[Simultaneous bilateral rupture of the quadriceps tendon].

Bilateral rupture of the quadriceps tendon is a rare injury. It usually occurs in obese older patients. Other predisposing factors are long-term chronic renal failure, gout, rheumatoid arthritis, diabetes mellitus, hyperparathyroidism and abuse of anabolic steroids. The most common cause of bilateral rupture is a sudden violent contraction of the quadriceps muscles with the knees semiflexed and the feet fixed. Examination reveals bilateral joint effusion, palpable or visible suprapatellar gaps, and an inability to extend both knees and lift the straight legs. Often the diagnosis is missed, and diagnostic confusion with other causes of inability to use the legs happens. We report one case of simultaneous bilateral rupture where treatment was delayed for several weeks because of diagnostic confusion.