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Association Between Alpha Angle and Acetabular Index in Screening for Developmental Dysplasia of the Hip
Jose Roberto Acosta Gomez1, German Roberto Acosta Gomez1, Vianey Espinosa Martinez1
1Orthopaedics, Hospital General de Mexico "Dr. Eduardo Liceaga", Mexico City, MEX.
Insights
Early detection of developmental dysplasia of the hip (DDH) is vital. Increased alpha angles in infants correlate with better acetabular index measurements, indicating normal hip development.
Area of Science:
- Pediatric Orthopedics
- Diagnostic Imaging
- Developmental Dysplasia of the Hip (DDH)
Background:
- Developmental dysplasia of the hip (DDH) is a spectrum of hip joint instability requiring early detection.
- Mexican regulations (Norma Oficial Mexicana - NOM) mandate pediatric hip screening.
- This study examines alpha angles and acetabular index in infants at six months.
Purpose of the Study:
- To investigate the relationship between alpha angles and acetabular index in pediatric patients at six months of age.
- To determine if increasing alpha angles correlate with improved acetabular index.
- To assess the diagnostic utility of alpha angles in identifying normal hip development.
Main Methods:
- 120 pediatric patients screened for hip issues using Graf's method before three months of age.
- Follow-up at six months included acetabular index measurement via institutional X-rays.
- Measurements were performed using the Carestream platform.
Main Results:
- A significant inverse relationship was found between left hip alpha angle and acetabular index (p=0.015).
- A significant relationship was observed between right hip alpha angle and acetabular index (p=0.017).
- These relationships were not significant for acetabular index values below 25°.
Conclusions:
- Universal hip screening is essential for early DDH detection.
- Alpha angle measurements greater than 70° are reliable indicators of normal hip health.
- This study supports the use of alpha angles in pediatric hip assessments.
Background:
Developmental dysplasia of the hip (DDH) is a critical orthopedic condition ranging from minor hip joint instability to complete dislocations, demanding early intervention to avoid severe complications, especially in children. In Mexico, stringent regulations under the Norma Oficial Mexicana (NOM) mandate hip screening for pediatric patients. The primary objective of this study is to investigate the relationship between alpha angles and the acetabular index in patients at six months of age, aiming to determine whether an increase in the alpha angle correlates with a better acetabular index.
Methods:
We included 120 patients who were screened for hip issues with Graf's methodology in June 2023 and September 2023 at the General Hospital of Mexico "Dr. Eduardo Liceaga" in Mexico City before three months of age and attended their follow-up appointment at six months of age, where acetabular index measurement was performed using the Carestream platform on institutional X-rays.
Results:
In our statistical analysis, we obtained a statistically significant relationship between an increase in the left hip alpha angle and a decrease in the left hip acetabular index (p=0.015) although it was not significant for an acetabular index of less than 25° (p=0.055). A significant relationship was observed between the right hip acetabular index and the right hip alpha angle (p=0.017) but not significant for an acetabular index less than 25° (p=0.10).
Conclusion:
Universal hip screening is crucial for the early detection of DDH. Our study emphasizes using alpha-angle measurements (>70°) as reliable indicators of normal hip health.
