Why Does My Foot/Ankle Hurt?

NormalRange_ToeJoints are the locations in your body where two bones meet. Movement of these bones against each other is what permits our bodies to move. Cartilage is located at end of our bones and is a smooth, slippery tissue that allows the bones to slide against one another with minimal friction.

Once cartilage is damaged, it cannot heal itself and the progressive deterioration leads to a loss of cartilage and exposed bone. Because pain sensors are located in bone and not in cartilage, it is the exposed bone that results in a painful joint.

Toe Pain

HalluxRigAny event, continued malalignment or disease process (i.e. inflammation) that injures the cartilage may cause joint damage or arthritis. A small cartilage injury may become larger and lead to widespread cartilage loss or degenerative joint disease over time. As the “wear and tear” on the MTP joint progresses, bone spurs or osteophytes can form on top of the bones. These bone spurs (osteophytes) can limit the motion of the joint because they are painful when the toe moves over them. With time, the spurs get larger, the cartilage starts to wear away and the toe becomes stiff. In the big toe, this condition is called Hallux Limitus or Hallux Rigidus.

Ankle Pain

AnkleDefect2There are a few different reasons why you may have Ankle Pain incuding diseases, trauma and arthritis. Diseases of the ankle consist of mostly of defects or damage caused by trauma or arthritis.  A defect of the talus (main ankle bone) usually involves the articular cartilage and the underlying bone and is mostly caused by a single or multiple traumatic events such as a sprained ankle in sports. Initially, the defect may consist only of cartilage damage caused by shearing stresses and the bone will be intact. However if there is a bone bruise following a high-impact force such as a motor vehicle accident, this can also cause a defect. Ankle trauma associated with a defect often leads to cysts or fluid pockets which develop inside the bone, underneath the damaged cartilage. These cysts are associated with persistent deep ankle pain which limit your ability to move or put weight on your ankle.

The defects can either heal with no symptoms or progress to deep ankle pain and/or the formation of bone cysts. The pain in the defects is most likely caused by an intermittent rise in the fluid pressure inside the bone that occurs on every step, which in turn sensitizes the nerves in the underlying bone. Cartilage has a liquid (water) and a solid component (collagen) that enables it to withstand compressive stress. A congruent joint surface, such as the ankle, is covered by thin articular cartilage. Incongruent joints (such as the knee) are covered by thicker cartilage. Fluid from the damaged cartilage can be forced into the fractured bone plate during activities such as walking, running or any movement that puts significant weight on the ankle. This intermittent rise in high fluid pressure will cause damage to the bone and the eventual formation of a cyst.