The effect of trochleoplasty on patellar stability and kinematics: a biomechanical study in vitro

J Bone Joint Surg Br. 2008 Jul;90(7):864-9. doi: 10.1302/0301-620X.90B7.20447.


Objective patellar instability has been correlated with dysplasia of the femoral trochlea. This in vitro study tested the hypothesis that trochleoplasty would increase patellar stability and normalise the kinematics of a knee with a dysplastic trochlea. Six fresh-frozen knees were loaded via the heads of the quadriceps. The patella was displaced 10 mm laterally and the displacing force was measured from 0 degrees to 90 degrees of flexion. Patellar tracking was measured from 0 degrees to 130 degrees of knee flexion using magnetic sensors. These tests were repeated after raising the central anterior trochlea to simulate dysplasia, and repeated again after performing a trochleoplasty on each specimen. The simulated dysplasia significantly reduced stability from that of the normal knee (p < 0.001). Trochleoplasty significantly increased the stability (p < 0.001), so that it did not then differ significantly from the normal knee (p = 0.244). There were small but statistically significant changes in patellar tracking (p< 0.001). This study has provided objective biomechanical data to support the use of trochleoplasty in the treatment of patellar instability associated with femoral trochlear dysplasia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomechanical Phenomena / methods
  • Cadaver
  • Evidence-Based Medicine
  • Humans
  • Joint Instability / etiology
  • Joint Instability / surgery*
  • Osteotomy / methods*
  • Patella / anatomy & histology
  • Patella / surgery*
  • Stress, Mechanical