Design of Hip Simulation Machine for Hip Labrum Testing

Abstract

The acetabular labrum is the connective tissue between femoral head and hip joint that acts like a shock absorber. Labral injury could happen after hip dislocation or internal derangement such as femeroacetabular impingement (FAI) syndrome. The surgeon usually attempts to repair or reconstruct the torn labrum to obtain the native hip biomechanical loading.  There has been no scientific evidence study for the different surgical techniques. Hip simulation machine was made to let a femur move in six conditions including step forward, step backward, abduction, adduction, internal rotation and external rotation. The hip was compressed with a force of half of the body weight (350 N). The purpose of this study was to study pressurization in three labral conditions including intact labrum, labral repair and labral reconstruction. The machine was designed and simulated by SolidWorks software. A device’s controller had two mode including a manual mode to set zero before an operation and automation mode to move in six conditions and compressed with a force of body weight. After the construction, the machine was tasted by using counterfeit pelvis and femur. The device was reformed before a real taste. Dissected cadaveric pelvises were used and measured pressure through the film piezoresistive load sensors. The testing result was helped the surgeon to make a decision in surgery process.