Bifocal Disruption of the Patellar Tendon with Avulsion of the Tibial Tuberosity: A Case Report

Abstract

Introduction: Bifocal disruption of the knee extensor system is rare. Coincident bifocal proximal and distal disruptions of the patellar tendon are extremely rare in adults. Case Report: A 38-year-old man presented to our clinic with severe right knee pain after falling down the stairs and abruptly bending the right knee. Plain radiographs of this knee showed tibial avulsion and a high riding patella, suggesting underlying Osgood-Schlatter disease, which was also present to a milder degree in the left knee. Magnetic resonance imaging confirmed an avulsion of the tibial tuberosity and showed concomitant avulsion of the patellar tendon without bone marrow edema. Computed tomography showed that the fragment of the tibial tuberosity had a dull-edged margin, and cortical bones were partially exposed. During surgery, the patellar tendon was divided into superficial and deep layers. The superficial layer was peeled from an attachment at the patella, while the deep layer was from the tibia and contained the fragment of the tibial tuberosity. The detached side of the fragment and tibia were coated with dense, fibrous tissue. Surgical repair was performed, with excellent outcomes. Radiographic and intraoperative findings suggested Osgood-Schlatter disease, which might cause avulsion of the tibial tuberosity. Conclusion: This is the first case of the bifocal proximal and distal rupture of the patellar tendon with the avulsion of the tibial tuberosity. Bifocal disruption of the patellar tendon should be considered in patients presenting with avulsion of the tibial tuberosity and suspected Osgood-Schlatter disease.