[A differential diagnosis of quadricipital amyotrophy syndrome: bilateral disinsertion of the quadriceps tendon].

When it occurs bilaterally, disinsertion of the quadriceps tendons may suggest quadricipital amyotrophy syndrome. Questioning and physical examination of the locomotor system usually lead to a diagnosis of mechanical lesion involving the extensor mechanism of the knee. If necessary, this diagnosis can be confirmed by ultrasonography and MRI of the knee. A search for predisposing factors may result in a specific treatment, but only surgery provides functional improvement.