Pain on either sides of the knee is usually related to meniscal tears, injuries to the collateral ligaments, and even to
arthritis. Pain in the back of the
knee can be caused by
arthritis or Bakers cysts (cystic accumulation of synovial fluid, also causes a swelling). So as you can see, arthritis can cause an overall knee pain. Ligament injury causes pain to worsen on walking, bending and stretching the knee.