Developmental dysplasia of the hip - Symptoms, Causes, Treatment & Prevention

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Overview

Developmental dysplasia of the hip (DDH) is a spectrum of abnormalities affecting the infantile or early‑childhood hip joint. The condition ranges from a shallow acetabulum (the socket) to a completely dislocated femoral head. When the joint is not properly formed, the hip may be unstable or subluxated, leading to abnormal wear and early arthritis if left untreated.

Who it affects

• Newborns and infants are the most common age group; most cases are identified before 6 months of age.
• Females are affected 3–5 times more often than males.
• Certain ethnic groups (e.g., Native American, Hispanic, and some Asian populations) have higher reported rates.

Prevalence

• Overall incidence in the United States is approximately 1–2 per 1,000 live births (CDC, 2022).
• In high‑risk groups (e.g., breech‑presenting infants), the incidence rises to 10–15 per 1,000 (Mayo Clinic, 2023).

Symptoms

The presentation can be subtle, especially in newborns, but several signs should prompt further evaluation.

Infants (0–12 months)

• Asymmetrical thigh or gluteal folds – one crease may be deeper or higher.
• Leg length discrepancy – the affected leg may appear shorter.
• Clicking or clunking when the hips are passively moved (Barlow and Ortolani maneuvers).
• Limited abduction – the infant cannot spread the legs apart beyond 45° on the affected side.
• Hip or groin pain – rare in newborns but may appear in older infants.

Older infants & children (1 year and up)

• Persistent limp or waddling gait.
• Pain in the groin, thigh, or buttock, especially after activity.
• Noticeable “hip click” during walking.
• Decreased range of motion, especially in abduction and internal rotation.
• Early onset osteoarthritis signs in adolescence (pain, stiffness).

Causes and Risk Factors

DDH is multifactorial—genetic, mechanical, and hormonal influences all play a role.

Genetic factors

• Family history of DDH (first‑degree relative) increases risk 2–3 fold.
• Certain gene polymorphisms (e.g., COL2A1, GDF5) have been linked in genome‑wide studies (NIH, 2021).

Mechanical factors

• Breech presentation (especially frank or complete breech) – risk up to 30 times higher.
• Crowded intra‑uterine space leading to abnormal hip positioning.

• First‑born status – the uterus is tighter in the first pregnancy.
• Large for gestational age (LGA) or oligohydramnios – both alter fetal positioning.

Hormonal influences

• Maternal estrogen surge near term relaxes the infant’s ligaments, increasing joint laxity.
• Infants of mothers with diabetes or thyroid disease may have altered collagen metabolism.

Other risk modifiers

• Female sex (estrogen‑mediated ligamentous laxity).
• Swaddling with hips in extension and adduction—a traditional practice in some cultures.
• Foot deformities such as clubfoot, which often coexist with hip dysplasia.

Diagnosis

Early detection dramatically improves outcomes. Diagnosis combines physical examination with imaging.

Physical examination

• Barlow test – attempts to dislocate an unstable hip by gently adducting and applying posterior pressure.
• Ortolani test – lifts a dislocated hip into the socket; a palpable “clunk” indicates a reducible dislocation.
• Assessment of limb length, gluteal folds, and range of motion.

Imaging modalities

• Ultrasound (Graf method) – first‑line for infants < 6 months; visualizes cartilaginous acetabulum & femoral head. Sensitivity ≈ 95 % (Cleveland Clinic, 2022).
• Radiographs (X‑ray) – used after 4–6 months when the femoral head ossifies; evaluates acetabular index and femoral head position.
• Magnetic Resonance Imaging (MRI) – reserved for complex or borderline cases, especially prior to surgery.
• Computed Tomography (CT) – rarely needed; may assist in pre‑operative planning for older children.

Screening recommendations

• Universal newborn hip exam (Barlow/Ortolani) within the first 48 hours of life (AAP, 2023).
• Targeted ultrasound for infants with risk factors (breech, family history, female, swaddling).
• Follow‑up ultrasounds at 6–12 weeks if initial study is abnormal or equivocal.

Treatment Options

Treatment goals are to maintain the femoral head within the acetabulum while the joint matures, preventing long‑term arthritis.

Non‑surgical management

• Pavlik harness – a soft brace that holds hips in 90° flexion and 45° abduction. Most effective when started < 6 weeks of age; success rates 80‑95 % (Mayo Clinic, 2024).
• Abduction braces (e.g., Denis‑Brown, Hip Abduction Orthosis) – used after 6 months or if Pavlik fails.
• Frequent monitoring – serial ultrasounds every 2–4 weeks to assess acetabular development.
• Parent education – proper harness application, skin care, and “hip‑friendly” swaddling.

Surgical options

Surgery is considered when closed reduction fails, the child presents after 6 months, or there is persistent dysplasia.

• Closed reduction with spica cast – under anesthesia the hip is reduced, then a plaster cast holds the position for 6–12 weeks.
• Open reduction – surgical exposure of the joint to remove obstacles (e.g., ligamentum teres, pulvinar) and directly place the femoral head.
• Femoral osteotomy – shortens and/or rotates the femur to improve alignment, often combined with open reduction.
• Pelvic osteotomy (Salter, Pemberton, or Dega) – reshapes the acetabulum to provide better coverage of the femoral head.
• Hip replacement – rare in children, usually reserved for severe arthritis in early adulthood.

Medications & adjuncts

• Analgesics (acetaminophen or ibuprofen) for post‑procedure pain.
• Prophylactic antibiotics administered peri‑operatively.
• Vitamin D and calcium supplementation if dietary intake is insufficient, supporting bone health.

Rehabilitation & lifestyle

• Gentle passive range‑of‑motion exercises once the brace is removed (under PT guidance).
• Weight‑bearing as tolerated after cast or surgery, typically 6–12 weeks post‑op.
• Avoid prolonged hip flexion > 90° or adduction positions during recovery.

Living with Developmental Dysplasia of the Hip

With early treatment, most children lead active, pain‑free lives. Practical tips help families navigate daily challenges.

Infant care

• Check harness skin every 2–3 hours; keep area clean and dry.
• Use “hip‑friendly” swaddles that allow thighs to spread – think “diamond‑shaped” wrap.
• Place baby on back to sleep (as per AAP guidelines) but ensure hips are not forced into extension.

Toddler & school‑age activity

• Encourage low‑impact sports (swimming, cycling) once cleared by the orthopedist.
• Monitor for limping after activities; report persistent pain to a physician.
• Maintain regular follow‑up X‑rays until skeletal maturity (usually 12–14 years for girls, 14–16 years for boys).

Psychosocial considerations

• Explain the condition in age‑appropriate language to reduce anxiety.
• Connect families with support groups (e.g., DDH Foundation) for shared experiences.
• School accommodations: a brief note from the orthopedist may allow extra time for bathroom breaks or modified PE.

Long‑term health maintenance

• Maintain a healthy weight to reduce stress on the hip joint.
• Engage in regular core‑strengthening and hip‑stability exercises after clearance.
• Annual orthopedic check‑up after skeletal maturity to screen for early arthritis.

Prevention

While not all cases are preventable, certain measures can lower risk.

• Avoid tight swaddling – keep hips flexed and abducted; use commercially available “hip‑safe” swaddling blankets.
• Prenatal care – optimal maternal nutrition and management of diabetes or thyroid disorders.
• Early ultrasound screening for breech infants or those with a family history.
• Educate caregivers about proper diaper changes and positioning to keep hips open.

Complications

If DDH is missed or inadequately treated, it can lead to significant morbidity.

• Early osteoarthritis – may develop in the second or third decade, leading to chronic pain and limited mobility.
• Leg length discrepancy – can cause gait abnormalities, scoliosis, or back pain.
• Avascular necrosis (AVN) of the femoral head – damage to the blood supply during reduction or casting; incidence ≈ 5–10 % in treated hips.
• Persistent limping or gait disturbance – may require orthotic devices or later reconstructive surgery.
• Post‑operative stiffness – especially after open reduction; intensive physiotherapy is essential.

When to Seek Emergency Care

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Sources: American Academy of Pediatrics (AAP) – Guidelines for DDH Screening 2023; Mayo Clinic; Centers for Disease Control and Prevention (CDC); National Institutes of Health (NIH) Genetics of Hip Dysplasia 2021; Cleveland Clinic Orthopedics; World Health Organization (WHO) – Child Development Reports.

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