Hip Arthrodesis

Indications

• Young patients (<30 years) with debilitating arthritis
• Previously infected hip with end-stage joint destruction
• Heavy laborers (Resurfacing may be a better option)

Prerequisites

• Adjacent joints (spine, knee, other hip) must be normal
• No active sepsis
• No major limb length discrepancy (fusion will cause further shortening)

Position of Fusion

• 30 degrees flexion: Clears foot and allows comfortable sitting
• 5 degrees adduction: Prevents abductor lurch
• 5 degrees external rotation: Prevents tripping

Instrumentation

• Rigid fixation of well-opposed joint surfaces with fixed-angle plates

Results & Complications

• Generally good; reports in children show >20 years of good function
• Failure often due to adjacent joint disease, which is the most common reason for conversion to Total Hip Replacement (THR)
• Complications:
  • 50% experience back pain
  • 40% have ipsilateral knee pain
  • 20% have contralateral hip pain
  • Non-union is uncommon but can occur

Conversion to THR

• Results are not as good as primary THR
• Challenges include:
  • Soft tissue contracture and wasting
  • Functional abductors are critical for good outcomes
  • Risks: Instability, limp, and pain