Rheumatoid Arthritis – Talonavicular Joint
Edited by Daniel Guss, MD
The talonavicular joint is a joint formed by the talus, the bottom half of the ankle joint, and the foot bone immediately in front of it called the navicular. The talonavicular joint is critical in allowing the foot to move inwards and outwards, as well as in a circular motion. When this joint wears out, either because of a trauma to the joint or because of inflammation from a disease such as rheumatoid arthritis, the cartilage in this joint can wear out and become arthritic, often causing stiffness and pain.
Physical Exam and Symptoms
On routine physical exam, motion is often severely limited through the hindfoot, particularly when assessing side-to-side (inversion-eversion) or rotational movement. There may also be swelling or bogginess in the foot just below the front of the ankle as well as along the inner aspect of the arch of the foot. Patients will frequently have direct tenderness to palpation along the top (dorsal) and inside (medial) aspect of the hindfoot. Other surrounding joints may also be affected causing additional tenderness and pain.
X-rays are helpful in diagnosing this condition. As the cartilage wears out in the joint, the space seen on x-ray between the talus and navicular bone narrows and bone spurs may form (Figure 1).
Figure 1: Normal vs Arthritic Talonavicular Joint
If the arthritis in the talonavicular joint is simply due to wear and tear or trauma, lab tests are often normal. Patients suffering from RA or related immune system disorders will often exhibit abnormal lab values on blood tests, such as a positive “rheumatoid factor.” Seeking out the results of such labwork may help confirm the diagnosis of rheumatoid arthritis if it is in question.
- Comfort shoes can be helpful in the treatment of this condition. A stiff sole or shank will prevent painful motion
- Activity modification will also be helpful. A stretching program to the back of the calf can decrease excessive stress through overworked joints.
- Weight loss to decrease the force going through this area of the foot will be beneficial, though exercise can be difficult with a painful foot or ankle.
- Bracing can be helpful by preventing the in and out movement generally associated with a talonavicular joint.
- Management of other medical conditions including rheumatoid arthritis may also be helpful.
- Orthopedists should also be involved when considering external bracewear, offloading devices, injection therapy, and/or surgical intervention.
When the talonavicular joint wears out to the point where the bones rubbing create significant pain, and other measures fail, one may consider fusing the bone. This means getting the two bones to heal across the joint thereby getting rid of the joints and its ability to allow motion, but also its ability to cause as much pain. This can be achieved using metal hardware such as screws, wires, or plates. Success of this procedure requires that the bone ends heal together and, when successful, is typically a very effective and durable pain relieving procedure. The procedure does, however, restrict future motion from that joint and this can make the foot somewhat stiffer—but few patients consider this an issue given the excellent long term pain relief that can be expected from this operation. Furthermore, by the time the joint wears out to the point of needing a fusion, it is often stiff anyway.
A bone graft procedure, in which a bone or bone substitute is taken from elsewhere and placed in the talonavicular joint, is often done with this procedure to increase the fusion rate (decrease the rate of non-union – the bone note healing). Sometimes it may also be necessary to fuse other joints to improve surgical outcomes (e.g. subtalar, calcaneocuboid or cuneiform-navicular joint). The fusion procedure eliminates RA as a disease process in THAT particular joint—but does not eliminate the systemic disease process itself nor does it relieve RA as a disease process in any of the other non-operated joints. Additionally, bone quality in patients who have RA can often be diminished (osteopenia), and this may require perioperative pharmacological management to maximize the bony healing response.
Generally speaking, the routine post-operative setting mandates a minimum of 6-12 weeks in a short leg cast to allow the bones to have the best chance of healing. Patients are usually started in a non-weight-bearing setting and gradually advanced to partial and then ultimately to full weight-bearing over the course of this recovery. Following cast removal, patients can begin graduated walking in a removable boot, such as a CAM walker. At this point, physical therapy should begin, with an emphasis on strengthening, swelling control, improving the range of motion (ROM) of the other non-fused joints, and gait retraining. Patients are often dramatically better by 12 weeks postoperatively, although it will generally takes upwards of one year to reach the point of maximal recovery.
In addition to the most common orthopaedic surgical complications listed elsewhere on this website, there are certain complications which can be considered more specific to talonavicular fusion surgery. Non-union is the most common of these, due to the poor blood supply in that region and the amount of force applied to that area when walking. Another complication associated with surgery performed on patients who have RA can be soft tissue problems such as wound healing or infection, because patients who have RA may have poor soft tissues and/or are often immunocompromised from having taken multiple anti-rheumatoid drugs over time to control the systemic disease.
Edited November 24, 2018
(Previously edited Chris DiGiovanni MD and Mark Perry, MD)