Individuals with isolated patellofemoral joint osteoarthritis exhibit higher mechanical loading at the knee during the second half of the stance phase.
BACKGROUND
Patellofemoral joint osteoarthritis is a highly prevalent disease and an important source of pain and disability. Nonetheless, biomechanical risk factors associated with this disease remain unclear. The purpose of this study was to compare biomechanical factors that are associated with patellofemoral joint loading during walking between individuals with isolated patellofemoral joint osteoarthritis and no osteoarthritis.


METHODS
MR images of the knee were obtained using a 3D fast-spin echo sequence to identify patellofemoral joint cartilage lesions. Thirty-five subjects with isolated patellofemoral joint osteoarthritis (29 females) and 35 control subjects (21 females) walked at a self-selected speed and as fast as possible. Peak knee flexion moment, flexion moment impulse and peak patellofemoral joint stress during the first and second halves of the stance phase were compared between groups.


RESULTS
When compared to the controls, individuals with patellofemoral joint osteoarthritis demonstrated significantly higher peak knee flexion moment (P=.03, Eta(2)=.07), higher knee flexion moment impulse (P=.03, Eta(2)=.07) and higher peak patellofemoral joint stress (P=.01, Eta(2)=.10) during the second half of the stance phase. No significant group difference was observed during the first half of the stance phase.


CONCLUSIONS
Findings of this study suggest that increased mechanical loading (i.e. knee flexion moment, impulse and patellofemoral joint stress) during the second half of the stance phase is associated with patellofemoral joint osteoarthritis. Prevention and rehabilitation programs for patellofemoral joint osteoarthritis may focus on reducing the loading on the patellofemoral joint, specifically during late stance.
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA. Electronic address: Hsiang-Ling.Teng@ucsf.edu.
Hsiang-Ling
HL
Teng
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA; Department of Physical Therapy, California State University, Sacramento, CA, USA. Electronic address: toran.macleod@csus.edu.
Toran D
TD
MacLeod
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA. Electronic address: deepak.kumar@ucsf.edu.
Deepak
D
Kumar
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA. Electronic address: Thomas.Link@ucsf.edu.
Thomas M
TM
Link
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA. Electronic address: Sharmila.Majumdar@ucsf.edu.
Sharmila
S
Majumdar
Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA; Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, USA. Electronic address: Richard.Souza@ucsf.edu.
Richard B
RB
Souza
D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D057071:Patellofemoral Joint / Q000503:physiopathology*; D013314:Stress, Mechanical; D016138:Walking / Q000502:physiology
Gait; Kinetics; Osteoarthritis; Patellofemoral joint; Stress