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Developmental dysplasia of the hip (DDH): diagnosis and treatment
CHILDREN'S ORTHOPAEDICS
Developmental dysplasia of the hip (DDH): diagnosis and treatment
spectrum of disease ranging from minor dysplasia of the hip to irreducible dislocation’. Dislocation of the hip joint is defined as displacement of the articulating bones leading to a complete separation of the joint surfaces. The definition of subluxation of the hip joint is that there is an incomplete separation of the joint surfaces but with some joint surface contact remaining. Dysplasia of the hip joint is defined as an abnormality of the development of the acetabulum resulting in a shallow and/or dysmorphic socket. DDH is a dynamic condition that may resolve or deteriorate with growth.2 This condition may be physiological or pathological and can be diagnosed clinically, ultrasonically and radiologically. There is some controversy in what constitutes a true physiological or pathological DDH (Table 1). This ‘vague’ definition of DDH makes effective research into the diagnosis and treatment of the condition difficult, as there are potential false positive and false negative diagnoses. Physiological DDH is the most common form. This physiological type resolves spontaneously and is usually identified from neonatal and infant clinical and sonographic screening programmes. It is clearly important to separate physiological from pathological DDH when assessing and treating DDH. Serious complications may occur due to inappropriate overtreatment of physiological DDH. Untreated or undiagnosed pathological DDH may not resolve spontaneously and can persist as an acetabular dysplasia, hip joint subluxation or irreducible hip joint dislocation, all of which can be associated with future premature symptomatic hip osteoarthrosis in the young adult. Of those individuals under the age of 60 years requiring a total hip replacement for osteoarthrosis, up to 30% are thought to have signs of hip dysplasia.3 The diagnosis of DDH excludes primary pathologies such as syndromic, neurological or neuromuscular aetiologies e.g. cerebral palsy, teratogenic hip joint dislocations such as those present in Larson’s Syndrome or arthrogryposis.1
Robin W Paton Qaisar Choudry
Abstract This paper describes the definition, investigation, imaging and treatment of developmental dysplasia of the hip (DDH). There is controversy in what constitutes physiological or pathological DDH. The results of hip screening programmes are disappointing. DDH may be diagnosed by clinical, sonographic or radiological means. The clinical diagnosis is confirmed by sonographic imaging (in the first months of life). Late presenting pathological DDH (>6 months of age) is usually diagnosed by an X-ray(s) of the pelvis. The majority of pathological DDH cases are female and unilateral, with the left hip joint being involved more commonly. Dysplasia, subluxation and dislocation of the hip joint may be associated with the development of premature osteoarthrosis in adults. The majority of neonatal hip joint instabilities and sonographic hip dysplasia spontaneously resolve without treatment. Persistent hip joint instability is initially treated with bracing/splintage, the majority resolving without further additional treatment. Some early presenting probable irreducible hip dislocations can be treated by manipulation under anaesthetic, hip arthrography plus the application of a hip spica. If this procedure fails, if it is not technically possible or if the dislocation presents ‘late’, more invasive surgery with open reduction of the hip joint and reconstructive surgery to the pelvis or femur may be necessary.
Incidence of DDH
Keywords DDH management; DDH screening; developmental
The condition is more common in females and on the left side. In the UK the incidence of irreducible hip dislocation in the screened population is between 0.5 and 0.8 per 1000 live births, though in clinically unscreened populations the incidence may be as high as 1.6 per 1000 live births.4,5 The incidence of irreducible hip dislocation varies in other countries, secondary to differing genetic and environmental factors. Radiological subluxation of the hip joint often has a poor outcome in adolescence and thankfully is less common than irreducible hip dislocation.6 The majority of clinically stable sonographically diagnosed dysplasia of the hip may resolve spontaneously.7e10 The aetiology and natural history of acetabular dysplasia diagnosed radiologically in the adult is unknown. Does this dysplasia develop from neonatal/infant dysplasia or does this problem develop in the adolescent individual or both? Even the true prevalence of dysplasia in adult is unknown, with the only published studies having severe methodological issues. It is thought that up to 2% of newborns may be diagnosed with hip joint instability. However, only 0.1e0.2% develop/ progress to irreducible dislocation of the hip joint.11
dysplasia; hip
Introduction Developmental dysplasia of the hip (DDH) is the most common lower limb condition affecting children.1 DDH is defined as ‘a
Robin W Paton MB.ChB FRCS FRCS (Orthopaedic) PhD FFST Consultant Orthopaedic Surgeon, Visiting Professor, School of Medicine, University of Central Lancashire (UCLAN), UK; King James IV Professor, Royal College of Surgeons of Edinburgh 2016, Honorary Senior Lecturer, University of Manchester, UK. Conflict of interest: I have received fees in private practice (Orthopaedics & Trauma) in the past 5 years. I closed my private and medico-legal practice in December 2015. I have not received any other consulting fees (i.e. I have not acted as a consultant to any organisations or companies). In the past 5 years I have completed one medical report (expert) on the subject of a late presentation of a hip dislocation in developmental dislocation of the hip. Qaisar Choudry MD MRCS FRCS (T & O) Consultant Orthopaedic Surgeon, Honorary Senior Lecturer, University of Central Lancashire (UCLAN), UK; Department of Trauma & Orthopaedics, Royal Blackburn Hospital, East Lancashire Hospitals NHS Trust, Blackburn, UK. Conflict of interest: none declared.
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Prognosis If an irreducible hip dislocation is not treated or it if is treated unsuccessfully then it is likely that a serious debilitating hip
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Please cite this article in press as: Paton RW, Choudry Q, Developmental dysplasia of the hip (DDH): diagnosis and treatment, Orthopaedics and Trauma (2016), http://dx.doi.org/10.1016/j.mporth.2016.05.015
CHILDREN'S ORTHOPAEDICS
Physiological and pathological DDH Physiological DDH (potential)
Pathological DDH (potential)
Resolved neonatal hip joint instability without acetabular dysplasia (previous þve Ortolani & Barlow hip joint manoeuvres) Graf type II ultrasound dysplasia (resolved to Graf Type 1)
Persistent neonatal hip joint Instability (þve Ortolani & Barlow hip joint manoeuvres) Persistent Graf Type(s) III & IV hip joint dysplasia/dislocation (possible Graf Type IIc) Graf Type IV hip dislocation/de-centred (irreducible) Radiological hip joint dysplasia, subluxation, irreducible dislocation (infant/child)
Graf Type III & IV ultrasound dysplasia (resolved to Graf Type 1)
Table 1
condition will ensue that may require a total hip joint replacement in later life. In a unilateral irreducible hip dislocation, there will be a short leg gait, a Trendelenburg limp, limited hip joint movements and later, the development of osteoarthrosis in the affected hip joint and also in the lower lumbar spine. In general, in a unilateral case the development of osteoarthrosis that is symptomatically severe enough to require a total hip replacement tends to occur in the patient’s early to mid-thirties (Figure 1). If the hip joint is treated (reduced) but the devastating complication of severe avascular necrosis of the femoral head develops, the likelihood of premature osteoarthrosis of the hip joint is also increased. In such cases, total hip joint replacement may be required in the late teens or early twenties. In untreated bilateral hip dislocation, although the gait is unusual (increased lumbar lordosis and bilateral Trendelenburg gait), symptomatic osteoarthrosis severe enough to require total hip replacements is usually delayed until the patient’s early forties. Chronic dysplasia of the hip joint often presents with severe symptomatic osteoarthrosis of the hip joint in the fifties age group. People with untreated severe irreducible subluxation associated with dysplasia of the hip joint may develop severe osteoarthrosis in their mid-twenties, earlier than is seen with complete irreducible dislocation of the joint.
DDH hip screening In England, the Newborn & Infant Physical Examination guidelines (NIPE) were published in 2008 (not applicable in Scotland).12 The recommendations were that all hip joints should be examined by the Ortolani and Barlow manoeuvres, ideally within 24 and certainly before 72 hours of birth. Clinical examination of the hip joints that have been passed as normal should be repeated by a competent Health Care Professional (HCA) by six to eight weeks of age (usually in primary care). If instability of the hip joints is detected or suspected at the first neonatal clinical examination, the hips should be imaged by sonographic imaging within two weeks of age, and if positive (sonograpically diagnosed Graf Types III or IV hips plus or minus clinical hip instability), the neonate should be referred for an expert opinion (usually a Paediatric Orthopaedic Surgeon) within three to four weeks of age. If a clinical abnormality is detected at the primary care clinical secondary hip joint screening examination at the six to eight week assessment, the child should be sent for urgent sonographic imaging of the hip joints, which if abnormal will require an urgent referral for an expert opinion (usually a Paediatric Orthopaedic Surgeon). The sonographic imaging can be undertaken by the Radiology or the Paediatric Orthopaedic Department, dependent on local expertise and historical referral patterns. Internationally, there is no consensus on the optimum hip screening protocol for DDH. There are different screening programmes in the countries of the European Union, Australia & North America, which range from universal neonatal hip joint examination only, to selective (universal neonatal hip joint examination plus sonographic hip imaging for clinically unstable or ‘at risk’ hips) to universal (clinical and sonographic neonatal hip examination/imaging of all neonate hip joints).6,12e16 An agreed clinical secondary hip joint screening examination (clinically and/or sonographically) at a later date is not a consistent guideline internationally. Certain conditions have been considered historically to be associated with DDH and these conditions include a strong family history, breech presentation, foot deformities (fixed congenital talipes equinovarus (CTEV), postural talipes equinovarus (TEV), congenital calcaneovalgus (CTCV), metatarsus adductus) and oligohydramnios.17 Recent research has suggested that only a strong family history (history of splintage of hip joints for hip instability/dysplasia or surgery for DDH in the neonate or infant in parents or close relatives), breech presentation and
Figure 1 Left hip dislocation with secondary osteoarthrosis of the joint (Crowe IV). A cemented right total hip joint replacement with acetabular augmentation for previous irreducible hip dislocation.
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Please cite this article in press as: Paton RW, Choudry Q, Developmental dysplasia of the hip (DDH): diagnosis and treatment, Orthopaedics and Trauma (2016), http://dx.doi.org/10.1016/j.mporth.2016.05.015
CHILDREN'S ORTHOPAEDICS
methods as the Barlow manoeuvre has a low positive predictive value (PPV) of 22%.13 It has been reported that 70% of clinical hip instabilities will resolve within two weeks of age and 88% within four weeks.24,25 The natural history of the majority of cases of clinical hip instability should be considered as a physiological not a pathological phenomenon due to the rate of spontaneous resolution. Clinical examination is often undertaken by inexperienced junior members of the paediatric and nursing teams. The diagnostic accuracy can be subjective in such a situation, potentially risking the over-diagnosis of clinical hip joint instability or the rarer false negative of missing hip joint instability. Due to the high spontaneous resolution rate, treatment of neonatal hip instability may be delayed for two to six weeks without adverse effects.26 Unilateral limitation of the hip joint (LHA) may be a useful clinical sign, although it is time dependent and of little use in the neonate. After eight weeks of age, unilateral LHA has a sensitivity of 78.3% and a PPV of 54.7% in the diagnosis of pathological DDH (Graf Type(s) III, IV and irreducible hip dislocation).27 Bilateral irreducible hip dislocation is thankfully very rare (<1:10 000 live births). It is difficult to identify before walking age, as some bilateral limitation of hip joints is a common normal variation. At walking age the abnormal gait raises suspicions (see treatment of DDH section). ‘Clicky’ hips are rarely associated with true hip instability (clinical or sonographic) or with pathological dysplasia/dislocation.6 Other inaccurate clinical signs include bilateral limitation of abduction, asymmetrical skin creases (without limitation of hip joint abduction) and leg length discrepancy (in the neonate).13,15,16
possibly congenital talipes calcaneo-valgus are true risk factors.6,13,14,18 The incidence/prevalence of clinically and sonographically diagnosed pathological DDH is statistically higher in females compared to male neonates and infants, and the left hip is more commonly involved.6 Universal sonographic examination runs the risk of overtreatment, and up to 7% of the population may be treated by splintage of the hip joints compared with 0.35% in selective sonographic screening programmes.19e21 It is claimed that universal neonatal sonographic hip screening programmes greatly reduce the rate of late presentation of irreducible dislocation of the hips joint,19,22 although this has been disputed on statistical grounds.9,14 In Switzerland & the USA, selective and universal ultrasound imaging of the hips has been abandoned/not recommended due to the risk of overtreatment of potential hip abnormalities without a robust evidence base to recommend this policy. In Sweden, better results, with a reduction of late presenting irreducible hip joint dislocation in DDH, have been identified if there are small numbers of well-trained, experienced hip screening teams undertaking the universal hip joint examinations in all neonates.23 Holen & Rosendahl have published data suggesting that the incidence of late dislocation is no different statistically comparing: universal clinical hip joint examination, universal clinical hip joint examination plus selective sonographic hip joint screening for ‘at risk factors’ & clinical hip instability, and universal clinical hip joint examination plus universal sonographic hip joint imaging. A recent systematic review of hip screening programmes noted that there was a lack of proper research methods and published evidence in the world’s literature. Out of nearly 4000 papers in the world literature that an American Academy of Orthopaedic Surgeons committee assessed, there were only 32 articles of a high enough standard from which they could recommend guidance for a hip screening policy.14 In general, the current consensus in the UK is that universal clinical examination combined with selective ultrasound screening of certain ‘at risk’ cases (strong family history and breech presentation) is a reasonable compromise as a primary screening policy, although in Germany & Austria universal clinical hip joint examination combined with universal sonographic hip imaging is currently advocated as national policy.
Sonographic Ultrasound imaging of the hip joints was initially developed by Graf, in Austria.22 This imaging has the advantages of using non-ionising radiation, it is dynamic, it is real time and it visualises the hip joint labrum, the gluteal muscles and the acetabulum. The images can be recorded in the medical records and the sonographic imaging can be combined with clinical hip joint examination. The Graf method of hip joint evaluation is helpful in classifying hip joints into normal (Graf Type I), minor/physiological/immature (Graf Type IIc) and pathological types (Graf Type III/IV and potentially Graf type IIc). As 90% of Graf Type II sonographic hip dysplasias resolve spontaneously, the majority are considered to be physiological or immature hip joints.6,9 If Graf Type III or IV hip joints are diagnosed sonographically but are clinically stable there is some controversy as to whether they should be treated immediately or if treatment should be delayed, as some of these hip joint abnormalities may resolve spontaneously.7,8 In general, most Graf Type III and IV hip joints are considered to be potentially pathological and are initially treated by splintage/bracing in most specialist centres. It is felt that although hip stability may occur spontaneously in such cases, residual hip dysplasia could be a potential long-term risk if left untreated. Unfortunately there is no robust evidence published in the literature to confirm or refute this view, although there is some evidence that persistent positive Ortolani manoeuvres or poor acetabular development may progress to
Physiological & pathological DDH Physiological DDH can be diagnosed either clinically or sonographically. Clinical The Ortolani & Barlow hip examination manoeuvres are used to diagnose clinical hip instability. The Ortolani manoeuvre is a test of hip joint reducibility and the Barlow manoeuvre is a clinical test of hip joint dislocatability. The classic clinical sign with the Ortolani manoeuvre is that of a ‘clunk’ on hip joint reduction. The Ortolani manoeuvre is the more useful of the two clinical
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Please cite this article in press as: Paton RW, Choudry Q, Developmental dysplasia of the hip (DDH): diagnosis and treatment, Orthopaedics and Trauma (2016), http://dx.doi.org/10.1016/j.mporth.2016.05.015
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major dysplasia or irreducibility in the future.28,29 If the hip joint is clinically unstable with a Graf Type IV hip joint on ultrasound imaging, most Paediatric Orthopaedic Surgeons would treat the hip joints immediately, as there is some evidence that residual hip pathology may be permanent if not treated at an early stage. Radiological The majority of DDH abnormalities within the first three to six months of life (depending on the centre) are diagnosed with hip ultrasound imaging. Sonography has been shown to be more accurate than radiographs in this age group.30 X-rays are particularly inaccurate under the age of three months, as the capital femoral epiphysis is unformed, poorly formed or lateralised, making the true position of the femoral head within the socket difficult to assess accurately. Radiologically, the hip may be dysplastic, subluxed or irreducibly dislocated. When the capital epiphysis has developed adequately this diagnostic imaging method is useful, particularly when combined with objective radiological measurements such as the acetabular index, the presence of a false acetabulum and the position of the femoral head in relation to the Hilgenreiner’s (horizontal) and Perkin’s (vertical) lines (Figure 2). Only in later age groups is the centre edge angle of diagnostic value. The correct acetabular index depends on the age of the child. As a general rule of thumb, if the acetabular index is <30 at one year of age and <20 at the age of two years, the hip joint is likely to be normal if the femoral head is located within the acetabulum. Accurate acetabular indices have been calculated and tabulated (with 95% confidence intervals of the mean) and these charts are useful in the clinical situation to assess if the radiographs are normal or not. Hip joint subluxation is classified radiologically by the Crowe index: Type I, <50% subluxed, Type II, 50e75% subluxed and Type III, 75e100% subluxed (Figure 3). Crowe Type IV is an irreducible dislocation of the joint (Figure 1).
Figure 3 Subluxation of the left hip joint: Crowe Type 3, 75% subluxed (late presentation in an 8-year-old female).
Treatment of DDH The treatment of DDH depends largely on the age of the child and the type of dysplasia/dislocation present. Neonatal DDH The diagnosis is primarily secondary to the universal clinical screening programme and the initial diagnosis is that of a positive Ortolani or Barlow manoeuvre of the hip joint. The child is usually assessed with sonographic imaging of the hips within two weeks (Figure 4), and if positive is referred to the appropriate specialist clinic within four weeks (some specialist clinics are ‘one-stop’, in that the clinical examination, sonographic imaging and treatment are all undertaken at the two week assessment). If the hip joint is clinically unstable (persistent Ortolani positive) and/or if the sonographic imaging confirms a Graf Type IV hip (or persistent sonographic acetabular dysplasia), the hip
Developmental dysplasia of the hip
Figure 2 A normal right hip and dislocation of the left hip joint with Hilgenreiner & Perkin Lines (graphic form).
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Figure 4 Sonographic image of the hip joint (normal).
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total. The majority of hip instabilities resolve with this regime and no further treatment would then be required. The child would require follow-up until walking age to confirm that the hip had developed appropriately with no residual dysplasia or avascular necrosis of the femoral head(s). Potential complications of hip splintage/bracing include avascular necrosis of the femoral head(s), irreducible hip dislocation (loss of reduction), inferior dislocation of the hip joint and femoral nerve palsy (and in the case of the Von Rosen splint, accessory nerve damage). The success rate published in the literature for Von Rosen and Pavlik devices varies from 50 to 95%, with a risk of avascular necrosis of the femoral head risk of about 1%.29 The true effectiveness of hip splintage/bracing) is difficult to ascertain accurately due to the spontaneous resolution rate and because there have been no controlled studies of splintage/bracing compared to no treatment.15 Irreducible hip dislocation The majority (66%) of irreducible hip dislocations present without a previous history of hip instability. The majority of late irreducible hip dislocations present after one year of age. The clinical presentation in a unilateral dislocation is of a short leg with a positive Galeazzi sign and limited abduction of the affected hip. In bilateral irreducible dislocation in a child of walking age there is in addition a bilateral Trendelenburg gait with an associated increased lumbar lordosis. Bilateral hip dislocation is relatively rare. Diagnosis of unilateral or bilateral irreducible hip dislocation is usually by X-ray. The femoral head is usually migrated superiorly, lateral to the Perkin’s line, with an associated false acetabulum (Figures 2 and 6). If the hip is deemed irreducible the treatment should be: Examination under anaesthetic (EUA) of the hip joint in the operating theatre. Under general anaesthetic, some hip joints that were thought to be irreducible pre-operatively may reduce. If the hip reduces in an acceptable position (extreme positions are associated with avascular necrosis (AVN) of the femoral head), an arthrogram should be undertaken. If this confirms that the femoral head is concentric without medial pooling of the dye or soft tissue interposition, the hip should be held post-operatively in a hip spica to allow stabilisation of the hip joint. Postsurgery, an MRI/CT scan should be undertaken to
Figure 5 Pavlik Wheaton Harness (with limited hip abduction on the right). Image courtesy Wheaton Brace Co. (wheatonbrace.com).
joint would usually be treated in a Pavlik (Figure 5) or Von Rosen harness/splint (the timing dependant on the centre, usually varying from immediately at birth to six weeks of age). The child would be reviewed regularly, on a weekly basis, to check that the harness/splint position is correct, and the hip joints reultrasounded after three and then six weeks. The Harness would usually be used 24 hours-a-day for six to twelve weeks in
Figure 6 (a) Bilateral irreducible dislocation of the hip joints in an 18-month-old, prior to open reduction and pelvic osteotomy. (b) Follow up X-ray of bilateral open reductions and pelvic osteotomy age 6 years.
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volume (Pemberton, Tonnis osteotomies). These hips also require the use of a hip spica post-surgery. Hip dysplasia in the child/adolescent with associated subluxation of the hip joint (Crowe Types II and III) This type of DDH presents rarely, but it is important to diagnose. The worse the subluxation of the joint, the worse the long-term prognosis will be. Paradoxically, symptomatic osteoarthrosis of the hip joint in severe dysplasia with associated subluxation usually occurs at an earlier age group than in irreducible dislocation of the joint. This is due to the poorer contact area, with a possible associated instability of the hip joint (telescoping). The clinical features may be of a leg discrepancy (short femur), limited abduction of the hip joint and restriction of the hip joint range of movement. Pain may be a later feature. Surgical treatment is with a femoral shortening osteotomy combined with a pelvic augmentation procedure (peri-acetabular Salter osteotomy in a child and triple pelvic osteotomy in an adolescent.). In older adolescents, salvage procedures such as Shelf procedures or
Figure 7 Hourglass constriction in a left irreducible hip dislocation in DDH (arthrogram).
confirm that the hip is within the joint (axial and sagittal views). The hip spica should remain on for six weeks, after which it should then be removed in the operating theatre, where the hip is re-assessed clinically and an X-ray taken (with a hip arthrogram in some cases). If the hip is confirmed to be within the joint, another hip spica should be applied in a non-extreme position for a further six to ten weeks before this is then removed in clinic. When a hip does not reduce on EUA, this is usually due to a soft tissue block secondary to an hourglass deformity of the hip capsule, a tight iliopsoas tendon and a hypertrophied ligamentum teres. With the hourglass constriction, the hip joint capsule is contracted anteriorly and inferiorly and the transverse acetabular ligament is tight. This is usually identified by a hip joint arthrogram (Figure 7). An open reduction should be undertaken with release of these tight structures. This is usually advocated at a minimum of 10 months of age (or later) to reduce the risk of AVN of the femoral head. However, there is some controversy as to whether surgery should potentially be delayed until the femoral capital ossific nucleus forms, as there is speculation by some experts that this ossific nucleus may protect against AVN. The surgical procedure can be by a medial (Ferguson) or anterior (Smith Peterson) approach. There are increased risks of AVN or late dysplasia in the medial approach and the majority of cases are currently treated by the anterolateral approach through a bikini incision. In the older child, additional surgical procedures may be necessary to reduce the hip joint concentrically within the acetabulum. These include shortening of the femur to lengthen the soft tissues to allow reduction of the femoral head without tension (often combined with a subtrochanteric derotation/varus femoral osteotomy to correct potential abnormal femoral neck anteversion). After 18 months of age the acetabulum may be deficient and may need to be augmented by a pelvic osteotomy to improve femoral head coverage and hip joint stability. There are two main types of pelvic osteotomy: those that increase anterolateral cover (the Salter osteotomy) and those that reduce
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Figure 8 X-ray of the pelvis and hips showing dysplasia of the right hip joint.
Figure 9 One year post-op after open reduction, left femoral shortening/derotation/varus osteotomy and pelvic osteotomy (Dega, volume reducing), (metalwork removed).
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Chiari osteotomies may be considered if hip joint/pelvic reconstruction is not felt to be possible.
7 Wood MK, Conboy V, Benson MKD. Does early treatment by abduction splintage improve the development of dysplastic but stable neonatal hips? J Pediatr Orthop 2000; 20: 302e5. 8 Castelein RM, Sauter AJ, de Vlieger M, van Linge B. Natural history of ultrasound hip abnormalities in clinically normal newborns. J Pediatr Orthop 1992; 12: 423e7. 9 Rosendahl K, Toma P. Ultrasound in the diagnosis of developmental dysplasia of the hip in newborns. The European approach. A review of methods, accuracy and clinical validity. Eur Radiol 2007; 17: 1960e7. 10 Holen KJ, Tegnander A, Bredland T, et al. Universal or selective screening of the neonatal hip using ultrasound? A prospective, randomised trial of 15,529 newborn infants. J Bone Joint Surg Br 2002; 84: 886e90. 11 Toma P, Valle M, Rossi U, Brunenghi GM. Paediatric hip- ultrasound screening for developmental dysplasia of the hip: a review. Eur J Ultrasound 2001; 14: 45e55. 12 Elliman D. NHS evidence, screening, Newborn Infant Physical Examination (NIPE) www.library.nhs.uk/screening/viewResource. aspx?resID¼269073. 13 Patel H. Preventative health care: 2001 update: screening and management of developmental dysplasia of the hip in newborns. CMAJ 2001; 164: 1669e77. 14 Detection and non-operative management of paediatric developmental dysplasia of the hip in infants up to six months of age. AAOS, www.aaos.org/research/guidelines/DDHGuidelineFINAL. pdf. 15 Shipman SA, Helfand M, Moyer VA, Yawn BP. Screening for developmental dysplasia of the hip: a systemic literature review for the US Preventative Services Task Force. Pediatrics 2006; 117: e557e76. 16 Lehmann HP, Hinton R, Morello P, Santoli J. Developmental dysplasia of the hip practice guideline: technical report. Committee on Quality Improvement and subcommittee on developmental dysplasia of the hip. Pediatrics 2000; 105: E57. 17 Screening for the detection of congenital dislocation of the hip. London: The Standing Medical Advisory Committee (SMAC), Department of Health and Social Security, 1986. 18 Paton RW, Choudry Q. Neonatal foot deformities and their relationship to developmental dysplasia of the hip: an 11-year prospective, longitudinal, observational study. J Bone Joint Surg Br 2009; 91: 655e8. 19 Von Kries R, Ihme N, Oberle D, et al. Effect of ultrasound screening on the rate of first operative procedures for developmental hip dysplasia in Germany. Lancet 2003; 362: 1883e7. 20 Paton RW, Srinivasan MS, Shah B, Hollis S. Ultrasound screening for hips at risk in developmental dysplasia. Is it worth it? J Bone Joint Surg Br 1999; 81: 255e8. 21 Paton RW, Hinduja K, Thomas CD. The significance of at risk factors in ultrasound surveillance of developmental dysplasia of the hip. A ten-year prospective study. J Bone Joint Surg Br 2005; 87: 1264e6. 22 Graf R. Hip sonography: 20 years experience and results. Hip Int 2007; 17(suppl. 5): S8e14. 23 Duppe H, Danielsson LG. Screening of neonatal instability and of developmental dislocation of the hip. A survey of 132,601 living newborn infants between 1956 and 1999. J Bone Joint Surg Br 2002; 84: 878e85.
Hip dysplasia (without subluxation) This condition may present in adolescence with significant pain and restriction of joint movement (Figure 8). In younger children it may present asymptomatically. 3D CT imaging of the hip joint may be necessary in order to adequately assess the cover of the femoral head and the shape of the acetabulum. If surgical reconstructive procedures are considered necessary in order to improve the morphology of the hip joint, operations such as a peri-acetabular osteotomy, Salter osteotomy, triple pelvic osteotomy (pubic, ischium and iliac bones), or Berne periacetabular osteotomies may need to be considered, depending on age. This may need to be combined with a proximal varus or de-rotation osteotomy of the femur. Figure 3 is a Crowe Type III dislocation of the hip joint in an eight year-old female patient, which if untreated would likely result in premature osteoarthrosis of this joint. The treatment is of femoral shortening derotation osteotomy combined with a pelvic augmentation procedure (peri-acetabular osteotomy). Figure 9 is the Crowe Type III hip following this hip reconstruction procedure, after removal of the metalwork one year post-operatively.
Summary DDH is a dynamic condition that may resolve or deteriorate with growth. The majority of neonatal hip joint instabilities and cases of sonographic hip dysplasia resolve spontaneously without treatment. Persistent hip joint instability is initially treated with bracing/ splintage, the majority resolving without further additional treatment. Some early presenting probable irreducible hip dislocations can be treated by manipulation under anaesthetic, hip arthrography and application of a hip spica. If this procedure fails, if it is not technically possible or if the dislocation presents late, then more invasive surgery with open reduction of the hip joint and reconstructive surgery to the pelvis or femur may be necessary. A
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24 Barlow TG. Early diagnosis and treatment of congenital dislocation of the hip. J Bone Joint Surg Br 1962; 44: 292e301. 25 Gardiner HM, Dunn PM. Controlled trial of immediate splinting versus ultrasonographic surveillance in congenitally dislocatable hips. Lancet 1990; 336: 1553e6. 26 Bache CE, Clegg J, Herron M. Risk factors for developmental dysplasia of the hip: ultrasonographic findings in the neonatal period. J Pediatr Orthop B 2002; 11: 212e8. 27 Choudry Q, Goyal R, Paton RW. Is limitation of hip abduction a useful clinical sign in the diagnosis of developmental dysplasia of the hip. Arch Dis Child 2013; 11: 862e6.
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28 Boeree NR, Clarke NM. Ultrasound imaging and secondary screening for congenital dislocation of the hip. J Bone Joint Surg Br 1994; 76: 525e33. 29 Lerman LA, Emans JB, Millis MB, et al. Early failure of Pavlik harness treatment in developmental dysplasia of the hip: clinical and ultrasound predictors. J Paed Orthop 2001; 3: 348e53. 30 McEvoy A, Paton RW. Ultrasound compared with radiographic assessment in developmental dysplasia of the hip. J R Coll Surg Edinb 1997; 42: 254e5.
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Developmental dysplasia of the hip (DDH): diagnosis and treatment
spectrum of disease ranging from minor dysplasia of the hip to irreducible dislocation’. Dislocation of the hip joint is defined as displacement of the articulating bones leading to a complete separation of the joint surfaces. The definition of subluxation of the hip joint is that there is an incomplete separation of the joint surfaces but with some joint surface contact remaining. Dysplasia of the hip joint is defined as an abnormality of the development of the acetabulum resulting in a shallow and/or dysmorphic socket. DDH is a dynamic condition that may resolve or deteriorate with growth.2 This condition may be physiological or pathological and can be diagnosed clinically, ultrasonically and radiologically. There is some controversy in what constitutes a true physiological or pathological DDH (Table 1). This ‘vague’ definition of DDH makes effective research into the diagnosis and treatment of the condition difficult, as there are potential false positive and false negative diagnoses. Physiological DDH is the most common form. This physiological type resolves spontaneously and is usually identified from neonatal and infant clinical and sonographic screening programmes. It is clearly important to separate physiological from pathological DDH when assessing and treating DDH. Serious complications may occur due to inappropriate overtreatment of physiological DDH. Untreated or undiagnosed pathological DDH may not resolve spontaneously and can persist as an acetabular dysplasia, hip joint subluxation or irreducible hip joint dislocation, all of which can be associated with future premature symptomatic hip osteoarthrosis in the young adult. Of those individuals under the age of 60 years requiring a total hip replacement for osteoarthrosis, up to 30% are thought to have signs of hip dysplasia.3 The diagnosis of DDH excludes primary pathologies such as syndromic, neurological or neuromuscular aetiologies e.g. cerebral palsy, teratogenic hip joint dislocations such as those present in Larson’s Syndrome or arthrogryposis.1
Robin W Paton Qaisar Choudry
Abstract This paper describes the definition, investigation, imaging and treatment of developmental dysplasia of the hip (DDH). There is controversy in what constitutes physiological or pathological DDH. The results of hip screening programmes are disappointing. DDH may be diagnosed by clinical, sonographic or radiological means. The clinical diagnosis is confirmed by sonographic imaging (in the first months of life). Late presenting pathological DDH (>6 months of age) is usually diagnosed by an X-ray(s) of the pelvis. The majority of pathological DDH cases are female and unilateral, with the left hip joint being involved more commonly. Dysplasia, subluxation and dislocation of the hip joint may be associated with the development of premature osteoarthrosis in adults. The majority of neonatal hip joint instabilities and sonographic hip dysplasia spontaneously resolve without treatment. Persistent hip joint instability is initially treated with bracing/splintage, the majority resolving without further additional treatment. Some early presenting probable irreducible hip dislocations can be treated by manipulation under anaesthetic, hip arthrography plus the application of a hip spica. If this procedure fails, if it is not technically possible or if the dislocation presents ‘late’, more invasive surgery with open reduction of the hip joint and reconstructive surgery to the pelvis or femur may be necessary.
Incidence of DDH
Keywords DDH management; DDH screening; developmental
The condition is more common in females and on the left side. In the UK the incidence of irreducible hip dislocation in the screened population is between 0.5 and 0.8 per 1000 live births, though in clinically unscreened populations the incidence may be as high as 1.6 per 1000 live births.4,5 The incidence of irreducible hip dislocation varies in other countries, secondary to differing genetic and environmental factors. Radiological subluxation of the hip joint often has a poor outcome in adolescence and thankfully is less common than irreducible hip dislocation.6 The majority of clinically stable sonographically diagnosed dysplasia of the hip may resolve spontaneously.7e10 The aetiology and natural history of acetabular dysplasia diagnosed radiologically in the adult is unknown. Does this dysplasia develop from neonatal/infant dysplasia or does this problem develop in the adolescent individual or both? Even the true prevalence of dysplasia in adult is unknown, with the only published studies having severe methodological issues. It is thought that up to 2% of newborns may be diagnosed with hip joint instability. However, only 0.1e0.2% develop/ progress to irreducible dislocation of the hip joint.11
dysplasia; hip
Introduction Developmental dysplasia of the hip (DDH) is the most common lower limb condition affecting children.1 DDH is defined as ‘a
Robin W Paton MB.ChB FRCS FRCS (Orthopaedic) PhD FFST Consultant Orthopaedic Surgeon, Visiting Professor, School of Medicine, University of Central Lancashire (UCLAN), UK; King James IV Professor, Royal College of Surgeons of Edinburgh 2016, Honorary Senior Lecturer, University of Manchester, UK. Conflict of interest: I have received fees in private practice (Orthopaedics & Trauma) in the past 5 years. I closed my private and medico-legal practice in December 2015. I have not received any other consulting fees (i.e. I have not acted as a consultant to any organisations or companies). In the past 5 years I have completed one medical report (expert) on the subject of a late presentation of a hip dislocation in developmental dislocation of the hip. Qaisar Choudry MD MRCS FRCS (T & O) Consultant Orthopaedic Surgeon, Honorary Senior Lecturer, University of Central Lancashire (UCLAN), UK; Department of Trauma & Orthopaedics, Royal Blackburn Hospital, East Lancashire Hospitals NHS Trust, Blackburn, UK. Conflict of interest: none declared.
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Prognosis If an irreducible hip dislocation is not treated or it if is treated unsuccessfully then it is likely that a serious debilitating hip
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Physiological and pathological DDH Physiological DDH (potential)
Pathological DDH (potential)
Resolved neonatal hip joint instability without acetabular dysplasia (previous þve Ortolani & Barlow hip joint manoeuvres) Graf type II ultrasound dysplasia (resolved to Graf Type 1)
Persistent neonatal hip joint Instability (þve Ortolani & Barlow hip joint manoeuvres) Persistent Graf Type(s) III & IV hip joint dysplasia/dislocation (possible Graf Type IIc) Graf Type IV hip dislocation/de-centred (irreducible) Radiological hip joint dysplasia, subluxation, irreducible dislocation (infant/child)
Graf Type III & IV ultrasound dysplasia (resolved to Graf Type 1)
Table 1
condition will ensue that may require a total hip joint replacement in later life. In a unilateral irreducible hip dislocation, there will be a short leg gait, a Trendelenburg limp, limited hip joint movements and later, the development of osteoarthrosis in the affected hip joint and also in the lower lumbar spine. In general, in a unilateral case the development of osteoarthrosis that is symptomatically severe enough to require a total hip replacement tends to occur in the patient’s early to mid-thirties (Figure 1). If the hip joint is treated (reduced) but the devastating complication of severe avascular necrosis of the femoral head develops, the likelihood of premature osteoarthrosis of the hip joint is also increased. In such cases, total hip joint replacement may be required in the late teens or early twenties. In untreated bilateral hip dislocation, although the gait is unusual (increased lumbar lordosis and bilateral Trendelenburg gait), symptomatic osteoarthrosis severe enough to require total hip replacements is usually delayed until the patient’s early forties. Chronic dysplasia of the hip joint often presents with severe symptomatic osteoarthrosis of the hip joint in the fifties age group. People with untreated severe irreducible subluxation associated with dysplasia of the hip joint may develop severe osteoarthrosis in their mid-twenties, earlier than is seen with complete irreducible dislocation of the joint.
DDH hip screening In England, the Newborn & Infant Physical Examination guidelines (NIPE) were published in 2008 (not applicable in Scotland).12 The recommendations were that all hip joints should be examined by the Ortolani and Barlow manoeuvres, ideally within 24 and certainly before 72 hours of birth. Clinical examination of the hip joints that have been passed as normal should be repeated by a competent Health Care Professional (HCA) by six to eight weeks of age (usually in primary care). If instability of the hip joints is detected or suspected at the first neonatal clinical examination, the hips should be imaged by sonographic imaging within two weeks of age, and if positive (sonograpically diagnosed Graf Types III or IV hips plus or minus clinical hip instability), the neonate should be referred for an expert opinion (usually a Paediatric Orthopaedic Surgeon) within three to four weeks of age. If a clinical abnormality is detected at the primary care clinical secondary hip joint screening examination at the six to eight week assessment, the child should be sent for urgent sonographic imaging of the hip joints, which if abnormal will require an urgent referral for an expert opinion (usually a Paediatric Orthopaedic Surgeon). The sonographic imaging can be undertaken by the Radiology or the Paediatric Orthopaedic Department, dependent on local expertise and historical referral patterns. Internationally, there is no consensus on the optimum hip screening protocol for DDH. There are different screening programmes in the countries of the European Union, Australia & North America, which range from universal neonatal hip joint examination only, to selective (universal neonatal hip joint examination plus sonographic hip imaging for clinically unstable or ‘at risk’ hips) to universal (clinical and sonographic neonatal hip examination/imaging of all neonate hip joints).6,12e16 An agreed clinical secondary hip joint screening examination (clinically and/or sonographically) at a later date is not a consistent guideline internationally. Certain conditions have been considered historically to be associated with DDH and these conditions include a strong family history, breech presentation, foot deformities (fixed congenital talipes equinovarus (CTEV), postural talipes equinovarus (TEV), congenital calcaneovalgus (CTCV), metatarsus adductus) and oligohydramnios.17 Recent research has suggested that only a strong family history (history of splintage of hip joints for hip instability/dysplasia or surgery for DDH in the neonate or infant in parents or close relatives), breech presentation and
Figure 1 Left hip dislocation with secondary osteoarthrosis of the joint (Crowe IV). A cemented right total hip joint replacement with acetabular augmentation for previous irreducible hip dislocation.
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methods as the Barlow manoeuvre has a low positive predictive value (PPV) of 22%.13 It has been reported that 70% of clinical hip instabilities will resolve within two weeks of age and 88% within four weeks.24,25 The natural history of the majority of cases of clinical hip instability should be considered as a physiological not a pathological phenomenon due to the rate of spontaneous resolution. Clinical examination is often undertaken by inexperienced junior members of the paediatric and nursing teams. The diagnostic accuracy can be subjective in such a situation, potentially risking the over-diagnosis of clinical hip joint instability or the rarer false negative of missing hip joint instability. Due to the high spontaneous resolution rate, treatment of neonatal hip instability may be delayed for two to six weeks without adverse effects.26 Unilateral limitation of the hip joint (LHA) may be a useful clinical sign, although it is time dependent and of little use in the neonate. After eight weeks of age, unilateral LHA has a sensitivity of 78.3% and a PPV of 54.7% in the diagnosis of pathological DDH (Graf Type(s) III, IV and irreducible hip dislocation).27 Bilateral irreducible hip dislocation is thankfully very rare (<1:10 000 live births). It is difficult to identify before walking age, as some bilateral limitation of hip joints is a common normal variation. At walking age the abnormal gait raises suspicions (see treatment of DDH section). ‘Clicky’ hips are rarely associated with true hip instability (clinical or sonographic) or with pathological dysplasia/dislocation.6 Other inaccurate clinical signs include bilateral limitation of abduction, asymmetrical skin creases (without limitation of hip joint abduction) and leg length discrepancy (in the neonate).13,15,16
possibly congenital talipes calcaneo-valgus are true risk factors.6,13,14,18 The incidence/prevalence of clinically and sonographically diagnosed pathological DDH is statistically higher in females compared to male neonates and infants, and the left hip is more commonly involved.6 Universal sonographic examination runs the risk of overtreatment, and up to 7% of the population may be treated by splintage of the hip joints compared with 0.35% in selective sonographic screening programmes.19e21 It is claimed that universal neonatal sonographic hip screening programmes greatly reduce the rate of late presentation of irreducible dislocation of the hips joint,19,22 although this has been disputed on statistical grounds.9,14 In Switzerland & the USA, selective and universal ultrasound imaging of the hips has been abandoned/not recommended due to the risk of overtreatment of potential hip abnormalities without a robust evidence base to recommend this policy. In Sweden, better results, with a reduction of late presenting irreducible hip joint dislocation in DDH, have been identified if there are small numbers of well-trained, experienced hip screening teams undertaking the universal hip joint examinations in all neonates.23 Holen & Rosendahl have published data suggesting that the incidence of late dislocation is no different statistically comparing: universal clinical hip joint examination, universal clinical hip joint examination plus selective sonographic hip joint screening for ‘at risk factors’ & clinical hip instability, and universal clinical hip joint examination plus universal sonographic hip joint imaging. A recent systematic review of hip screening programmes noted that there was a lack of proper research methods and published evidence in the world’s literature. Out of nearly 4000 papers in the world literature that an American Academy of Orthopaedic Surgeons committee assessed, there were only 32 articles of a high enough standard from which they could recommend guidance for a hip screening policy.14 In general, the current consensus in the UK is that universal clinical examination combined with selective ultrasound screening of certain ‘at risk’ cases (strong family history and breech presentation) is a reasonable compromise as a primary screening policy, although in Germany & Austria universal clinical hip joint examination combined with universal sonographic hip imaging is currently advocated as national policy.
Sonographic Ultrasound imaging of the hip joints was initially developed by Graf, in Austria.22 This imaging has the advantages of using non-ionising radiation, it is dynamic, it is real time and it visualises the hip joint labrum, the gluteal muscles and the acetabulum. The images can be recorded in the medical records and the sonographic imaging can be combined with clinical hip joint examination. The Graf method of hip joint evaluation is helpful in classifying hip joints into normal (Graf Type I), minor/physiological/immature (Graf Type IIc) and pathological types (Graf Type III/IV and potentially Graf type IIc). As 90% of Graf Type II sonographic hip dysplasias resolve spontaneously, the majority are considered to be physiological or immature hip joints.6,9 If Graf Type III or IV hip joints are diagnosed sonographically but are clinically stable there is some controversy as to whether they should be treated immediately or if treatment should be delayed, as some of these hip joint abnormalities may resolve spontaneously.7,8 In general, most Graf Type III and IV hip joints are considered to be potentially pathological and are initially treated by splintage/bracing in most specialist centres. It is felt that although hip stability may occur spontaneously in such cases, residual hip dysplasia could be a potential long-term risk if left untreated. Unfortunately there is no robust evidence published in the literature to confirm or refute this view, although there is some evidence that persistent positive Ortolani manoeuvres or poor acetabular development may progress to
Physiological & pathological DDH Physiological DDH can be diagnosed either clinically or sonographically. Clinical The Ortolani & Barlow hip examination manoeuvres are used to diagnose clinical hip instability. The Ortolani manoeuvre is a test of hip joint reducibility and the Barlow manoeuvre is a clinical test of hip joint dislocatability. The classic clinical sign with the Ortolani manoeuvre is that of a ‘clunk’ on hip joint reduction. The Ortolani manoeuvre is the more useful of the two clinical
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major dysplasia or irreducibility in the future.28,29 If the hip joint is clinically unstable with a Graf Type IV hip joint on ultrasound imaging, most Paediatric Orthopaedic Surgeons would treat the hip joints immediately, as there is some evidence that residual hip pathology may be permanent if not treated at an early stage. Radiological The majority of DDH abnormalities within the first three to six months of life (depending on the centre) are diagnosed with hip ultrasound imaging. Sonography has been shown to be more accurate than radiographs in this age group.30 X-rays are particularly inaccurate under the age of three months, as the capital femoral epiphysis is unformed, poorly formed or lateralised, making the true position of the femoral head within the socket difficult to assess accurately. Radiologically, the hip may be dysplastic, subluxed or irreducibly dislocated. When the capital epiphysis has developed adequately this diagnostic imaging method is useful, particularly when combined with objective radiological measurements such as the acetabular index, the presence of a false acetabulum and the position of the femoral head in relation to the Hilgenreiner’s (horizontal) and Perkin’s (vertical) lines (Figure 2). Only in later age groups is the centre edge angle of diagnostic value. The correct acetabular index depends on the age of the child. As a general rule of thumb, if the acetabular index is <30 at one year of age and <20 at the age of two years, the hip joint is likely to be normal if the femoral head is located within the acetabulum. Accurate acetabular indices have been calculated and tabulated (with 95% confidence intervals of the mean) and these charts are useful in the clinical situation to assess if the radiographs are normal or not. Hip joint subluxation is classified radiologically by the Crowe index: Type I, <50% subluxed, Type II, 50e75% subluxed and Type III, 75e100% subluxed (Figure 3). Crowe Type IV is an irreducible dislocation of the joint (Figure 1).
Figure 3 Subluxation of the left hip joint: Crowe Type 3, 75% subluxed (late presentation in an 8-year-old female).
Treatment of DDH The treatment of DDH depends largely on the age of the child and the type of dysplasia/dislocation present. Neonatal DDH The diagnosis is primarily secondary to the universal clinical screening programme and the initial diagnosis is that of a positive Ortolani or Barlow manoeuvre of the hip joint. The child is usually assessed with sonographic imaging of the hips within two weeks (Figure 4), and if positive is referred to the appropriate specialist clinic within four weeks (some specialist clinics are ‘one-stop’, in that the clinical examination, sonographic imaging and treatment are all undertaken at the two week assessment). If the hip joint is clinically unstable (persistent Ortolani positive) and/or if the sonographic imaging confirms a Graf Type IV hip (or persistent sonographic acetabular dysplasia), the hip
Developmental dysplasia of the hip
Figure 2 A normal right hip and dislocation of the left hip joint with Hilgenreiner & Perkin Lines (graphic form).
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Figure 4 Sonographic image of the hip joint (normal).
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total. The majority of hip instabilities resolve with this regime and no further treatment would then be required. The child would require follow-up until walking age to confirm that the hip had developed appropriately with no residual dysplasia or avascular necrosis of the femoral head(s). Potential complications of hip splintage/bracing include avascular necrosis of the femoral head(s), irreducible hip dislocation (loss of reduction), inferior dislocation of the hip joint and femoral nerve palsy (and in the case of the Von Rosen splint, accessory nerve damage). The success rate published in the literature for Von Rosen and Pavlik devices varies from 50 to 95%, with a risk of avascular necrosis of the femoral head risk of about 1%.29 The true effectiveness of hip splintage/bracing) is difficult to ascertain accurately due to the spontaneous resolution rate and because there have been no controlled studies of splintage/bracing compared to no treatment.15 Irreducible hip dislocation The majority (66%) of irreducible hip dislocations present without a previous history of hip instability. The majority of late irreducible hip dislocations present after one year of age. The clinical presentation in a unilateral dislocation is of a short leg with a positive Galeazzi sign and limited abduction of the affected hip. In bilateral irreducible dislocation in a child of walking age there is in addition a bilateral Trendelenburg gait with an associated increased lumbar lordosis. Bilateral hip dislocation is relatively rare. Diagnosis of unilateral or bilateral irreducible hip dislocation is usually by X-ray. The femoral head is usually migrated superiorly, lateral to the Perkin’s line, with an associated false acetabulum (Figures 2 and 6). If the hip is deemed irreducible the treatment should be: Examination under anaesthetic (EUA) of the hip joint in the operating theatre. Under general anaesthetic, some hip joints that were thought to be irreducible pre-operatively may reduce. If the hip reduces in an acceptable position (extreme positions are associated with avascular necrosis (AVN) of the femoral head), an arthrogram should be undertaken. If this confirms that the femoral head is concentric without medial pooling of the dye or soft tissue interposition, the hip should be held post-operatively in a hip spica to allow stabilisation of the hip joint. Postsurgery, an MRI/CT scan should be undertaken to
Figure 5 Pavlik Wheaton Harness (with limited hip abduction on the right). Image courtesy Wheaton Brace Co. (wheatonbrace.com).
joint would usually be treated in a Pavlik (Figure 5) or Von Rosen harness/splint (the timing dependant on the centre, usually varying from immediately at birth to six weeks of age). The child would be reviewed regularly, on a weekly basis, to check that the harness/splint position is correct, and the hip joints reultrasounded after three and then six weeks. The Harness would usually be used 24 hours-a-day for six to twelve weeks in
Figure 6 (a) Bilateral irreducible dislocation of the hip joints in an 18-month-old, prior to open reduction and pelvic osteotomy. (b) Follow up X-ray of bilateral open reductions and pelvic osteotomy age 6 years.
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volume (Pemberton, Tonnis osteotomies). These hips also require the use of a hip spica post-surgery. Hip dysplasia in the child/adolescent with associated subluxation of the hip joint (Crowe Types II and III) This type of DDH presents rarely, but it is important to diagnose. The worse the subluxation of the joint, the worse the long-term prognosis will be. Paradoxically, symptomatic osteoarthrosis of the hip joint in severe dysplasia with associated subluxation usually occurs at an earlier age group than in irreducible dislocation of the joint. This is due to the poorer contact area, with a possible associated instability of the hip joint (telescoping). The clinical features may be of a leg discrepancy (short femur), limited abduction of the hip joint and restriction of the hip joint range of movement. Pain may be a later feature. Surgical treatment is with a femoral shortening osteotomy combined with a pelvic augmentation procedure (peri-acetabular Salter osteotomy in a child and triple pelvic osteotomy in an adolescent.). In older adolescents, salvage procedures such as Shelf procedures or
Figure 7 Hourglass constriction in a left irreducible hip dislocation in DDH (arthrogram).
confirm that the hip is within the joint (axial and sagittal views). The hip spica should remain on for six weeks, after which it should then be removed in the operating theatre, where the hip is re-assessed clinically and an X-ray taken (with a hip arthrogram in some cases). If the hip is confirmed to be within the joint, another hip spica should be applied in a non-extreme position for a further six to ten weeks before this is then removed in clinic. When a hip does not reduce on EUA, this is usually due to a soft tissue block secondary to an hourglass deformity of the hip capsule, a tight iliopsoas tendon and a hypertrophied ligamentum teres. With the hourglass constriction, the hip joint capsule is contracted anteriorly and inferiorly and the transverse acetabular ligament is tight. This is usually identified by a hip joint arthrogram (Figure 7). An open reduction should be undertaken with release of these tight structures. This is usually advocated at a minimum of 10 months of age (or later) to reduce the risk of AVN of the femoral head. However, there is some controversy as to whether surgery should potentially be delayed until the femoral capital ossific nucleus forms, as there is speculation by some experts that this ossific nucleus may protect against AVN. The surgical procedure can be by a medial (Ferguson) or anterior (Smith Peterson) approach. There are increased risks of AVN or late dysplasia in the medial approach and the majority of cases are currently treated by the anterolateral approach through a bikini incision. In the older child, additional surgical procedures may be necessary to reduce the hip joint concentrically within the acetabulum. These include shortening of the femur to lengthen the soft tissues to allow reduction of the femoral head without tension (often combined with a subtrochanteric derotation/varus femoral osteotomy to correct potential abnormal femoral neck anteversion). After 18 months of age the acetabulum may be deficient and may need to be augmented by a pelvic osteotomy to improve femoral head coverage and hip joint stability. There are two main types of pelvic osteotomy: those that increase anterolateral cover (the Salter osteotomy) and those that reduce
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Figure 8 X-ray of the pelvis and hips showing dysplasia of the right hip joint.
Figure 9 One year post-op after open reduction, left femoral shortening/derotation/varus osteotomy and pelvic osteotomy (Dega, volume reducing), (metalwork removed).
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Chiari osteotomies may be considered if hip joint/pelvic reconstruction is not felt to be possible.
7 Wood MK, Conboy V, Benson MKD. Does early treatment by abduction splintage improve the development of dysplastic but stable neonatal hips? J Pediatr Orthop 2000; 20: 302e5. 8 Castelein RM, Sauter AJ, de Vlieger M, van Linge B. Natural history of ultrasound hip abnormalities in clinically normal newborns. J Pediatr Orthop 1992; 12: 423e7. 9 Rosendahl K, Toma P. Ultrasound in the diagnosis of developmental dysplasia of the hip in newborns. The European approach. A review of methods, accuracy and clinical validity. Eur Radiol 2007; 17: 1960e7. 10 Holen KJ, Tegnander A, Bredland T, et al. Universal or selective screening of the neonatal hip using ultrasound? A prospective, randomised trial of 15,529 newborn infants. J Bone Joint Surg Br 2002; 84: 886e90. 11 Toma P, Valle M, Rossi U, Brunenghi GM. Paediatric hip- ultrasound screening for developmental dysplasia of the hip: a review. Eur J Ultrasound 2001; 14: 45e55. 12 Elliman D. NHS evidence, screening, Newborn Infant Physical Examination (NIPE) www.library.nhs.uk/screening/viewResource. aspx?resID¼269073. 13 Patel H. Preventative health care: 2001 update: screening and management of developmental dysplasia of the hip in newborns. CMAJ 2001; 164: 1669e77. 14 Detection and non-operative management of paediatric developmental dysplasia of the hip in infants up to six months of age. AAOS, www.aaos.org/research/guidelines/DDHGuidelineFINAL. pdf. 15 Shipman SA, Helfand M, Moyer VA, Yawn BP. Screening for developmental dysplasia of the hip: a systemic literature review for the US Preventative Services Task Force. Pediatrics 2006; 117: e557e76. 16 Lehmann HP, Hinton R, Morello P, Santoli J. Developmental dysplasia of the hip practice guideline: technical report. Committee on Quality Improvement and subcommittee on developmental dysplasia of the hip. Pediatrics 2000; 105: E57. 17 Screening for the detection of congenital dislocation of the hip. London: The Standing Medical Advisory Committee (SMAC), Department of Health and Social Security, 1986. 18 Paton RW, Choudry Q. Neonatal foot deformities and their relationship to developmental dysplasia of the hip: an 11-year prospective, longitudinal, observational study. J Bone Joint Surg Br 2009; 91: 655e8. 19 Von Kries R, Ihme N, Oberle D, et al. Effect of ultrasound screening on the rate of first operative procedures for developmental hip dysplasia in Germany. Lancet 2003; 362: 1883e7. 20 Paton RW, Srinivasan MS, Shah B, Hollis S. Ultrasound screening for hips at risk in developmental dysplasia. Is it worth it? J Bone Joint Surg Br 1999; 81: 255e8. 21 Paton RW, Hinduja K, Thomas CD. The significance of at risk factors in ultrasound surveillance of developmental dysplasia of the hip. A ten-year prospective study. J Bone Joint Surg Br 2005; 87: 1264e6. 22 Graf R. Hip sonography: 20 years experience and results. Hip Int 2007; 17(suppl. 5): S8e14. 23 Duppe H, Danielsson LG. Screening of neonatal instability and of developmental dislocation of the hip. A survey of 132,601 living newborn infants between 1956 and 1999. J Bone Joint Surg Br 2002; 84: 878e85.
Hip dysplasia (without subluxation) This condition may present in adolescence with significant pain and restriction of joint movement (Figure 8). In younger children it may present asymptomatically. 3D CT imaging of the hip joint may be necessary in order to adequately assess the cover of the femoral head and the shape of the acetabulum. If surgical reconstructive procedures are considered necessary in order to improve the morphology of the hip joint, operations such as a peri-acetabular osteotomy, Salter osteotomy, triple pelvic osteotomy (pubic, ischium and iliac bones), or Berne periacetabular osteotomies may need to be considered, depending on age. This may need to be combined with a proximal varus or de-rotation osteotomy of the femur. Figure 3 is a Crowe Type III dislocation of the hip joint in an eight year-old female patient, which if untreated would likely result in premature osteoarthrosis of this joint. The treatment is of femoral shortening derotation osteotomy combined with a pelvic augmentation procedure (peri-acetabular osteotomy). Figure 9 is the Crowe Type III hip following this hip reconstruction procedure, after removal of the metalwork one year post-operatively.
Summary DDH is a dynamic condition that may resolve or deteriorate with growth. The majority of neonatal hip joint instabilities and cases of sonographic hip dysplasia resolve spontaneously without treatment. Persistent hip joint instability is initially treated with bracing/ splintage, the majority resolving without further additional treatment. Some early presenting probable irreducible hip dislocations can be treated by manipulation under anaesthetic, hip arthrography and application of a hip spica. If this procedure fails, if it is not technically possible or if the dislocation presents late, then more invasive surgery with open reduction of the hip joint and reconstructive surgery to the pelvis or femur may be necessary. A
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Ó 2016 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Paton RW, Choudry Q, Developmental dysplasia of the hip (DDH): diagnosis and treatment, Orthopaedics and Trauma (2016), http://dx.doi.org/10.1016/j.mporth.2016.05.015