Is the Intramedullary Skeletal Kinetic Distractor a Safe Measure for Bone Lengthening? A Systematic Review

Background The intramedullary skeletal kinetic distractor (ISKD) is one of the relatively recent methods developed to overcome the complications of conventional bone lengthening methods, such as external fixators. These complications include pain, muscle transfixation, pin-tract infection, reduced joint motion, and prolonged fixation time. However, ISKD-specific complications such as uncontrollable lengthening and hardware failure make the outcomes of ISKD lengthening questionable. In this article, we review published literature on the efficacy and complications of the ISKD device. Methods A database search was conducted in PubMed, Ovid Medline, Ovid Full Text, Springer link, EBSCO Medline, Science Direct, ISI Web of Knowledge, and Google Scholar. We included English articles with extractable data about the study population and outcomes, reporting ISKD implantation in the femur or tibia of skeletally mature patients. The included studies were too heterogeneous for a metaanalysis to be performed. Results Fifteen of 89 potentially relevant citations were found to match the inclusion criteria. The most common causes of limb-length discrepancy indicating an ISKD implantation were traumatic and congenital. The average lengthening achieved, average patient discharge period, mean follow-up time, average consolidation time and index, average distraction time and index, and number of patients requiring additional operations as well as other outcome measures are discussed in this article. The most common complications were runaway nail, difficulty in achieving lengthening, and poor bone regenerate formation. Conclusion Even though the classic complications of external lengthening are virtually diminished, alterations to the current design of the ISKD are needed to avoid the distraction- related complications. Risk of unplanned surgery could be minimized through proper patient selection and proper surgical techniques.