Essential Insights On Managing The Rheumatoid Foot

Given the challenges that rheumatoid arthritis can pose with lower extremity deformities, this author reviews essential diagnostic considerations, offers a primer on common arthritis medications and potential side effects, and provides pertinent insights on surgical procedures that may have an impact.

Rheumatoid arthritis (RA) is a seropositive immunological disease of the body that often manifests in the foot with significant deformities and is estimated to affect 1 to 2 percent of the population. It is a progressive, debilitating disease that can present in the skin as ulcerations, in the subcutaneous tissues as rheumatoid nodules, in the blood vessels as rheumatoid vasculitis, and in the eyes, kidneys and liver.

   In our practice, we estimate that 25 percent of RA positive patients present with significant foot and ankle problems. At any one time, nearly 50 percent of patients with RA have active symptoms involving the foot and ankle.1

   Rheumatoid arthritis can have a “classic” presentation with hypertrophy of the metatarsal heads, pain and clawtoes. The chronic RA patient will have lesser metatarsophalangeal joint (MPJ) deformities and the disease often manifests with polyarthropathy. When faced with a multitude of symptoms and deformities, the foot and ankle surgeon can find RA to be challenging.

   Among the general population, women are more frequently afflicted with RA than men. Typically, the patient is an older female who presents with generalized aches and pains, often with severe pain lingering in the foot. The patient also has difficulty walking and getting shoes fitted. The patient’s feet can look like those of a typical bunion patient with intractable porokeratosis (IPKs) or have the characteristic look of degenerative joint disease (DJD) of all the lesser metatarsal joints and rearfoot. Patients often state their chief complaint as their feet being deformed and having seen their parents and grandparents suffer from this deformity. While the disease occurs most often in adults, it can manifest in a childhood form.

Salient Diagnostic Insights

Rheumatoid arthritis in the foot has a classic appearance both clinically and radiographically. Clinically, the appearance of a patient with RA may include multiple metatarsalgia (often “lumps and bumps”) with prominent, hypertrophic metatarsal heads and limited range of motion at the ankle. The patient often complains of pain and swelling that are not relieved by narcotic analgesics.

   Other RA deformities include hallux rigidus, clawtoes and digital deformities such as overlapping digits. There is usually an equinus present and the patient often cannot dorsiflex the foot, sometimes due to a talonavicular spur that limits range of motion. The midfoot and rearfoot are usually affected with arch collapse and one may see a rocker bottom deformity in late stages of the disease.

   Synovitis is usually a pathognomonic sign and biopsy is helpful in this regard. Articular cartilage degenerates and one sees attenuation and non-functional tendons, often swollen with tenosynovitis. Imaging techniques such as magnetic resonance imaging (MRI), computed tomography (CT) and bone scan can be very helpful in making a definitive diagnosis.

   Radiographically, RA presents with subluxation and dislocation of the lesser MPJs. When there is a high index of clinical suspicion of RA, the medical management team often diagnoses RA via laboratory analysis with many proprietary labs offering an “arthritis panel” to test patients with an analysis of lab data such as rheumatoid factor (RF), antinuclear antibodies (ANA), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).

   In addition to lab values, a high degree of suspicion is warranted when a patient presents with painful nodules, deformities, swelling, indurations and crepitus. Many patients present with weakness, fever, myalgias and a generalized feeling of “not feeling well.” Furthermore, patients may present with respiratory conditions, back pain, neuritis and gastrointestinal symptoms. These signs and symptoms can easily be misdiagnosed as ailments such as systemic lupus erythematosus, Reiter’s syndrome, Sjogren’s syndrome and fibromyalgia. Hence, it is of the utmost importance to diagnose and treat this disease in communication with a medical management team.

   Some of the common differential diagnoses include: psoriatic arthritis, gout, fibromyalgia, other myalgias, systemic lupus erythematosus and other rheumatologic disorders. Often a full workup, including lab data, X-rays, MRI, nuclear medicine scans and joint aspiration, will assist in formulating a diagnosis. Bone density tests such as dual-energy X-ray absorptiometry (DXA) is sometimes useful to differentiate between osteopenia and RA.

Keys To Initial Podiatric And Medical Management Of RA

Initial podiatric management includes offloading the forefoot from shearing forces. One can accomplish this with well-fitted shoe gear such as an extra depth shoe, orthotics or custom braces.

   If the initial podiatric management is not successful, medical and surgical intervention is required, often in conjunction with a medical management team that includes a specialist such as an internist or rheumatologist. When conservative measures fail, Lawry and colleagues note that “approximately 20 percent of all procedures for RA are performed on the foot.”2

   One can institute the medical treatment of RA with a Medrol® Dosepak or nonsteroidal anti-inflammatory drug (NSAID) of choice, and appropriate referral to a rheumatologist or internist for “disease altering drugs.” Physicians can control the pain with bracing and narcotic analgesics if the pain is severe.

What You Should Know About DMARDs And Biologic Medications

The rheumatologist may prescribe disease modifying anti-rheumatic drugs (DMARDs), which can be life changing and induce remission. The DMARDs will alter the disease by slowing the progression of the joint damage. These drugs are immune modifiers.
Methotrexate (Rheumatrex®, Dava Pharmaceuticals) is one of the most commonly prescribed DMARDs. This medication has side effects such as gastrointestinal disturbances and liver disturbances, and is known to cause birth defects. Patients on methotrexate require regular lab work to ensure careful monitoring and check for blood and bone marrow dyscrasias. Often folic acid such as Metanx™ (Pamlab) is useful in conjunction with methotrexate to decrease side effects. One may use methotrexate both in adults and children.

   Biologics include etanercept (Enbrel®, Amgen/Pfizer), adalimumab (Humira®, Abbott Laboratories), abatacept (Orencia®, Bristol-Myers Squibb), infliximab (Remicade®, Centocor Ortho Biotech), rituximab (Rituxan®, Genentech), certolizumab pegol (Cimzia®, UCB) and golimumab (Simponi™, Centocor Ortho Biotech). Patients take these drugs parenterally and under careful supervision to avoid extravasation into surrounding soft tissues. These drugs are often said to “neutralize” the body’s immune response to this immunological disease.

   The foot and ankle surgeon needs to be aware that the biologics can increase the incidence of infection. When preparing a patient for surgery, it is important to minimize the effects of the biologics in an attempt to minimize infection. Patients often stop taking these drugs six weeks prior to surgical intervention and take pre- and postoperative antibiotics to prevent infection. A similar issue occurs with patients on long-term oral steroids.

   Other older medications that are still useful in the treatment of rheumatoid arthritis include hydroxychloroquine (Plaquenil®, Sanofi-Aventis) and sulfasalazine (Azulfidine®, Pfizer). Podiatric surgeons should be aware that hydroxychloroquine has known ocular side effects. Another treatment for lesser forms of RA is minocycline although this drug has vestibular side effects that may affect balance postoperatively. The foot surgeon should be aware of this side effect when allowing the patient to ambulate. Leflunomide (Arava®, Sanofi-Aventis) works effectively with or without methotrexate, and has a similar side effect profile. Cyclosporine (Neoral®, Novartis) is potent and decreases joint damage, but is often a drug of last resort. One may use azathioprine (Imuran®, Prometheus Labs) in this scenario.

   Physicians who use these medications strive for remission in the patient with RA. For all patients with RA who have been on these drugs, the preoperative assessment should include a complete hemogram and platelet count.

Essential Insights On Surgical Treatment Options

   When it comes to surgical management, the focus is on resecting the offending bone, generally via a resection arthroplasty. Researchers have noted numerous other procedures including: Keller arthroplasty combined with resection of lesser MPJs; metatarsal head resection with resection of dislocated bases of the proximal phalanx of lesser toes; MPJ resection combined with relocation of the plantar fat pad; and implant arthroplasty of first MPJ joint combined with resections of the lesser MPJs.3-6

   Rheumatoid arthritis often affects the ankle. If conservative treatments such as bracing and offloading fail, surgical intervention is required. If symptoms are mild, early surgical intervention may include ankle arthroscopy with synovectomy.

   When there are severe osteophytes and ankylosis, ankle fusion again is the surgical treatment of choice. Surgeons can achieve ankle fusion using fixation with two crossing screws, an Ilizarov frame or an intramedullary nail. The goal of surgery is to create a stable construct for plantigrade ambulation with complete fusion of the joint.

   The surgeon or the rheumatologist needs to check the cervical spine as this is often involved and will interfere with general endotracheal anesthesia. The rheumatologist should conduct a joint survey to see if certain locations, such as the back, elbows or neck, require extra padding on the OR table. In addition, many of these patients have adrenal suppression so discuss the use of steroids postoperatively with the rheumatologist managing the patient. Often, patients need a postoperative dose of IV steroids to counteract adrenal suppression.

   When the hindfoot is involved, triple arthrodesis is often the necessary treatment of choice. The surgeon needs to be sure to perform a “neutral” triple arthrodesis as there is often heel valgus that one should not overcorrect to bring the hindfoot to a neutral position. Typically, one uses two screws for the subtalar joint, one to two screws for the talonavicular joint (it is the hardest to fuse), along with a four-hole locking or compression plate. Fixate the calcaneocuboid joint with one screw and a four-hole compression or locking plate for stability.

   There are many other modalities for fixation including compression staples, a combination of internal and external fixation, and keeping patients non-weightbearing. Often, a tendo-Achilles lengthening or gastroc recession is needed to reduce the equinus deformity and an antalgic gait.

   The surgical plan generally involves a Keller arthroplasty for the first MPJ with an external 0.062-inch Kirschner wire.7 Initially pioneered by Hoffman in 1912, this has led to numerous procedures and modifications.8 Many surgeons opt to fuse the first MTP joint. However, this requires extensive non-weightbearing precautions, which, in turn, can cause pain in other joints of the body. Therefore, it is recommended to use caution before opting to fuse the first MPJ unless the joint is unstable. The surgeon should address the lesser metatarsals via resection arthroplasty (panmetatarsal head resection) with K-wires although the fifth MPJ does not require a K-wire. This is up to the surgeon’s preference.

   Be sure to evaluate or have the cervical spine evaluated. Manage corticosteroids and disease altering drugs to avoid infection. It is useful to employ preoperative antibiotics such as cefuroxime (Ceftin, GlaxoSmithKline) 1.5 g one hour preoperatively and two to three hours postoperatively. I do not typically discharge my patients with oral antibiotics although this is up to surgeon preference. Pain management is important and can occur with peripheral blocks or a pain pump implanted by the surgeon.

   The use of platelet-rich plasma (PRP) is very useful in my hands. We find this creates hemostasis, reduces inflammation and reduces swelling. In addition, many surgeons apply a temporary (disposable) wound VAC to keep the swelling down or a final layer of bandage with an Unna boot dressing.

Case Study: When A Patient With Mild RA Presents With Prominent Metatarsal Heads And Severe IPKs

The patient is a 68-year-old woman with “mild” RA. Another physician previously performed a Chevron bunionectomy, an elevational second metatarsal osteotomy and extensor release of the second MPJ. She developed increasing prominent metatarsal heads and severe IPKs. She had predislocation syndrome, an elevated second toe and an increasing painful hallux limitus/rigidus.

   I performed a complete history and physical examination. Other comorbidities included hypertension and low back pain. She was taking prednisone and oral NSAIDs for her RA. Her vital signs were stable. It was her choice to not undergo any further conservative care and opt for surgical correction.

   I modified the approach in this foot due to prior surgery. In light of her previous second metatarsal surgery, radiographs demonstrated a second metatarsal nonunion (fixated with cerclage wire). Our approach was to address the first ray. Management of the first MPJ is controversial, according to Coughlin.9 I performed a Keller arthroplasty/ bunionectomy with removal of hypertrophic synovial tissue and hourglass capsule repair.

   A 0.062-inch K-wire provided stability for four to six weeks. I instilled PRP into the pseudo-joint prior to closure and used platelet-poor plasma in the subcutaneous layer.

   Vandeputte and colleagues compared patients undergoing a Keller-Lelièvre arthroplasty of the first MPJ with patients undergoing a Hoffmann resection of the lesser metatarsal heads.10 The authors found no difference in functional results between the two groups except toe strength, which was greater after fusion. Ninety-three percent of the Keller group were satisfied in comparison to 87 percent of those who had the Hoffman resection.

   Rather than using the second/third web space approach to remove the second and third metatarsal heads, I used a standard approach over the second MPJ to take down the nonunion. This approach gave us better access to the second MPJ to perform joint resection of the second metatarsal head and remove the nonunion. I used a post-osteotomy technique to elevate the bone with an osteotomy and rotate it out gently with a towel clip and scalpel to preserve viable soft tissue attachments. I removed damaged synovium as necessary.

   I removed the third and fourth metatarsal heads via an incision between the third and fourth web spaces. I again placed PRP into each wound prior to closure and utilized K-wires for the second, third and fourth metatarsals.

   I addressed the fifth metatarsal via a lateral approach to avoid skin necrosis and this metatarsal was not pinned. I applied a soft dressing and used an Unna boot dressing to reduce the swelling.

In Conclusion

Significant deformities can result from rheumatoid arthritis. In addition to performing the appropriate diagnostic workup, podiatric physicians should work in concert with a rheumatologist and have a strong understanding of arthritis medications and appropriate preoperative measures to help prevent side effects such as infection.

   In addition to these measures, proper procedure selection and post-op management can help facilitate favorable outcomes for our patients.

   Dr. Gordon is in private practice at Foot Care Associates in Houston and Sugar Land, Texas. He is the former Chief of the Podiatry Section in the Department of Surgery at Memorial Hermann Hospital Southwest in Houston. He is a Fellow of the American College of Foot and Ankle Surgeons, and is board certified in foot and ankle surgery.

   The author thanks Joyce Lee, DPM, for her review and suggestions for this article.

   For further reading, see “A Guide To Perioperative Management Of The Rheumatoid Patient” in the September 2010 issue of Podiatry Today and “What You Should Know About New Antirheumatic Medications” in the April 2005 issue.

References:

1. Hamalainen M, Raunio P. Long term follow up of rheumatoid forefoot surgery. Clin Orthoped Rel Res 1997; 340(7):34-38. 2. Lawry GV, Fan PT, Bluestone R. Polyarticular vs. monoarticular gout: a prospective, comparative analysis of clinical features. Medicine 1988; 67(5):335-343. 3. McGarvey, SR, Johnson, KA. Keller arthroplasty in combination with resection arthroplasty of the lesser metatarsophalangeal joint in rheumatoid arthritis. Foot Ankle 1988; 9(2):75-80 4. Clayton ML, Leidholt JD, Clark W. Arthroplasty of rheumatoid metarsophalangeal joints (an outcome study). Clin Orthop 1997; 340(7):48-57. 5. Cracchiolo A, Weltmer JB, Lian G, Dalseth T, Dorey F. Arthroplasty of the first metarsophalangeal joint with a double-stem silicone implant (Results in patients who have degenerative joint disease failure of previous operations, or rheumatoid arthritis). JBJS 1992; 74(4):552-563. 6. Moeckel, BH, Sculco TP, Alexiades MM, Dossick PH, Inglis AE, Ranawat CS. The double stemmed silicone rubber implant for rheumatoid arthritis of the first metarsophalangeal joint (Long term results). JBJS 1992; 74(4):564-570. 7. Hulse N, Thomas A. Metatarsal head resection in the rheumatoid foot: 5-year follow-up with and without resection of the first metatarsal head. JFAS 2006; 45(2):107-112. 8. Hoffman P. An operation for severe grades of contracted clawed toes. Am J Orthop Surg 1912; 9:441-449. 9. Coughlin MJ. Rheumatoid forefoot reconstruction (A long term follow up study). JBJS 2000; 82(3):322-341. 10. Vandeputte G, Steenwerckx A, Mulier T, Peeraer L, Dereymaeker G. Forefoot reconstruction in rheumatoid arthritis patients (Keller-Lelievre-Hoffman versus arthrodesis MTP1-Hoffman). Foot Ankle Int 1999; 20(7):438-443.