TY - JOUR
T1 - Individuals with patellofemoral pain exhibit greater patellofemoral joint stress
T2 - A finite element analysis study
AU - Farrokhi, S.
AU - Keyak, J. H.
AU - Powers, C. M.
PY - 2011/3
Y1 - 2011/3
N2 - Objective: To test the hypothesis that individuals with patellofemoral pain (PFP) exhibit greater patellofemoral joint stress profiles compared to persons who are pain-free. Methods: Ten females with PFP and ten gender, age, and activity-matched pain-free controls participated. Patella and femur stress profiles were quantified utilizing subject-specific finite element (FE) models of the patellofemoral joint at 15° and 45° of knee flexion. Input parameters for the FE model included: (1) joint geometry, (2) quadriceps muscle forces, and (3) weight-bearing patellofemoral joint kinematics. Using a nonlinear FE solver, quasi-static loading simulations were performed to quantify each subject's patellofemoral joint stress profile during a static squatting maneuver. The patella and femur peak and mean hydrostatic pressure as well as the peak and mean octahedral shear stress for the elements representing the chondro-osseous interface were quantified. Results: Compared to the pain-free controls, individuals with PFP consistently exhibited greater peak and mean hydrostatic pressure as well as peak and mean octahedral shear stress for the elements representing the patella and femur chondro-osseous interface across the two knee flexion angles tested (15° and 45°). Conclusions: The combined finding of elevated hydrostatic pressure and octahedral shear stress across the two knee flexion angles supports the premise that PFP may be associated with elevated joint stress. Therefore, treatments aimed at decreasing patellofemoral joint stress may be indicated in this patient population.
AB - Objective: To test the hypothesis that individuals with patellofemoral pain (PFP) exhibit greater patellofemoral joint stress profiles compared to persons who are pain-free. Methods: Ten females with PFP and ten gender, age, and activity-matched pain-free controls participated. Patella and femur stress profiles were quantified utilizing subject-specific finite element (FE) models of the patellofemoral joint at 15° and 45° of knee flexion. Input parameters for the FE model included: (1) joint geometry, (2) quadriceps muscle forces, and (3) weight-bearing patellofemoral joint kinematics. Using a nonlinear FE solver, quasi-static loading simulations were performed to quantify each subject's patellofemoral joint stress profile during a static squatting maneuver. The patella and femur peak and mean hydrostatic pressure as well as the peak and mean octahedral shear stress for the elements representing the chondro-osseous interface were quantified. Results: Compared to the pain-free controls, individuals with PFP consistently exhibited greater peak and mean hydrostatic pressure as well as peak and mean octahedral shear stress for the elements representing the patella and femur chondro-osseous interface across the two knee flexion angles tested (15° and 45°). Conclusions: The combined finding of elevated hydrostatic pressure and octahedral shear stress across the two knee flexion angles supports the premise that PFP may be associated with elevated joint stress. Therefore, treatments aimed at decreasing patellofemoral joint stress may be indicated in this patient population.
KW - Articular cartilage
KW - Biomechanics
KW - Finite element analysis
KW - Patellofemoral pain
UR - http://www.scopus.com/inward/record.url?scp=79951852416&partnerID=8YFLogxK
U2 - 10.1016/j.joca.2010.12.001
DO - 10.1016/j.joca.2010.12.001
M3 - Article
C2 - 21172445
AN - SCOPUS:79951852416
SN - 1063-4584
VL - 19
SP - 287
EP - 294
JO - Osteoarthritis and Cartilage
JF - Osteoarthritis and Cartilage
IS - 3
ER -