Pavlik harness treatment is the standard of care for developmental dysplasia of the hip in infants younger than 6 months. The effect of Pavlik harness treatment on the achievement of motor milestones has not previously been reported.

In this prospective cohort study, 35 patients were prospectively enrolled to participate and received questionnaires with sequential clinical visits monitoring treatment of their developmental dysplasia of the hip. One-sample Student t-tests assessed differences in milestone attainment age, and the Benjamini-Hochberg procedure was conducted to decrease the false discovery rate. Post hoc power analyses of each test were conducted. The age of achievement of eight early motor milestones were recorded and compared with a previously published cohort of healthy infants.

Infants treated with a Pavlik harness achieved four early motor milestones markedly later than the reported age of achievement in a historical control group. These milestones included “roll supine” (5.3 vs. 4.5 months; P = 0.039), “roll prone” (5.7 vs. 5.0 months; P = 0.039), “sit” (6.4 vs. 5.2 months; P < 0.001), and “crawl on stomach” (7.7 vs. 6.6 months; P = 0.039). However, there was no difference in time to achievement of later motor milestones of “crawl on knees,” “pull to stand,” and “independent walking.”

Several early motor milestones were achieved at a statistically significantly later time than historical control subjects not treated in a Pavlik harness. Despite statistical significance, the small delays in early motor milestones were not thought to be clinically significant. No differences were observed in the later motor milestones, including knee crawling, standing, and independent walking. Clinicians and parents may be reassured by these findings.

Therapeutic Level II—prospective study.