Rheumatoid Hindfoot Arthritis

Clinical Presentation

Patients with rheumatoid arthritis of the hindfoot will often present with swelling, pain, and deformity that localizes to the ankle and hindfoot region. Although such symptoms can be the first signs of rheumatoid arthritis (RA), these patients have usually already been diagnosed with this malady before seeking the care of the orthopaedic foot and ankle specialist. As RA has an inflammatory component, patients with focal bogginess and pain in the hindfoot are more suspicious for this condition. While pain, swelling, and deformity can be associated with other types of arthritis, (post-traumatic arthritis, osteoarthritis, septic arthritis, etc.). RA should be considered if these are ruled out particularly if significant inflammation is present. Patients often cannot discern between a problem affecting their hindfoot or their ankle, but in both cases, they are likely to point to the lateral (outside) or posterior (back) portions of the back of their ankle and hindfoot.

These symptoms are frequently worse after prolonged standing or walking, and involvement of the other side (i.e., symmetrical arthritis) is not uncommon. In more progressed cases, deformity of the ankle and/or hindfoot can exist, which usually results in a valgus malalignment. To the patient, this can look like the foot/heel is splaying outward, the foot is turning, and/or the leg is rotating. When the problem becomes severe enough, this valgus malposition can cause subfibular abutment, whereby the heel of the foot becomes so displaced that it comes in contact with the outside of the ankle. This is very painful and can be a common cause for presentation to the foot and ankle specialist.

Patients with long-standing RA, particularly those who have been medically treated are often very “tolerant of pain” and may present for the first time with more advanced stages of hindfoot rheumatoid arthritis than would be typical for other types of arthritis.

Physical Examination

Careful physical examination is an important part of this work-up for the patient, and often demonstrates swelling of the ankle and/or back part of the foot (hindfoot), associated warmth of the skin from the increased blood flow, soft tissue bogginess, and possibly even a superficial skin rash, nail changes, and hard nodules or lumps in the skin called rheumatoid nodules. These patients will also commonly demonstrate a noticeable limp and a shortened stride length because of their relative pain and deformity. In all cases, the opposite extremity should be examined for similar involvement, as should the joints both above and below these areas (knee/ankle, mid/forefoot).

Imaging Studies

When advanced rheumatoid disease is present at a level which causes the patient to seek the care of a physician, plain radiographs should be considered a routine portion of the diagnostic work-up. These x-rays usually demonstrate symmetric loss of joint space of the involved joints, often with a generalized osteopenia of the surrounding bone. There are usually very few bone spurs, although there may be evidence of erosion of the bone where the joint capsule attaches (periarticular erosions). The joints most commonly involved with rheumatoid arthritis in the hindfoot are the subtalar and talonavicular joints, often in conjunction with the ankle joint. Since polyarticular RA is common, these patients frequently present with involvement of multiple articulations as opposed to just one.

MRI can be helpful in some cases but is certainly not mandatory for making the diagnosis or providing further care in most situations. The study might help demonstrate the soft tissue component of this condition, highlighted by significant thickening and swelling of the joint capsules, with increased fluid in the involved joints. There may also be evidence of a limited blood supply (avascular necrosis) to some of the bones, such as the navicular.

Treatment

Non-Operative Treatment

Non-operative treatment can be extremely effective in many of these patients upon initial presentation, unless their disease and/or deformity is severe. The central element of successful non-operative treatment of rheumatoid arthritis affecting the hindfoot remains control of the deformity and motion and quieting down the inflammatory response. There now exists a number of effective pharmacologic agents (medicines in pill or injectable form) designed to control the inflammatory and destructive components of rheumatoid arthritis, including the use of disease-modifying agents such as antitumor necrosis factor compounds. Medications such as methotrexate may also be used to help to control the condition. Management and administration of these medications, however, should typically be overseen by a rheumatologist. The job of the orthopaedist is to utilize activity, shoe modifications, and bracing to improve pain and function.

The following nonsurgical treatments are helpful in controlling the symptoms from the involved joints:

Low impact activity modification through these involved joints will often help decrease symptoms and swelling. Often activities such as walking on uneven terrain or hard surfaces, can disproportionately aggravate symptoms, so avoidance of such situations can also be very helpful in controlling the patient’s symptoms.
Ankle/hindfoot braces or even orthotics can help limit the motion to the involved joint and, by extension, decrease the symptoms. Braces or AFOs come in a variety of styles and can help immobilize arthritic joints and control deformities.
Comfortable shoe wear will provide additional support to these involved joints and also help accommodate any prescribed brace and/or orthotic wear.

Operative Treatment

When non-operative measures fail, surgical management for RA of the hindfoot can be remarkably helpful. Although unusual, patients can occasionally present quite early in the disease process, and therefore benefit from a minimally invasive synovectomy procedure to remove the inflamed lining of the involved joint/tendons, and temporarily provide pain relief from the primary symptom-generating joint. Unfortunately, since this intervention does not stop or treat the RA specifically, the inflammatory process will often gradually recur over time. Under those circumstances, or when patients present initially with more moderate to severe rheumatoid involvement, surgery to fuse the affected joint(s) becomes very beneficial. This can be equally helpful as a durable long term solution when there is significantly debilitating deformity present. Specific choice of surgical treatment is dictated by which joints are affected by the arthritis and/or the presence of any associated deformity (ex. flatfoot).

Common variations of these procedures may include:

Talonavicular fusion, if the talonavicular joint is primarily involved.
Subtalar fusion, if the subtalar joint is involved in isolation.
Double or Triple arthrodesis Fusion of the subtalar, talonavicular, and/or calcaneo-cuboid joints is beneficial if some or all of these joints are affected by rheumatoid arthritis, by virtue of significant articular erosion (damage to the joint cartilage) or deformity.

All of the above procedures can commonly include the use of autogenous (from the patient) bone grafting or the use of other bone graft substitutes to enhance the healing potential, if deemed necessary based on the ability of the patient to heal the fusion.

Realignment procedures: It may be necessary to combine these procedures with a procedure to rebalance the position of the foot, such as a calcaneal osteotomy. This is done to allow the forces to be loaded evenly through the hindfoot after the patient has recovered from surgery.
Ankle fusion or Ankle Replacement : For end-stage involvement of the ankle joint, an ankle fusion or an ankle replacement may be indicated, but this procedure is typically considered separately from any intervention for the hindfoot joints. Unfortunately, to date there exists no successful joint replacement for any of the hindfoot joints, so when these are diseased enough to warrant surgery, the procedure of choice remains fusion rather than replacement.

Recovery

Fusion or arthrodesis surgery of one or more hindfoot joints in patients with RA is usually a highly successful operation, well received by patients as long as they heal without complication. While no fusion operation is ideal since by definition it stiffens a natural joint, in this case it is generally pleasing to patients because it still improves function. What the patients lose in motion (although many begin stiff before surgery anyway due to the disease process), they more than make up for in pain relief, deformity correction, and the ability to stand and walk for longer periods. Recovery from the surgery depends upon the particular operation, but in general fusion of these major joints requires a 3-6 week period of non-weight-bearing and casting, followed by an additional 4-6 week period of progressive mobilization in either a cast or a boot with therapy. Even though most patients are healed and weaned to a regular shoe or sneaker by 3-4 months post-operatively, it is not unusual for the patient to require one year to reach the point of maximum medical improvement. In the absence of complications, a good functional level can generally be expected once the patient is healed after hindfoot surgery.

Potential Complications

If surgery is performed, there is always a risk of complication. These may be somewhat increased in a patient with rheumatoid arthritis. It is important to coordinate surgery timing with the patient’s rheumatologist as some medicines may need to be stopped prior to surgery to minimize these risks. Although infection and wound healing issues are by far and away the most common issues associated with hindfoot surgery in patients who have RA, the most commonly encountered post-operative risks/problems in such patients are:

Edited on September 25, 2017

Previously edited by Chris DiGiovanni, MD

mf/ 5.15.18