Hi,
The knee pain can be due to bony involvement- weak bones, infection, degenerated bones/ inflammations bursae or ligaments around joint/ torn ligaments in joint /reduced fluid in the joint / simple calcium and vitamin D deficiency. Whatever the cause your knee is not able to bear your weight making it a point of concern.The pain radiating down is due to pressed
nerve (which supplies the calf) by joint.
In such condition, you need assessment of the joint condition by investigation like MRI. This will reveal the cause and facilitate specific management (which could be
NSAID drugs, calcium, vitamin D and
glucosamine supplements / physiotherapy/ surgery). In acute pain you should give rest to the joint.
Use hot or
cold pack/ take pain medicine like
Ibuprofen over the counter till you can get appointment of an orthopedic knee specialist. Reducing weight by diet control and yoga exercises/ walking when possible would facilitate the relief.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Vasudha Jayant Athavale