Case: We present a 17-year-old male patient with an initially missed posterior sternoclavicular fracture dislocation who presented with symptoms related to thrombotic emboli arising from a pseudoaneurysm. He was treated 6 weeks after injury with a figure-of-eight tendon allograft repair with good clinical outcomes.

Conclusion: This is a unique presentation that highlights the significant risk of a missed diagnosis, life-threatening complications that may ensue, and biomechanically superior surgical intervention.