# Ultrasound for hip dysplasia – disparities between community and tertiary paediatric services

## TL;DR

The study finds that ultrasound reports for hip dysplasia in infants vary significantly between community and tertiary centers, leading to potential misdiagnoses.

## Contribution

The study highlights the lack of standardized ultrasound reporting for hip dysplasia and its impact on diagnostic accuracy in community settings.

## Key findings

- Moderate agreement (Rho = 0.60-0.61) was found between community and tertiary ultrasound reports for hip dysplasia.
- Over 25% of hips classified as abnormal in community reports may be normal, and more than 15% of dysplastic hips could be undetected.
- Variability in reporting increases with greater hip dysplasia, suggesting a need for standardized guidelines.

## Abstract

Explore the differences in ultrasound reporting between community ultrasound centres and a high‐volume paediatric tertiary centre in diagnosing developmental dysplasia of the hip (DDH).

One hundred infants less than 6 months of age from a paediatric hip registry, who underwent ultrasounds in both community and tertiary centres within a 2‐week interval.

One percent of a 200‐hip sample reported scan quality. Alpha angles were reported in 84.5% (n = 169) of community reports and 78.5% (n = 157) of tertiary centre reports. Femoral head coverage was reported similarly in both environments at 94.5% in community and 93.5% in tertiary. Beta angle appeared in 45% (n = 90) and 2% (n = 4), respectively. Bland Altman plots revealed that there existed variation in ultrasound interpretation especially in more dysplastic hips. The concordance correlation coefficient showed only moderate agreement (Rho = 0.60 for alpha angles, Rho = 0.61 for femoral head coverage), and interrater reliability on hip classification reached moderate agreement (Cohen's Kappa = 0.57 for alpha angle, and 0.45 for femoral coverage) between community and tertiary hospital reports.

Reliance on the community‐acquired ultrasound report as a true reflection of the state of a hip is not completely justified. The lack of standardized reporting poses challenges for community clinicians in starting treatment or making appropriate referrals. Only a moderate agreement has been observed between the community and tertiary scans. Consequently, over 25% of hips classified as abnormal are potentially normal, and more than 15% dysplastic hips could be undetected.

Ultrasonography is crucial for assessing hip dysplasia in infants less than 6 months. Community clinicians rely on ultrasound reports rather than images for management decisions. However, the absence of standardized guidelines for reporting leads to varied practices. Our study found that although there is moderate agreement between the community and tertiary scans, greater degrees of dysplasia resulted in increased variance in reporting. Consequently, over 25% of hips classified as abnormal are potentially normal, and more that 15% dysplastic hips could be undetected. Future efforts should focus on standardization of reporting, credentialling centres, and improving training for community ultrasonographers.