Hello, 
Contusion is a bruise around the tissues, the tiny blood vessels break & bleed causing inflammation within the joint & structures around it. This generally occurs after a fall.
Elderly patients need therapy to preserve strength & stability. Sometimes, agony & pain, 
restlessness during the hospital stay may cause delirium in the elderly patients.
She needs immediate help from a 
Psychiatrist or a therapist/counselor so that she can take medications & therapy to stay away from developing 
dementia.
Neglect may cause dementia to complicate to 
memory loss & poorer recovery, longer hospital stay.
However, don't lose hope. People with contusion who have been diagnosed with dementia can recover. Patients have recovered their previous level of functioning. 
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Nupur K, General & Family Physician