Management of 12-Month-Old with Asymmetrical Hip Crease and Increased Acetabular Angles
This child requires prompt pediatric orthopedic referral within 2-4 weeks for evaluation and potential treatment, as the acetabular angles of 25-26 degrees at 12 months of age are borderline elevated and warrant specialist assessment to prevent progressive acetabular underdevelopment. 1
Interpretation of Imaging Findings
The radiographic findings indicate mild developmental dysplasia of the hip (DDH):
Acetabular index interpretation: Normal acetabular index is approximately 30° in newborns and progressively decreases with growth and maturation. 2 At 12 months of age, acetabular angles of 25-26 degrees are at the upper limit of normal to mildly increased, representing mild acetabular dysplasia. 2
Positive prognostic signs: The bilateral capital femoral epiphyses have begun to ossify, are normally located, and appear symmetrical, which indicates the hips are concentrically reduced. 1 This is critical because development of the acetabular cavity is determined by the presence of a concentrically reduced femoral head. 3
Recommended Management Algorithm
Immediate Action
Refer to pediatric orthopedic surgeon within 2-4 weeks to prevent further acetabular underdevelopment and establish a monitoring plan. 1 The American Academy of Orthopaedic Surgeons emphasizes that prompt evaluation is appropriate for children with radiographic evidence of dysplasia. 1
Specialist Evaluation Will Determine
Observation versus intervention: At 12 months with concentrically reduced hips and only mild acetabular dysplasia, many cases will improve with continued growth and weight-bearing. 3 The acetabular index typically decreases in response to concentric hip reduction. 2
Serial radiographic monitoring: The orthopedic surgeon will establish a surveillance protocol with radiographs at regular intervals (typically every 3-6 months initially) to assess whether the acetabular angles are improving or worsening. 4
Treatment threshold: If the acetabular dysplasia persists or worsens despite observation, surgical intervention (typically pelvic osteotomy) may be indicated. 3 However, at this age with mild dysplasia and reduced hips, immediate surgical treatment is unlikely. 3
Key Prognostic Factors
The evolution of the acetabular index over time is the best parameter to predict persistent acetabular dysplasia at maturity. 3 This is why serial monitoring is essential:
- If acetabular angles continue to decrease with growth, no intervention may be needed. 3
- If angles remain elevated or increase, surgical correction becomes more likely. 3
Critical Pitfalls to Avoid
Do not delay referral: While these findings represent mild dysplasia, untreated or inadequately treated DDH leads to early degenerative joint disease, with DDH causing up to one-third of total hip arthroplasties in patients under 60 years. 4
Do not assume symmetry equals normal: Bilateral involvement can occur, and the asymmetrical hip crease suggests clinical concern that prompted appropriate imaging. 1
Do not use bracing at this age: The Pavlik harness and other abduction devices are indicated for infants under 6 months with unstable or dislocated hips. 5, 6 At 12 months with reduced hips, bracing is not appropriate. 5
Parent Counseling
- Explain that the hip sockets are slightly shallow for age but the hip joints are in proper position. 2
- Emphasize the importance of orthopedic follow-up to monitor development. 4
- Reassure that with appropriate monitoring, most cases of mild dysplasia improve with growth, but specialist oversight is essential to determine if intervention becomes necessary. 3