Minimally invasive plate osteosynthesis for humeral shaft nonunion: A report of two cases

Introduction: We treated two cases of humeral shaft nonunion by minimally invasive plate osteosynthesis (MIPO) without autogenous bone grafting. Presntation of case: Case 1: An osteosynthesis with intramedullary nailing (IMN) was performed on a 17-year-old female for a humeral shaft fracture at another hospital; however, bony union was not obtained. We removed the nail and screws, then performed MIPO without autogenous bone grafting. At the final follow-up of 4 years after the surgery, she had obtained full range of motion. Case 2: Osteosynthesis with Rush pins had been performed in a 73-year-old female for a humeral shaft fracture at another hospital. Five months later, a revision surgery using IMN was performed at the same hospital; however, this led to nonunion. We removed the IMN and performed MIPO without autogenous bone grafting. At the final follow-up 2 years after surgery, she had obtained full range of motion. Discussion: The cause of nonunion is the lack of mechanical instability and/or biological activity. In these cases, from the findings of radiography and bone scintigraphy, mechanical instability was thought to be the primary cause; therefore, in order to enhance stability, we used a locking plate. Because we can see that these cases are biologically active, we decided not to use bone grafting. Both our cases successfully achieved bony union and excellent functional recovery using this method. Conclusion: We performed MIPO without exposure of the nonunion site and autogenous bone grafting in two cases of humeral shaft nonunion, and obtained successful clinical outcomes.