Developmental Dysplasia of the Hip (DDH): Treatments, Rehabilitation, and Outlook

How to treat DDH?

Treating Developmental Dysplasia of the Hip (DDH) involves a spectrum of interventions, from non-surgical bracing in infancy to complex surgical procedures in older individuals, followed by crucial kinesiologically-driven rehabilitation to restore optimal hip function and prevent long-term complications.

Understanding Developmental Dysplasia of the Hip (DDH)

Developmental Dysplasia of the Hip (DDH), formerly known as congenital hip dislocation, is a condition where the hip joint has not formed correctly. This can range from a mild instability or looseness of the joint to a complete dislocation of the femoral head from the acetabulum (hip socket). The hip joint, a ball-and-socket articulation, relies on proper alignment and depth of the acetabulum for stability and efficient movement. When dysplastic, the shallow socket and/or improperly formed femoral head can lead to abnormal biomechanics, accelerated wear and tear, pain, and eventually osteoarthritis if left untreated. Early diagnosis is paramount for successful outcomes, as the hip joint is highly moldable in infancy.

Principles of DDH Treatment

The primary goals of DDH treatment are to:

• Achieve and maintain stable reduction: Ensure the femoral head is correctly seated within the acetabulum.
• Promote normal acetabular development: Encourage the hip socket to deepen and mature properly.
• Restore optimal hip joint mechanics: Re-establish anatomical alignment and joint congruence.
• Prevent long-term complications: Mitigate the risk of pain, limited mobility, gait abnormalities, and premature osteoarthritis.

Treatment strategies are highly dependent on the patient's age at diagnosis, the severity of the dysplasia, and the presence of any associated complications.

Non-Surgical Treatment Approaches (Infancy and Early Childhood)

For infants, non-surgical methods are the first line of treatment due to the high plasticity of their bones and cartilage.

• Pavlik Harness:

  • Mechanism: This is the most common and effective treatment for DDH diagnosed in infants under six months of age. The soft harness holds the infant's hips and knees bent up and out (flexed and abducted), allowing the femoral head to naturally settle deeply into the acetabulum. This position encourages normal development of the hip socket.
  • Duration: Typically worn full-time for 6-12 weeks, with regular follow-up appointments and ultrasound monitoring to assess progress.
  • Kinesiological Relevance: The harness facilitates a physiologically optimal position for hip joint development, promoting concentric seating of the femoral head which is crucial for acetabular modeling.

• Abduction Braces/Casts:

  • Mechanism: For infants older than six months, or those who don't respond to the Pavlik harness, more rigid bracing (e.g., an abduction brace or a spica cast) may be used. These devices maintain the hip in a stable, abducted position.
  • Application: Often applied after a successful closed reduction (manual manipulation of the hip back into place under sedation or anesthesia).
  • Duration: Worn for several months, with periodic cast changes or brace adjustments.

Surgical Treatment Approaches (Older Children and Adults)

When non-surgical methods are unsuccessful, or when DDH is diagnosed later in childhood or adulthood, surgical intervention becomes necessary.

• Closed Reduction with Spica Cast:

  • Procedure: For children aged 6-18 months, if the hip cannot be reduced with a harness, the orthopedic surgeon manually manipulates the femoral head back into the acetabulum under general anesthesia.
  • Post-Procedure: A spica cast is applied to maintain the reduction for several months.

• Open Reduction:

  • Procedure: If closed reduction is unsuccessful, or for children over 18 months with persistent dislocation, open surgery is performed. The surgeon makes an incision to directly visualize the hip joint and remove any obstacles (e.g., inverted labrum, hypertrophied ligamentum teres) preventing reduction, then places the femoral head into the acetabulum.
  • Post-Procedure: A spica cast is typically applied to protect the hip during initial healing.

• Osteotomies (Pelvic and/or Femoral):

  • Procedure: These procedures involve cutting and reshaping the bones of the pelvis (e.g., Salter, Dega, Pemberton, Ganz periacetabular osteotomy) or the femur (femoral shortening or derotational osteotomy) to improve the coverage of the femoral head by the acetabulum and optimize joint alignment.
  • Purpose: To create a more stable and anatomically correct hip joint, distribute forces more evenly, and reduce the risk of premature osteoarthritis.
  • Application: Often performed in older children, adolescents, and young adults with residual dysplasia or symptomatic hip impingement.

• Total Hip Arthroplasty (THA):

  • Procedure: In adults with severe DDH-related osteoarthritis that is no longer manageable with conservative measures, a total hip replacement may be necessary. The damaged joint surfaces are removed and replaced with prosthetic components.
  • Considerations: DDH often presents unique challenges for THA due to altered anatomy, bone deficiencies, and muscle imbalances. Specialized techniques and implants may be required.

The Role of Rehabilitation and Kinesiology

Regardless of the treatment method, rehabilitation is a critical component of the recovery process, especially for those undergoing surgical interventions. A structured exercise program, guided by a physiotherapist or kinesiologist, is essential for restoring function and preventing long-term issues.

Goals of Exercise Rehabilitation

• Restoring Range of Motion (ROM):

  • Focus: Gentle, controlled movements to regain full, pain-free hip flexion, extension, abduction, adduction, and rotation.
  • Exercises: Passive and active-assisted range of motion exercises, gentle stretching (e.g., hip flexor stretch, piriformis stretch), and eventually active ROM exercises. Emphasis on maintaining the "safe zone" of hip motion as advised by the surgeon.

• Strengthening Key Muscle Groups:

  • Focus: Addressing muscle imbalances and weakness that often accompany DDH. Strengthening the muscles around the hip is crucial for dynamic stability and efficient movement.
  • Exercises:
    • Gluteal Muscles (Medius, Minimus, Maximus): Crucial for hip abduction, external rotation, and extension, providing stability in single-leg stance and during gait. Examples: clam shells, side-lying leg raises, glute bridges, band walks.
    • Core Stabilizers (Transverse Abdominis, Multifidus, Obliques): Essential for pelvic stability, which directly impacts hip function. Examples: planks, bird-dog, dead bug.
    • Hip Flexors (Psoas, Iliacus): Important for gait and leg swing, but often tight; focus on balanced strengthening and flexibility.
    • Hip Adductors and External Rotators: Targeted exercises to ensure balanced muscle strength around the joint.

• Improving Proprioception and Balance:

  • Focus: Re-educating the nervous system about joint position and movement, enhancing balance, and reducing the risk of falls or re-injury.
  • Exercises: Single-leg standing, balance board exercises, tandem stance, dynamic balance drills.

• Gait Retraining:

  • Focus: Correcting compensatory walking patterns that may have developed due to pain, instability, or muscle weakness.
  • Exercises: Structured walking drills, treadmill training with focus on step length and symmetry, progressing from partial to full weight-bearing as tolerated.

• Progressive Load Management:

  • Focus: Gradually increasing the demands on the healing hip joint to prepare it for daily activities, and eventually, higher-level functional movements or sports.
  • Approach: Start with low-impact, controlled exercises and progressively introduce more challenging movements, resistance, and impact as the hip demonstrates tolerance and strength.

Considerations for Exercise Prescription

• Individualized Approach: Rehabilitation protocols must be tailored to the specific surgical procedure, individual healing rates, age, and pre-existing activity levels.
• Pain Monitoring: Exercise should be performed within a pain-free range. Any increase in pain or discomfort should prompt a review of the exercise program.
• Avoiding High-Impact Activities: Initially, high-impact activities (running, jumping) and deep hip flexion/adduction are typically restricted to protect the healing joint.
• Long-Term Maintenance: Patients should be educated on the importance of ongoing exercise to maintain hip health, strength, and flexibility, especially given the increased risk of future osteoarthritis.

Long-Term Outlook and Management

The long-term outlook for DDH largely depends on the age at diagnosis and the effectiveness of treatment. Early diagnosis and appropriate intervention generally lead to excellent outcomes with normal hip function. However, even with successful treatment, individuals with a history of DDH may have a higher propensity for developing hip osteoarthritis later in life due to subtle residual anatomical variations or altered joint mechanics.

Ongoing management includes:

• Periodic Medical Follow-ups: To monitor hip joint health and detect any signs of degenerative changes.
• Lifestyle Modifications: Maintaining a healthy weight to reduce joint load.
• Regular, Appropriate Exercise: Continuing a lifelong regimen of hip-strengthening, flexibility, and low-impact cardiovascular exercises to support joint health and function.

When to Seek Professional Help

If you suspect DDH in an infant (e.g., asymmetrical leg folds, limited hip abduction, clicking hip), or if an older child or adult experiences persistent hip pain, limping, or stiffness, it is crucial to consult with a healthcare professional. Diagnosis and treatment of DDH require the expertise of orthopedic surgeons, pediatricians, and rehabilitation specialists. Early intervention can significantly improve outcomes and quality of life.