Distraction osteogenesis and nonunion of the docking site: is there an ideal treatment option?

Docking sites are the result of a classic bone transport technique for dealing with bone loss. Union may prove to be the rate-limiting step in the duration of treatment. Strategies to improve union have focused on surgical manipulation such as immediate coaptation of the margins of the segmental defect in the process of acute shortening to prevent fibrocartilaginous capping of the ends of bone during transport. This procedure has the highest success rate for union but is limited by its effect on the limb's vascularity. Other techniques for improving union involve compression, alternate compression-distraction, and bone grafts, all of which induce union to a variable degree. The application of external stimulators and bone morphogenetic proteins, the use of which is supported in fracture healing and even regenerate formation, is as yet unproven at docking sites.