Tibial length growth curves for ambulatory children and adolescents with cerebral palsy

AIM The aim of this study was to generate growth curves for ambulatory children and adolescents with cerebral palsy (CP) using tibial lengths and to determine if they differed according to sex or Gross Motor Function Classification System(GMFCS) level. METHOD Growth data were studied from a cohort of 750 participants (442 males, 308 females [1199 visits]; mean age 10y 9mo, SD 3y 4mo, range 4-21y) with CP (hemiplegia, n=163; diplegia, n=573; triplegia, n=11; quadriplegia n=2; GMFCS levels I-III), and 165 typically developing children (96 males, 115 females; [211 visits]) mean age 10y 9mo, SD 4y 2mo, range 4-19y). Tibial length measurements calculated from data collected during routine gait analyses were validated using anthropometric tibial length measurements and were used to generate growth curves for males and females classified as GMFCS level I, II, or III. Growth was compared in participants of different sexes and GMFCS levels using the median curves. RESULTS Growth curves for males and females (GMFCS levels I-III) with estimate lines for 3rd, 10th, 25th, 50th, 75th, 90th, and 97th centiles were generated. Mean tibial length was greater in males than in females in all GMFCS levels. Tibial lengths were shorter in participants classified as GMFCS level III than in those classified as GMFCS level I or II. INTERPRETATION To our knowledge this is the first large-scale investigation of bone growth in ambulatory children and adolescents with CP. The large sample made it possible to generate growth curves and to provide insight into growth trends. The study findings serve as a basis for analysis of the relationships between growth, function, and treatment outcomes.