Dynamization of External Fixator



- Discussion:
      - most effective way to reduce pin bone stress and motion
      - dynamization compensates for fragment end resorption;
      - failure to adjust the fixator for maximum maintenance of fragment contact can leave the fracture surfaces fixed apart;

- Technique:
      - adjust fixator to obtain good fragment apposition;
      - apply compression across the fracture site & maintain stability thru application of gentle axial compression every few weeks;
      - once frx shows evidence of healing consider loosening frame construct to allow controlled motion at the fracture site;
             - frame is weakened by taking off top set of pin clamps or moving pin clamps further from the tibial shaft;
             - fixator should be left on until fracture is non mobile, non painful, and radiographically healed;
      - once sufficient callus is present, fixator is removed and treatment is completed with a cast or brace;
      - if early fibular healing occurs, fibulectomy should be performed to permit impaction of the tibial fragment

- Reverse Dynamization:
      - changing from low stiffness to high stiffness after fourteen days
      - effect markedly increased the healing compared with constant low, medium, or high-stiffness fixators





Mechanical Influences on Tibial Fracture Healing.

Bone-healing patterns affected by loading, fracture fragment stability, fracture type, and fracture site compression.

Role of mechanical loading in the progressive ossification of a fracture callus.

Correlations between mechanical stress history and tissue differentiation in initial fracture healing.

Healing of rabbit tibial fractures using external fixation. Effects of removal of the fixation device.

134 tibial shaft fractures managed with the Dynamic Axial Fixator.

Effect of dynamization on gap healing of diaphyseal fractures under external fixation.

Effect of early axial dynamization on tibial bone healing: a study in dogs.

Dynamisation of tibial fractures.

Dynamization timing and its effect on bone healing when using the Orthofix Dynamic Axial Fixator.

Cyclical micromovement and fracture healing.

Unilateral external fixation until healing with the dynamic axial fixator for severe open tibial fractures.

Treatment of open tibial fractures with the Orthofix fixator.

Sliding performance of unilateral external fixators for tibia.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, July 22, 2013 11:56 am