A probabilistic approach for modelling bone fracture healing under Ilizarov circular fixator

Area of Science:

• Orthopedic biomechanics
• Biomedical engineering
• Computational modeling

Background:

• Ilizarov circular fixator (ICF) is used for bone fracture treatment, but uncertainties in critical factors affect the fracture site's mechanical microenvironment.
• The impact of these uncertainties on fracture healing outcomes remains incompletely understood.

Purpose of the Study:

• To investigate the effects of uncertainties in fracture gap size (GS), weight-bearing (P), wire pretension (T), and wire diameter (WD) on the mechanical microenvironment.
• To utilize computational modeling and engineering reliability analysis to quantify these effects.

Main Methods:

• Computational modeling was employed to simulate the mechanical microenvironment of bone fractures stabilized with an ICF.
• Engineering reliability analysis was used to assess the sensitivity of the mechanical microenvironment to variations in key parameters.
• The study specifically analyzed uncertainties in fracture gap size, weight-bearing levels, wire pretension, and wire diameter.

Main Results:

• The mechanical microenvironment is highly sensitive to uncertainties in weight-bearing (P) and fracture gap size (GS).
• Increased uncertainty in P (COV_P from 0.1 to 0.9) reduced the probability of success (PoS) by over 50%.
• Increased uncertainty in GS (COV_GS from 0.1 to 0.9) decreased PoS by approximately 30%.
• Uncertainties in wire pretension (T) and wire diameter (WD) had minimal impact on PoS (<5% change).

Conclusions:

• Weight-bearing and fracture gap size are critical factors influencing the mechanical stability of fractures treated with ICF.
• Minimizing uncertainties in these parameters is essential for optimizing the mechanical microenvironment and promoting successful bone healing.
• Variations in wire pretension and diameter have a negligible effect on fracture healing outcomes.