Arthritis means inflammation of the joints. Osteoarthritis is the most common of many different forms of arthritis and results from the normal aging process and use of the joints. It is also known as degenerative joint disease. It usually develops slowly over the course of many years, although some conditions may cause it to develop more quickly. Ankle osteoarthritis is usually the result of a previous injury to the ankle.
At the points where bones meet to form joints there is a cushion of rubbery, smooth cartilage that protects the ends of the bones and, in the case of articular joints (where the bones form a movable joint) allows the bones to easily glide over each other. With time and use, or traumatic damage, the cartilage becomes thinner, rougher, and more brittle. Eventually a point is reached where the bone ends are no longer fully protected and they begin to rub against the roughened cartilage or each other. This friction causes inflammation and pain in the joint. As the osteoarthritis progresses the joint becomes less mobile and may become deformed, resulting in loss of full function. Due to insufficient blood supply, cartilage is not able to repair itself.
The ankle actually has three joints. The inferior tibiofibular joint is the connection between the lower parts of the tibia (shinbone) and fibula (the outer bone of the shin). The talocrural joint, often called the true ankle joint, is formed where the distal ends of the tibia and the fibula enclose the upper surface of the talus (one of the bones in the hind part of the foot). Under the true ankle joint is the third joint, known as the subtalar joint, where the talus rests on top of the calcaneus (heel bone).
As described above, osteoarthritis of the ankle develops primarily as a result of a previous ankle injury, for example a bone fracture. The articular cartilage may have been damaged directly, during the initial injury, or the injury may have caused a difference to the mechanical function of the joint, setting up abnormal stresses on the joint.
Some conditions, for example being flat-footed, may predispose a person to ankle osteoarthritis, and carrying excess weight places increased strain on the ankle joint, which may lead to the development of arthritis.
A family history of ankle osteoporosis will increase your risk of developing it as there appears to be a genetic component to the disease.
- Pain in the ankle. At the start of the disease pain is usually present only when first moving, for example first thing in the morning. It may improve with continued movement but, as the condition progresses, pain may become constant and debilitating.
- Loss of flexibility in the ankle
- Joint stiffness and swelling
- Reduced ability to bear weight on the ankle
- In severe cases bone deterioration leading to deformity of the joint
Your doctor will take your full medical history and ask you questions relating to your general health and activity level, any family history of osteoarthritis, any past ankle injuries, and your current condition and symptoms. Your ankle will be visually assessed for swelling and deformity, and physically examined and manipulated to evaluate the level of strength, stiffness and disability. Your doctor will listen for crepitus, which is a grinding noise commonly heard when bones rub directly against each other. You may be asked to walk so the doctor can assess your bone alignment and your particular gait.
X-rays will be taken to view the condition of the bones. An MRI (magnetic resonance imaging) scan might be taken to look at the soft tissues of the ankle joint, for example, the articular cartilage and the ligaments and tendons. Bone scans may also be performed if your doctor thinks it necessary.
Treatment for ankle osteoarthritis is usually non-surgical and is aimed at reducing painful symptoms and maintaining or improving joint function.
Over the counter non-steroidal anti-inflammatory medicine (NSAIDs) and pain medication such as acetaminophen (Tylenol) will help reduce your symptoms. Your doctor may inject the ankle with a steroid that can provide rapid relief. These injections can be very effective but due to potentially serious side effects cannot be administered often.
An ankle brace or an AFO (ankle-foot orthosis) can help support your ankle joint and reduce pressure on the bones.
Wearing supportive shoes that are correctly fitted will ensure that your ankle is maintained in a correct position and abnormal force is not being placed on the joints. Low wide heels that can be laced up are preferable to open shoes, sandals or slippers. Heels that are slightly rounded at the back can help you walk more easily. Heel inserts can be used to help cushion shock as you walk, as can high quality insoles.
If you are overweight, making an effort to lose some weight can relieve stress on the ankle joints, which carry almost all the body weight.
Nutritional supplements such as glucosamine or chondroitin may support normal joint function.
Physical therapy, including exercises to strengthen and increase the mobility of the ankle, will enable you to move your ankle more freely.
If surgery is necessary your doctor will discuss the options available and make recommendations based on your particular condition. One possible procedure is called arthrodesis, which permanently fuses some bones together. Normal ankle function would be lost, but the bone fusion would prevent further painful movement of the bones against each other. Another, rare, surgical option is joint replacement. In this case damaged parts of the joint would be removed and replaced with artificial implants.
Your doctor or physical therapist will probably suggest some exercises for you, and you should always seek medical approval before beginning an exercise program. In general, you should try to strengthen the muscles of the foot and ankle to help support the joint, and to increase the range of motion of the ankle. Non-weight-bearing exercise such as swimming and cycling can be helpful. Activities that cause increased pain should be eliminated.