A case of anterior cruciate ligament tear accompanied by avulsion fractures of tibial tuberosity and Gerdy's tubercle

Abstract 

A 54-year-old man visited our clinic due to a painful swelling of his right knee. He had attempted a forceful kick by his right leg during a Sepak Takraw-like sports activity, only to fail to hit the ball. He felt a popping sense on the knee and collapsed, even without direct trauma. Imaging studies revealed a disruption of the anterior cruciate ligament (ACL), and separate avulsion fractures of the tibial tuberosity and Gerdy's tubercle. The fractures were stabilized by two cancellous screws, respectively. The intra-operative fluoroscopy demonstrated a manifest ACL insufficiency. A simultaneous reconstruction of the ligament was not performed. At 6months after surgery, he had no difficulty in his activities of daily living. The involved knee joint was believed to have undergone a forceful pivot shift mechanism. Injuries to the ACL can be suspected from indirect signs on the radiologic images by a careful reconstitution of the injury mechanism and the associated lesions. Manifest osseous lesions on the plain radiographs can herald a major ligamentous injury and may be interpreted as an indirect sign of the ACL injury, which helps to establish a relevant management plan.

Keywords: Anterior cruciate ligament, Plateau fracture, Avulsion fracture, Mechanism of injury