Open tibia plateau fracture with intra-osseous dislocation of the patella and quadriceps tendon rupture: a case report

Both tibial plateau fractures and extensor apparatus injuries are serious injuries to the knee joint that generally do not occur in the same patient. We report a rare case of open tibial plateau fracture combined with quadriceps tendon rupture and complete displacement of the patella into the tibial plateau fracture. The case involved a male who was 19 years old who had been in a motorcycle accident. The patient was admitted to our department with an open tibial plateau fracture 3 h post-injury. X-ray showed a tibial plateau fracture and complete displacement of the patella into the tibial plateau. CT showed an avulsion fracture in the patella and tibial intercondylar eminence. Concomitant quadriceps tendon injury and both anterior and posterior cruciate ligament tibial insertion avulsion fractures were considered. The operative findings of emergency surgery confirmed our preoperative diagnosis. Single-stage quadriceps tendon repair and ORIF for the tibial plateau fracture were performed. Satisfactory restoration of function was acquired at the last follow up. The most difficult aspect of this case was the determination of the cause of the intra-osseous dislocation of the patella into the tibial plateau. The most likely mechanism of the injury may be that the patient experienced transient posterior dislocation of the knee during the injury. Rupture of the quadriceps tendon should be considered with posterior dislocation of the knee, and the patella was pushed into the tibial plateau fracture by force after the rupture of the quadriceps tendon.