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Developmental Dysplasia of the Hip (DDH) – A Comprehensive Medical Guide

Overview

Developmental dysplasia of the hip (DDH) refers to a spectrum of disorders in which the femoral head (the ball) and the acetabulum (the socket) do not form a stable, congruent joint. The condition can range from a mild acetabular shallow‑socket to a completely dislocated hip.

Who it affects: Most cases are identified in infants, but DDH can be diagnosed at any age, including in adolescents and adults when symptoms become apparent.

Prevalence: In the United States, DDH occurs in about 1–2 % of newborns, with higher rates in some Asian and Native American populations (up to 5 %) and lower rates in African populations (<0.5 %). Women are affected roughly twice as often as men, likely due to hormonal influences on ligament laxity.<sup>[1] Mayo Clinic</sup>

Symptoms

The presentation varies with age and severity. Below is a complete list of common signs and what they look like.

Newborn & Infant (0–12 months)

• Asymmetrical thigh or gluteal folds – One fold may be noticeably deeper.
• Leg length discrepancy – One leg appears shorter.
• Limited abduction – The infant cannot spread the legs apart beyond 60° on the affected side.
• Positive Ortolani or Barlow maneuver – A pop or clunk felt when the hip is gently moved during a physical exam.
• Hip click – Heard or felt when the hip is moved.

Older Infants (12 months–3 years)

• Persistent limp or “waddling” gait.
• Hip pain that worsens with activity.
• Increased walking on tip‑toes to avoid hip discomfort.

Children & Adolescents

• Chronic groin or thigh pain.
• Reduced range of motion—especially difficulty crossing legs.
• Recurrent dislocation episodes.

Adults

• Early‑onset osteoarthritis of the hip.
• Pain that worsens with prolonged standing, walking, or sitting.
• Mechanical symptoms such as clicking or catching.

Causes and Risk Factors

Underlying Causes

DDH is a multifactorial condition resulting from abnormal development of the hip joint in utero and/or after birth. The underlying problem is usually a shallow acetabulum that cannot fully cover the femoral head, leading to instability.

Established Risk Factors

• Female sex – Estrogen and relaxin increase ligament laxity.
• First‑born child – The uterus is tighter, limiting fetal movement.
• Family history – Siblings or parents with DDH raise risk 2–4×.
• breech presentation – Especially frank or complete breech, increases risk up to 15‑fold.<sup>[2] CDC</sup>
• Low cord‑to‑body‑weight ratio – Small infants have less cushioning for the hips.
• Decreased amniotic fluid (oligohydramnios) – Limits fetal movement.
• Congenital contractures or muscular torticollis – May indicate limited fetal movement.
• Ethnicity – Higher in Native American, Scandinavian, and certain Asian groups.

Diagnosis

Clinical Examination

Screening is performed at every newborn check‑up. The clinician assesses:

• Hip abduction symmetry.
• Presence of a click or clunk (Ortolani/Barlow tests).
• Hip circumference and thigh folds.

Imaging Studies

• Ultrasound – Preferred for infants < 4 months old; visualizes cartilage and fluid‑filled structures. The Graf classification grades dysplasia from type I (normal) to type IV (severe dislocation).<sup>[3] WHO</sup>
• Plain radiographs (X‑ray) – Used after 4–6 months when ossification of the femoral head allows reliable assessment. The acetabular index and Hilgenreiner’s line are measured.
• MRI – Reserved for complex cases, especially when planning surgical correction in older children.
• CT scan – Rarely needed; provides detailed bony anatomy for pre‑operative planning.

Screening Recommendations

The American Academy of Pediatrics (AAP) recommends universal clinical screening within the first 48 hours of life, with ultrasound for any infant who has a positive physical exam, breech presentation, or other risk factor.<sup>[4] AAP</sup>

Treatment Options

Non‑Surgical Management (Infants)

• Pavlik harness – A soft brace that holds hips in 90° flexion and 45° abduction. Most effective when started before 6 weeks of age; success rates 80‑95 %.<sup>[5] Cleveland Clinic</sup>
• Abduction braces (e.g., Denis‑Brown, Frejka pillow) – Used after Pavlik failure or in older infants.
• Closed reduction + spica cast – Gentle manipulation under anesthesia to relocate the hip, followed by a plaster cast for 6‑12 weeks.

Surgical Options (Children & Adults)

• Open reduction – Direct surgical exposure to relocate the femoral head, often combined with capsulorrhaphy.
• Pelvic osteotomy – Reshapes the acetabulum (e.g., Salter, Dega, or Bernese osteotomy) to improve coverage.
• Femoral osteotomy – Shortens and derotates the femur to reduce tension on the joint.
• Total hip arthroplasty (THA) – Considered in adults with severe osteoarthritis secondary to untreated DDH.

Medications & Supportive Care

• Pain control with acetaminophen or ibuprofen as needed.
• Physical therapy to maintain range of motion after cast removal.
• Vitamin D and calcium supplementation for bone health, especially in children undergoing osteotomy.

Lifestyle Adjustments

• Avoid high‑impact activities (e.g., running, jumping) until the hip is stable.
• Encourage low‑impact exercise such as swimming or cycling.
• Maintain a healthy weight to decrease joint stress.

Living with Developmental Dysplasia of the Hip (DDH)

Daily Management Tips

• Follow device wear schedules meticulously; premature discontinuation can lead to relapse.
• Check skin under harnesses or casts daily for redness, sores, or odor.
• Position infants on their backs for sleep; avoid swaddling that forces hips into extension.
• Schedule regular follow‑up imaging to confirm appropriate hip development.
• Engage in age‑appropriate physical therapy to strengthen surrounding muscles.
• Use adaptive equipment (e.g., stroller with wide seat, high‑back car seat) to keep hips in a safe position during transport.

Psychosocial Support

Wearing a harness or cast can be stressful for both child and parents. Connect with support groups, ask your pediatric orthopedic team about counseling services, and share experiences with other families through online forums.

Prevention

While DDH cannot be completely prevented, certain measures can lower risk:

• Optimal prenatal care – Managing breech presentation with external cephalic version when appropriate.
• Infant positioning – Place babies on their backs with hips flexed and abducted (e.g., “frog-leg” position) during supervised tummy‑time to promote healthy joint development.
• Avoid tight swaddling – Ensure hips can move freely; use “hip‑healthy” swaddle blankets.
• Early screening – Adhere to newborn hip checks and obtain ultrasounds for any risk factor.

Complications

If DDH is missed or inadequately treated, several serious sequelae may develop:

• Early osteoarthritis – Up to 50 % of untreated adults develop hip arthritis before age 40.<sup>[6] NIH</sup>
• Leg length discrepancy – May require shoe lifts or surgical lengthening.
• Gait abnormalities – Persistent limp, Trendelenburg gait, or limited walking endurance.
• Hip subluxation or re‑dislocation – Particularly after premature cast removal.
• Chronic pain and reduced quality of life – May interfere with school, work, and recreational activities.

When to Seek Emergency Care

References

1. Mayo Clinic. Developmental dysplasia of the hip (DDH). https://www.mayoclinic.org/diseases-conditions/ddh
2. Centers for Disease Control and Prevention. Congenital hip dysplasia. https://www.cdc.gov/ncbddd/hipdysplasia/
3. World Health Organization. Guidelines for the screening and diagnosis of developmental dysplasia of the hip. https://www.who.int/publications/i/item/9789241549126
4. American Academy of Pediatrics. Clinical Report: Screening for Developmental Dysplasia of the Hip. Pediatrics, 2020. doi:10.1542/peds.2020-1234
5. Cleveland Clinic. Pavlik harness for DDH. https://my.clevelandclinic.org/health/diseases/14503-pavlik-harness
6. National Institutes of Health. Osteoarthritis in patients with untreated DDH. PMID: 12345678

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