Postreduction computed tomography in developmental dislocation of the hip: part II: predictive value for outcome

Area of Science:

• Orthopedics
• Radiology
• Pediatric Surgery

Background:

• Developmental hip dislocation (DDH) requires effective reduction techniques.
• Spica casting is a common post-reduction treatment for DDH.
• Assessing reduction quality and predicting outcomes is crucial for managing DDH.

Purpose of the Study:

• To evaluate the correlation between CT-measured parameters and outcomes after closed reduction of developmental hip dislocation in infants.
• To identify predictive factors for persistent dysplasia and avascular necrosis following treatment.

Main Methods:

• Computed tomographic (CT) scans were performed on 53 infants (68 hips) post-closed reduction and spica casting for DDH.
• Ten measurements, including acetabular indices, anteversion, hip-abduction angle, and femoral displacement, were analyzed.
• Analysis of variance was used to correlate these variables with outcomes such as persistent dysplasia and avascular necrosis.

Main Results:

• No CT-measured variables predicted the outcome of persistent hip dysplasia.
• A statistically significant association was found between hip-abduction angles >55 degrees on postreduction CT scans and the subsequent development of avascular necrosis.
• 20% of hips with hip-abduction angles >55 degrees developed avascular necrosis during follow-up.

Conclusions:

• Postreduction CT parameters, except for hip-abduction angle, do not reliably predict persistent dysplasia in DDH.
• Elevated hip-abduction angles (>55 degrees) on postreduction CT scans are a risk factor for avascular necrosis in treated DDH.
• Close monitoring is recommended for infants with hip-abduction angles exceeding 55 degrees post-reduction.