Tibial Lengthening Over Nails (LON)

Abstract

With tibial lengthening by distraction osteogenesis, the patient is required to wear an external fixator for an extended period while the regenerated bone matures. To decrease the lengthy external fixation treatment times, we have developed a method to lengthen adult tibias over intramedullary (IM) nails, which we term “lengthening over nails” (LON). At the end of the distraction period, the patient returns to the operating room for locking screw insertion and external fixator removal. The IM nail prevents bending or shortening of the immature regenerated bone. We use an Ilizarov three-ring fixator with one wire and one half-pin proximally and two wires distally. Compared with femoral LON, tibial LON is technically easier. In 20 cases, we have seen only one deep infection. It appeared late, after complete consolidation of the regenerated bone, and was successfully resolved by removing the IM nail. The disadvantages of the LON technique include an increase in both blood loss and operative time, risk of IM infection, and limitation of its use by the type and level of deformity and presence of infection. The benefit of a markedly reduced external fixation time, however, may outweigh these disadvantages in selected adults.