The influence of nylon cerclage on diaphyseal bone strength: an experimental evaluation of Partridge bands on rabbits.

Partridge-designed nylon bands which are used for the cerclage of fractured osteoporotic bones. These bands were given elevations on their inner surfaces to raise the band from the bone surface and thus minimize the negative effects on the periosteal blood circulation. It has previously been shown that the Partridge bands, when applied to a diaphyseal bone, cause a mechanical irritation to the periosteum resulting in an increased callus formation by comparison with the case when corresponding bands with no elevations are applied. It has been suggested that the increased amount of callus would result in increased strength. We have studied the effect of bands designed in accordance with Partridge, compared with corresponding bands having no elevations, in terms of torsion strength (maximum torque capacity), on intact rabbit femora. The results show an increased torsion strength in the femora to which Partridge bands had been applied for eight weeks, while the femora to which corresponding plain nylon bands had been applied had decreased in strength. The experimental study performed supports Partridge's recommendation to use the bands as cerclage in the internal fixation of fractured osteoporotic bones, preferably in combination with further internal fixation materials.