Helmet treatment of deformational plagiocephaly: the relationship between age at initiation and rate of correction.

BACKGROUND The purpose of this study was to evaluate the relationship between age at initiation of helmet therapy for deformational plagiocephaly and the rate of correction. METHODS Infants treated for deformational plagiocephaly with a helmet orthosis between 2009 and 2010 were included. Patients were stratified prospectively by the age at which treatment was initiated: group 1, younger than 20 weeks (n = 26); group 2, 20 to 23.9 weeks (n = 59); group 3, 24 to 27.9 weeks (n = 82); group 4, 28 to 31.9 weeks (n = 62); group 5, 32 to 35.9 weeks (n = 45); group 6, 36 to 40 weeks (n = 29), and group 7, older than 40 weeks (n = 43). Pretreatment and posttreatment calvarial asymmetry was measured using direct anthropometry and reported as a transcranial difference. RESULTS Three hundred forty-six infants were included; initial transcranial difference was equivalent on all paired-group comparisons. Duration of helmet therapy positively correlated with age at initiation (r = 0.89, p < 0.05). The rate of change in transcranial difference correlated negatively with age at treatment onset (r = -0.88, p < 0.05): group 1, 0.93 mm/week; group 2, 0.64 mm/week; group 3, 0.59 mm/week; group 4, 0.56 mm/week; group 5, 0.41 mm/week; group 6, 0.42 mm/week; and group 7, 0.42 mm/week). At the conclusion of therapy, all groups had improved calvarial symmetry, albeit less completely in groups 6 and 7. CONCLUSIONS The correction rate of plagiocephaly with helmet therapy decreases with increasing infant age; after 32 weeks, there is a slow and relatively constant rate of change. Improvement can still be achieved in infants older than 12 months. CLINICAL QUESTION/LEVEL OF EVIDENCE Therapeutic, II.