Kinematic Trajectories Throughout Childhood in Cerebral Palsy: The Influence of Age and Orthopaedic Surgery

Gait abnormalities are common in children with cerebral palsy (CP), but no prior studies have examined longitudinal changes in gait kinematics throughout childhood. The purpose of this study was to analyze changes in gait (i.e., trajectories) throughout childhood to determine the influence of age and orthopedic surger(ies) on kinematic outcomes. Prospective cohort. Children with unilateral or bilateral spastic CP [Gross Motor Function Classification System (GMFCS) I-III] were recruited between ages 17 to 40 months. Instrumented gait analyses (IGA) were performed serially over ages 6 to 21 years to collect kinematic data at self-selected, bare-foot walking speed. The primary outcome measure was the change in Gait Profile Score (ΔGPS), a validated measure of gait function. ΔGPS was analyzed by age distribution (ΔGPS were compared using ANOVA with Tukey HSD posthoc analyses. Changes in component GVS (ΔGVS) were compared using Welch's t-tests. 31 children (62 sides) were included [diplegic(16), hemiplegic(15); GMFCS: I(13), II(14), III(4)]. Children completed a total 5.8±1.6 IGAs, 2.5±1.3 years apart. Comparing the ΔGPS between the initial (at 5.8±1.1 years) and final IGA (at 17.8±2.1 years), 86% of the limbs were improved or unchanged. 180 total visits provided 298 intervals of ΔGPS that were classified as nonsurgical (n=235) or surgical (n=63). Significantly more GPS improvement was identified in age intervals with surgery (-1.4±2.9) compared to without surgery (0.1±2.4) (p=0.0004). By age interval, significantly more GPS improvement was identified in the Comparing the effect of surgery on ΔGPS by age, surgical intervention was associated with an “improved” outcome for only the Trajectories of gait function in children with CP are greatly influenced by age and surgical intervention. Improvements in gait are more likely in early versus late childhood. Surgeries in the 10-15 and ≥15 age intervals showed less change in patients’ GPS scores, yet gait function was largely maintained over the longer term. Orthopedic surgery had a positive impact for all three age groups, with the greatest post-surgical changes seen in children under age 10 years. The results of this longitudinal prospective study may be used to help inform the best timing for gait correction surgery in bilateral CP. Information gleaned regarding the positive role of orthopedic surgery on gait may be imparted during parent/patient pre-operative counseling to help in decision-making.