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Establishing reference values for the pubofemoral distance in normal infant medial hips by ultrasound
Yongguang Ban1, Qinhua Luan1,2, Miao Shi3
1Shandong Medical Imaging Research Institute Affiliated to Shandong University, Jinan, PR China.
Insights
Pubofemoral distance (PFD) reference values were established for infants aged 0-12 months. PFD increases with age but is not affected by gender or hip laterality, aiding developmental dysplasia of the hip (DDH) treatment monitoring.
Area of Science:
- Pediatric Orthopedics
- Medical Imaging
- Developmental Biology
Background:
- The pubofemoral distance (PFD) is a key metric for assessing hip reduction efficacy in treating developmental dysplasia of the hip (DDH).
- Establishing normative PFD values in healthy infants is crucial for accurate diagnosis and treatment monitoring.
- Current literature lacks established reference PFD values for normal infant hips.
Purpose of the Study:
- To determine reference pubofemoral distance (PFD) values in the medial hip of normal infants.
- To investigate the influence of age, laterality, and gender on PFD measurements in infants.
- To provide a basis for evaluating hip development and treatment outcomes in pediatric patients.
Main Methods:
- A cohort of 240 infants (0-12 months) with Graf type Ia/Ib hips underwent transinguinal ultrasound.
- Pubofemoral distance (PFD) was measured as the distance between the superior pubic ramus and the femoral head.
- Infants were stratified into eight age groups; inter-observer reproducibility was assessed.
Main Results:
- Mean PFD values showed a significant linear increase with age in both left and right hips (r > 0.68, P < 0.0001).
- No significant differences in PFD were observed between left and right hips (P = 0.345) or between genders (P = 0.149).
- Inter-observer reproducibility for PFD measurements was excellent.
Conclusions:
- This study successfully established reference pubofemoral distance (PFD) values for infants aged 0-12 months.
- PFD measurements increase with age and are not significantly influenced by hip laterality or infant gender.
- These normative data are valuable for the follow-up and management of infants diagnosed with developmental dysplasia of the hip (DDH).
Background:
Measuring the pubofemoral distance (PFD) is important for evaluating the effectiveness of hip reduction in the treatment of developmental dysplasia of the hip (DDH). However, reference PFD values have not been established in normal infants.
Purpose:
To investigate variations in PFD values measured in normal infant medial hips stratified by age, laterality, and gender.
Material And Methods:
A total of 240 infants diagnosed with Graf type Ia and/or Graf type Ib hips by ultrasonography were stratified into eight age groups: 0-1 month; 1-2 months; 2-3 months; 3-4 months; 4-5 months; 5-6 months; 6-7 months; and 7-12 months. The bilateral medial hips were scanned with transinguinal ultrasound. The PFD was defined as the distance between the lateral edge of the superior ramus of pubic bone and the medial edge of the femoral head. Inter-observer reproducibility was assessed.
Results:
Among the 240 infants, there were 371 Graf type Ia hips and 109 Graf type Ib hips. Mean ± SD bilateral PFD values of eight groups were measured separately. There were no significant differences in mean PFD values for left or right hips (t = 0.946, P = 0.345) or mean bilateral PFD values in male and female infants (t = 1.445, P = 0.149). Mean PFD values increased linearly with age (left: r = 0.680, P < 0.0001; right: r = 0.682, P < 0.0001). Inter-observer reproducibility was excellent.
Conclusion:
This study established reference PFD values from the medial hip in infants aged 0-12 months. PFD values increased with age, but were not significantly influenced by laterality or gender. These data provide detailed information that can support follow-up of infants treated for DDH.
