All patients in the series successfully completed treatment and reached the desired limb length with radiographic evidence of consolidation. The average leg length increase was 35 mm (21–75 mm). No infection, malunion, or joint contracture was observed. A length of less than 100 mm of the thick portion of the nail in the distal fragment is associated with the likelihood of a “runaway nail” (distraction index > 1.5 mm/d). Six patients had poor regenerate requiring bone grafting. Likelihood of poor regenerate was associated with number of previous operations on the lengthened bone. Three patients had nails that were difficult to distract and required closed manipulation under anesthesia