Dual Magnetically Expandable Intramedullary Nails for Treatment of a Large Bony Defect in a Patient with Sarcoma: A Case Report.

Aim: To describe the surgical technique of performing an all-internal lengthening to address a large diaphyseal femur defect in the sarcoma patient. Background: Various strategies exist to address large intercalary bone defects with various biomechanical and biological implications. Case description: A 23-year-old female with high-grade osteosarcoma of her left femur underwent wide resection and an internal reconstruction of a 12.5-cm femoral defect using dual magnetic lengthening intramedullary nails resulting in restoration of leg lengths, and pre-resection function with minimal residual disability. Conclusion: Preoperative chemotherapy, wide resection and post-operative chemotherapy for osteosarcoma are the current standard of care. Resection often leads to large bone defects requiring complex reconstruction. Following intercalary bone resection, biological reconstruction is a consideration. An all-inside technique was developed in an effort to minimise complications of long-term external fixation for distraction osteogenesis, or extensile secondary grafting procedures for induced membrane strategy. Clinical significance: This previously unreported surgical technique allows for an all-internal lengthening of large diaphyseal bone defects. While specifically used in an oncologic post-resection setting, this technique is applicable to the broader limb reconstruction and lengthening practice and overcomes some inherent limitations to previously described techniques. How to cite this article: Copp J, Magister S, Napora J,