Effects of Weight-Bearing on Tibiofemoral, Patellofemoral, and Patellar Tendon Kinematics in Older Adults

Abstract

Quantification of natural knee kinematics is essential for the assessment of joint function in the diagnosis of pathologies. Combined measurements of tibiofemoral and patellofemoral joint kinematics are necessary because knee pathologies, such as progression of osteoarthritis and patellar instability, are a frequent concern in both articulations. Combined measurement of tibiofemoral and patellofemoral kinematics also enables calculation of important quantities, specifically patellar tendon angle, which partly determines the loading vector at the tibiofemoral joint and patellar tendon moment arm. The goals of this research were to measure the differences in tibiofemoral and patellofemoral kinematics, patellar tendon angle (PTA), and patellar tendon moment arm (PTMA) that occur during non-weight-bearing and weight-bearing activities in older adults. Methods: High-speed stereo radiography was used to measure the kinematics of the tibiofemoral and patellofemoral joints in subjects as they performed seated, non-weight-bearing knee extension and two weight-bearing activities: lunge and chair rise. PTA and PTMA were extracted from the subject’s patellofemoral and tibiofemoral kinematics. Kinematics and the root mean square difference (RMSD) between non-weight-bearing and weight-bearing activities were compared across subjects and activities. Results: Internal rotation increased with weight-bearing (mean RMSD from knee extension was 4.2 ± 2.4° for lunge and 3.6 ± 1.8° for chair rise), and anterior translation was also greater (mean RMSD from knee extension was 2.2 ± 1.2 mm for lunge and 2.3 ± 1.4 mm for chair rise). Patellar tilt and medial–lateral translation changed from non-weight-bearing to weight-bearing. Changes of the patellar tendon from non-weight-bearing to weight-bearing were significant only for PTMA. Conclusions: While weight-bearing elicited changes in knee kinematics, in most degrees of freedoms, these differences were exceeded by intersubject differences. These results provide comparative kinematics for the evaluation of knee pathology and treatment in older adults.

Length Changes of the Medial Patellofemoral Ligament During In Vivo Knee Motion: An Evaluation Using Dynamic Computed Tomography

“…Next to muscle contraction, weightbearing also has an effect on patellofemoral kinematics. 16,17,23 Yet, our length change patterns largely correspond with a recent study investigating MPFL length changes during a weightbearing lunge motion, also demonstrating a decrease in MPFL length during early flexion. 18 This finding may conceivably indicate that the importance of active weightbearing relative to active nonweightbearing knee motion may be secondary for the assessment of MPFL length changes compared with interindividual variability.…”

“…Last, MPFL length changes were assessed during a nonweightbearing open-kinetic chain active flexion-extension-flexion movement, which might not be representative of different activities during daily life. 17 However, our approach is more realistic than that of previous studies examining changes in MPFL length during passive knee flexion. Notwithstanding these limitations, this study offers valuable insights into length changes of the native MPFL during knee flexion, which is essential to obtain a better understanding of MPFL reconstruction and its related complications.…”

Load-Dependent Characteristics of Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty: A Biomechanical Study

“…Studies have shown that increased weight bearing changes knee kinematics and contact characteristics. 1 2 3) Both biomechanical and physiological mechanisms of TKAs are associated with the mechanical stresses that are related to osteoarthritis. 4 5) For patients with severe and advanced osteoarthritis, TKAs are the best treatment option.…”