Developmental Dysplasia of the Hip (DDH)

Developmental dysplasia of the hip, commonly abbreviated as DDH, describes a spectrum of conditions in which the femoral head and acetabulum do not develop a normal stable relationship. The hip may be mildly shallow and stable, partially displaced, dislocatable, or completely dislocated.

DDH can be present at birth or become apparent during early development. Early diagnosis is important because treatment is generally simpler and more effective when hip instability or displacement is identified before major structural changes occur.

What Is Developmental Dysplasia of the Hip?

DDH is not a single condition.

It includes several degrees of abnormal hip development, from a shallow acetabulum to complete displacement of the femoral head from the socket.

The relationship between the femoral head and acetabulum is important because normal contact between them helps guide healthy hip development during infancy and childhood.

What Is the Normal Hip Joint?

The hip is a ball-and-socket joint.

The femoral head forms the ball, while the acetabulum forms the socket.

In a normally developing hip, the femoral head is centered within the acetabulum and the socket gradually deepens as the child grows.

What Happens in DDH?

In DDH, the femoral head may not remain properly centered within the acetabulum.

The socket may remain too shallow, the hip may be unstable, or the femoral head may partially or completely dislocate.

Longstanding displacement can affect the shape of both the femoral head and acetabulum.

What Is Hip Instability?

Hip instability means that the femoral head can move abnormally within or out of the acetabulum.

Some unstable hips can be gently dislocated during examination, while others are already dislocated and can be reduced back into the socket.

What Is Hip Subluxation?

Subluxation means that the femoral head is partially displaced but still maintains some contact with the acetabulum.

Persistent subluxation can interfere with normal acetabular development and may progress if untreated.

What Is Hip Dislocation?

Hip dislocation occurs when the femoral head is no longer centered within the acetabulum.

In infants, a dislocated hip may sometimes be reducible, while longstanding dislocation can become more difficult to reposition because of soft-tissue tightening and structural changes.

What Is Acetabular Dysplasia?

Acetabular dysplasia means that the hip socket is shallower or less developed than expected.

The femoral head may still be located within the socket but receive insufficient coverage.

Residual acetabular dysplasia can persist into childhood, adolescence, or adulthood even after hip stability has improved.

What Causes DDH?

DDH is usually multifactorial rather than caused by one single problem.

Factors associated with increased risk include:

• Family history of DDH
• Breech presentation
• Female sex
• First pregnancy
• Reduced space within the uterus
• Associated foot or neck positioning abnormalities
• Abnormal postnatal hip positioning

Is Breech Presentation a Risk Factor?

Yes.

Babies who remain in breech position during late pregnancy have a higher risk of DDH.

Hip imaging may therefore be recommended even when the newborn physical examination appears normal.

Is DDH Hereditary?

Family history increases risk, suggesting that genetic factors contribute to DDH.

However, not every child with a family history develops dysplasia, and many affected children have no known family history.

Why Is DDH More Common in Girls?

DDH is diagnosed more frequently in girls.

The reason appears to involve a combination of ligamentous laxity, hormonal influences, fetal positioning, and genetic susceptibility.

Can Both Hips Be Affected?

Yes.

DDH may involve one hip or both hips.

When only one side is affected, asymmetry may become more apparent as the child grows.

Can Swaddling Affect Hip Development?

Yes.

Tight swaddling that keeps the hips and knees extended and pressed together can increase stress on developing hips.

Hip-safe swaddling allows the hips to remain flexed and move apart naturally.

What Are the Signs of DDH in a Newborn?

Many newborns with DDH have no obvious visible symptoms.

Possible findings include:

• Hip instability during examination
• Limited hip abduction
• Unequal leg position
• Apparent leg-length difference
• Asymmetric thigh or buttock creases

Skin-crease asymmetry alone is not sufficient to diagnose DDH.

What Is the Ortolani Test?

The Ortolani test is a newborn examination maneuver used to determine whether a dislocated femoral head can be gently reduced into the acetabulum.

A characteristic palpable movement may indicate a reducible dislocated hip.

The test should be performed by trained healthcare professionals and is most useful in young infants.

What Is the Barlow Test?

The Barlow maneuver assesses whether an apparently located hip can be gently displaced from the socket.

It helps identify instability in the newborn period.

As the child becomes older, these early instability tests become less useful because soft tissues may tighten around a dislocated hip.

What Is Limited Hip Abduction?

Limited abduction means that the affected hip does not move outward as freely as expected.

It becomes an especially important clinical sign in older infants because fixed dislocation can restrict hip movement.

What Is the Galeazzi Sign?

The Galeazzi sign is assessed by comparing knee height while the hips and knees are flexed.

A lower knee on one side can suggest apparent shortening caused by unilateral hip dislocation or another limb-length problem.

Can Uneven Skin Creases Diagnose DDH?

No.

Asymmetric thigh or buttock creases can occur in normal babies and are not reliable enough to diagnose DDH by themselves.

Hip examination and appropriate imaging are more important.

What Are the Signs After a Child Begins Walking?

Possible signs include:

• Limping
• Walking with the trunk leaning to one side
• Apparent leg-length difference
• Reduced hip movement
• Waddling gait when both hips are affected
• Increased lumbar lordosis in bilateral dislocation

Does DDH Cause Pain in Babies?

Usually not.

Infants with DDH often have little or no pain, which is why screening and physical examination are important.

Pain becomes more relevant in older children, adolescents, or adults with residual dysplasia and abnormal joint loading.

How Is DDH Diagnosed?

Diagnosis is based on risk factors, physical examination, and age-appropriate imaging.

The choice between ultrasound and X-ray depends partly on the maturity of the infant's hip bones.

When Is Hip Ultrasound Used?

Ultrasound is particularly useful during early infancy because much of the femoral head is still cartilaginous and cannot be fully evaluated on X-ray.

Ultrasound can assess hip position, stability, femoral head coverage, and acetabular development.

What Is the Graf Classification?

The Graf method uses ultrasound measurements and morphology to classify infant hip development.

It can help distinguish normally developing hips, immature hips, dysplastic hips, and more significantly displaced hips.

Ultrasound findings should be interpreted together with age and clinical examination.

When Are X-Rays Used?

X-rays become increasingly useful as the femoral head ossifies and the infant becomes older.

Pelvic radiographs can evaluate acetabular development, femoral head position, hip symmetry, and residual dysplasia.

What Is the Acetabular Index?

The acetabular index is an X-ray measurement used to assess the slope and development of the acetabulum.

It can help monitor whether a dysplastic socket is improving with growth or remains too shallow.

Interpretation depends on the child's age.

What Are Hilgenreiner and Perkin Lines?

Hilgenreiner and Perkin lines are reference lines used on pediatric pelvic X-rays to help assess the position of the femoral head and hip development.

They are especially useful before complete ossification of the femoral head.

When Is MRI Used?

MRI is not routinely required for initial screening.

It may be used after reduction to confirm that the femoral head is appropriately positioned within the acetabulum, especially when the hip cannot be adequately assessed by standard imaging.

MRI can also evaluate cartilage and soft-tissue anatomy without ionizing radiation.

When Is CT Used?

CT may be used selectively to evaluate hip position after reduction or to define complex bony anatomy.

Because it involves radiation, MRI is often preferred when suitable for the clinical question.

Does Every Immature Hip Need Treatment?

No.

Some mildly immature hips in very young infants develop normally with observation.

Treatment depends on age, ultrasound findings, stability, risk factors, and whether the hip is improving on follow-up.

What Is the Goal of DDH Treatment?

The main goal is to obtain and maintain a stable, concentrically reduced femoral head within the acetabulum.

A well-centered femoral head provides the mechanical stimulus necessary for normal development of the hip socket.

Treatment also aims to minimize complications and preserve long-term hip function.

How Is DDH Treated in Young Infants?

In young infants with reducible hip instability or dislocation, a positioning brace is often the first treatment.

The most commonly used device is the Pavlik harness.

What Is a Pavlik Harness?

The Pavlik harness is a soft brace that holds the hips in a flexed and gently abducted position while allowing movement.

The goal is to keep the femoral head centered within the acetabulum so normal development can continue.

Does the Pavlik Harness Force the Hip Into Position?

No.

The harness should not force the hips into an extreme position.

It is designed to maintain a safe functional position while allowing spontaneous movement and reduction.

How Long Is the Pavlik Harness Used?

Treatment duration varies according to age, severity, stability, and the response seen on examination and ultrasound.

Regular follow-up is necessary to confirm that the hip has reduced and remains appropriately positioned.

Why Is Follow-Up During Harness Treatment Important?

A harness that is not controlling the hip appropriately should not simply be continued indefinitely.

Follow-up examination and ultrasound help determine whether treatment is working and whether another approach is needed.

What Are the Risks of Pavlik Harness Treatment?

Complications are uncommon when the harness is properly fitted and monitored, but possible problems include:

• Skin irritation
• Femoral nerve palsy
• Excessive hip positioning
• Failure to achieve reduction
• Femoral head blood-supply complications in inappropriate positioning

What Happens If the Harness Does Not Work?

If the hip remains dislocated despite appropriate harness treatment, continuing the same treatment for too long may not be useful.

Depending on age and hip anatomy, treatment may progress to another brace, closed reduction, or surgical reduction.

What Is Closed Reduction?

Closed reduction is a procedure in which the femoral head is placed into the acetabulum without making a surgical incision into the hip joint.

It is usually performed under anesthesia.

After a stable reduction is obtained, the hip is commonly maintained in a spica cast.

What Is a Hip Spica Cast?

A hip spica cast surrounds the pelvis and one or both thighs to hold the hip in a stable position after reduction.

The position must balance hip stability with protection of the femoral head blood supply.

What Is Arthrography?

Arthrography involves injecting contrast material into the hip joint during a procedure to outline cartilaginous structures and help assess the quality of reduction.

It may be used during closed or open reduction in selected children.

What Is Open Reduction?

Open reduction is a surgical procedure used when the femoral head cannot be safely or stably positioned in the acetabulum with closed methods.

The surgeon removes or releases structures that prevent reduction and places the femoral head into the socket.

When Is Open Reduction Needed?

Open reduction may be considered when:

• Closed reduction cannot achieve a stable centered hip
• The child presents at an older age
• Soft tissues prevent reduction
• Previous treatment has failed
• The hip repeatedly redislocates

What Is a Femoral Osteotomy?

Femoral osteotomy is a procedure in which the upper femur is cut and realigned.

Shortening, varus correction, or rotational correction may be used in selected older children to improve hip reduction and decrease excessive pressure on the femoral head.

Why Is Femoral Shortening Sometimes Performed?

In older children with a high-riding dislocated hip, the surrounding muscles and soft tissues may be very tight.

Shortening the femur can reduce the force required to place the femoral head into the acetabulum and may help protect the hip from excessive pressure during reduction.

What Is Pelvic Osteotomy?

Pelvic osteotomy changes the shape or orientation of the acetabulum to improve coverage of the femoral head.

It may be needed when acetabular dysplasia is significant or does not improve sufficiently after reduction.

What Types of Pelvic Osteotomy Are Used?

The procedure is selected according to age, hip congruence, acetabular shape, and remaining growth.

Examples include:

• Salter osteotomy
• Pemberton osteotomy
• Dega osteotomy
• Other reconstructive pelvic osteotomies

Can Femoral and Pelvic Osteotomy Be Performed Together?

Yes.

In selected older children, open reduction may be combined with femoral and pelvic osteotomy during the same treatment period.

The exact combination depends on hip anatomy and the degree of dysplasia.

Does Every Child With DDH Need Surgery?

No.

Many infants diagnosed early can be successfully managed with bracing.

Surgical treatment becomes more likely when diagnosis is delayed, the hip cannot be reduced with a brace, or significant structural dysplasia persists.

Why Is Early Diagnosis Important?

The younger hip has greater remodeling potential, and early instability can often be treated with simpler methods.

A longstanding dislocated hip can develop secondary changes in the acetabulum, femoral head, femoral neck, capsule, and surrounding muscles.

These changes can make later treatment more complex.

What Is Residual Acetabular Dysplasia?

Residual acetabular dysplasia means that the hip socket remains too shallow even after the femoral head has been reduced and stabilized.

Some hips improve naturally with growth, while others continue to have insufficient femoral head coverage and require additional treatment.

Why Is Long-Term Follow-Up Necessary?

A hip that appears stable after early treatment may still develop residual dysplasia later.

Periodic imaging during growth helps evaluate acetabular development and identify persistent problems before adulthood.

What Is Avascular Necrosis in DDH Treatment?

Avascular necrosis, also called osteonecrosis, refers to damage caused by impaired blood supply to the developing femoral head.

It is one of the important complications that treatment techniques are designed to minimize.

Excessive or unsafe hip positioning can increase the risk, which is why reduction and immobilization must be carefully controlled.

Can DDH Cause Leg-Length Difference?

Yes.

A unilateral dislocated hip can make one leg appear shorter.

Longstanding dislocation, growth disturbance, or treatment-related complications can also contribute to leg-length discrepancy.

Can DDH Cause a Limp?

Yes.

Children diagnosed after they begin walking may develop a limp because of altered hip mechanics, muscle weakness, or apparent limb shortening.

Bilateral dislocation can produce a waddling gait.

What Is Trendelenburg Gait?

Trendelenburg gait results from ineffective hip abductor mechanics.

The pelvis may drop on the opposite side or the trunk may shift over the affected hip while walking.

It can occur in older children or adults with longstanding hip dysplasia or dislocation.

Can Untreated DDH Cause Arthritis?

Yes.

A shallow acetabulum provides reduced coverage of the femoral head and can concentrate forces over a smaller area of joint cartilage.

Over time, this can contribute to labral injury, cartilage degeneration, pain, and early hip osteoarthritis.

Can DDH Cause Problems in Adolescence?

Yes.

Residual acetabular dysplasia may become symptomatic during adolescence or young adulthood even if the hip was never completely dislocated.

Symptoms can include groin pain, activity-related discomfort, clicking, reduced endurance, or feelings of instability.

Can Adults Have Developmental Hip Dysplasia?

Yes.

Some patients are first diagnosed in adolescence or adulthood because mild dysplasia was not recognized during infancy.

Adult developmental dysplasia usually presents differently from infant hip instability and may require hip-preservation treatment rather than pediatric reduction techniques.

How Is Adult Hip Dysplasia Diagnosed?

Standing pelvic X-rays are used to evaluate femoral head coverage, acetabular orientation, joint space, and hip alignment.

MRI may be used to assess the labrum and cartilage when symptoms and surgical planning require additional information.

What Is the Lateral Center-Edge Angle?

The lateral center-edge angle is an X-ray measurement used in older adolescents and adults to estimate how much of the femoral head is covered by the acetabulum.

It is one of several measurements used to assess acetabular dysplasia and should not be interpreted in isolation.

What Is Periacetabular Osteotomy?

Periacetabular osteotomy, commonly abbreviated as PAO, is a hip-preservation procedure used in selected adolescents and adults with symptomatic acetabular dysplasia and relatively preserved joint cartilage.

The acetabulum is repositioned to improve femoral head coverage while preserving the native hip joint.

Who May Be Suitable for PAO?

Suitability depends on symptoms, acetabular anatomy, hip congruence, cartilage condition, age, and degree of osteoarthritis.

PAO is not appropriate for every dysplastic hip and is generally less suitable when advanced joint degeneration is already present.

Is Hip Arthroscopy Alone Enough for Dysplasia?

Not always.

Arthroscopy can treat selected labral or cartilage problems, but it does not correct inadequate acetabular coverage.

When structural dysplasia is the primary mechanical problem, treatment planning should address the underlying bony anatomy.

Is Hip Replacement Ever Needed?

Total hip replacement may be considered in adults with advanced painful osteoarthritis caused by longstanding developmental dysplasia.

It is not the standard treatment for infants or children with active DDH.

Can DDH Be Prevented?

Not every case can be prevented because genetic and prenatal factors cannot be changed.

Hip-safe positioning after birth may help avoid additional stress on an unstable developing hip.

Screening of high-risk babies and early recognition remain particularly important.

How Should Babies Be Carried?

Positions that allow the hips to remain flexed and naturally spread apart are generally considered more favorable for hip development than positions that force the legs straight together.

Baby carriers should provide appropriate support without forcing the hips into an extreme position.

Can Double Diapering Treat DDH?

Double diapering is not considered an adequate treatment for a truly unstable, dysplastic, or dislocated hip.

When treatment is necessary, an appropriately fitted orthopedic device and structured follow-up are required.

Can Physical Therapy Correct DDH?

Physical therapy does not reposition a dislocated infant hip or reshape a significantly dysplastic acetabulum by itself.

Rehabilitation may become useful later for restoring movement, strength, and function after casting or surgery.

What Are the Possible Complications of DDH?

Possible long-term problems include:

• Persistent hip instability
• Residual acetabular dysplasia
• Recurrent dislocation
• Hip stiffness
• Avascular necrosis
• Leg-length difference
• Altered walking pattern
• Labral damage
• Early hip osteoarthritis

When Should a Baby Be Evaluated?

Pediatric orthopedic evaluation may be appropriate when:

• Hip instability is detected during newborn examination
• The baby was in breech presentation
• There is a strong family history of DDH
• Hip abduction is limited
• Leg length appears unequal
• Ultrasound shows persistent dysplasia or instability
• A hip remains dislocated despite bracing

When Should an Older Child Be Evaluated?

Assessment may be appropriate when there is:

• Persistent limping
• Waddling gait
• Apparent leg-length difference
• Limited hip movement
• Known previous DDH requiring follow-up
• Residual acetabular dysplasia on X-ray

When Should an Adolescent or Adult Be Evaluated?

Persistent groin pain, activity-related hip pain, clicking, reduced endurance, or radiographic acetabular dysplasia may justify specialist evaluation.

Early hip-preservation assessment can be especially important before advanced cartilage degeneration develops.

Developmental Dysplasia of the Hip Treatment in Antalya

Treatment of developmental dysplasia of the hip begins with determining the child's age, hip stability, femoral head position, acetabular development, and whether the hip can be reduced safely.

Young infants with reducible instability or dislocation may be treated with a Pavlik harness and close ultrasound follow-up. When bracing is unsuccessful or diagnosis occurs later, closed reduction and a hip spica cast may be considered.

Older children or hips that cannot be concentrically reduced may require open reduction, femoral osteotomy, pelvic osteotomy, or a combination of procedures. Long-term follow-up is important because residual acetabular dysplasia can remain even after early hip stability is achieved.

Adolescents and adults with symptomatic residual hip dysplasia may require a different approach, including hip-preservation procedures such as periacetabular osteotomy in appropriately selected patients.

Frequently Asked Questions About Developmental Dysplasia of the Hip

What is developmental dysplasia of the hip?

DDH is a spectrum of abnormal hip development ranging from a shallow acetabulum and instability to partial or complete dislocation of the femoral head.

What are the risk factors for DDH?

Breech presentation, family history, female sex, and certain positioning factors are among the commonly recognized risk factors.

Does DDH cause pain in babies?

Usually not. Many affected infants have no pain, which is why newborn examination and screening of high-risk babies are important.

What is the Pavlik harness?

It is a soft brace used in selected young infants to maintain the hips in a position that supports stable reduction and normal development.

Does every baby with DDH need surgery?

No. Many infants diagnosed early can be treated successfully with bracing and careful follow-up.

What happens if the Pavlik harness does not work?

Depending on age and anatomy, treatment may progress to closed reduction, spica casting, or open surgical reduction.

What is residual acetabular dysplasia?

It means that the hip socket remains shallower than expected even after the femoral head has been stabilized within the joint.

Can DDH cause arthritis later in life?

Yes. Persistent acetabular dysplasia can increase abnormal joint loading and contribute to labral damage and early hip osteoarthritis.

Why is long-term follow-up necessary?

Hip stability can improve while the acetabulum remains underdeveloped, so periodic imaging may be needed throughout growth.

Can adults be treated for developmental hip dysplasia?

Yes. Selected adolescents and adults with symptomatic dysplasia and preserved cartilage may be candidates for hip-preservation surgery such as periacetabular osteotomy.