PMC8205268_01
Knee kinematics (gait analysis). Knee kinematics of the involved limb at 10, 12 and 14 years of age. Gait deterioration at 12 years indicated the need for surgery to improve knee flexion during swing phase (peeak reduced to 40 ). Gait normalized at 2 years post-surgery (peak 60 )
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At this time, other kinematic, kinetic and spatiotemporal variables were within normal ranges ( Fig. 2 ). Posterior compartment volumes were symmetrical in both limbs. 3D gait analysis revealed a lack of right knee flexion during the swing phase (peak flexion: 40 ), decreased ankle plantar flexion at the end of the stance phase and the beginning of swing phase, and a decrease in gait speed, compared with the previous assessment at 10 years (Fig. 2).
Graph showing the fatty infiltration of leg muscle, expressed as a percentage of the total volume, for the vastus intermedius at 12 years of age, before the Judet quadricepsplasty. The data were assessed by a DIXON sequence using MRI images taken different levels.
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MRI scan revealed a medial-distal impairment of the vastus intermedius (VI), associated with fatty infiltration and atrophy of the anterior compartment (Table II) in her right leg compared with the left leg. Muscle fat quantification using the DIXON sequence revealed an increased fat fraction in the distal third of the VI (20%) compared with the uninvolved limb (3%) (Fig. 3).
A 3-dimensional illustration of the thighs of the child aged 14, 2 years post Judet quadricepsplasty. Each thigt muscle volume was assessed with MRI using an E-THRIVE sequence by manual segmentation of cross sectional area of each slice 9, 10 and showed atrophy of the whole anterior compartment, and more specifically of the Vastus intermedius. a) 3 dimensional reconstructions of thigh muscles based on manual segmentation completed with voxel remesh technique. b) MRI Axial section of the distal third of both thighs. c) 3 dimensional reconstructions: axial section. Vastus intermedius is colored in red on each figure and surrounded with a dotted line.
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Accordingly, anterior compartment volume ratio reduced post-operatively (0.49 at 14 years) (Fig. 4), but increased to preoperative levels by the age of 16 years (0.62) due to an increase in VI volume (Table II).