What management approach would you recommend for a 9-year-old male with low back pain, Paget's disease of the L3 vertebra, and bilateral hip osteoarthritis, who is scheduled for right hip replacement surgery in 5 months?

Management of Paget's Disease in a 9-Year-Old with Hip Osteoarthritis

This patient should receive intravenous pamidronate therapy to treat the Paget's disease of L3 prior to hip replacement surgery, along with comprehensive pain management and physical therapy for both the spinal and hip conditions.

Assessment of Current Condition

The patient presents with a complex case involving:

• 9-year-old male with low back pain
• Paget's disease of L3 vertebra confirmed by bone scan
• Bilateral hip osteoarthritis
• Scheduled right hip replacement in 5 months
• Normal laboratory values (calcium, renal function, TSH, alkaline phosphatase)

Management Algorithm

1. Paget's Disease Management

Paget's disease in a pediatric patient is extremely rare and concerning, particularly with upcoming orthopedic surgery. Despite normal alkaline phosphatase, the bone scan confirmation warrants treatment:

• First-line therapy: IV pamidronate 1

  • Indicated for moderate to severe Paget's disease
  • Particularly important before orthopedic surgery to reduce disease activity
  • Reduces risk of implant loosening and excessive intraoperative blood loss 2
  • Dosing should be determined by pediatric endocrinology consultation

• Monitoring:

  • Baseline and follow-up alkaline phosphatase levels at 3-6 months 3
  • Repeat bone scan to assess treatment response
  • MRI of lumbar spine to evaluate extent of vertebral involvement

2. Pain Management for Low Back Pain

• Non-pharmacological approaches:

  • Physical therapy focusing on core strengthening and proper body mechanics
  • Weight management if applicable
  • Activity modification and pacing 4

• Pharmacological management:

  • First-line: Acetaminophen (weight-appropriate dosing)
  • If inadequate response: NSAIDs at lowest effective dose
  • Avoid opioids unless absolutely necessary 4

3. Pre-Surgical Management for Hip Osteoarthritis

• Imaging assessment:

  • MRI of hip without IV contrast (rated 9/9 for appropriateness) 4
  • CT hip without IV contrast to assess bone quality before surgery 4

• Non-pharmacological interventions:

  • Physical therapy focusing on maintaining hip range of motion
  • Assistive devices (cane or crutches) to reduce weight-bearing 4
  • Appropriate footwear to reduce mechanical stress 4

• Pain management:

  • Acetaminophen and NSAIDs as first-line therapy
  • Consider image-guided corticosteroid injection if pain is severe 4

Special Considerations

1. Timing of bisphosphonate therapy:

   • Should be initiated promptly, at least 2-3 months before scheduled hip surgery
   • May need to adjust surgery timing based on response to Paget's treatment

2. Surgical planning:

   • Ensure orthopedic surgeon is aware of Paget's disease diagnosis
   • Consider cementless total hip arthroplasty which has shown good outcomes in patients with Paget's disease 2

3. Multidisciplinary approach:

   • Pediatric endocrinology for Paget's disease management
   • Pediatric orthopedics for hip replacement
   • Physical therapy for both conditions
   • Pain management specialist if needed

Monitoring and Follow-up

• Regular assessment of pain and function
• Monitor alkaline phosphatase levels every 3 months
• Repeat imaging of L3 vertebra to assess treatment response
• Regular physical therapy evaluations
• Pre-surgical optimization with bisphosphonate therapy

Pitfalls to Avoid

1. Delaying treatment of Paget's disease - Even with normal alkaline phosphatase, treatment before surgery is crucial to reduce complications
2. Overlooking the connection between conditions - Low back pain may be exacerbated by altered gait from hip osteoarthritis
3. Inadequate pre-surgical planning - Failure to control Paget's disease activity before surgery increases risk of implant loosening 2
4. Overreliance on opioids - Focus should be on disease-modifying treatments and appropriate non-opioid pain management

The presence of Paget's disease in a pediatric patient with planned orthopedic surgery represents a high-risk scenario that requires aggressive management to optimize surgical outcomes and prevent complications.