Acute tibial tubercle avulsion fractures are uncommon, and these injuries typically occur in mature-appearing adolescent boys involved in jumping sports, particularly basketball. The developmental anatomy of the tibial tuberosity and the changes surrounding normal physiologic epiphysiodesis render this structure susceptible to acute avulsion fractures. Possible associated injuries include patellar and quadriceps avulsions, collateral and cruciate ligament tears, and meniscal damage. The treatment of this injury is based on the amount of displacement and associated injuries. Nondisplaced fractures are treated nonoperatively with cast immobilization. Displaced fractures require open reduction and internal fixation. Even in Type III injuries, the outcome is usually excellent.