Background: Only a few studies have investigated the change in energy cost and functional ability after lower limb bone surgeries in children with cerebral palsy (CP).

Research Objectives: To examine the effect of intervention (surgery) in the operated group over time on: Energy cost values, Walking functions, and on Functional mobility.

Setting: Motion analysis laboratory and the child development and rehabilitation center at Assaf Harofeh Medical Center.

Methods: Participants in the study consisted of 41 children with CP. The study consisted of two groups: one that had undergone surgery (the operated group) and a control group. The operated group consisted of 20 children with CP who were candidates for Femoral Derotation Osteotomy (FDO) or Tibial Derotation Osteotomy (TDO), or both. They were examined three times: the first was one day prior to surgery; the second was six months after surgery; and the third was about a year after surgery. Each examination included: anthropometric measurements, energy cost measurement using the Heart beat cost index (HBCI) in the stair climbing test, assessment of function during walking using the Functional assessement questionnaire (FAQ) and assessment of motor function using the Gross motor functional classification system (GMFCS). Control group consisted of 21 children with CP in ages compatible to the operated group, who had not been operated during the passing year. The control group was examined two times, the second a year after the first. The examination was the same as in the operated group.

Main Results: In the operated group, a significant change (p< 0.0076) was observed in energy cost values over time following surgical intervention. The change was indicated in decreasing energy cost values from measurement to measurement (from value of 0.91 to value of 0.48). Significant decrease was found in the third measurement, as compared to the first measurement (p=0.0026). In the control group, a decrease, although not significant (p=0.062) was observed in energy cost values. Angles values measured in both hip and tibia a year after surgery were changed significantly (p< 0.004). Angles values after surgery were measured within normal range.

Conclusions: This study indicates that the FDO and TRO have effected over time on the energy cost values in the operated group.