title: Using real-time MRI to quantify altered joint kinematics in subjects with patellofemoral pain and to evaluate the effects of a patellar brace or sleeve on joint motion.
abstract: Abnormal patellofemoral joint motion is a possible cause of patellofemoral pain, and patellar braces are thought to alleviate pain by restoring normal joint kinematics. We evaluated whether females with patellofemoral pain exhibit abnormal patellofemoral joint kinematics during dynamic, weight-bearing knee extension and assessed the effects of knee braces on patellofemoral motion. Real-time magnetic resonance (MR) images of the patellofemoral joints of 36 female volunteers (13 pain-free controls, 23 patellofemoral pain) were acquired during weight-bearing knee extension. Pain subjects were also imaged while wearing a patellar-stabilizing brace and a patellar sleeve. We measured axial-plane kinematics from the images. Females with patellofemoral pain exhibited increased lateral translation of the patella for knee flexion angles between 0 degrees and 50 degrees (p = 0.03), and increased lateral tilt for knee flexion angles between 0 degrees and 20 degrees (p = 0.04). The brace and sleeve reduced the lateral translation of the patella; however, the brace reduced lateral displacement more than the sleeve (p = 0.006). The brace reduced patellar tilt near full extension (p = 0.001), while the sleeve had no effect on patellar tilt. Our results indicate that some subjects with patellofemoral pain exhibit abnormal weight-bearing joint kinematics and that braces may be effective in reducing patellar maltracking in these subjects.
authors.affiliation: Department of Mechanical Engineering, Stanford University, James H. Clark Center, Room S-355 MC 5450, 318 Campus Drive, Stanford, California 94305-5450, USA. cdraper@stanford.edu
authors.forename: Christine E
authors.initials: CE
authors.lastname: Draper
authors.forename: Thor F
authors.initials: TF
authors.lastname: Besier
authors.forename: Juan M
authors.initials: JM
authors.lastname: Santos
authors.forename: Fabio
authors.initials: F
authors.lastname: Jennings
authors.forename: Michael
authors.initials: M
authors.lastname: Fredericson
authors.forename: Garry E
authors.initials: GE
authors.lastname: Gold
authors.forename: Gary S
authors.initials: GS
authors.lastname: Beaupre
authors.forename: Scott L
authors.initials: SL
authors.lastname: Delp
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D017760:Bone Malalignment / Q000503:physiopathology; D001915:Braces; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000473:pathology* / Q000503:physiopathology; D007719:Knee Joint / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D046788:Patellofemoral Pain Syndrome / Q000473:pathology* / Q000503:physiopathology*