Bilateral atraumatic rupture of the patellar ligament is a rare lesion, usually associated with systemic diseases and drugs such as steroids and fluoroquinolones. This report presents a case of bilateral atraumatic rupture of the patellar ligament in a 43-year-old male with obesity, type 2 diabetes mellitus, and who was being treated with a systemic corticosteroid for autoimmune disease (Wegener granulomatosis). These factors caused chronic degenerative and inflammatory changes in the ligaments, confirmed by the histological examination. Due to tissue quality, a primary ligament repair associated to an augmentation with semitendinosus tendon was performed. After 1 year, the patient presented satisfactory evolution, regaining the full range of motion and returning to his usual activities without sequelae.
Keywords: histology; knee/surgery; patellar ligament.