Abstract
Background
Developmental dysplasia of the hip (DDH) is a common condition that is highly treatable in infancy but can lead to the lifelong morbidity of premature osteoarthritis if left untreated. Current diagnostic methods lack reliability, which may be improved by using 3-D ultrasound.
Objective
Conventional 2-D US assessment of DDH has limitations, including high inter-scan variability. We quantified DDH on 3-D US using the acetabular contact angle (ACA), a property of the 3-D acetabular shape. We assessed ACA reliability and diagnostic utility.
Materials and methods
We prospectively collected data from January 2013 to December 2014, including 114 hips in 85 children divided into three clinical diagnostic groups: (1) normal, (2) initially borderline but ultimately normal without treatment and (3) dysplastic requiring treatment. Using custom software, two observers each traced acetabula twice on two 3-D US scans of each hip, enabling automated generation of 3-D surface models and ACA calculation. We computed inter-observer and inter-scan variability of repeatability coefficients and generated receiver operating characteristic (ROC) curves.
Results
The 3-D US acetabular contact angle was reproduced 95% of the time within 6° in the same scan and within 9° in different scans of the same hip, vs. 9° and 14° for the 2-D US alpha angle (P < 0.001). Areas under ROC curves for diagnosis of developmental dysplasia of the hip were 0.954 for ACA and 0.927 for alpha angle.
Conclusion
The 3-D US ACA was significantly more reliable than 2-D US alpha angle, and the 3-D US measurement predicted the presence of DDH with slightly higher accuracy. The ACA therefore shows promising initial diagnostic utility. Our findings call for further study of 3-D US in the diagnosis and longer-term follow-up of infant hip dysplasia.
Similar content being viewed by others
References
Storer SK, Skaggs DL (2006) Developmental dysplasia of the hip. Am Fam Physician 74:1310–1316
Shorter D, Hong T, Osborn DA (2013) Cochrane review: screening programmes for developmental dysplasia of the hip in newborn infants. Evid Based Child Health 8:11–54
Dezateux C, Rosendahl K (2007) Developmental dysplasia of the hip. Lancet 369:1541–1552
Zieger M (1986) Ultrasound of the infant hip. Part 2. Validity of the method. Pediatr Radiol 16:488–492
Gwynne Jones DP, Vane AG, Coulter G et al (2006) Ultrasound measurements in the management of unstable hips treated with the Pavlik harness: reliability and correlation with outcome. J Pediatr Orthop 26:818–822
Morin C, Zouaoui S, Delvalle-Fayada A et al (1999) Ultrasound assessment of the acetabulum in the infant hip. Acta Orthop Belg 65:261–265
Falliner A, Schwinzer D, Hahne HJ et al (2006) Comparing ultrasound measurements of neonatal hips using the methods of Graf and Terjesen. J Bone Joint Surg Br 88:104–106
Jaremko JL, Mabee M, Swami VG et al (2014) Potential for change in US diagnosis of hip dysplasia solely caused by changes in probe orientation: patterns of alpha-angle variation revealed by using three-dimensional US. Radiology 273:870–878
Ozonoff MB (1992) Pediatric orthopedic radiology, 2nd edn. Saunders, Philadelphia
American Institute of Ultrasound in Medicine (2013) AIUM practice guideline for the performance of an ultrasound examination for detection and assessment of developmental dysplasia of the hip. J Ultrasound Med 32:1307–1317
Bland JM, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:307–310
Simon EA, Saur F, Buerge M et al (2004) Inter-observer agreement of ultrasonographic measurement of alpha and beta angles and the final type classification based on the Graf method. Swiss Med Wkly 134:671–677
Roovers EA, Boere-Boonekamp MM, Geertsma TS et al (2003) Ultrasonographic screening for developmental dysplasia of the hip in infants. Reproducibility of assessments made by radiographers. J Bone Joint Surg Br 85:726–730
Mabee M, Dulai S, Thompson RB et al (2014) Reproducibility of acetabular landmarks and a standardized coordinate system obtained from 3D hip ultrasound. Ultrason Imaging 37:267–276
Cheng E, Mabee M, Swami VG et al (2014) Ultrasound quantification of acetabular rounding in hip dysplasia: reliability and correlation to treatment decisions in a retrospective study. Ultrasound Med Biol 1:56–63
Bialik V, Bialik GM, Blazer S et al (1999) Developmental dysplasia of the hip: a new approach to incidence. Pediatrics 103:93–99
Roposch A, Liu LQ, Hefti F et al (2011) Standardized diagnostic criteria for developmental dysplasia of the hip in early infancy. Clin Orthop Relat Res 469:3451–3461
Acknowledgments
The authors are grateful for the Radiology Society of North America (RSNA) Research Seed Grant #RSD1425 and the Canadian Institutes of Health Research (CIHR) Institute of Human Development Child and Youth Health (IHDCYH) Grant NI15-004, which provided research funding for this work.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflicts of interest
None
Rights and permissions
About this article
Cite this article
Mabee, M.G., Hareendranathan, A.R., Thompson, R.B. et al. An index for diagnosing infant hip dysplasia using 3-D ultrasound: the acetabular contact angle. Pediatr Radiol 46, 1023–1031 (2016). https://doi.org/10.1007/s00247-016-3552-8
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00247-016-3552-8