Detecting postoperative change in children with cerebral palsy: net nondimensional versus body mass oxygen...

Area of Science:

• Biomedical Engineering
• Pediatric Orthopedics
• Movement Science

Background:

• Cerebral palsy (CP) often affects gait, increasing the energy cost of walking.
• Equinus deformity surgery aims to improve gait kinematics and reduce energy expenditure in children with CP.
• Accurate measurement of energy cost changes is crucial for evaluating surgical outcomes.

Purpose of the Study:

• To determine if the net nondimensional oxygen utilization scheme can identify postoperative improvements in walking energy cost in children with CP.
• To compare the efficacy of the net nondimensional scheme against a body mass normalization scheme.

Main Methods:

• Evaluated 10 children with spastic cerebral palsy before and 9 months after equinus deformity surgery.
• Measured oxygen utilization (VO₂) during treadmill walking at 2 km/hr and 3 km/hr.
• Calculated mass-relative VO₂ and net nondimensional VO₂, using coefficient of variation to assess inter-subject variability.

Main Results:

• Postoperative improvements in gait kinematics were observed.
• Both mass-relative VO₂ and net nondimensional VO₂ demonstrated significant postoperative improvement.
• The net nondimensional VO₂ scheme detected improvements with lower inter-subject variability compared to body mass normalization.

Conclusions:

• The net nondimensional oxygen utilization scheme is a sensitive tool for detecting postoperative improvements in energy cost of walking in children with cerebral palsy.
• This scheme offers a more consistent measure of recovery than body mass normalization in this pediatric population.