Spontaneous and simultaneous rupture of both quadriceps tendons.

The seventh case known to be reported in the literature on simultaneous rupture of both quadriceps tendons occurred in a 60-year-old man with diabetes mellitus. The patient was treated by surgical repair of both tendon ruptures with a satisfactory return of function. Diabetes mellitus may be a predisposing condition for the bilateral rupture, but does not prevent either the tendon or wound from healing.