What are the treatment guidelines for babies after open reduction of hip dysplasia, including physical therapy and monitoring of developmental milestones?

Post-Operative Management After Open Reduction of Hip Dysplasia

After open reduction for hip dysplasia, babies require close monitoring with serial imaging, typically do not need formal physical therapy during the immobilization phase, and should be expected to walk later than typical developmental milestones—with walking age depending on the timing of surgery and duration of immobilization.

Immediate Post-Operative Care and Immobilization

Spica cast immobilization is the standard treatment following open reduction, with the duration typically ranging from 6-12 weeks depending on the surgical approach and associated procedures 1, 2. During this period:

• No formal physical therapy is indicated while the child is in the spica cast, as the hip needs protected healing time 3
• Parents should receive written instructions on cast care and positioning 3
• The child will be non-weight bearing during the immobilization period 2, 4

Surveillance Imaging Protocol

Serial radiographic monitoring is essential to detect complications early, particularly avascular necrosis (AVN) and redislocation:

• Radiographs should be obtained at each follow-up visit to assess concentric reduction and detect AVN of the femoral head 2, 4
• The first follow-up typically occurs within 2-4 weeks post-operatively to confirm maintained reduction 5
• Ultrasound is not the preferred modality after open reduction in older infants, as radiographs provide better assessment of bony acetabular development and femoral head position 3
• Continue radiographic surveillance at regular intervals (typically every 3-6 months initially, then annually) to monitor acetabular development and detect late complications 6

Expected Complications and Risk Factors

Approximately one-third of patients require secondary surgical procedures within the first 4 years after open reduction 1. Key complications include:

• AVN occurs in 13-15% of cases, with higher rates associated with severity of initial hip dislocation 1, 2, 4
• Redislocation rates are approximately 4% with appropriate immobilization 2
• Children over 18 months at the time of open reduction who do not receive concurrent acetabular osteotomy have higher reoperation rates 1

Developmental Milestones and Walking Expectations

Walking will be significantly delayed compared to typical developmental milestones, and parents need clear counseling about this:

• Normal walking age is 12-15 months, but children after open reduction typically walk much later 5
• Expected walking age depends on the age at surgery and duration of immobilization—a child who undergoes open reduction at 18-24 months may not walk until 30-36 months or later 1, 7
• The child will need time to regain muscle strength and coordination after cast removal before attempting independent ambulation 7, 8
• Do not rush weight-bearing activities—allow the child to progress naturally once cleared by the orthopedic surgeon 2, 4

Role of Physical Therapy

Formal physical therapy is generally not recommended during the immediate post-operative period, but may have a role later:

• During spica cast immobilization: No physical therapy is indicated 3
• After cast removal: Written home exercise instructions are typically sufficient rather than formal physical therapy 3
• Physical therapy may be considered if significant muscle weakness or gait abnormalities persist beyond the expected recovery period, but this is not routinely prescribed 3
• The evidence does not support routine physical therapy as standard care after open reduction for DDH 3

Long-Term Monitoring Algorithm

Continue hip examinations and radiographic surveillance through childhood to detect residual dysplasia:

• Follow-up radiographs at age 1 and 4 years to assess acetabular development 6
• Continue clinical hip examinations at all well-child visits through age 5 6
• Monitor acetabular index values—the mean acetabular index should normalize to approximately 22-23° by age 5 years 2, 4
• Use Severin classification to grade radiographic outcomes at skeletal maturity 2, 7, 4

Common Pitfalls to Avoid

Several critical errors can compromise outcomes:

• Do not allow premature weight-bearing before the surgeon clears the child, as this increases AVN risk 2, 4
• Do not assume normal radiographs at cast removal mean the hip is fully healed—continued surveillance is essential to detect late subluxation 1, 7
• Do not dismiss parental concerns about delayed walking as "just developmental variation"—ensure adequate follow-up to rule out complications 5
• In children over 18 months, failure to perform concurrent acetabular osteotomy at the time of open reduction increases the likelihood of requiring future reoperation 1

Prognosis and Counseling Points

Parents should understand the long-term implications:

• 71-82% of children achieve satisfactory outcomes (Severin Class I-II) with appropriate treatment 7, 4
• Untreated or inadequately treated DDH leads to early degenerative joint disease, with DDH causing up to one-third of total hip arthroplasties in patients under 60 years 6
• Residual dysplasia detected during childhood should be corrected surgically to alter the natural history and improve hip joint longevity 8
• The severity of initial hip dislocation is the strongest predictor of AVN development, not the treatment method itself 1