Pseudarthrosis of the rabbit tibia: a model for congenital pseudarthrosis?

The purpose of this study was to create a rabbit model of a pseudarthrosis of the tibia by passively constricting circumferential diaphyseal growth. A circumferential strip of Marlex mesh was placed around both tibiae of eight growing rabbits. It was sutured as a circumferential tube on the experimental tibia and not sutured together on the control side. The experimental tibiae developed significant narrowing, cystic changes, and sclerosis. Five of 11 experimental tibiae went on to pathological fracture, compared to no fractures in the eight control tibiae. The mesh was sutured together around both tibiae in another six rabbits. Release of the band 6 weeks later allowed healing of the narrowed tibiae, with or without an experimentally produced fracture. We conclude a passive constriction phenomenon may contribute to the development of congenital pseudarthrosis of the tibia. Removal of the band improved the chances of healing, which has implications for the treatment of children.