This study evaluates the feasibility and utility of contrast-enhanced ultrasound to provide real-time assessment of blood flow to the femoral head in infants undergoing surgical reduction for developmental dysplasia of the hip.

For children presenting with late-diagnosed developmental dysplasia of the hip, a closed or open hip reduction followed by hip spica casting may be indicated if conservative treatment fails. Although closed or open reduction and casting is largely successful for relocating a hip, iatrogenic avascular necrosis remains a major source of morbidity as a result of the surgical procedure.

Although recent evidence has demonstrated that postoperative gadolinium-enhanced magnetic resonance (MR) studies may be useful in assessing perfusion of the hip after surgery, these studies are not performed until after the cast is placed and they do not elucidate the specific intraoperative steps that increase risk for osteonecrosis. Contrast-enhanced ultrasound (CEUS) may be a reliable and effective alternative.

Inclusion Criteria:

• Males or females between 4 months and up to and including 24 months of age at the time of surgery.
• Diagnosed with DDH.
• Failed conservative treatment, or present with late-diagnosed DDH (where conservative treatment would not be appropriate to initiate at their age), and are undergoing closed or open reduction and spica casting.
• Informed consent (parental permission)

Exclusion Criteria:

• > 24 months of age at the time of surgery.
• Subjects with DDH who are successfully treated with conservative measures and do not require surgical reduction.
• Previous open hip reduction of the affected side
• Children with known complex congenital heart disease or unstable cardiopulmonary conditions (as noted in the package labeling for Lumason) including acute myocardial infarction, acute coronary artery syndromes, worsening or unstable congestive heart failure or serious ventricular arrhythmias will be excluded.
• History of allergic reaction to Lumason, sulfur hexafluoride, sulfur hexafluoride lipid microsphere components, or other ingredients in Lumason (polyethylene glycol, distearoylphosphatidylcholine (DSPC), dipalmitoylphosphatidylglycerol sodium (DPPG-Ns), palmitic acid).Parental/guardian permission (informed consent) and if appropriate, child assent.

The surgeon and musculoskeletal radiologist administering the contrast-enhanced ultrasound will not be blinded at the time of the intervention; however, they will be blinded when comparing the results of the CEUS to standard-of-care perfusion MRI and 3-years postop radiographs.