[Experimental tear fractures of the tendinous insertion of the os calcis (author's transl)].

Tear fractures of the os calcis are rare. If they do occur, the cause may be osteoporosis. This could be proved in an experimental study rupturing the achilles tendon. Usually, the tendon is the weakest link in the muscle-tendon-bone-chain. In case of osteoporosis, the insertion of the tendon is more vulnerable.