In vivo patellofemoral contact mechanics during active extension using a novel dynamic MRI-based methodology

• Published in: Osteoarthritis and cartilage Vol. 21; no. 12; pp. 1886 - 1894
• Main Authors: Borotikar, B.S, Sheehan, F.T
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2013
• Subjects: Accuracy; Adolescent; Adult; Biomechanical Phenomena; Cartilage; Cartilage, Articular - physiology; Female; Femur; Humans; Knee; Magnetic resonance imaging; Magnetic Resonance Imaging, Cine; Osteoarthritis; Patella; Patellofemoral Joint - physiology; Patellofemoral pain syndrome; Range of Motion, Articular - physiology; Reference Values; Rheumatology; Sensitivity; Weight-Bearing; Young Adult; Knee; Cartilage; Femur; Sensitivity; Accuracy; Magnetic resonance imaging; Patella; Patellofemoral pain syndrome; Osteoarthritis
• ISSN: 1063-4584; 1522-9653
• DOI: 10.1016/j.joca.2013.08.023

Summary Objectives To establish an in vivo , normative patellofemoral (PF) cartilage contact mechanics database acquired during voluntary muscle control using a novel, dynamic, magnetic resonance (MR) imaging-based, computational methodology and validate the contact mechanics sensitivity to the known sub-millimeter methodological accuracies. Design Dynamic cine phase-contrast and multi-plane cine (MPC) images were acquired while female subjects ( n  = 20, sample of convenience) performed an open kinetic chain (knee flexion-extension) exercise inside a 3-T MR scanner. Static cartilage models were created from high resolution three-dimensional static MR data and accurately placed in their dynamic pose at each time frame based on the cine-PC (CPC) data. Cartilage contact parameters were calculated based on the surface overlap. Statistical analysis was performed using paired t -test and a one-sample repeated measures ANOVA. The sensitivity of the contact parameters to the known errors in the PF kinematics was determined. Results Peak mean PF contact area was 228.7 ± 173.6 mm2 at 40° knee angle. During extension, contact centroid and peak strain locations tracked medially on the femoral and patellar cartilage and were not significantly different from each other. At 25°, 30°, 35°, and 40° of knee extension, contact area was significantly different. Contact area and centroid locations were insensitive to rotational and translational perturbations. Conclusion This study is a first step towards unfolding the biomechanical pathways to anterior PF pain and osteoarthritis (OA) using dynamic, in vivo , and accurate methodologies. The database provides crucial data for future studies and for validation of, or as an input to, computational models.