Stimulation of bone union with dynamic beams of Konzal's "R" external fixator.

Background: Treatment of septic long bone non-union remains a complex therapeutic problem. External stabilisation with Konzal's "R" fixator has been used in the Orthopaedic Department of CPME for years and allows for rigid stabilisation of bone fragments and good mutual alignment. Tried and tested in the treatment of osteitis, the fixator, however, offers limited possibilities for dynamisation and interfragmental compression. The following article presents a modernised design of Konzal's "R" with dynamic beams.

Material And Methods: The efficacy of dynamisation of the fixator with the modernised design was compared with that of the earlier technique of eccentric shifting of static beams by assessing the time of bone union, the average number of pin restabilisations required, and the percentage of "partial unions" in two groups treated with the different methods.

Results: In the dynamic beam group, mean time to bone union was shorter by 5.1 months on average. This group also recorded a significantly lower percentage of "partial unions" (<50% of diaphysial circumference) as well as a lower count of necessary pin restabilisations per patient. There was no correlation between time to bone union and the duration of active inflammation prior to the surgical treatment or the presence of an open fistula.

Conclusions: 1. The modernised design allows for dynamic load bearing by the bone tissue between the fragments rather than by the fixator's static beams. 2. The biomechanical principle of the fixator provides for optimal bone healing and shortens the time to bone union.