An elderly lady felt a 'snap' at the back of her leg while exercising.
There is a discontinuity seen in the achilles tendon with a hypoechoic gap present between the tendon ends. The tendon lacks the usual taut appearance, instead appearing think and 'wavy'. Echogenic fibrin can be seen in the second image. The lack of continuity of the two ends is seen in the loop.
If there is prominent fibrin deposits or significant tendinopathy (a risk factor for rupture) then the clear ends and hypoechoic gap may not be seen, instead edge shadowing from the ruptured ends may be more prominent. The lack of continuity of the two ends can be seen while performing the Simmonds (Thompson) test or by gentle plantar and dorsiflexion.