It would be comfortable and really convenient if you had your knees for almost any form of everyday movement like walking, running, climbing stairs etc. Your knee is the largest joint your body and connects three bones – the Femur, Tibia and Patella. This complex joint bears most of your body weight, which is why it degenerates gradually as you age and becomes prone to injuries. 
Here are a few examples of common knee injuries seen in older people:

1. Fractures: The most common fracture is that of the Patella or knee cap. Osteoporosis is a common cause of knee fractures in the elderly as this condition causes bones to become weak and brittle.

2. Meniscal tear: The Menisci are two rubbery wedges of cartilage between the thigh boneand shin bone. These menisci can suddenly tear due to ageing. A Meniscus tear due toageing is often referred to as Degenerative Meniscus Tear.

3. Anterior Cruciate Ligaments (ACL): The ACL is a ligament that joins the upper and lowerleg bones and keeps the knee stable. ACL tears are commonly seen in athletes. However,older people are also prone to these injuries with trivial falls.

4. Bursitis: Bursae are tiny fluid-filled sacs that cushion the knee. The inflammation of theseBursae – Bursitis – can result in swelling and stiffness in your knees.

5. Tendon tears: Tendons are soft tissues that connect the muscles to the bones, and a tearin these tendons is often caused due to different physical activities that overstretch thesetendons.

Any of the injuries mentioned earlier can be a cause of concern in the elderly, and you should consult a doctor if you experience knee pain for over a week and face difficulty doing simple everyday movements.