Cerebral palsy (CP) is a neuromuscular disorder that affects the motor control of muscles. CP children exhibit abnormal walking patterns and frequently develop lower limb, long bone deformities. To improve functionality and guide orthopaedic treatments effectively, it is critical to elucidate the relationship existing between bone morphology and movement of the lower limbs CP children.
The hypothesis of this study is that gait abnormalities result in bone deformities. The investigation of this complex relationship represents the core of this thesis.
The examination of magnetic resonance images and gait analysis of healthy and CP children showed different development in femoral and tibial morphology and varied gait characteristics between them. Similarly, different correlations between bone morphology and gait characteristics resulted in healthy and CP children.
Gait characteristics also varied between CP children. An objective and quantitative graphical classification method of CP gait patterns was developed. This classified the CP children in overlapping clusters according to their gait patterns, confirming the presence of multiple gait abnormalities on the same lower limb for CP children.
With the intention to define the effect of the walking characteristics on the bone structure, femoral muscle and hip contact forces in healthy and CP children with different walking strategies were estimated by using inverse dynamic analysis. The different gait styles resulted in different loadings on the developing femur bone. These constituted the loading conditions for bone growth analysis.
A three-dimensional finite element model for femoral growth was developed and mechanobiological theories applied in order to predict femur changes over time in healthy and CP children. The models predicted higher femoral anteversion and neck-shaft angle formation in children with CP, emphasizing how different gait characteristics can influence bone morphology.
This information has potential to explain and eventually prevent or treat the development of bone deformities in CP children.
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