Efficacy of passive helmet therapy for deformational plagiocephaly: report of 1050 cases

There has been a tremendous increase in the incidence of deformational plagiocephaly in children throughout the world. Therapeutic options include observation, active counterpositioning, external orthotics, and surgery. The current treatment in the US is highly debated, but it typically includes external orthotic helmets in patients with moderate to severe plagiocephaly presenting between 4 and 10 months of age or in children with significant comorbidities limiting passive (no-pressure) therapy. The present study was designed to evaluate 3 key issues: 1) the accuracy of the Argenta classification in defining a progressive degree of severity, 2) identification of an upper age limit when treatment is no longer effective, and 3) the effectiveness of an off-the-shelf prefabricated helmet in correcting deformational plagiocephaly.

An institutional review board-approved retrospective study was conducted of all patients at the authors' clinic in whom deformational plagiocephaly was assessed using the Argenta classification system over a 6-year period; the patients underwent helmet therapy, and a minimum of 3 clinic visits were recorded. Inclusion criteria consisted of an Argenta Type II-V plagiocephalic deformity. Patients' conditions were categorized both by severity of the deformity and by patients' age at presentation. Statistical analysis was conducted using survival analysis.

There were 1050 patients included in the study. Patients with Type III, IV, and V plagiocephaly required progressively longer for deformity correction to be achieved than patients with Type II plagiocephaly (53%, 75%, and 81% longer, respectively [p < 0.0001]). This finding verified that the Argenta stratification indicated a progressive severity of deformity. No statistically significant difference in the time to correction was noted among the different age categories, which suggests that the previously held upper time limit for correction may be inaccurate. An overall correction rate to Type I plagiocephaly of 81.6% was achieved irrespective of severity and degree of the original deformity. This suggests that an inexpensive off-the-shelf molding helmet is highly effective and that expensive custom-fitted orthoses may not be necessary. The patients in the older age group (> 12 months) did not have a statistically significant longer interval to correction than the patients in the youngest age group (< 3 months). The mean length of follow-up was 6.3 months.

Patients treated with passive helmet therapy in the older age group (> 12 months) had an improvement in skull shape within the same treatment interval as the patients in the younger age group (< 3 months). This study supports the use of passive helmet therapy for improvement in deformational plagiocephaly in infants from birth to 18 months of age and verifies the stratification of degree of deformity used in the Argenta classification system.