Barlow’s Test: Purpose, Procedure, Positive Result, and Accuracy

What Is Barlow’s Test Used For?

Barlow’s test is a clinical examination maneuver used to assess hip instability in newborns and young infants. It helps identify developmental dysplasia of the hip (DDH), a condition in which the hip joint develops abnormally, potentially allowing the femoral head to move partially or completely out of the acetabulum.

The test specifically determines whether a hip that is initially located within the acetabulum is dislocatable when gentle pressure is applied during the examination. It is commonly performed alongside Ortolani’s test as part of the newborn hip examination.

Developmental dysplasia of the hip includes a spectrum of abnormalities, ranging from mild acetabular underdevelopment and hip instability to subluxation and complete dislocation. Early identification is important because appropriate assessment and treatment can reduce the risk of persistent hip displacement, abnormal gait, and premature degenerative joint disease.

Barlow’s test is most useful during the neonatal period and early infancy, when the hip joint is relatively mobile. However, it should not be used as the sole method of diagnosing or excluding DDH. Clinical examination, appropriate follow-up, and selective imaging are important components of evaluation. [1,2]

How to Perform Barlow’s Test

Barlow’s test is performed with the infant relaxed and lying supine. The examiner assesses each hip separately using gentle, controlled movements.

Step-by-Step Procedure

1. Position the infant: Place the newborn on their back on a firm, comfortable examination surface.
2. Flex the hip and knee: Hold the infant’s hip and knee in approximately 90 degrees of flexion.
3. Stabilize the thigh: Gently hold the infant’s knee and proximal thigh while maintaining control of the hip joint.
4. Adduct the hip: Slowly bring the thigh toward the midline of the body.
5. Assess hip stability: During adduction, use gentle pressure directed posteriorly through the femur to determine whether the femoral head moves out of the acetabulum. The examiner assesses for palpable displacement rather than relying on an audible click.
6. Repeat on the opposite side: Examine the other hip using the same gentle technique.

Important safety point: The maneuver must be gentle. The examiner should never forcefully attempt to dislocate the femoral head. Excessive or repeated provocative pressure is unnecessary and may cause harm. Contemporary guidance emphasizes careful palpation and avoidance of forceful posterior pressure.

What Is a Positive Barlow’s Test?

A positive Barlow’s test occurs when the femoral head can be displaced out of the acetabulum during the gentle adduction maneuver. The hip is therefore considered unstable or dislocatable.

The most important finding is a palpable sensation of the femoral head moving out of the socket. An isolated clicking sound without palpable instability is not equivalent to a positive Barlow test and is generally not considered diagnostic of DDH.

A positive result indicates hip instability but does not, by itself, establish the severity of acetabular dysplasia or determine whether treatment is immediately necessary. Some hips with early neonatal instability stabilize spontaneously, whereas persistent instability requires appropriate specialist assessment.

Barlow’s Test vs. Ortolani’s Test

Barlow’s and Ortolani’s tests assess related but different features of hip stability.

• Barlow’s test: Attempts to identify a hip that can be displaced out of the acetabulum. It assesses whether the hip is dislocatable.
• Ortolani’s test: Identifies a dislocated or subluxated femoral head that can be gently reduced into the acetabulum during hip abduction. It assesses whether the displaced hip is reducible.

These maneuvers are often performed as part of the same clinical examination. A positive Barlow test should prompt careful assessment of hip stability, including the Ortolani maneuver when appropriate. An Ortolani-positive hip warrants prompt referral to a clinician experienced in pediatric hip disorders. [1]

Barlow’s Test Accuracy

The diagnostic accuracy of Barlow’s test varies according to the population examined, the examiner’s experience, the definition of DDH, and the reference standard used.

The sensitivity of 66% and specificity of 95% have been reported for this test in some clinical summaries. These figures should not be interpreted as universal values for every newborn population.

A systematic review and meta-analysis published in 2022 evaluated clinical examination methods against ultrasonographic assessment. The combined Ortolani–Barlow examination had a pooled sensitivity of 36% and specificity of 98%. A more recent systematic review published in 2024 reported a sensitivity of 46% and specificity of 99.1% for the combined maneuvers when identifying a dislocated hip. These estimates concern the combined examination rather than Barlow’s test in isolation. [2,3]

The findings illustrate an important clinical principle: a positive Barlow or Ortolani examination is highly informative, but a negative examination does not reliably exclude DDH. Serial physical examinations and selective imaging remain important when clinical findings or risk factors warrant further evaluation.

Clinical Significance and Limitations

Barlow’s test is a useful component of newborn hip screening, but its interpretation requires clinical judgment.

A positive result in the first days of life does not necessarily mean that the infant will develop persistent hip dysplasia or require treatment. Mild neonatal instability may resolve naturally. Persistent instability, a positive Ortolani sign, or other concerning findings require further assessment.

The test also becomes less useful as the infant grows. By approximately three months of age, a persistently dislocated hip may become less mobile and more difficult to displace or reduce using these maneuvers. Limited or asymmetric hip abduction becomes increasingly important during the examination of older infants.

Ultrasonography is particularly useful for assessing the infant hip before substantial femoral head ossification. Pelvic radiography becomes more useful later in infancy, depending on the child’s age and clinical circumstances. The choice and timing of imaging should follow appropriate clinical guidance.

Risk factors that may support additional evaluation include breech presentation, a family history of DDH, previous clinical hip instability, and concerning physical examination findings. A normal Barlow test should not override an otherwise suspicious examination or significant risk factors. [1,4]

Frequently Asked Questions (FAQ)

1. What is the main purpose of Barlow’s test?

Barlow’s test assesses hip instability in newborns and young infants by determining whether the femoral head can be gently displaced out of the acetabulum. It is used as part of the clinical assessment for developmental dysplasia of the hip.

2. What is a positive Barlow test?

A positive test occurs when gentle hip adduction and controlled posteriorly directed pressure cause the femoral head to move out of the acetabulum. The key finding is palpable displacement, not simply an audible click.

3. What is the difference between Barlow’s and Ortolani’s tests?

Barlow’s test identifies a hip that can be dislocated, whereas Ortolani’s test identifies a displaced hip that can be reduced into the acetabulum. Both maneuvers help assess hip instability in infants.

4. What are the sensitivity and specificity of Barlow’s test?

Sensitivity of 66% and specificity of 95% have been reported in some clinical summaries. However, diagnostic accuracy varies. Published meta-analyses of the combined Barlow–Ortolani examination report different estimates, depending on the population and diagnostic criteria.

5. Can a negative Barlow test rule out developmental dysplasia of the hip?

No. A negative result does not exclude DDH because some affected infants have no detectable instability during physical examination. Follow-up examinations and selective imaging may be necessary.

6. At what age is Barlow’s test most useful?

It is most useful during the neonatal period and early infancy. Its usefulness decreases as the hip becomes less mobile, particularly when a dislocated hip becomes fixed.

7. Does a positive Barlow test always require treatment?

No. Some mildly unstable neonatal hips stabilize spontaneously. Management depends on the infant’s age, examination findings, persistence of instability, imaging results when indicated, and specialist assessment.

8. Is Barlow’s test painful or dangerous for the infant?

When performed correctly by a trained clinician, the maneuver should be gentle and controlled. Forceful or repeated attempts to dislocate the hip should be avoided.

9. What imaging is used to investigate suspected DDH?

Hip ultrasonography is generally preferred in young infants because it evaluates the cartilaginous hip structures. Pelvic radiography becomes more useful as the infant grows and the femoral head ossifies. Imaging decisions depend on age, examination findings, and risk factors.

10. Who should evaluate an infant with a positive Barlow test?

A pediatrician or clinician experienced in newborn hip examination should assess the infant and arrange appropriate follow-up. Persistent instability or other concerning findings warrant pediatric orthopedic evaluation.

References

1. Shaw BA, Segal LS; American Academy of Pediatrics. Evaluation and Referral for Developmental Dysplasia of the Hip in Infants. Pediatrics. 2016;138(6). Read the clinical report.
2. Diagnostic Performance of Clinical Examination Versus Ultrasonography in the Detection of Developmental Dysplasia of Hip: A Systematic Review and Meta-Analysis. PubMed. 2022. Read the study.
3. Does This Infant Have a Dislocated Hip? The Rational Clinical Examination Systematic Review. JAMA. 2024. Read the study on PubMed.
4. Barlow Test. Orthofixar. Read the Orthofixar reference.