Patellofemoral joint contact forces during activities with high knee flexion

Abstract

The patellofemoral (PF) joint plays an essential role in knee function, but little is known about the in vivo loading conditions at the joint. We hypothesized that the forces at the PF joint exceed the tibiofemoral (TF) forces during activities with high knee flexion. Motion analysis was performed in two patients with telemetric knee implants during walking, stair climbing, sit-to-stand, and squat. TF and PF forces were calculated using a musculoskeletal model, which was validated against the simultaneously measured in vivo TF forces, with mean errors of 10% and 21% for the two subjects. The in vivo peak TF forces of 2.9-3.4 bodyweight (BW) varied little across activities, while the peak PF forces showed significant variability, ranging from less than 1 BW during walking to more than 3 BW during high flexion activities, exceeding the TF forces. Together with previous in vivo measurements at the hip and knee, the PF forces determined here provide evidence that peak forces across these joints reach values of around 3 BW during high flexion activities, also suggesting that the in vivo loading conditions at the knee can only be fully understood if the forces at the TF and the PF joints are considered together. ß

Patella morphological alteration after patella instability in growing rabbits

“…On the other hand, the patellofemoral joint plays an essential role in knee function. Trepczynski et al [22] demonstrated that the force of the patellofemoral joint ranged from <1 body weight during walking to >3 body weights during high flexion activities. Considering the articulation, ossification, and pressure between the patella and femoral trochlea, the alteration in patellar morphology after patellar instability in children and adolescents makes sense.…”

Is body mass index associated with patellofemoral pain and patellofemoral osteoarthritis? A systematic review and meta-regression and analysis

“…The PF joint plays a critical role in knee joint function, particularly during daily activities involving large ranges of flexion such as squatting, stair ascent and descent, where it is subjected to loads ∼ 2 to 3×BW 10. Thus, any increase in body mass will heighten the load on the PF joint, potentially increasing joint stress and structural deterioration.…”

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

“…Large inter-study variations have been reported, which are likely due to the different modeling methods and assumptions used across studies [25]. More importantly, these models are rarely validated and even the input parameters accuracy is often unknown [27]. Thus, the quality of the output variables is uncertain.…”