Arthritis is the inflammation and swelling of the tissues surrounding the joint with the associated deterioration of the cartilage. There are many types of arthritis, but only three main types commonly occur in the foot, osteoarthritis, rheumatoid arthritis, and gouty arthritis. This page will focus on osteoarthritis.
Osteoarthritis is the breakdown of the cartilage within the joint. The joint cartilage is a spongy tissue that covers the ends of the bones in a joint. Healthy cartilage helps with shock absorption and allows the bones to glide over each other. When the cartilage wears down, this exposes the underlying bone.
This causes painful and limited joint movement. Bone spurs may develop on the surrounding joint area. Inflammation is not believed to play much of a role in osteoarthritis. Mouse over the image to the right to see the deterioration in the joint.
The intra-operative image to the left shows a defect in the cartilage in the 1st MPJ, metatarsal phalangeal joint. A cartilage defect is an area of cartilage that has been damaged.
Osteoarthritis may appear similar or may appear as smaller lesions that are more diffuse or widespread. The cartilage may only be thin, as opposed to an isolated complete loss of cartilage as seen in this image. Isolated cartilage defects are treated much differently than widespread osteoarthritis. Mouse over the image to see the area highlighted.
Causes of Foot Arthritis
There are many causes of osteoarthritis: Arthritis of the 1st MPJ Great toe joint
• faulty foot mechanics
• maligned joint
One of the most common areas in the foot to develop arthritis is the big toe joint. The cause is generally due to faulty foot mechanics. A combination of tight calf muscles, over-pronation, and too much forefoot mobility can lead to jamming at the big toe joint and eventual arthritis.
This condition is called hallux limitus or hallux rigidus. The hallux is the medical term for the big toe. Limitus and rigidus describe the limited joint motion and the rigidity of the toe. In the X-ray on the right, there is both losses of joint space and a build-up of bone around the joint. Mouse over the image for a close-up of arthritis.
Arthritis also occurs commonly in the middle of the foot. In the X-ray to the right, there is no visible space between the bones in the middle of the foot. The joints in the middle of the foot have deteriorated and the surrounding bones have developed cysts in them. This is an example of severe midfoot arthritis. Mouse over the image to see close-up views and labels of normal joint space and an arthritic joint.
The most important treatments for osteoarthritis in the foot are:
1. Controlling abnormal motion in the foot.
2. Protected activity and movement of the joint.
If there are faulty foot mechanics which have contributed to the development of arthritis, it is important to control the abnormal motion with orthotics, to prevent further joint deterioration. Once arthritis has developed, it is important to continue to move the joint.
A supportive, rigid shoe with limited flexibility and will help to decrease the stress through the midfoot and the great toe joint.
Osteoarthritis is not an inflammatory disease, but anti-inflammatory medications will help decrease surrounding inflammation and minimize some of the pain. They should be reserved for episodes of pain, as opposed to long-term therapy.
For ankle arthritis, an AFO brace (ankle foot orthosis), may reduce pain while allowing for more ambulation.
The last resort is surgery. There are many options for surgery on an arthritic joint. Bone spurs can be removed from the joint and the joint can be drilled to stimulate new cartilage growth. The joint can be removed or replaced and the joint can be fused.
The type of procedure depends on the person, their activity level, the strength of their bone, and their pain level. If there is no pain, then no surgery should be performed. If the pain is limiting daily activities, then some type of procedure should be considered, but only after conservative therapy has failed.
The most definitive procedure is joint fusion. A joint fusion involves removing the cartilage and holding the two bones together with screws and/or a plate. The two bones eventually grow together and become one bone. The idea of fusing a joint is not an idea which appeals to most people. But, joint fusions tend to eliminate pain and return function to the foot. A joint fusion can be a very effective procedure.
Example of a joint fusion:
Osteoarthritis of the great toe joint Fusion of the great toe joint for arthritis arthritis-fusion3.jpg arthritis-fusion4.jpg
The arthritic joint before surgery. The joint is pulled apart to visualize the cartilage. The bone spurs around the joint are removed. The cartilage is scraped off the surface to expose the bone.
arthritis-fusion5.jpg arthritis-fusion6.jpg arthritis-fusion7.jpg arthritis-fusion8.jpg
The joint, without the cartilage, is re-approximated. A screw is placed across the joint to prevent movement. A second screw is placed across the joint. Bone fills in and replaces the joint. The joint no longer moves.
X-ray of great toe joint fusion with screwsIn the radiograph to the right, the screws can be visualized crossing the big toe joint after the fusion has been performed.
The recovery time depends on the joint fused. A cast boot and 6-8 weeks of crutches can be common for many procedures. Full recovery time can take 6 months, and for the swelling and pain to decrease, sometimes up to a year. Joint fusion is not the only surgical option, it is recommended to talk with your doctor about which option is the best for you.