Development of an EMG-informed neuromusculoskeletal modelling framework to measure knee joint contact forces during walking in patients with medial dominant knee osteoarthritis and varus alignment
Abstract
Knee OA is a complex disease where aberrant gait biomechanics may contribute substantially to progression of structural joint damage and symptoms. Medial opening wedge high tibial osteotomy (MOWHTO) is a limb realignment surgery intended to lessen loads on the medial compartment of the tibiofemoral joint in patients with medial dominant knee OA and varus alignment. As it is difficult to directly measure knee joint contact forces (KJCF) the effect of MOWHTO on joint loading remains unclear. Neuromusculoskeletal (NMSK) modelling can estimate these forces. Therefore, purposes of this thesis were to: 1) develop an electromyography (EMG)-informed NMSK modelling framework to predict tibiofemoral medial and lateral compartment KJCF during walking in patients with medial dominant knee OA and varus alignment, and 2) evaluate the effect of MOWHTO on KJCFs during walking.
Chapters 2 and 3 sought to better understand the effects of adjusting patient-specific model parameters. Chapter 2 evaluated results from patient-specific NMSK models using two control modes. Results indicated the EMG-assisted control mode, compared to the EMG-driven control mode, provided greater consistency between knee flexion torques and KJCFs were better aligned with previous studies. Chapter 3 compared patient-specific EMG-assisted models with a neutral varus angle (0º) and a patient-specific varus angle. No statistically significant differences occurred in the KJCFs between models after adjusting this parameter. Chapter 4 investigated: 1) the effect of medial opening wedge HTO on medial and lateral tibiofemoral compartment KJCFs during walking, using the established patient-specific EMG-assisted modelling framework, 2) changes in the external knee adduction moment (EKAM) and muscle co-contraction indices (CCIs), and 3) associations between the changes in medial compartment KJCF and EKAM and CCIs. There were moderate improvements in medial KJCFs (standardized response mean, SRM>0.60) and small-to-large reductions in the EKAM (SRM>0.90) and CCIs (SRM>0.20). Correlations between changes in medial KJFCs and EKAM and muscle CCI were low-to-moderate (r
Results from this thesis contribute to the development of a patient-specific EMG-assisted modelling framework to predict KJCF during walking in patients with medial dominant knee OA and varus alignment. The EMG-assisted NMSK modeling framework suggests medial opening wedge HTO substantially decreases knee medial compartment load during walking.