25. Limb Equalisation

• Limb equalisation surgery, also called limb lengthening surgery, is performed when correction with shoes is inadequate, often at > 2,5 cm discrepancy
• Multiple surgical procedures are available to correct limb length
  • Some are complex, but by combining two or more of them we can reduce the complexity and the number of operations required
• Temporary epiphysiodesis – using screws or staples across the epiphyseal plate
  • Can only be used in skeletally immature patients, of course
  • This prevents further growth of the longer limb until the short limb has “caught up”
• Permanent epiphysiodesis – the surgical destruction of the epiphyseal plate
  • Can only be used in skeletally immature patients, of course
  • The epiphysis of the longer limb is removed (then turned 90° and re-inserted)
  • If timed correctly, the shorter limb will continue to grow but stop growing when it reaches the length of the operated limb
• Limb shortening
  • By osteotomy
  • Is less complex and has faster healing period than limb lengthening
  • Femoral osteotomy is preferred over tibial osteotomy
  • The ends are fixated together
• Limb lengthening by callotasis (= distraction osteogenesis)
  • First, a part of the bone is removed by osteotomy
  • A distracting device is used to distract the area of the bony callus
    • The distracting device may be external or internal
    • Internal rods are often used
  • The distraction is adjusted multiple times daily and for very small lengths each time
    • New bone will fill the gap
  • After the target length has been reached, the patient must gradually put more and more weight on the bone to strengthen the new bone
• Monitoring and post-operative
  • During distraction, x-ray is routinely taken to monitor
  • 3 – 4 weeks after distraction is complete the distraction device is left in place to provide stabilization
  • Weight-bearing is recommended to mature the bone
• Complications
  • Infections
  • Angular deformities like varus or valgus due to non-axial weight-bearing
  • Joint contractures due to muscle imbalances