P3D324: Optimizing Newborn Screening Process for Developmental Dysplasia of the Hip

Purpose/Objectives: Developmental Dysplasia of the Hip (DDH) accounts for up to 10% of hip replacements in the United States. However, with early identification 90% can be corrected with bracing. There is a varying consensus among expert groups regarding the optimal time that screening should be recommended. Exams can be inconclusive when obtained before 4 weeks of age due to physiologic laxity. However, multiple studies have demonstrated that initiation of bracing after 7 weeks of age is strongly associated with an additional need for surgical intervention because the hip begins to ossify. This project seeks to evaluate our current DDH process to identify if there are omissions or delays in care that may theoretically lead to suboptimal outcomes.

Design/Methods: Using our institution’s electronic medical record, all infants ≥35 weeks who received a hip ultrasound between January 2021 and January 2023 were identified. Data collection included date of birth, gestational age, sex, indication for ultrasound, date ultrasound was ordered, date ultrasound was performed, results of ultrasound, and any subsequent subspecialty care related to findings. The primary outcome was time to ultrasound. Chi-square and T-tests as appropriate were used to compare outcomes by indication, need for subspecialty care, and whether the infant delivered at our institution versus an outside hospital.

Results: A total of 197 infants underwent hip ultrasound with a median time to initial ultrasound of 9.1 weeks (Table 1). Of these, 42 infants (21%) delivered at an outside hospital. Indications for screening, including breech presentation and abnormal exam, were identified in 161 and 34 respective orders. There were 15 infants (9.3%) with breech presentation who had an abnormal initial ultrasound and 10 (6.1%) who were ultimately referred to orthopedics; the median time to ultrasound for those referred was 9.3 weeks (IQR 7.4 – 11.1). Those who delivered at outside hospitals were delayed in screening (median 10.3 weeks) and were more likely to require referral to orthopedics (7/42 versus 10/155, p=0.037).

Conclusion/Discussion: Screening for hip dysplasia is generally performed after 7 weeks at our institution, and therefore success with bracing is predicted to be suboptimal. A limitation of our current study design is that we do not identify the proportion of infants who may have risk factors for DDH that are not actually screened. However, our proportions suggest that many infants delivered at outside hospitals are being missed since they account for >50% of our pediatric population and only 21% of referrals. We anticipate that the need to refer out of network for orthopedic care further compounds the likelihood of delay in initiating therapy. For these reasons, we propose that screening for DDH be performed at our institution by 6 weeks. Further efforts will be necessary to improve our identification of at-risk infants.