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PAPERS: Nerys F Woolacott, Milo A Puhan, Johann Steurer, and Jos Kleijnen Ultrasonography in screening for developmental dysplasia of the hip in newborns: systematic review BMJ 2005; 330: 1413 [Abstract] [Full text]

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Developmental Dysplasia of the Hip Screening - a never ending story

Jose R Fernandez Alvarez, A. McKee, H. Rabe   (3 August 2005)

Unsystematic review on ultrasound screening for DDH

Karen Rosendahl   (9 October 2005)

Developmental Dysplasia of the Hip Screening - a never ending story 3 August 2005
Jose R Fernandez Alvarez, Neonatal Fellow Royal Sussex County Hospital, Trevor Mann Baby Unit, Eastern Road, Brighton, BN2 5BE East Sussex, A. McKee, H. Rabe Send response to journal: Re: Developmental Dysplasia of the Hip Screening - a never ending story	Dear Sirs, We read with interest the review article by Woolacott et al. ´Ultrasonography in screening for developmental dysplasia of the hip in newborns: systematic review´(10). It was an extensive and complete review including articles that are not in English. However we would have to disagree with the final conclusion and there are numerous points we would like to highlight: Firstly in many of the studies including the one from Rosendahl et al. in 1994 infants were scanned early in the first week of life (8). Timing for ultrasound is crucial. The majority of the babies scanned this early will have a Type IIa (Graf) hip and as a consequence will require further screening and possibly postural treatment (although not proven to be effective). This will increase costs and anxiety. However ultrasound scanning at 60 days of life has shown to reduce the number of subjects with type IIa hip by 64 – 78 % (1). This could help reduce overall costs, especially in view of most of these hips being normal at follow-up (1). The second point we would like to mention is that in this report the only study commenting about sensitivity in ultrasound revealed a value of 88.5 % (7). On the other hand clinical examination sensitivities of 87 – 99 % in highly experienced examiners have been reported (1,5). Comparing the accuracy of clinical examination to ultrasound screening seems reasonable for a study, but does not reflect common practice. While in England hip examinations are mainly performed by the least experienced member of staff (SHO) at discharge from hospital, the national ultrasound screening at 4 - 8 weeks of age in Germany is only performed by registered primary care paediatricians after a compulsory training of at least 400 supervised scanned hips. The paediatric training for general practioners in the UK is also quite variable, so that you cannot commonly assume a high experience, either. Moreover sensitivity and positive predictive value of the Barlow-Ortolani test are extremely low if sonography was assumed to be the gold standard and if sonography results worse than type IIa were considered pathologic (1). There might not be enough clear evidence in favour of or against general ultrasound screening, but there is certainly not much evidence in favour of clinical examination, either (1,2,4). Thirdly cost-effectiveness was not addressed, probably because current evidence is controversial. However in a recent cost-effectiveness analysis from the Netherlands general ultrasound screening at 3 months did not seem to be more expensive than clinical examination (6). Reports from the UK Hip Trial and from Rosendahl in 1995 came to similar conclusions in the past (3,9). It would be probably expensive to exchange a clinical hip screening with an ultrasound screening system depending on the existing health care system and training system of the physicians involved. This question has not been investigated, yet. So, if general ultrasound screening was to be introduced in the UK, who would do it? Paediatricians, GPs, Orthopaedics or Radiologists? How many more doctors would you need to meet the requirements in the population? What would be the training like in order to achieve a nationwide consistently high expertise with this ultrasound test? Is the current clinical training sufficient to say it is as good as ultrasound screening? Is it worthwhile going through all these questions if the difference is probably going to be marginal? Our conclusion is that depending on the health care system and the training system of physicians general ultrasound screening of the hips is probably the more sensitive, more cost effective and less intrusive method for the patient´s routine screening examination of the hips. It helps to reduce late DDH and is associated with shorter and less intrusive treatment (7,8,10). References 1. Baronciani D, Atti G, Andiloro F et al. Screening for developmental dysplasia of the hip: From theory to practice. Pediatrics 1997; 99(2): E5. 2. Bialik V. Clinical hip instability in the newborn by an orthopaedic surgeon and a paediatrician. J Pediatr Orthop 1986; 6: 703 – 705. 3. Elbourne D, Dezateux C, Arthur R et al. Ultrasonography in the diagnosis and management of developmental hip dysplasia (UK hip trial) :clinical and economic results of a multicentre randomised controlled trial. Lancet 2002; 360: 2009 – 2017. 4. Godward S, Dezateux C. Surgery for congenital dislocation of the hip in the UK as a measure of outcome of screening. MRC working party on CDH. Lancet 1998; 351 (9110): 1149 – 1152. 5. Patel H and Canadian Task Force on Preventive Health Care. Preventive health care, 2001 update: Screening and management of developmental dysplasia of the hip in newborns. CMAJ 2001; 164 (12): 1669 – 1677. 6. Roovers EA, Boere-Boonekamp MM, Zielhuis GA et al. Post-neonatal ultrasound screening for developmental dysplasia of the hip. A study of cost-effectiveness in the Netherlands [doctoral thesis]. Eschede, Netherlands: University of Twente, 2004. 7. Roovers EA, Boere-Boonekamp MM, Castelein RM et al. Effectiveness of ultrasound screening for developmental dysplasia of the hip. Arch Dis Child Fetal Neonatal Ed 2005; 90: F25 – 30. 8. Rosendahl K, Markestad T, Lie RT. Ultrasound screening for developmental dysplasia of the hip in the neonate: the effect on treatment rate and prevalence of late cases. Pediatrics 1994; 94: 47 – 52. 9. Rosendahl K. Cost-effectiveness of alternative screening strategies for developmental dysplasia of the hip. Arch Ped Adolesc Med 1995; 149: 643- 648. 10. Woolacott NF, Puhan MA, Steurer J and Kleijnen J. Ultrasonography in screening for developmental dysplasia of the hip in newborns: systematic review. BMJ 2005; 330: 1413 – 1418. Competing interests: None declared
Unsystematic review on ultrasound screening for DDH 9 October 2005
Karen Rosendahl, Consultant Paediatric Radiologist Great Ormond Street Hospital for Children, NHS Trust, Great Ormond Street London WC1N 3JH, UK Send response to journal: Re: Unsystematic review on ultrasound screening for DDH	October 10th, 2005 BMJ Dear Editor, In BMJ,doi:10.1136/bmj.38450.646088.EO (published 1 June 2005), Woolacott et al. presents a systematic review on ultrasonography in screening for developmental dysplasia (DDH) of the hip in newborns. The authors have done an extensive amount of work based on data from the existing medical literature; however, a correct use of such data requires a minimum of knowledge about the diagnostic methods used, and about the disease addressed. Unfortunately, the paper is flawed with inconsistencies. First, hip ultrasound was developed by Graf alone, who started his experimental work in 1978, thoroughly described the sonoanatomy of the hip joint, and defined the standard section through the deepest part of the acetabulum, upon which most modified techniques are based on1-21. In 1984, Harcke reported on a dynamic technique while Morin in 1985 used the “femoral head coverage” in classifying the hips into normal and pathological 22;23. His technique was slightly modified by Terjesen in 198924. Second, although the authors aimed at examining papers on newborns, three out of ten target articles address infant screening (20, 25, 26). One of their ten target articles, ref.28, does not appear in Tables 1 and 2, which is rather confusing. Moreover, the authors wrongly state that a modified technique after Terjesen was used in our randomised trial (ref 21), although they state that we chose to treat new-borns presenting with Graf type IIIa or worse25. The correct information is that we used Graf’s technique, with a simplified classification into morphologically normal, immature, slight dysplasia or severe dysplasia according to a-angle, +/- instability. Third, the authors give the readers the impression that DDH in new- borns include hip instability alone, which subsequently develops into dysplasia in cases of persisting subluxation or dislocation, and that dysplasia diagnosed in newborns is one entity. This is not the case. After refining the ultrasound techniques and classification systems used, it has become possible to classify dysplasia into severe or mild, with or without additional instability, and to tailor treatment and follow-up thereafter. Postponing therapy for those suffering severe dysplasia/dislocation would result in late DDH with dislocation for a high per cent. Differing between varying degrees of late DDH when discussing the effect of screening strategies is crucial. When comparing the rates of late DDH between the two RCT’s included in the present review, the authors did not discuss the fact that the criteria for late DDH between one and four months of age, when the diagnosis was based on ultrasound, differed between the two studies. Moreover, they suggested that the differences in rates might reflect an increased level of experience since the most recently published paper reported on lower rates. However, data-collection was performed during the same period of time (1988-1990/92). The different rates are more likely to be caused by differences in ultrasound technique used (modified Morin vs. modified Graf), the number of examiners (one- examiner study vs. four examiners) and the criteria used for early and for late DDH. Since the pathology in most cases of DDH is already present at birth, the term late DDH is commonly defined as DDH diagnosed after one month of age. In the present review, the authors argue that the term late DDH should be used after several months, when the diagnosis is more obvious, and when those showing physiologically immaturity in the new-born period have normalized. They also recommend that a randomized study comparing the effect of ultrasound screening at one and at three months of age should be performed. I do not agree. In my opinion a major challenge for future work on hip-screening is to standardise the ultrasound techniques used, to agree on criteria for early and late DDH and to ensure that the examiners are adequately trained. Sincerely, Karen Rosendahl Reference List (1) Graf R. The diagnosis of congenital hip-joint dislocation by the ultrasonic Combound treatment. Arch Orthop Trauma Surg 1980; 97(2):117- 133. (2) Graf R. The ultrasonic image of the acetabular rim in infants. An experimental and clinical investigation. Arch Orthop Trauma Surg 1981; 99(1):35-41. (3) Graf R. [The anatomical structures of the infantile hip and its sonographic representation]. Morphol Med 1982; 2(1):29-38. (4) Graf R. [The importance of sonography in the examination of the infant hip]. Biomed Tech (Berl) 1983; 28(11):257-263. (5) Graf R. New possibilities for the diagnosis of congenital hip joint dislocation by ultrasonography. J Pediatr Orthop 1983; 3(3):354-359. (6) Graf R. [The sonographic evaluation of hip dysplasia using convexity diagnosis]. Z Orthop Ihre Grenzgeb 1983; 121(6):693-702. (7) Graf R. Fundamentals of sonographic diagnosis of infant hip dysplasia. J Pediatr Orthop 1984; 4(6):735-740. (8) Graf R. Classification of hip joint dysplasia by means of sonography. Arch Orthop Trauma Surg 1984; 102(4):248-255. (9) Graf R, Heuberer I. [Sonographically monitored hip dysplasia]. Wien Klin Wochenschr 1985; 97(1):18-27. (10) Graf R. [Hip sonography in infancy. Procedure and clinical significance]. Fortschr Med 1985; 103(4):62-66. (11) Graf R. [Possibilities, problems and present status of hip sonography of infant hips]. Radiologe 1985; 25(3):127-134. (12) Graf R, Tschauner C, Steindl M. [Does the IIa hip need treatment? Results of a longitudinal study of sonographically controlled hips of infants less than 3 months of age]. Monatsschr Kinderheilkd 1987; 135(12):832-837. (13) Graf R. [Sonographic diagnosis of hip dysplasia. Principles, sources of error and consequences]. Ultraschall Med 1987; 8(1):2-8. (14) Graf R. [Sonography of the hip in infants]. Z Orthop Ihre Grenzgeb 1990; 128(4):355-356. (15) Graf R. Hip sonography--how reliable? Sector scanning versus linear scanning? Dynamic versus static examination? Clin Orthop Relat Res 1992;(281):18-21. (16) Graf R. [Hip ultrasonography. Basic principles and current aspects]. Orthopade 1997; 26(1):14-24. (17) Graf R. [Developmental hip disorders in infants. Diagnosis and therapy]. Orthopade 1997; 26(1):1. (18) Graf R. Ultrasound measurements of the newborn hip--comparison of two methods in 657 newborns. Acta Orthop Scand 1998; 69(5):550-551. (19) Graf R. [Ultrasound examination of the hip. An update]. Orthopade 2002; 31(2):181-189. (20) Tschauner C. Earliest diagnosis of congenital dislocation of the hip by ultrasonography. Historical background and present state of Graf's method. Acta Orthop Belg 1990; 56(1 ( Pt A)):65-77. (21) Tschauner C, Klapsch W, Graf R. [The effect of ultrasonography screening of hips in newborn infants on femur head necrosis and the rate of surgical interventions]. Orthopade 1993; 22(5):268-276. (22) Harcke HT, Clarke NM, Lee MS, Borns PF, MacEwen GD. Examination of the infant hip with real-time ultrasonography. J Ultrasound Med 1984; 3(3):131-137. (23) Morin C, Harcke HT, MacEwen GD. The infant hip: real-time US assessment of acetabular development. Radiology 1985; 157(3):673-677. (24) Terjesen T, Bredland T, Berg V. Ultrasound for hip assessment in the newborn. J Bone Joint Surg Br 1989; 71(5):767-773. (25) Rosendahl K, Markestad T, Lie RT. Ultrasound screening for developmental dysplasia of the hip in the neonate: the effect on treatment rate and prevalence of late cases. Pediatrics 1994; 94(1):47-52. (26) Rosendahl K, Markestad T, Lie RT. Developmental dysplasia of the hip: prevalence based on ultrasound diagnosis. Pediatr Radiol 1996; 26(9):635-639. Competing interests: None declared