Ankle osteoarthritis
Ankle osteoarthritis is a degenerative joint condition that occurs when the protective cartilage covering the ends of the ankle bones gradually deteriorates. This chronic condition often leads to pain, stiffness, and reduced mobility, significantly affecting the quality of life of those affected. In this article, we will explore the underlying mechanisms, characteristic symptoms, and treatment options available to relieve symptoms and improve functionality in patients with ankle osteoarthritis.
What is ankle osteoarthritis?
Ankle osteoarthritis (not to be confused with ankle arthritis), just like osteoarthritis of other joints, corresponds to a significant loss of cartilage tissue in the tibia and the talus, which together form the ankle joint with the fibula.
The cartilage of the ankle is thin but robust, which may explain why osteoarthritis can often be well tolerated for a long time. The ankle supports about five times your body weight with every step when you walk normally, without running or jumping. Considering overweight or obesity is important.
Painful decompensation of ankle osteoarthritis may occur 20, 30, or even 40 years after an ankle fracture. It occurs more quickly in the case of a pilon tibial fracture or talus fracture, in the case of an open fracture or fracture-dislocation of the ankle. Unlike other joints, ankle osteoarthritis is neither primary nor essential; it is always secondary to trauma or a chronic inflammatory disease.
The symptoms of ankle osteoarthritis
The main symptoms are:
- Pain: This is mechanical pain, meaning it occurs with movement and subsides with rest. It can be more or less disabling.
It can also be inflammatory pain, meaning it gradually increases and can eventually become severe enough to cause sleeplessness in cases of chronic inflammatory involvement or during an osteoarthritis flare-up. - Stiffness: Osteoarthritis causes joint stiffness; the inflammatory state of the tissues is more significant, they thicken and become more rigid. Stiffness also causes a limitation of the joint's range of motion, acting as a natural pain-relieving mechanism.
- Deformation: When post-traumatic, ankle osteoarthritis can be deforming, into varus or valgus positions. The morphology of the knee (varus knee or valgus knee), and the morphology of the foot (high-arched foot or flat valgus foot) can contribute to the deformation.
- Thickening of the ankle: An osteoarthritic ankle is generally thicker than a healthy ankle, and it will remain so regardless of the treatment considered. This thickening involves the synovial membrane, the joint capsule, and even the subcutaneous tissues. It is important to differentiate this thickening from other causes, such as an ankle cyst, which can also cause localized swelling.
How to recognize ankle osteoarthritis?
The diagnosis of ankle osteoarthritis is initially suspected during the clinical interview, based on a history of prior trauma or inflammatory rheumatism. Physical examination typically reveals painful restriction of ankle mobility accompanied by periarticular thickening. Diagnosis is subsequently confirmed by plain radiographs of the ankle.
The cornerstone of the radiological workup in ankle osteoarthritis is the weight-bearing radiographic assessment. The following standardized protocol is systematically performed in the standing position, ensuring adequate axial loading of the joints: bilateral ankle radiographs including anteroposterior, 20° internal rotation, lateral, and Meary's bracketed views, as well as bilateral foot radiographs in anteroposterior and lateral projections.
Weight-bearing imaging is essential as axial loading of the joints highlights the areas of joint space narrowing, thereby localizing the cartilaginous lesions with greater diagnostic accuracy.
What are the causes of ankle osteoarthritis?
Ankle osteoarthritis is due to 2 main causes:
- post-traumatic ankle osteoarthritis
- inflammatory arthritis.
Post-traumatic ankle osteoarthritis accounts for 80% of ankle osteoarthritis cases. It complicates ankle fractures, fractures of the tibial plafond and talus, chronic ligament problems after recurrent sprains, and extra-articular fractures that have healed with malunion. Inflammatory arthritis represents 20% of ankle osteoarthritis cases. These types of osteoarthritis are seen in patients with chronic inflammatory diseases such as rheumatoid arthritis, psoriatic arthritis, and spondyloarthritis.
Ankle Osteoarthritis FAQ
Medical treatment with painkillers, non-steroidal anti-inflammatory drugs, icing, and temporary immobilization of the joint is the first step to ease the pain. Wearing orthopedic insoles can relieve pain in cases of reducible or partially reducible joint or extra-articular deformities. Cortisone injection under ultrasound guidance can be effective as a last resort.
Ankle osteoarthritis is a significant loss of cartilage in the tibia and the talus; it is post-traumatic, following fractures, fracture dislocations, or repeated ankle sprains. Ankle arthritis may be inflammatory, as part of inflammatory rheumatism, with cartilage damage during inflammatory flare-ups. Ankle arthritis can be septic, caused by a joint infection.
The main risk with ankle osteoarthritis is pain, any sport can be practiced as long as the pain is bearable and tolerated.