We report the results of intramedullary leg lengthening conducted between 2002 and 2009 using the Intramedullary Skeletal Kinetic Distractor in 69 unilateral lengthenings involving 58 femora and 11 tibiae. We identified difficulties that occurred during the treatment and assessed whether they were specifically due to the implant or independent of it. Paley’s classification for evaluating problems, obstacles and complications with external fixators was adopted, and implant-specific difficulties were continuously noted. There were seven failures requiring premature removal of the device, in four due to nail breakage and three for other reasons, and five unsuccessful outcomes after completion of the lengthening. In all, 116 difficulties were noted in 45 patients, with only 24 having problem-free courses. In addition to the difficulties arising from the use of external fixators, there were almost the same number again of implant-specific difficulties.

Nevertheless, successful femoral lengthening was achieved in 52 of the 58 patients (90%). However, successful tibial lengthening was only achieved in five of 11 patients (45%).

We performed one-stage lengthening using intercalary autogenous bone graft in 34 metatarsals and seven proximal phalanges in 21 patients with congenitally short metatarsals. At operation, in order to decrease the tension in the surrounding soft tissues, we gradually distracted the osteotomies of the affected bones for 20 to 30 minutes. The patients, all women, were followed up for a mean period of 2.1 years (1 to 6.5). The average gain in length for the 34 metatarsal procedures was 14 mm (6 to 21), equivalent to an increase of 32% (11 to 51), and for the seven proximal phalangeal lengthenings 8 mm (5 to 11), an increase of 54% (47 to 65). There was no evidence of neurovascular impairment. The technique of gradual distraction during operation is simple and effective. It overcomes the disadvantages of one-stage lengthening such as a small gain in length and neurovascular damage