Abstract
Introduction: It is commonly believed that markedly increased femoral anteversion is a primary abnormality and a consistent feature of hip dysplasia. It is also considered to be one of the main factors leading to redislocation. Apart from limited cadaveric studies, the true normal range of anteversion in infants is largely unknown. We measured femoral anteversion in infants using ultrasound. We are presenting our results measuring the femoral anteversion in both normal and DDH hips.
Methods and materials: Anteversion measurements are taken at the time of routine ultrasound screening for Developmental Dysplacia of Hip. This method was previously validated. We measured femoral anteversion in 76 infants with normal hips. We measured femoral ante-version in 27 hips with DDH. The mean femoral ante-version in normal babies is compared to the value in the babies with hip dysplasia using unpaired t-test.
Results: The mean value of femoral anteversion in normal babies in our series was 46.75° with 95% reference interval of 36.34° to 57.17°. The mean femoral anteversion in dysplastic hips was 50.39° with a 95% reference interval of 34.88° to 65.89°. The difference between normal and dysplastic hips was statistically significant (p value −0.0095 and 95% CI of 6.36° to 0.90°). This showed a small increase of femoral anteversion in the dysplastic hips.
Conclusion: We established reference ranges of femoral anteversion in normal and dysplastic hips. Our series showed only a small increase of femoral anteversion in the dysplastic hips. We showed that the markedly increased femoral anteversion was not a primary abnormality in hip dysplasia.
Local Host: British Society for Children’s Orthopaedic Surgery. Conference Theme: Congenital Deficiencies of the Lower Limb. These abstracts were prepared by A.Catterall.
