Spontaneous and simultaneous bilateral rupture of the quadriceps tendon. A case report.

Simultaneous bilateral rupture of the quadriceps tendon has rarely been reported; it generally occurs in association with chronic metabolic disorders, such as chronic renal failure, obesity, diabetes mellitus and secondary hyperparathyroidism. The case presented here was in an 85-year-old man with no known risk factors, who sustained simultaneous and spontaneous rupture of both quadriceps tendons. The patient suffered from spinal stenosis and degenerative changes in the knee menisci. These findings suggest that instability of the knee due to meniscal damage, and quadriceps weakness as a result of spinal stenosis, may have played a significant role in the pathogenesis of this injury.