A technique for enhancing union of allograft to host bone

The aim of limb-salvage surgery in malignant bone I tumours in children is to restore function and eradicate local disease with as little morbidity as possible. Allografts are associated with a high rate of complications, par ticularly malunion at the allograft-host junction. We describe a simple tec hnique which enhances union of allograft to host bone taking advantage of t he discrepancy in size between the adult allograft and the child's bone. Th is involves Lifting a flap of periosteum before resection from the host bon e, which is then telescoped into the allograft medullary canal, which may r equire internal burring or splitting, for a distance of 1.5 to 2 cm and cov ering the bone junction with the periosteal flap, This is more stable than conventional end-to-end opposition, For each centimetre of telescoping the surface area available for bony union is increased more than three times. T he periosteal flap also augments union. Additional surface fixation with a plate and screws is not necessary. We have used this technique in nine children, in eight of whom there was co mplete union at a mean of 16 weeks. Delayed union, associated with generali sed limb osteoporosis, occurred in one, Early mobilisation, with weight-bea ring by three weeks, was possible, There was only one fracture of the allog raft.