Among the factors determining the stability of external fi xator osteosyntheses the deciding factor is the confi guration of the montage. The authors examined the stability of unilateral and
V-forms used in crural fractures together with a Budapest University of Technology task force. They performed osteotomy on cadaver bones and used a total of 12 kinds of montage variations. The various montages were exposed to 5 types of static load, their stability was tested, and fi nite element model experiments were performed. The load tests were evaluated by computer and the charts were compared. It was concluded that unilateral montages are most stable when the pins are placed in the greatest possible distance from each other within one segment and the rods are far from each other. In case of V-frame symmetrically inserted pins should be avoided in the
second plane for better stability. Finite element model has verifi ed the biomechanical observations. During the biomechanical experiment the authors have gained useful experiences for
further clinical practice.

DOI: 10.17489/biohun/2011/1/06