Bilateral, spontaneous and simultaneous rupture of the quadriceps tendon in chronic renal failure and secondary hyperparathyroidism. Report of five cases.

Bilateral and simultaneous rupture of the quadriceps tendon of the knee without significant trauma in five patients, two males and three females, with chronic renal failure and secondary hyperparathyroidism is reported. Ruptures of the extensor mechanism are relatively rare injuries. Unilateral rupture is more common.