Ankle arthritis can follow any damage to the joint, such as a single injury (fracture, for example), repeated minor trauma (recurrent ankle sprain, for example), or any other insult to the joint. Degenerative joint disease may be the end stage of ankle arthritis.
As with arthritis in other joints, the hallmarks of ankle arthritis are:
- Swelling and warmth
- Limitation of motion
- Altered function
Pain is mostly anterior to the ankle joint. Pain that is worse early in the morning is suggestive of rheumatoid arthritis (RA); pain that is worse at the end of the day is suggestive of osteoarthritis. Plantarflexion and dorsiflexion of the ankle worsen the pain, with dorsiflexion usually affected first.
Determining whether the patient has a history of previous injury, malalignment, or constitutional symptoms such as fever or a positive family history of gout or rheumatologic problem such as RA can be very helpful in the diagnosis ankle arthritis. The physician must always be aware that monoarthritis can be the first manifestation of a generalized joint disorder.
As with arthritis of other joints, certain factors determine pathogenesis and progression. Age, weight, joint morphology, genetics and environmental factors are important determinants in ankle arthritis. However, osteoarthritis presents less commonly in the ankle than in other lower limb joints.
Pathology and pathophysiology
Any direct or indirect damage to the joint cartilage can lead to ankle arthritis and cause osteoarthritis at the end. The development of joint destruction can be considered in five stages:
- Breakdown of articular surface
- Synovial irritation
- Impaired remodeling
- Eburnation of bone (bony sclerosis)
The smooth articular cartilage is injured and becomes rough like a shaggy carpet. Friction against the rough surface generates cartilage particles that are absorbed by the synovium, where they cause an inflammatory response. Irritation of the synovium can produce degradative enzymes and mediators that may influence chondrocyte activity; limited cartilage remodeling can occur. With chronic and deep erosion of articular surface and exposed subchondral bone, synovial fluid enters the cancellous bone and produces cavities (cyst) that are filled with fibrous tissue (sclerosis) and lined with a thin shell of cortical bone.
The joint becomes stiffer, more painful, and more deformed as the condition advances.
Common causes include:
- Primary osteoarthritis
- Post-traumatic arthritis
- Rheumatoid arthritis
- Neuropathic arthritis
- Pigmented villonodular synovitis (PVNS)
- Synovial chondromatosis
- Septic arthritis
Radiographic and laboratory findings
Laboratory tests have little value unless inflammatory arthritis, gout, or infectious arthritis is suspected. Complete blood count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein level (CRP) are the routine tests to check an infectious source. To diagnose a rheumatoid condition, serum anti-cyclic citrullinated peptide antibody and interleukin-6 are superior to rheumatoid factor.
Imaging evaluation is useful to confirm a clinical diagnosis and to narrow the differential diagnosis. The standard X-rays include standing AP, lateral, and mortise views of the ankle. Common findings on plain radiographs include osteophytes, subchondral cysts, and joint space narrowing.
CT scan can more accurately visualize the bony pathologies with arthritis, and MRI can detect soft tissue and chondral lesions earlier and with greater accuracy.
The goals of treatment are to reduce pain and to improve function. Non-steroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and occasionally narcotics can reduce pain in mild to moderate arthritis. Corticosteroid injection is helpful for short-term relief, and hyaluronic acid injections have produced symptomatic relief in ankle arthritis.
Leg muscle atrophy has been noted in patients with ankle arthritis. Physical therapy is helpful early in the course of ankle arthritis to maintain range of motion and strength. General exercise to maintain body weight is recommended. A body mass index of less than 25 kg/m2 can minimize damage over time from excessive force due to body weight.
Stabilization of the ankle with an ankle support, whether soft neoprene or rigid ankle foot orthoses (AFOs), can reduce pain and improve walking. A double upright PTB brace can reduce the normal pressure through the ankle joint. A less-expensive way to reduce load across the ankle is an energy-absorbing heel placed on a shoe. The prototype shoe modification is SACH, solid ankle-cushioned heel; a soft wedge-shaped heel cushion may act in a similar fashion.
Ankle arthroscopy is a useful procedure to treat and possibly prevent ankle arthritis. Synovectomy, debridement of soft tissue impingement or meniscoid lesions, loose body removal, repair of osteochodral lesions, excision of osteophytes, and chondroplasty can be useful procedures for patients with ankle arthritis.
In ankle arthritis with tibial deformity, correction of the alignment is essential to improve the pain by altering distribution of load to healthier parts of the joint. The ideal patient for this procedure is a young patient with varus or valgus ankle deformity and mild to moderate arthritis. The osteotomy should be done at the center of rotational angulation (CORA) to achieve the maximum correction. The CORA is the intersection of the two lines that define the deformity, lines that are drawn to represent the mechanical axis of the proximal and distal segments. The correction can be achieved with a single opening or closing wedge osteotomy or by a gradual correction with distraction using an Illizarov device.
Distraction arthroplasty is based on the hypothesis that healing of arthritic cartilage can occur when the joint is unloaded and subjected to intermittent intra-articular fluid pressure changes. Unloading is achieved with an articulated ring external fixator, which is applied for three months to distract the joint. It is indicated in patients younger than age 50 with end-stage osteoarthritis being considered for arthrodesis or replacement, who have failed a minimum of 6 months of conservative treatment.
Fusion of the tibiotalar joint has been shown to be one of the most predictable methods of treating painful arthritis of the ankle. Although there are numerous methods for creating a stable arthrodesis, the relief of painful symptoms once fusion is achieved has proved to be consistent. The decision on whether to perform open or arthroscopic ankle fusion relies on both patient and surgeon factors. Arthroscopic fusion is best reserved for ankle osteoarthritis without large bone defects and malalignment. The optimal position for ankle fusion is 0 degrees of flexion, 0 to 5 degrees of valgus, and 5 to 10 degrees of external rotation with slight posterior displacement of the talus. Most current techniques of ankle arthrodesis achieve fusion in 80% to 90% of patients. Biomechanical studies have shown that three screws are stronger construct than are two screws for tibiotalar fusion.
The ideal patient for this procedure is a lightweight, sedentary, older patient with end-stage ankle osteoarthritis who has minimal deformity, good range of motion of the ankle, and a good soft-tissue envelope. Fixed-bearing implants have shown disappointing results and are known to have a high rate of early failures. This elevated failure rate is caused by both the high stresses across the ankle joint and a lack of adequate implant motion, each jeopardizing implant fixation and resulting in polyethylene wear and early component loosening. To help counter these problems with total ankle replacement, Buechel and Pappas developed the mobile bearing total ankle system. More recent designs with mobile bearing surfaces have improved the outcome of total ankle replacement.
Symptoms of pain and disability relating to ankle arthritis can be controlled with early diagnosis and appropriate intervention to correct specific causes such as cartilage damage, ankle instability, infection, gout, or rheumatoid arthritis. Unfortunately, a large number of patients may progress to altered joint mechanics and osteoarthritis of the ankle joint, requiring additional treatment and intervention.
Holistic medicine recognizes a multiplicity of causes for arthritis, including diet, nutritional deficiencies, environmental toxins, a weakened immune system, joint stress, liver or intestinal toxicity (dysbiosis), and constitutional predispositions (miasms). A combination of natural therapies can offer benefits for patients without the weakening effects of symptomatic drugs. Different remedies can be used in different phases of arthritis:
- Acute inflammation — aconitum, belladonna, apis, bryonia
- Chronic inflammation — rhus tox, rhododen, ledum
- Degenerative changes — ruta, calcarea carbonica, causticum
Ankle arthritis, osteoarthritis, arthropathy
Skills and competencies
- History taking — pain (location, severity, timing ), previous injury, family history
- Physical exam of the ankle — tenderness, deformity, stability tests
- Interpretation of plain radiographs of the ankle joint