Retained Male Component After Intra-operative Dissociation of a Tibial Magnetic Lengthening Nail: A Case Report covering Technical Challenges and Management Strategies

Background Magnetically driven telescopic intramedullary lengthening nails permit internal distraction osteogenesis without external fixation. While removal is typically uncomplicated, component dissociation at the telescoping junction has been reported as an infrequent but challenging complication. Case Presentation A 17-year-old female with congenital posteromedial tibial bowing underwent tibial lengthening at age 13 using a PRECICE tibial nail (8.5 × 155 mm). Planned implant removal was delayed due to the COVID-19 pandemic. At removal 4 years post-surgery, intra-operative dissociation occurred at the telescoping junction. The female (magnetic) component and interlocking screws were successfully removed, but the male (non-magnetic) component could not be safely extracted despite multiple retrograde techniques and was left in situ to avoid cortical window creation and possible iatrogenic fracture. At 3 months, the patient remained asymptomatic and had returned to unrestricted activity. Discussion Published reports describe retrieval of dissociated or broken magnetic lengthening nails using cortical window or unroofing osteotomy techniques. In this case, delayed retention and the distal flare geometry of the smallest tibial nail may have contributed to mechanical capture, but this remains hypothesis-generating rather than proven. Conclusion Surgeons using magnetic lengthening nails should anticipate potential dissociation during removal, particularly when removal is delayed beyond consolidation. Pre-operative planning should include availability of instruments for escalation and frank patient counselling regarding potential for retained hardware. Early planned removal after achieving lengthening objectives may reduce complication risk.