Patellofemoral Mechanics: a Review of Pathomechanics and Research Approaches

Abstract

Purpose of ReviewThe patellofemoral joint is a complicated articulation of the patella and femur that is prone to pathologies. The purpose of this review is to report on the current methods of investigating patellofemoral mechanics, factors that affect joint function, and future directions in patellofemoral joint research with emerging technologies and techniques. Recent Findings While previous hypotheses have suggested that the patella is only a moment arm extender, recent literature has suggested that the patella influences the control of knee moments and forces acting on the tibia as well as contributes to various aspects of patellar function with minimal neural input. With advancements in simulating a six-degrees-of-freedom patellofemoral joint, we have gained a better understanding of patella motion and have shown that geometry and muscle activations impact patella mechanics. Research into influences on patella mechanics from other joints such as the hip and foot has become more prevalent. Summary In this review, we report current in vivo, in vitro, and in silico approaches to studying the patellofemoral joint. Kinematic and anatomical factors that affect patellofemoral joint function such as patella alta and tilt or bone morphology and ligaments are discussed. Moving forward, we suggest that advanced in vivo dynamic imaging methods coupled to musculoskeletal simulation will provide further understanding of patellofemoral pathomechanics and allow engineers and clinicians to design interventions to mitigate or prevent patellofemoral pathologies.

A Review of the Lateral Patellofemoral Joint: Anatomy, Biomechanics, and Surgical Procedures

“…Superficial Retinacular Layer Iliotibial Band A tight IT band has been associated with lateral patellar tracking, which can exacerbate lateral instability. 11 The arciform fibers running from the iliotibial band to the patella are perpendicular or oblique to both the iliotibial band and the patella. This also means that this connection is perpendicular or oblique to the direct line of longitudinal force for both the iliotibial band and the extensor mechanism helping to keep the patella from translating medially.…”

“…During knee range of motion, the patella is guided to engage with the trochlea because of the posterior pull of the VMO and VLO on either side of the knee. 11 , 12 The VLO force is directed 35° proximal-laterally off the femoral axis and counteracts the proximal-medial force of the VMO. 13 An imbalance of these muscles can lead to differential stresses on the patellar facets.…”

Quantitative evaluation of the biomechanical and viscoelastic properties of the dog patellar tendon in response to neuromuscular blockade at different stifle angles

“…Knee extensors comprise the quadriceps muscle and tendon, medial and lateral patellar retinaculum, patella, patellar tendon (PT), and tibial tubercle [ 2 ]. The PT also plays a crucial role in transferring the force from the quadriceps to the tibia [ 3 ]. The proximal attachment (inferior pole) is mainly affected if the PT becomes inflamed from constant strain.…”

Positive outcomes following Autologous Matrix-Induced Chondrogenesis (AMIC) in the treatment of retropatellar chondral lesions: a retrospective analysis of a patient registry

“…Unfortunately, articular cartilage has minimal regenerative capacity due to its avascular and hypocellular character [ 3 ]. In the patellofemoral joint (PFJ), this low friction environment is essential as the patella glides in the trochlear groove, enhancing the moment arm of the quadriceps [ 4 ] as well as contributing to the optimization of control strategies in locomotion [ 5 ]. While patellofemoral compressive forces have been calculated to be somewhat more than 4 times body weight [ 6 ] there is also data that shows these can be as high as 11 times body weight [ 7 ].…”