This is the current release of the guideline.

This guideline updates a previous version: Karmazyn BK, Gunderman R, Coley BD, Blatt ER, Bulas D, Fordham L, Podberesky DJ, Prince JS, Paidas C, Rodriguez W, Expert Panel on Pediatric Imaging. ACR Appropriateness Criteria® developmental dysplasia of the hip--child. [online publication]. Reston (VA): American College of Radiology (ACR); 2007. 7 p. [40 references]

The appropriateness criteria are reviewed biennially and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

Developmental dysplasia of the hip (DDH)

To evaluate the appropriateness of initial radiologic examinations for developmental dysplasia of the hip (DDH)

Utility of radiologic examinations in differential diagnosis

Literature Search Procedure

The Medline literature search is based on keywords provided by the topic author. The two general classes of keywords are those related to the condition (e.g., ankle pain, fever) and those that describe the diagnostic or therapeutic intervention of interest (e.g., mammography, MRI).

The search terms and parameters are manipulated to produce the most relevant, current evidence to address the American College of Radiology Appropriateness Criteria (ACR AC) topic being reviewed or developed. Combining the clinical conditions and diagnostic modalities or therapeutic procedures narrows the search to be relevant to the topic. Exploding the term "diagnostic imaging" captures relevant results for diagnostic topics.

The following criteria/limits are used in the searches.

1. Articles that have abstracts available and are concerned with humans.
2. Restrict the search to the year prior to the last topic update or in some cases the author of the topic may specify which year range to use in the search. For new topics, the year range is restricted to the last 5 years unless the topic author provides other instructions.
3. May restrict the search to Adults only or Pediatrics only.
4. Articles consisting of only summaries or case reports are often excluded from final results.

The search strategy may be revised to improve the output as needed.

The total number of source documents identified as the result of the literature search is not known.

Strength of Evidence Key

Category 1 - The conclusions of the study are valid and strongly supported by study design, analysis and results.

Category 2 - The conclusions of the study are likely valid, but study design does not permit certainty.

Category 3 - The conclusions of the study may be valid but the evidence supporting the conclusions is inconclusive or equivocal.

Category 4 - The conclusions of the study may not be valid because the evidence may not be reliable given the study design or analysis.

The topic author drafts or revises the narrative text summarizing the evidence found in the literature. American College of Radiology (ACR) staff draft an evidence table based on the analysis of the selected literature. These tables rate the strength of the evidence for all articles included in the narrative text.

The expert panel reviews the narrative text, evidence table, and the supporting literature for each of the topic-variant combinations and assigns an appropriateness rating for each procedure listed in the table. Each individual panel member forms his/her own opinion based on his/her interpretation of the available evidence.

More information about the evidence table development process can be found in the ACR Appropriateness Criteria® Evidence Table Development document (see "Availability of Companion Documents" field).

Modified Delphi Technique

The appropriateness ratings for each of the procedures included in the Appropriateness Criteria topics are determined using a modified Delphi methodology. A series of surveys are conducted to elicit each panelist's expert interpretation of the evidence, based on the available data, regarding the appropriateness of an imaging or therapeutic procedure for a specific clinical scenario. American College of Radiology (ACR) staff distributes surveys to the panelists along with the evidence table and narrative. Each panelist interprets the available evidence and rates each procedure. The surveys are completed by panelists without consulting other panelists. The ratings are a scale between 1 and 9, which is further divided into three categories: 1, 2, or 3 is defined as "usually not appropriate"; 4, 5, or 6 is defined as "may be appropriate"; and 7, 8, or 9 is defined as "usually appropriate." Each panel member assigns one rating for each procedure per survey round. The surveys are collected and the results are tabulated, de-identified and redistributed after each round. A maximum of three rounds are conducted. The modified Delphi technique enables each panelist to express individual interpretations of the evidence and his or her expert opinion without excessive bias from fellow panelists in a simple, standardized and economical process.

Consensus among the panel members must be achieved to determine the final rating for each procedure. Consensus is defined as eighty percent (80%) agreement within a rating category. The final rating is determined by the median of all the ratings once consensus has been reached. Up to three ratings rounds are conducted to achieve consensus.

If consensus is not reached, the panel is convened by conference call. The strengths and weaknesses of each imaging procedure that has not reached consensus are discussed and a final rating is proposed. If the panelists on the call agree, the rating is proposed as the panel's consensus. The document is circulated to all the panelists to make the final determination. If consensus cannot be reached on the call or when the document is circulated, "No consensus" appears in the rating column and the reasons for this decision are added to the comment sections.

Not applicable

The guideline developers reviewed published cost analyses.

Criteria developed by the Expert Panels are reviewed by the American College of Radiology (ACR) Committee on Appropriateness Criteria.

ACR Appropriateness Criteria®

Clinical Condition: Developmental Dysplasia of the Hip – Child

Variant 1: Patient younger than 4 months of age, positive physical findings (Ortolani or Barlow maneuvers).

Radiologic Procedure	Rating	Comments	RRL*
Ultrasound (US) hips	8	Preferably at the age of 4 to 6 weeks.	O
X-ray hips	2	Anteroposterior (AP) view
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

Variant 2: Patient younger than 4 months of age, equivocal physical findings.

Radiologic Procedure	Rating	Comments	RRL*
Ultrasound (US) hips	8	Preferably at the age of 4 to 6 weeks.	O
X-ray hips	2
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

Variant 3: Patient younger than 4 months of age, breech presentation or positive family history. Without physical findings.

Radiologic Procedure	Rating	Comments	RRL*
Ultrasound (US) hips	8	Preferably at the age of 4 to 6 weeks.	O
X-ray hips	2
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

Variant 4: Patient 4 months of age or older, clinically suspicious for developmental dysplasia of the hip (DDH) (limited abduction or abnormal gait).

Radiologic Procedure	Rating	Comments	RRL*
X-ray hips	8	Anteroposterior (AP) view
Ultrasound (US) hips	3	May be used if the femoral heads are not yet ossified.	O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

Variant 5: Clinical suspicion for teratogenic dysplasia.

Radiologic Procedure	Rating	Comments	RRL*
X-ray hips	8	Anteroposterior (AP) view
Ultrasound (US) hips	5	May be used if the femoral heads are not yet ossified.	O
Rating Scale: 1,2,3 Usually not appropriate; 4,5,6 May be appropriate; 7,8,9 Usually appropriate			*Relative Radiation Level

Summary of Literature Review

Definition

Developmental dysplasia of the hip (DDH), formerly known as congenital dislocation of the hip, comprises a spectrum of abnormalities including abnormal acetabular shape (dysplasia) and malposition of the femoral head, ranging from dislocatable hip and mild subluxation to fixed dislocation.

Incidence

It is difficult to assess the true incidence of DDH as definition varies and there is no gold standard test. Incidence varies from 1.5 to 20 per 1,000 births. In the United States, DDH affects 1.5 per 1,000 of the Caucasian population. It less frequently affects African Americans. It is four to eight times more common in females. It is also more common in patients with a family history of DDH, in first-born children, in large infants, and in infants with a history of oligohydramnios. It is three times more common in the left hip than the right, likely due to the normal left occiput anterior position in utero, which places the left hip against the mother's spine and limits its abduction.

Etiology

The origin and pathogenesis of DDH are multifactorial. Abnormal laxity of the ligaments and hip capsule is seen in patients and families with DDH. The maternal hormone relaxin may also be a factor. Mechanical factors of reduced in utero space and movement restriction are thought to be causative in the setting of oligohydramnios and being the first-born child. Extreme hip flexion with knee extension, as in breech position, tends to promote femoral head dislocation and leads to shortening and contracture of the iliopsoas muscle.

Natural History

The natural history of DDH depends on the type and degree of hip abnormality. Mild dysplasia may never manifest clinically or become apparent until adult life, whereas severe dysplasia is most likely to present clinically during childhood. Most DDH identified during the newborn period represents hip laxity and immaturity. About 60% to 80% of abnormalities identified by physical examination and more than 90% that are identified by ultrasound (US) resolve spontaneously. Untreated subluxed and dislocated hips can lead to early degenerative joint disease and impaired function.

Diagnosis

The diagnosis of DDH may be made by clinical examination or by imaging methods such as radiography or US.

Clinical Evaluation

The American Academy of Pediatrics recommends a well-baby visit at 1-2 weeks, and at 2, 4, 6, 9, and 12 months of age. As part of the clinical evaluation, it is important to elicit risk factors for DDH. Examination findings suggesting DDH include a positive Ortolani or Barlow test, asymmetric skin folds, and shortening of the thigh observed on the dislocated side. The Ortolani test is designed to enable the already dislocated hip to be detected by causing the femoral head to slip into the acetabulum, resulting in a "clunk" that can be felt or heard. The Barlow test aims to elicit a dislocation followed by reduction and identifies unstable hips missed by the Ortolani test.

In children older than 3 months of age, these tests are less likely to be positive. Limitation of hip abduction and asymmetric thigh folds secondary to shortening are more useful clinical signs of DDH. Once a child is walking, there is a typical limp and the child often toe-walks on the affected side. If both hips are dislocated, increased lumbar lordosis, prominent buttocks, and a waddling gait pattern are present. The physical examination may be misleading as no "click" is elicited. The sensitivity and specificity of the clinical examination depend on the expertise of the evaluator. Effectiveness of clinical screening varies, depending on whether an orthopedic surgeon, experienced pediatrician, or intern performs the examination.

Radiographic Evaluation

Radiographs are readily available and relatively low in cost. The main limitations are radiation exposure and inability to demonstrate the cartilaginous femoral head. In the first 3 months of life, when the femoral heads are composed entirely of cartilage, radiographs are of limited value. By 4 to 6 months of age, with the appearance of femoral head ossification, radiographs become more reliable.

Radiographs may be performed to assess the hips in children with clinical diagnosis of DDH, to monitor hip development after treatment, and to assess longer-term outcomes. Radiographs are also valuable for patients with neuromuscular disorders, myelodysplasia, or arthrogryposis (teratologic dislocation) to assess other bony abnormalities.

Radiography of the pelvis should be obtained with hips in neutral position. Frog-leg view may be obtained to assess reduction when neutral view is abnormal. The radiographic evaluation consists predominantly of a visual assessment; however, measurement of the acetabular index is an objective parameter that may be used in the diagnosis and follow-up of patients with DDH. There is interobserver variability that casts doubt on the reliability of the acetabular index based on a single reading.

Ultrasound Evaluation

US evaluation of the hip is performed using a high-frequency linear array transducer. Two methods have emerged: a static acetabular morphology method proposed by Graf and a dynamic stress technique proposed by Harcke.

The Graf method is based on a single coronal image. Graf developed a morphologic and geometric hip classification scheme (types I-IV) using an alpha angle, which measures the osseous acetabular roof angle, and a beta angle, which defines the position of the echogenic fibrocartilaginous acetabular labrum. The different categories can be grouped in three hip types.

Normal hip: Type I hips are normal and require no treatment. The alpha angle is greater than 60 degrees.

Immature hip: Type IIa hips are seen in infants less than 3 months of age. The hip is normally located, but the bony acetabulum promontory is rounded and the alpha angle is 50 to 59 degrees. These patients require no treatment, and there is a small risk of delayed DDH. Follow-up is recommended to confirm normal development.

Abnormal hip: Type IIb has similar features as type IIa, but is detected in children older than 3 months. Types IIc, D, III, and IV represent progressive abnormal hips with frank subluxation in types III and IV. Alpha angle is <50 degrees in types IIc and D and <43 degrees in types III and IV.

Interobserver variability raises concerns about the operator dependence of US evaluation for DDH and may explain the variability of US screen-positive rates found in the literature.

Harcke developed the dynamic or real-time method, which attempts to visualize the Barlow and Ortolani maneuvers on US. This technique is performed in both the coronal and transverse planes, with and without stress. The modified Barlow maneuver is performed by holding the knee with the hip flexed 90 degrees and in adduction. The femur is pushed (pistoned) posteriorly. The ACR guidelines for hip US combine the static and dynamic techniques.

US during the first 4 weeks of life often reveals the presence of minor degrees of instability and acetabular immaturity, but nearly all of them resolve on follow-up. It is therefore recommended to perform US studies at the age of 4 to 6 weeks.

Other Imaging Modalities

Computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate DDH in patients with casts following surgery or closed reduction to confirm that the hip has been successfully reduced. CT and MRI can also be used to evaluate complex hip dislocations, for presurgical planning, and for evaluation of avascular necrosis (AVN). Arthrography is used primarily in the operating room by the orthopedic surgeon to evaluate lateral displacement of the femoral head and congruity following closed reduction of the hip, and to assess for labral infolding that might prevent proper reduction.

Ultrasound Screening for Developmental Dysplasia of the Hip

There is no consensus on the best method of screening for DDH. The goal of a screening program is to detect all patients with DDH early, when therapy is most effective and noninvasive, and to identify those patients without DDH in whom unnecessary treatment may be costly and harmful. Delayed diagnosis increases the risk of complications, and infants diagnosed after 6 months of age often require surgical correction. However, screening carries potential harm. Most of the clinically and US-detected DDH will resolve spontaneously. Screening may, therefore, lead to overtreatment. The most common and serious complication of nonsurgical treatment is AVN. The decision on the best method of screening is complex, as evidenced by a recent conclusion of the United States Preventive Services Task Force that was "unable to assess the balance of benefits and harms of screening" for DDH. Two types of screening can be performed: universal screening, in which all neonates are evaluated, and selective screening, in which only those at high risk are evaluated.

Universal Ultrasound Screening

Universal newborn screening with US for DDH is performed in some European countries. Universal screening increases detection of DDH, which leads to higher rates of treatment with abduction splinting. However, there is no evidence that it decreases late diagnosis of DDH. This may lead to increased expense, unnecessary treatment, and increased post-treatment complications of AVN. For these reasons, universal screening was not recommended by the American Academy of Pediatrics.

Selective Ultrasound Screening

Risk Factors

Risk factors for DDH include breech presentation, positive family history, and female gender. Additional risk factors include maternal primiparity, oligohydramnios, and congenital anomalies. The American Academy of Pediatrics recommends hip imaging for female infants born in the breech position, and optional hip imaging for males born in the breech position or females with a positive family history of DDH.

Selective US screening can identify DDH in children at high risk for DDH with negative physical examination. However, selective US screening has not been shown to significantly reduce late diagnosis of DDH.

Positive Physical Examination

The American Academy of Pediatrics guideline published in 2000 did not recommend US for evaluation of positive physical examination. However, recent studies show that 41% to 58% of abnormal findings on physical examination were negative on US studies, thus leading to unnecessary treatment. The value of selected US screening in infants with positive physical examination was addressed in a prospective 33-center United Kingdom Hip Trial. In that study, it was found that the use of US examinations in infants with clinically detected hip instability allowed a reduction in abduction splinting and was not associated with an increase in abnormal hip development or higher rates of surgical treatment. This policy was found to reduce costs.

Treatment

It is widely assumed that early treatment results in improved outcome. Although there is agreement in the literature that patients with dislocation should be treated and that those with stable "clicking" hips should be followed clinically, there is some disagreement regarding the treatment of patients with unstable (lax, but not displaced) hips. Some advocate early treatment for every patient with instability. Others prefer clinical observation, because a significant number of these patients (80%) progress spontaneously to clinically normal status.

Summary

• Recent studies show that 41% to 58% of abnormal findings on physical examination were negative on US studies, thus leading to unnecessary treatment.
• The value of selected US screening in infants with positive physical examination was addressed in a prospective 33-center study by the United Kingdom Hip Trial. In that study, it was found that the use of US examinations in infants with clinically detected hip instability allowed a reduction in abduction splinting and was not associated with an increase in abnormal hip development or higher rates of surgical treatment.
• Performing a hip US in children with positive physical examination was found to reduce costs.
• A recent decision tree analysis from a thorough review of the literature was published by Children's Hospital of Boston, Boston, Massachusetts. Foldback analysis and sensitivity analysis were performed. The conclusion is that the optimum strategy, associated with the highest probability of having a non-arthritic hip at the age of sixty years, was to screen all neonates for hip dysplasia with a physical examination and to use hip US selectively for infants who are at high risk.
• The American Academy of Pediatrics guideline published in 2000 did not recommend US for evaluation of positive physical examination.

Relative Radiation Level Designations

Relative Radiation Level*	Adult Effective Dose Estimate Range	Pediatric Effective Dose Estimate Range
O	0 mSv	0 mSv
	<0.1 mSv	<0.03 mSv
	0.1-1 mSv	0.03-0.3 mSv
	1-10 mSv	0.3-3 mSv
	10-30 mSv	3-10 mSv
	30-100 mSv	10-30 mSv
*RRL assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (e.g., region of the body exposed to ionizing radiation, the imaging guidance that is used). The RRLs for these examinations are designated as NS (not specified).

Algorithms were not developed from criteria guidelines.

The recommendations are based on analysis of the current literature and expert panel consensus.

Selection of appropriate radiologic imaging procedures for evaluation and early diagnosis of developmental dysplasia of the hip (DDH)

Most of the clinically and ultrasound (US)-detected developmental dysplasia of the hip (DDH) will resolve spontaneously. Screening may, therefore, lead to overtreatment. The most common and serious complication of nonsurgical treatment is avascular necrosis (AVN).

Relative Radiation Level (RRL)

Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, both because of organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared to those specified for adults. Additional information regarding radiation dose assessment for imaging examinations can be found in the American College of Radiology (ACR) Appropriateness Criteria® Radiation Dose Assessment Introduction document (see "Availability of Companion Documents" field).

The American College of Radiology (ACR) Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists, and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient's clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient's condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the U.S. Food and Drug Administration (FDA) have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination.

An implementation strategy was not provided.

Not applicable: The guideline was not adapted from another source.

The American College of Radiology (ACR) provided the funding and the resources for these ACR Appropriateness Criteria®.

Committee on Appropriateness Criteria, Expert Panel on Pediatric Imaging

Panel Members: Boaz K. Karmazyn, MD; Richard Gunderman, MD, PhD; Brian D. Coley, MD; Dorothy Bulas, MD; Matthew Garber, MD; Marc S. Keller, MD; James S. Meyer, MD; Sarah S. Milla, MD; Charles Paidas, MD; Peter D. Pizzutillo, MD; Daniel J. Podberesky, MD; Jeffrey Scott Prince, MD

Not stated

This is the current release of the guideline.

This guideline updates a previous version: Karmazyn BK, Gunderman R, Coley BD, Blatt ER, Bulas D, Fordham L, Podberesky DJ, Prince JS, Paidas C, Rodriguez W, Expert Panel on Pediatric Imaging. ACR Appropriateness Criteria® developmental dysplasia of the hip--child. [online publication]. Reston (VA): American College of Radiology (ACR); 2007. 7 p. [40 references]

The appropriateness criteria are reviewed biennially and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

Electronic copies: Available in Portable Document Format (PDF) from the American College of Radiology (ACR) Web site.

Print copies: Available from the American College of Radiology, 1891 Preston White Drive, Reston, VA 20191. Telephone: (703) 648-8900.

The following are available:

• ACR Appropriateness Criteria®. Overview. Reston (VA): American College of Radiology; 2 p. Electronic copies: Available in Portable Document Format (PDF) from the American College of Radiology (ACR) Web site.
• ACR Appropriateness Criteria®. Literature search process. Reston (VA): American College of Radiology; 1 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Evidence table development. Reston (VA): American College of Radiology; 4 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.
• ACR Appropriateness Criteria®. Radiation dose assessment introduction. Reston (VA): American College of Radiology; 2 p. Electronic copies: Available in Portable Document Format (PDF) from the ACR Web site.

None available

This NGC summary was completed by ECRI on March 29, 2006. This NGC summary was updated by ECRI Institute on July 2, 2009. This NGC summary was updated by ECRI Institute on December 10, 2010.

Instructions for downloading, use, and reproduction of the American College of Radiology (ACR) Appropriateness Criteria® may be found on the ACR Web site .