This prospective longitudinal multicenter study of ambulatory children with cerebral palsy (CP) examined changes in outcome tool score over time, tool responsiveness, and used a systematic method for defining minimum clinically important differences (MCIDs). Three hundred and eighty‐one participants with CP (Gross Motor Function Classification System [GMFCS] Levels I–III; age range 4–18y, mean age 11y [SD 4y 4mo]; 265 diplegia, 116 hemiplegia; 230 males, 151 females). At baseline and follow‐up at least 1 year later, Functional Assessment Questionnaire, Gross Motor Function Measure, Pediatric Quality of Life Inventory, Pediatric Outcomes Data Collection Instrument, Pediatric Functional Independence Measure, temporal–spatial gait parameters, and oxygen cost were collected. Adjusted standardized response means determined tool responsiveness for nonsurgical (n=292) and surgical (n=87) groups at GMFCS Levels I to III. Most scores reaching medium or large effect sizes were for GMFCS Level III. Nonsurgical group change scores were used to calculate MCID thresholds for ambulatory children with CP. These values were verified by examining participants who changed GMFCS levels. Tools measuring function were responsive when a change large enough to cause a change in GMFCS level occurred. MCID thresholds assess change in study populations over time, and serve as the basis for designing prospective intervention studies.

This prospective cross‐sectional multicenter study assessed the relationships between Gross Motor Function Classification System (GMFCS) level and scores on outcome tools used in pediatric orthopedics. Five hundred and sixty‐two participants with cerebral palsy (CP; 339 males, 223 females; age range 4‐18y, mean age 11y 1mo [SD 3y 7mo]; 400 with diplegia, 162 with hemiplegia; GMFCS Levels I‐III;) completed the study. The Functional Assessment Questionnaire (FAQ), Gross Motor Function Measure (GMFM) Dimensions D and E, Pediatric Quality of Life Inventory (PedsQL), the Pediatric Outcomes Data Collection Instrument (PODCI), Pediatric Functional Independence Measure (WeeFIM), temporal‐spatial gait parameters, and O2 cost were collected during one session. Descriptive characteristics are reported by GMFCS level clinicians can use for comparison with individual children. Tools with a direct relationship between outcome scores and GMFCS levels were the PODCI Parent and Child Global Function, Transfers & Basic Mobility, and Sports and Physical Function; PODCI Parent Upper Extremity Function; WeeFIM Self‐care and Mobility; FAQ Question 1; GMFM Dimensions D and E; GMFM‐66; O2 cost; and temporal‐spatial gait parameters. Child report scores differed significantly higher than Parent scores for six of eight PODCI subscales and three of four PedsQL dimensions. Children classified into different GMFCS levels function differently.

Background-Lower-extremity musculotendinous surgery is standard treatment for ambulatory children with deformities such as joint contractures and bony torsions resulting from cerebral palsy (CP). However, evidence of efficacy is limited to retrospective, uncontrolled studies with small sample sizes focusing on gait variables and clinical examination measures. The aim of this study was to prospectively examine whether lower-extremity musculotendinous surgery in ambulatory children with CP improves impairments and function measured by gait and clinical outcome tools beyond changes found in a concurrent matched control group.

ABBREVIATIONS BIABioelectrical impedance analysis CCC Concordance correlation coefficient DXA Dual-energy X-ray absorptiometry AIM This study assessed the accuracy of measurements of body fat percentage in ambulatory individuals with cerebral palsy (CP) from bioelectrical impedance analysis (BIA) and skinfold equations.METHOD One hundred and twenty-eight individuals (65 males, 63 females; mean age 12y, SD 3, range 6-18y) with CP (Gross Motor Function Classification System [GMFCS] levels I (n=6), II (n=46), and III (n=19) participated. Body fat percentage was estimated from (1) BIA using standing height and estimated heights (knee height and tibial length) and (2) triceps and subscapular skinfolds using standard and CP-specific equations. All estimates of body fat percentage were compared with body fat percentage from dual-energy X-ray absorptiometry (DXA) scans. Differences between DXA, BIA, and skinfold body fat percentage were analyzed by comparing mean differences. Agreement was assessed by Bland-Altman plots and concordance correlation coefficients (CCC).RESULTS BMI was moderately correlated with DXA (Pearson's r=0.53). BIA body fat percentage was significantly different from DXA when using estimated heights (95% confidence intervals [CIs] do not contain 0) but not standing height (95% CI À1.9 to 0.4). CCCs for all BIA comparisons indicated good to excellent agreement (0.75-0.82) with DXA. Body fat percentage from skinfold measurements and CP-specific equations was not significantly different from DXA (mean 0.8%; SD 5.3%; 95% CI À0.2 to 1.7) and demonstrated strong agreement with DXA (CCC 0.86).INTERPRETATION Accurate measures of body fat percentage can be obtained using BIA and two skinfold measurements (CP-specific equations) in ambulatory individuals with CP. These findings should encourage assessments of body fat in clinical and research practices.

The relationships between different levels of severity of ambulatory cerebral palsy, defined by the Gross Motor Function Classification System (GMFCS), and several pediatric outcome instruments were examined. Data from the Gross Motor Function Measure (GMFM), Pediatric Orthopaedic Data Collection Instrument (PODCI), temporal-spatial gait parameters, and oxygen cost were collected from six sites. The sample size for each assessment tool ranged from 226 to 1047 participants. There were significant differences among GMFCS levels I, II, and III for many of the outcome tools assessed in this study. Strong correlations were seen between GMFCS level and each of the GMFM sections D and E scores, the PODCI measures of Transfer and Mobility, and Sports and Physical Function, Gait Velocity, and Oxygen Cost. Correlations among tools demonstrated that the GMFM sections D and E scores correlated with the largest number of other tools. Logistic regression showed GMFM section E score to be a significant predictor of GMFCS level. GMFM section E score can be used to predict GMFCS level relatively accurately (76.6%). Study data indicate that the assessed outcome tools can distinguish between children with different GMFCS levels. This study establishes justification for using the GMFCS as a classification system in clinical studies.