcus S
authors: MS
authors: Kirkpatrick
authors: Saandeep
authors: S
authors: Mani
authors: Laura G
authors: LG
authors: Smith
authors: Andrew J
authors: AJ
authors: Cosgarea
authors: Juay Seng
authors: JS
authors: Tan
authors: John J
authors: JJ
authors: Elias
mesh_terms: D001696:Biomechanical Phenomena; D017760:Bone Malalignment / Q000503:physiopathology / Q000601:surgery*; D002358:Cartilage, Articular / Q000293:injuries / Q000502:physiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007719:Knee Joint / Q000502:physiology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures; D057071:Patellofemoral Joint / Q000502:physiology / Q000503:physiopathology; D011312:Pressure; D016059:Range of Motion, Articular; D013977:Tibia / Q000502:physiology / Q000503:physiopathology / Q000601:surgery*; D016474:Weight-Bearing