Key words
education - training - quality assurance - musculoskeletal system - pediatrics
Introduction
Developmental dysplasia of the hip (DDH), formerly known as congenital dislocation
of the hip (CDH), is a condition that includes a wide spectrum of severity, which,
if left untreated, may cause significant long-term complications (including intra-articular
lesions in the pre-arthritic stage and early onset osteoarthritis [1]
[2] thus leading to severe disability during early adult life.
Most cases of DDH, if diagnosed and treated early, are potentially reversible. All
aspects of DDH have long been a source of debate, and universal agreement has not
been reached. There is disagreement regarding the etiology and pathogenesis (genetic
vs. mechanical), the preferred diagnostic approach (clinical vs. ultrasound (US)),
the most effective screening policy (selective vs. universal) and the appropriate
treatment approach.
Screening by US is well established as a critical element in the evaluation of the
infant hip. However, there are many different techniques in use [3]
[4]
[5]
[6]. The value of US screening is dependent on adherence to correct technique which
underlines the critical importance of standardized training, audit and quality control
[7].
The aim of this meeting was to achieve consensus on all of the above-mentioned issues,
to propose an evidence-based approach to the problem of DDH, and to develop a system
for early detection, diagnosis and treatment.
Meeting background
The meeting was held in Csolyospalos, Hungary in September 2018. 24 medical doctors
(radiologists, orthopedic surgeons, pediatricians, general practitioners), with expertise
in DDH diagnosis and management, were invited to participate. Several countries were
represented, including Austria, Cyprus, Germany, Greece, Hungary, Iran, Ireland, Italy,
Switzerland, Turkey and the UK.
Participants prepared a summary of the current evidence on specific topics, which
then served as the basis for discussion. Questionnaires about the most important points
were then distributed to the participants, who had to vote either for or against the
proposals.
Depending on the proportion of votes received, the strength of the recommendations
was recorded as follows:
-
strong agreement supports the recommendation (≥ 90 %)
-
general agreement supports the recommendation (≥ 70 % – < 90 %)
-
general agreement weakly supports the recommendation (≥ 50 % – < 70 %)
-
there is not enough evidence to support the recommendation (< 50 %)
Following the meeting, the moderators of each session provided a summary of their
topics which is summarized in this paper, under the following headings:
-
Terminology
-
Etiology and pathogenesis
-
Epidemiology and risk factors
-
Detection of DDH
-
US examination and techniques
-
Timing of US screening
-
Selective vs. universal US
-
Treatment
-
Training/auditing/accreditation
-
Future plans
Terminology
The term “developmental dysplasia of the hip” (DDH) (dysplasia: Greek word meaning
“abnormal growth or development of an organ or tissue”) [8] has replaced congenital dislocation of the hip (CDH) (Klisic, 1984), [9]. There are two reasons for this: (a) it better describes the spectrum of pathology
[10]
[11], which ranges from simple immaturity to complete dislocation of the hip joint; (b)
it introduces the term “developmental” (instead of “congenital”), implying that the
disorder can develop even after birth.
Developmental dysplasia of the hip (DDH) is in fact a spectrum of disorders of the
developing hip [12]
[13], encompassing:
-
Hip abnormalities found on US and/or radiography without any clinical findings. Left
untreated, these may present later as a frank dislocation.
-
Hip instability, such that the femoral head can be dislocated partially or fully from
the acetabulum by an examiner, but relocates spontaneously.
-
Dislocated but reducible hip.
-
Dislocated hip that cannot be reduced.
There was strong agreement in support of the use of the term “developmental dysplasia
of the hip” (DDH) as the most appropriate term to describe the condition. (A)
Etiology and Pathogenesis
Etiology and Pathogenesis
Many theories have been proposed to explain the etiology and mechanism of DDH.
Embryologically the femoral head is fully formed with a spherical configuration, a
short neck and a primitive greater trochanter at 11 weeks [14]. With the subsequent development of the labrum, the femoral head is held centered
in the acetabulum by the surface tension of the synovial fluid. Further interaction
between the femoral head and the joint cartilage results in the normal development
of the hip joint both antenatally and postnatally.
The etiology of DDH is thought to be multifactorial; a combination of genetic/constitutional
[15] and mechanical factors [16]
[17] is believed to be involved in the pathogenesis of the disorder.
The higher frequency of dislocations in females, familial/ethnic predisposition and
geographical variation [18] support the genetic theory [19].
Abnormal forces transmitted to the femoral head, either before birth (breech presentation,
left-sided predominance, etc.), at delivery (vaginal birth with breech presentation)
or after birth (swaddling effect) constitute the basis of the mechanical theory [14]
[19].
Regarding breech presentation, a study in 2010 [20] compared the incidence of DDH between breech twins (all with flexed hips and knees)
and breech singletons (more of whom had flexed hips and extended knees); the breech
singletons had a significantly higher incidence of DDH, supporting the specific importance
of breech position with extended knees (frank breech).
There was strong agreement that the etiology and pathogenesis of the disorder is multifactorial.
(A)
Epidemiology and risk factors
Epidemiology and risk factors
Estimates of the incidence of DDH are highly variable [21]. This is mainly due to the wide variation in the definition of the disorder, the
way it is diagnosed (clinical or imaging, US or X-ray, etc.) and the child’s age at
the time of the diagnosis [22]
[23]. The wide geographical variation of the disorder makes the situation even more complicated.
The incidence per 1000 live births ranges from 0.06 in Africans in Africa to 76.1
in Native Americans, with significant variability between and within racial groups
and geographic location [24].
Based on the results of two relatively recent meta-analyses [18]
[25], one of the most significant risk factors for DDH is breech presentation. Family
history, female sex and maternal primiparity are also considered significant risk
factors [26]. Other risk factors include ethnic background, co-existing lower limb or musculoskeletal
deformities [27]
[28], mechanical restriction before delivery (oligohydramnios, multiple pregnancies)
or after birth (swaddling) [29].
The presence of risk factors alerts the clinician to the need to perform a thorough
clinical and imaging examination. However, most of the DDH cases are diagnosed in
babies without any identifiable risk factors. Therefore, DDH screening based solely
on risk factor identification is not justified [11]
[30].
There was strong agreement that certain risk factors including breech presentation,
female sex and family history are very important, with breech presentation being the
most significant risk factor. (A)
Detection of DDH
Clinical examination of the newborn can detect hip instability but not acetabular
dysplasia. The development of US has advanced our understanding of the normal development
of the hip and allows monitoring of the dislocated, unstable and dysplastic hip [31]
[32]
[33]
[34]
[35].
Clinical examination is not sensitive enough to identify every child with DDH. The
reported specificity is 90 %. The sensitivity, however, is reported as being as low
as 50 %. US has been proved to be more sensitive and more specific for the diagnosis
with significantly higher reported sensitivity and specificity (> 90 %). The latter
arguably is an underestimation, if we exclude sonographers who have not been properly
trained [36]
[37]
[38]
[39]
[40].
Other imaging modalities (X-ray, CT, MRI) are not routinely used for the detection
of DDH. X-ray, which has been the mainstay for imaging diagnosis in the past, has
been effectively replaced by US, which offers earlier, radiation-free diagnosis.
Other imaging modalities may have a role in cases of late diagnosis of DDH or monitoring/guiding
of therapy and/or maturation, when US is no longer feasible [41]. In the past arthrography was considered a gold standard for the evaluation of dislocated
hips and for the identification of tissues between the femoral head and the acetabulum
[42]. However, it provides indirect information on these structures. A study by Abril
et al. [43] demonstrated significant concordance between US and arthrography. Therefore, while
arthrography may have a role in the assessment and treatment of the late case (open/closed
reduction) [44], the same information is provided more directly by US in the context of early diagnosis.
CT and MRI may be used to image the consequences of misdiagnosis later in the course
of the disorder or for surgical planning [45].
There was strong agreement that clinical examination alone is suboptimal for assessing
children for the possibility of DDH. US assessment is essential. (A)
US examination techniques
US examination techniques
The commonly known US techniques used worldwide are the Graf technique which is mainly
used in Europe [3], the Terjesen technique [4] originating in Scandinavia (Terjesen et al, 1989), the Harcke technique developed
in the United States [5] and the Suzuki technique developed in Japan [6]. A detailed description of the abovementioned techniques, is beyond the scope of
this article.
A comparative literature review of these techniques was carried out via PubMed and
seven papers were identified that compared two or more of these methods with each
other.
Diaz A et al. [46] examined 208 babies (416 hips) with the Graf, Harcke and Suzuki techniques. Overall
the three methods correlated well with regard to the severity of the pathology, but
they found the Graf technique to be the most reliable.
Czubak et al. [47] compared the Graf and Terjesen techniques in 657 newborns (1312 hips) with a mean
age of 23 days. The authors found that both techniques had similar results, but favored
the Terjesen technique, as more specific and simpler. It is worth mentioning that
in this study, 2 hips that were classified as Type III hips according to Graf, were
classified as normal according to Terjesen.
Langford et al. [48] compared the Graf and Terjesen techniques and concluded that sonographers need to
be trained in the Graf technique in order to get accurate results.
Falliner et al. [49] compared the Graf and Terjesen techniques in 232 neonates under 4 days old. In order
to determine the reproducibility of the methods, 50 hips were evaluated by two skilled
examiners. Statistical comparison showed a good correlation between the two techniques
and proved no obvious difference in regard to inter-observer reliability. However,
the Graf technique offered better reproducibility and intra-observer reliability.
Peterlein et al. [50] examined 207 newborns with both the Terjesen and Graf techniques and investigated
the inter- and intra-observer reliability for the measurements of alpha angle, beta
angle and femoral head coverage (FHC). They found better reliability for the alpha
angle, followed by the beta angle and finally by the FHC, regardless of the experience
level of the investigator.
Pacheco et al. [51] investigated 225 infants at a mean age of 7.79 weeks with the Graf, Harcke and Terjesen
techniques and calculated the specificity and sensitivity for each. They found the
Graf technique to be the most sensitive and specific, and proved that the alpha angle
was the most reliable criterion on which to base a treatment decision.
Kotlarsky et al. [52] published a review article in 2015, comparing the Graf, Suzuki and Harcke techniques.
Their conclusion was that the Graf technique fulfilled the requirements for an effective
US technique, offering simple, precise, quantitative and consistent definitions for
examination and diagnosis.
Comparative presentation of the results of the abovementioned studies are presented
in [Table 1].
Table 1
Studies comparing different US techniques.
|
article
|
reliability
|
sens/specif
|
interobserver
|
intraobserver
|
reproducibility
|
|
Diaz A et al. (1994) – Compares Graf vs. Harcke vs. Suzuki
|
graf
|
–
|
–
|
–
|
–
|
|
Czubak et al. (1998) – Compares Graf vs. Terjesen
|
equal
|
terjesen
|
terjesen
|
–
|
–
|
|
Langford et al. (2001) – compares Graf vs. Terjesen
|
graf (needs more experience)
|
–
|
–
|
–
|
–
|
|
Falliner et al. (2006) – compares Graf vs. Terjesen
|
equal
|
graf
|
equal (except for students)
|
graf
|
graf
|
|
Peterlein et al. (201) – compares Graf vs. Terjesen
|
graf
|
–
|
–
|
–
|
graf
|
|
Pacheco et al. (2012) – compares Graf vs. Terjesen vs. Harcke
|
graf
|
graf
|
–
|
–
|
–
|
|
Kotiarsky et al. (2015) – compares Graf vs. Suzuki vs. Harcke
|
graf
|
graf
|
–
|
–
|
–
|
In summary, our literature review strongly suggests that the Graf technique seems
to be superior to the other techniques. A recent review has also reinforced this position
[53].
The Graf technique correlates the pathology and severity of acetabular dysplasia,
with the patient’s age, thus offering a patient-specific diagnostic and treatment
algorithm [7]. The scanning technique per se is standardized, and its application and principles
have been thoroughly described [54]. The value of structured training by authorized teachers has been recognized [55]. Mistakes may be avoided by strict adherence to the technique, so only appropriately
trained and certified sonographers should be allowed to scan. Continuous quality control
and audit should also be offered [7].
The technical details of the technique were also thoroughly discussed during the meeting.
Adoption of the scanning principles (including equipment, technique and documentation)
as presented in detail in the teaching manual [54] is mandatory.
There was strong agreement that the preferred US examination technique, for the early
detection and treatment of DDH, is the Graf technique. Strict adherence to the principles
of the technique, as presented in the teaching manual, is mandatory. (A)
Timing of US screening
Several papers make the point that closed treatment of DDH is more successful if instituted
earlier [56]
[57]
[58]
[59]. From this, the view may be taken that the earlier the scan is carried out and any
necessary treatment is begun, the better.
On the other hand, some authors have expressed concern regarding overdiagnosis arising
from scanning occurring very early [23]
[60]. In the German language literature, Grill and Muller [61] similarly expressed concern about overdiagnosis, when scans are performed in the
first week.
There is a range of recommendations in the literature regarding the time to scan.
The German language literature generally recommends scanning before six weeks of age
[62]
[63]
[64]
[65]. There is quite a variation in the English language literature. Tyagi et al. [66] described scanning at an average of 5 weeks. Bacche et al. [67], Imrie et al. [68] and Clarke et al. [27], all described scanning at 6 weeks. Kolb et al. [69] and Schaeffer et al. [70], both recommended scanning at 6 to 8 weeks. Choudry et al. [71] recommended scanning babies with unilateral limitation of abduction at 8 weeks.
Pillai et al. [72] reported that the specificity and accuracy of US with the Graf technique was at
its highest at 3 months of age.
Some authors have made a distinction between babies who have clinical signs of instability
and those who are being screened without any clinical abnormality [27]
[73].
To summarize, the picture which emerges is that earlier diagnosis facilitates earlier
treatment, which is more successful, but it has been suggested that scanning too early
can risk overtreatment, as many hips which appear immature at first will mature later.
There is support for early scanning in babies with clinical signs. Otherwise, in the
German language literature, the recommendation is to scan before six weeks of age,
while in the English language literature, the range of recommended ages for scanning
babies without clinical signs goes from just under six weeks to three months.
At this meeting, it was pointed out that the standard practice in Austria is to scan
the baby’s hips twice: first at birth and then again between the 4th and 7th week of life. This allows treatment to begin as soon as possible, and therefore more
successfully. However, even if dysplasia is only detected on the second scan, between
the 4th and 7th week, the hip is still within the maturation curve. There was strong support for
the view that, given the maturation process of the hip, the earlier a problem is identified
and treated the better. It should be possible for a trained examiner to distinguish
between clearly abnormal hips and those which may simply be immature and can be followed
up, thus avoiding the danger of overtreatment.
There was strong agreement at this meeting that US screening should be carried out
as soon as possible, but no later than the sixth week of life. (A)
Selective vs. universal US screening
Selective vs. universal US screening
The literature surrounding this question is very varied. To some extent, it reflects
an evolution of understanding over time, but also variation in practice between different
countries.
There have been some reviews that cast doubt upon the whole practice of US screening
[11]
[74]
[75]
[76]. A Cochrane review [75]
[76] concluded that neither US strategy had been demonstrated to improve clinical outcomes,
including late diagnosed DDH and surgery. A Canadian review in 2001 [74] concluded there was “fair evidence” to exclude both “general US screening” and “selective
screening”. Shipman et al. [11], based in the USA, carried out a meta-analysis, in which they were critical of the
literature on screening and interventions for DDH.
Leaving these criticisms of the evidence in the literature aside, the debate about
universal vs. selective screening revolves to a large extent around effectiveness,
cost, and the possibility of overdiagnosis and overtreatment.
Several papers have claimed good results with a regime of selective US screening [27]
[77]
[78]
[79]
[80]. In a Norwegian study, Holen et al. [77] argued based on their findings that “when clinical screening is of high quality”,
universal US was not necessary. Instead they favored selective screening based on
clinical findings and risk factors. Mahan et al. [78] in the USA described an analytic model and they argued that the best approach was
to clinically screen all neonates and then to use US selectively for infants at high
risk. Laborie et al. [79] from Norway referred to a regime of selective screening resulting in an “acceptable”
rate of early treatment and low rates of subluxated/dislocated hips. In an Australian
study Leba et al. [80] highlighted the cost of screening but showed good results from selective screening.
Clarke et al. [27] in the UK also showed good results using a system of selective screening based on
breech presentation, family history and foot deformity.
However, there have been a number of studies pointing to patients with DDH who would
have been missed by a selective US screening regime [67]
[81]
[82]. A review in the USA [82] looked at skeletally mature patients who had had surgery for the late consequences
of DDH. 85.3 % of them would not have been screened in a selective US screening program.
Starting in the early 1990 s, evidence of the potential of universal US screening
began to be published in the English language [83]
[84] and since then a number of papers reinforcing this have been published [56]
[69]
[85]
[86]
[87]
[88]. In 2004 Wirth et al. [85] from Germany reported that a program of “general” US screening had resulted in a
dramatic decrease in surgical procedures, hospitalizations and late presentation.
Tschauner et al. [56] from Austria reported that a cohort of babies who had come through a universal screening
program had a 98.9 % success rate with treatment. A year later, vonKries et al. [86] from Germany reported a reduction in the rate of operative procedures due to “general”
US screening, but cautioned that further assessment was required to balance this benefit
against potential overtreatment and adverse effects. Reporting on the outcomes of
the Austrian universal screening program, Thalinger et al. [87] showed a significant decrease in the rates of open reduction, pelvic surgery, and
hospital admissions for DDH. Kolb et al. [69], also from Austria, observed that risk factors had a low impact within their group. Therefore,
they were also in favor of universal screening. Guler et al. [88] from Turkey reported on their population of babies who underwent US screening with
satisfactory results and thus recommended its use.
At this meeting, a speaker from Ireland described how a system of US screening for
DDH had been initiated over the previous four years, starting from a highly variable
situation in the country. A system of selective US screening was now almost in place.
At this time, resources were not available for universal screening. However, an added
dimension in Ireland was an extremely litigious climate, in which other health service
screening programs had been subjected to legal action because of false negatives.
This meant that caution was necessary in initiating any screening program, while making
sure the objectives were realistic and clearly communicated.
The Swis team presented the design and application of a nationwide universal screening
program, which was introduced under the name “The Mongolian Project” [89]
[90]
[91]. The project, which included more than 300 000 scans and over 4000 successfully
treated children, was commended as a very worthy and successful initiative. It was
seen as a good example of how a universal screening, early-scan and early-treatment
national policy can be successfully implemented nationwide, even when healthcare resources
are scarce.
A presenter from Austria described how universal US screening had been established
in that country since 1992, and had been shown to be successful and cost-effective.
Universal US screening has been in place in Germany since 1996. The German language
literature supports this position, in terms of reduced late diagnosis and reduced
rates of late surgery related to dysplasia [61]
[63]
[92].
One of the presenters at this meeting, having practiced both in Austria and in the
UK, reported on the striking contrast between the two systems. In the UK, where selective
rather than universal US screening is employed, there is an incidence of late diagnosis
of DDH which is almost unknown in Austria. Over a four-year period, one pediatric
center in the UK had 114 patients requiring operations for DDH. 91 of these were late
presentations (63 with no risk factors). 62 patients had open surgery, and 52 had
closed reduction and spica application, with 8 subsequently requiring open surgery.
It was stated that there appeared to be resistance in a system employing selective
screening to moving to universal screening despite the evidence, probably largely
due to issues regarding logistics and resources.
One issue for debate is whether the benefits of universal US screening justify the
cost. Paton et al. [93] from the UK called its value into question, suggesting that it could not be justified
on the grounds of cost. However, Clegg et al. [84], also from the UK, showed as far back as 1999 that the cost appeared justified in
terms of the treatment savings. Further UK studies [84]
[95] suggested that universal screening did not incur increased costs. More recently,
Thaler et al. [96] from Austria demonstrated that the cost of a universal US screening program was
more than offset by the costs of surgical and non-surgical treatments that had been
avoided, and that therefore the policy was indeed cost-effective. The German language
literature supports this position. Ihme et al. [92] compared the costs of hip surgery due to DDH at two different time periods (patients
who received US and a historical group) and demonstrated that the costs of hip US
were lower than the costs of hip surgery. This position was further supported by the
study by Farr [65].
At this meeting, the presenters expressed the view that a policy of universal US screening
is indeed cost-effective, citing the studies by Clegg et al. [84] and Thaler et al. [96]. This is true, particularly when we include the prospective costs, including late
surgery which is avoided by early diagnosis and treatment. The difficulty is in making
the case for the initial investment, based on the expectation of overall cost savings
in the longer term.
Another concern which has been expressed is the possibility of overdiagnosis and overtreatment,
with the associated risk of avascular necrosis [29]
[60]
[66]. Most notably, in their guidelines published in 2016, the American Academy of Pediatrics
[29] recommended against universal US screening in North America, citing “expense, inconvenience,
inconsistency, subjectivity, and high false-positive rates”.
However, the point has been made that a universal US screening system can actually
reduce the non-operative treatment rate since treatment is based on objective rather
than subjective clinical criteria [97]
[98].
At this meeting, the prevailing view was the latter, i. e. that the objectivity provided
by US screening that is carried out and interpreted correctly, should not result in
babies being treated unnecessarily. However, some attendees observed that in a system
in which babies are treated according to US findings at an early age, overtreatment
might happen.
Another area of expressed uncertainty concerns later outcomes of babies with hip dysplasia
[56]
[99]. Thalinger et al. [87], reporting on the late outcomes of the Austrian screening program, did show a decrease
in the frequency of late pelvic osteotomy arising from hip dysplasia.
At this meeting, there was strong agreement that a system of universal US screening
results in a reduction in the need for later pelvic osteotomies, quoting in particular
the findings of Grill and Muller [61] and Thalinger et al. [87].
In summary, while the German language literature is supportive of universal US screening,
the English language literature presents a mixed picture. To a large extent this is
reflective of geographical variation. It is clear that universal US screening results
in a low rate of late diagnosis. What varies between studies is the extent to which
this approach outperforms selective screening, and whether this extra benefit is offset
by cost, or the possibility of overdiagnosis and overtreatment, with its attendant
risk. Some believe that the degree to which this lowered rate of late diagnosis translates
into a reduction of the sequelae of dysplasia at skeletal maturity also remains to
be established.
At this meeting it was stated that this variation in findings reported in the literature
was probably due to studies not being comparable. Techniques could vary, the scans
could be carried out by individuals with varying levels of training, the definition
of “risk factors” could vary, the quality of clinical screening could vary and different
outcome measures may have been used.
In addition, the definition of “cost” could vary depending on what factors were included.
The consensus group emphasized two points:
Firstly, there should be a differentiation between clinical effectiveness and cost-effectiveness.
The former is what healthcare providers should aim to practice and must be the gold
standard, whereas the latter (cost-effectiveness) is a compromise and should be honestly
explained to parents and to the public.
Secondly, all studies that assessed cost-effectiveness compared the cost of a universal
screening program to the cost of surgical treatment for DDH. None of the studies included
long-term effects such as quality of life, the need for future hip replacement, and
loss of the ability to work. The published German, Austrian, Swiss and Coventry studies
demonstrated that although there is a marginal increase in the universal screening
cost, it is a good value for the money.
Reference was made to a recent report by Biedermann and Eastwood [98] from Austria and the UK, respectively. This was a joint review calling for a “paradigm
shift” towards universal US screening, stating that it results in the lowest late
presentation rates, low treatment rates, a lower rate of surgery on the infant hip,
and a reduction in the rate of surgery for DDH in later life. They also make the point
that avascular necrosis can be avoided, and that modern orthoses should have a zero
rate of AVN. The dominant outcome of the discussion was one of support for this “paradigm
shift”.
There was strong agreement in favor of universal US screening. (A)
There was strong agreement that, when all short- and long-term costs are taken into
account, a system of universal US screening is cost-effective. (A)
There was general agreement that a system of universal US screening using the Graf
technique would not result in over-treatment. (B)
There was strong agreement that a system of universal US screening using the Graf
technique will result in a reduction of later problems with dysplasia. (A)
Treatment
According to the classification system developed by Graf [41]
[54], Type I hips are mature hips, so they do not require any treatment. Type IIa hips
are immature hips and as long as their degree of maturity is age-appropriate, treatment
is not required. However, they should reach maturity by three months of age. Otherwise,
they are re-classified as Type IIb and require treatment. Treatment is required for
any hip that is classified as Type IIa minus or worse. Therefore, Type IIc, D, III
& IV hips always require treatment. [Table 2] summarizes the abovementioned classification/treatment scheme.
Table 2
Treatment of DDH according to Graf’s hip classification.
|
hip type
|
age
|
type Description
|
treatment
|
|
I
|
any age
|
mature hip
|
not required
|
|
IIa
|
< 6 weeks
|
immature hip
|
US follow-up
|
|
IIa(+)
|
6–12 weeks
|
immature hip
|
not required/ optional follow-up
|
|
IIa(–)
|
6–12 weeks
|
delayed ossification
|
treatment is recommended
|
|
IIb
|
> 12 weeks
|
dysplastic hip
|
|
IIc
|
any age
|
heavily dysplastic hip
|
|
D, III, IV
|
any age
|
Decentered hip
|
DDH treatment according to Graf consists of (a) femoral head reduction, (b) maintenance
of head relocation (retention) and (c) correction of any residual acetabular dysplasia
(maturation).
Early initiation of treatment is strongly recommended as a substantial part of maturation
of the hip joint occurs within the first three months. By six weeks, the baby’s hip
is already half-way along this steep part of the maturation curve. Therefore, it is
very important for treatment to be initiated before six weeks of age. Correct use
of an abduction device is the mainstay of treatment. A combination of flexion (110˚)
and abduction (45˚) prevents avascular necrosis of the femoral head, as this position
avoids excessive pressure on the femoral head against the hyaline cartilage of the
acetabulum.
The essential elements of early treatment are:
-
Reduction: This is required in Types D, III and IV. Provided treatment is initiated
early enough, this should be achieved by the position of flexion and a safe degree
of abduction as has been described above. Treatment position may be reached by a spica
cast, although in newborns some centers prefer the use of an external harness.
-
Retention: This is required in Type IIc unstable and in Type D, III and IV hips that
have been effectively reduced. Retention is achieved by an external device, again
combining flexion with a safe degree of abduction.
-
Maturation: This is required in Type IIa minus, Type IIb, Type IIc stable, and in
hips of more severe grades, which have been reduced if necessary, and retained as
above. An external device maintains the hip in flexion and a safe degree of abduction.
Treatment should be continued until the hip reaches Graf Type I.
There are a number of specific varieties of splints and harnesses available for treatment.
The reported success rate is variable but for the most part is in excess of 90 % [90]
[100]
[101]
[102]
[103]. The likely reasons for the reported variation are the selection of the threshold
for treatment, the variable length of treatment, the variable age of the children
when treatment begins and the different definitions of failure by the reporting authors.
At this meeting, no recommendation was made for any specific device. Rather the important
point was the position of the hips during treatment.
The underlying principle of the favored treatment approach is to start treatment early.
If the femoral head does not relocate by closed means, as may happen particularly
in older babies, open reduction may be required. In older children with centered hips
but residual dysplasia, pelvic osteotomy may become necessary. However, these issues
are outside the scope of this meeting, which was focused on closed treatment facilitated
by early diagnosis.
There was strong agreement that the important principle of treatment is the application
of a device placing the hips in the appropriate degrees of flexion and abduction.
The type of device is less important than early and accurate diagnosis and early initiation
of treatment. (A)
Training, auditing, accreditation
Training, auditing, accreditation
It was recognized at this meeting that teaching of the Graf technique must be standardized.
Who is trained will vary from country to country, but at a minimum, it must be a health
care professional. In order to help with this standardization, a set of slides was
prepared and presented. They summarize the theoretical content of the basic course.
Future work on these will include further refinement of the slides and translation
into languages other than English.
Regarding future development of the course, there was support for including a section
on the basic physics of US and for making the theory of the course available online
prior to attendance.
Practical sessions should include all theoretical and practical aspects of the technique,
including scanning demonstration on a phantom and/or babies.
The ideal duration of the course should be two days.
Regarding further training, it was agreed that the update/accreditation course should
only be taken by those who have done the basic course, normally at least six months
previously. This course should also be standardized. Further issues, to be addressed
at future meetings, include required practical training and experience following the
basic course, accreditation of instructors, and re-accreditation.
Another area for future development will be the formation of national committees whose
roles would include approval of training courses, examiners and instructors, re-accreditation
of examiners and instructors, and quality management. Such committees would in turn
connect with the international organization (ICODE – the International Interdisciplinary
Consensus Committee on DDH Evaluation).
There was strong agreement on the following points (A):
US examiners should at a minimum be health care professionals.
The training courses should be standardized. Further development of the courses is
desirable.
Candidates for the update/accreditation course should have first completed the basic
course, normally at least six months prior.
Future plans
The group has now been formalized as the International Interdisciplinary Consensus
Committee on DDH Evaluation (ICODE). The objectives of the group are:
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To work towards consensus on the various issues regarding DDH, in particular policies
for detection and early treatment.
-
To promote, standardize and continually improve teaching and training in the Graf
technique of infant hip US.
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To use its international network to support research, audit and quality improvement
in the field of detection and early treatment of DDH.
An ICODE website has been set up and is being developed. It can be accessed via www.icode.expert
The group will continue to meet, with the next meeting scheduled for Heraklion, Crete,
in May/June 2019. As it develops, the group will aim to widen its efforts internationally
with the goal of achieving the best possible outcomes from DDH worldwide.
