Spontaneous, bilateral, quadriceps tendon rupture caused by local exposure to methidathion.

Spontaneous, bilateral, quadriceps tendon rupture is a rare injury. Many predisposing conditions have been reported that contribute to quadriceps tendon degeneration. We report a case of a 42-year-old farmer with spontaneous, bilateral, quadriceps tendon rupture and clear medical history. Clinical and laboratory investigations revealed no risk factors for tendon degeneration but the patient reported that he was exposed locally to methidathion 1 week before the rupture. Methidathion is an organophosphate insecticide commonly used in agriculture that is highly toxic via the dermal route. Methidathion induces lipid pre-oxidation and consequently alters quadriceps tendon blood supply and ultrastructure. The injury was treated with early surgical repair and final outcome was excellent 44 months postoperatively.