Migration of a Lumbar Spinal Fusion Rod Into the Posterolateral Knee

Study Design. Case report (level V evidence). Objective. We report a case of a 33-year-old man with Marfan syndrome that visited our clinic for left knee pain and stiffness. Radiographs of the left knee and lumbar spine demonstrated a spinal rod in the posterolateral left knee and its origin being a broken rod from his previous unilateral spinal fusion 17 years prior. Summary of Background Data. Spinal arthrodesis is a common treatment modality for a wide range of spinal pathologies including infection, trauma, congenital and developmental deformities, and degenerative conditions. A rare complication that may arise from said procedure is implant migration, most often a result of pseudoarthrosis. Methods. Description of the case report. Results. Patient was taken to the operating room 2 weeks later for an uneventful removal of the implant and immediate improvement with pain and range of motion. Conclusion. Spinal implant migration is a rare complication most often due to implant failure from pseudoarthrosis. In the case presented, this phenomenon was likely attributed to the use of unilateral instrumentation coupled with Marfan syndrome, shown to lead to insufficient implant stability and poorer fusion rates, respectively. Level of Evidence: 5