Combined Tibial Tubercle Avulsion Fracture and Patellar Avulsion Fracture: An Unusual Variant in an Adolescent Patient.

Traumatic extensor dysfunction of the knee in children is a rare injury, with the majority resulting from tibial tubercle avulsion fracture or patellar sleeve fracture. We report a rare case of combined patellar avulsion fracture and tibial tubercle fracture. With open anatomic reduction, both injuries were successfully treated. While many variations of tibial tubercle fracture have been reported, the authors believe this to be the first report in the English-language literature of this particular combined injury to the knee extensor mechanism in an adolescent. Advanced imaging with computed tomography provided vital information to aid with operative planning, especially since the majority of the unossified tubercle was not seen on plain radiographs, and all fracture fragments were originally believed to be from the tibial tubercle. Computed tomography distinguished the patellar fracture from the tibial tubercle fragments, verifying preoperatively the complexity of the injury.