1.  What is osteoarthritis ??
There is a smooth layer on the ends of bone called cartilage .
loss of this layer is osteoarthritis.

2.  What are the causes ??
There is no specific cause. The contributing causes areage , obesity,
abuse, previous injury or some form of metabolic disorders

3.  Are all knee pains osteoarthritis ??
NO, there are many other causes of knee pains

4.  What are the other causes ?
Focal cartilage defects , ligament injuries , meniscal injuries ,
patella femoral problems etc...

5.  How do I know I have osteoarthritis ?
Symptoms are like pain, crepitus , difficulty in getting up from floor etc

6.  If I have osteoarthritis , is joint replacement the only 
NO, depending on the stage of arthritis other treatment options are there.
option??

7.   What are they ?
Medicines and injections in early days and joint preserving realignment
surgeries in middle stage and in late stages only,  joint replacement is
done 

8.   For other causes ??
For issues with  ligament , meniscus or focal cartilage Arthroscopy i.e
key hole surgery is the treatment .

9.  are the results of these procedures good ?
These are well established and well practiced procedures all over 
the world with more than 10 yrs of good results.