two care home workers who left a mute dementia patient in agony after she fell on the floor , then lied about what had happened , have been jailed .
ethel rider , 87 , suffered a broken pelvis and was left ` cowering ' in agony , her carers failed to seek medical help and simply lifted her back into bed .
because she is mute , mrs rider was unable to tell anyone what had happened .
it was only 24 hours later that a nurse realised she was in agonising pain and called an ambulance .
` she was left on the floor for 40 minutes .