Application of Accepted Use Criteria for the Treatment of Developmental Dysplasia of the Hip Decreases the Number of Infants Treated With a Pavlik Harness

BACKGROUND: This analysis examined how the application of the American Academy of Orthopedic Surgeons appropriate use criteria (AUC) for developmental dysplasia of the hip in infants would change treatment patterns and outcomes for Graf IIA hips at a single quaternary pediatric hospital. METHODS: After Institutional Review Board approval, patient medical records were reviewed and data were collected. Graf IIa hips were defined as alpha angle (AA) 50 to 59 degrees. AA and femoral head coverage (FHC) were measured from initial and 6-month ultrasounds and acetabular index (AI) was measured from radiographs at 6 months of age. Instability (positive Ortolani and Barlow tests) was noted. On the basis of the American Academy of Orthopedic Surgeons AUC for managing developmental dysplasia of the hip, hips were further categorized as normal (FHC ≥45%), borderline (FHC 35% to 44%), or dysplastic (FHC <35%). RESULTS: Overall, 13% (49/371) of Graf IIa hips (AA 50 to 59 degrees) were dysplastic (FHC <35%). Total 24% (89/371) were clinically unstable. Total 42% (37/89) of unstable Graf IIa hips were dysplastic. Only 4% of stable Graf IIa hips were dysplastic (12/282). Out of 371 Graf IIa hips, 256 were treated with Pavlik harness (n=250) or Rhino brace (n=6). Among stable, nondysplastic (SND) hips (those with normal and borderline FHC≥35%), 33% (52/158) were treated because of a more severe contralateral side. If the AUC had been applied, 67% (106/158) of SND Graf IIa hips would not have been treated. Among the n=162 hips that returned for a 6-month radiograph, there was no difference in AI in the 115 treated and 47 untreated SND hips (mean difference treatment vs. no treatment: -1.5, 95% CI, -3.1 to 0.2, P =0.0808). CONCLUSIONS: Using AUC recommendations, our center could reduce the number of SND Graf IIa hips we treat by 67%. Although 24% of Graf IIa hips were clinically unstable and 13% were dysplastic based on FHC, most Graf IIa hips had normal or borderline FHC per the AUC and may do well with observation and follow-up ultrasound at 12 weeks old. LEVEL OF EVIDENCE: Level III-diagnostic study.