What to Do with Erosive, Inflammatory Osteoarthritis

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CHICAGO—Is erosive, inflammatory osteoarthritis (EOA) a separate condition from osteoarthritis (OA)? Roberta Ramonda, MD, PhD, a rheumatologist at the University of Padova, Italy, spoke at the 2018 ACR/ARHP Annual Meeting on the clinical presentation of EOA and how it differs from OA.

EOA is characterized by a frequent aggressive clinical course and occurs most often in the hands of middle-aged women, when it is called erosive hand osteoarthritis. The mean age of onset is 50 years, while typically the earliest onset occurs at 36 years. Although EOA has been considered an uncommon clinical subset of generalized OA, Dr. Ramonda explained that debate continues over whether it is a separate condition with a pathophysiology distinct from OA.

Erosive Hand Osteoarthritis

Those rheumatologists who consider erosive hand OA to be a severe form of hand OA feel the difference in frequency and patterning of joint involvement between these two forms is not significant. Evidence is accumulating, however, to suggest the pathophysiology of erosive hand OA is distinct from hand OA, Dr. Ramonda noted. This evidence includes clinical and radiological distinctions that translate into aggressive clinical involvement in erosive hand OA, with higher clinical burden—more pain, disability, stiffness—and worse outcome than in non-erosive hand OA. Moreover, patients with erosive hand OA are more likely to be positive for HLA-DRB1*07.

Dr. Ramonda spoke about various threads of evidence that suggest erosive hand OA is associated with inflammatory mechanisms. These include clinical features, imaging tests and laboratory tests. Patients with EOA have many clinical features consistent with inflammation, such as abrupt onset of pain, swelling, redness and warmth. The abrupt onset of pain stands in contrast to hand OA, which is often characterized by a moderate onset of pain.

Patients with erosive hand OA ex­perience these inflammatory episodes frequently, and they often involve several joints simultaneously. They may also experience paresthesia of the fingertips and morning stiffness lasting less than 30 minutes. Eventually, patients with erosive hand OA will develop deformities of the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints, medial and lateral subluxations, as well as instability, flexion deformity and ankylosis. The instability and ankylosis of the interphalangeal joints result in a rapid progressive loss of function.

The X-rays of patients with erosive hand OA reveal erosions, ankylosis and joint space narrowing, Dr. Ramonda stated. Patients may also have osteophytosis, subluxation and periostitis. These may present as “gull-wing and sawtooth deformities,” with a subchondral pseudocyst or crumble erosion. This central bony erosion distinguishes erosive hand OA from hand OA, which does not have erosion, but rather bony enlargement in Heberden’s and Bouchard’s nodes. In addition, erosive hand OA affects primarily bilateral DIP and PIP joints, but hand OA tends most often to affect the carpometacarpal joint of the thumb. Erosive hand OA is thus defined radiographically by subchondral erosion, cortical destruction and subsequent reparative change, which may include bony ankylosis.

Ultrasound imaging of the joints of patients with erosive hand OA will reveal capsule distension, bone irregularity and osteophytes. Magnetic resonance imaging (MRI) features of erosive hand OA joints include synovitis, bone marrow edema and joint space narrowing. An MRI will also reveal bone damage, tenosynovitis and osteophytes.

Although experts have, to a large extent, characterized erosive hand OA, its diagnosis remains challenging due to lack of a uniform definition, and definitive classification and diagnostic criteria. Moreover, even though erosive hand OA is an area of active research, the pathophysiology remains murky, and clinical trials for patients with erosive hand OA remain few and far between. This continuous redefinition of the disease hampers patient recruitment for potential clinical trials.

EULAR Recommendations

Absent specific treatment recommendations for erosive hand OA, Dr. Ramonda directed rheumatologists to the 2018 update of the European League Against Rheumatism (EULAR) recommendations for the management of hand OA. Overall, the recommendations emphasize the importance of controlling symptoms and reducing pain. Patients should be educated and trained in ergonomic principles and pacing of activity. Moreover, patients should be offered assistive devices. The recommendations also suggest patients be given exercises to improve function and muscle strength, as well as to reduce pain. Patients with thumb OA should be offered orthoses for thumb relief and their use should be considered long term. All of these interventions should be done in partnership with the patient.

EULAR recommends the use of topical treatments over systemic treatment for hand OA for safety reasons and suggests topical non-steroidal anti-inflammatory drugs (NSAIDs) be considered the first pharmacological topical treatment of choice. When oral analgesics, such as NSAIDs, are used, EULAR suggests they be prescribed for a limited duration for symptom relief. Chondroitin sulfate (CS) may also be used in patients with hand OA for pain relief and functional improvement. Dr. Ramonda also reported from a few studies that CS is partially effective in erosive hand OA.^1-3

Although EULAR states that intra-articular injections of glucocorticoids should not generally be used in patients with hand OA, it noted they may be considered in patients with painful interphalangeal joints. Such pain is characteristic of erosive hand OA, and Dr. Ramonda presented the results of studies indicating this treatment could be effective and safe in select patients with erosive hand OA.^4,5 EULAR also recommends patients with hand OA not be treated with conventional or biological disease-modifying anti-rheumatic drugs (DMARDs). This recommendation applies to patients with erosive hand OA as well, because randomized clinical trials treating erosive hand OA with DMARDs (e.g., hydroxychloroquine, anakinra and adalimumab) indicated they were ineffective in reducing erosions.

In contrast, a recent study of etanercept in patients with erosive hand OA and inflamed joints found pain was significantly reduced after one year and radiographic scores were significantly improved.⁶ Another pilot trial found intramuscular clodronate was effective and safe in reducing pain and swelling and improving functionality.⁷ However, none of the currently available drugs has been shown to change the disease course. 

Lara C. Pullen, PhD, is a medical writer based in the Chicago area.

References

1. Rovetta G, Monteforte P, Molfetta G, Balestra V. Chondroitin sulfate in erosive osteoarthritis of the hands. Int J Tissue React. 2002;24(1):29–32.
2. Rovetta G, Monteforte P, Molfetta G, Balestra V. A two-year study of chondroitin sulfate in erosive osteoarthritis of the hands: Behavior of erosions, osteophytes, pain and hand dysfunction. Drugs Exp Clin Res. 2004;30(1):11–16.
3. Scarpellini M, Lurati A, Vignati G, et al. Biomarkers, type II collagen, glucosamine and chondroitin sulfate in osteoarthritis follow-up: The ‘Magenta osteoarthritis study.’ Orthop Traumatol. 2008 Jun;9(2):81–87.
4. Utsinger PD, Resnick D, Shapiro RF, Wiesner KB. Roentgenologic, immunologic, and therapeutic study of erosive (inflammatory) osteoarthritis. Arch Intern Med. 1978 May;138(5):693–697.
5. Favero M, Ramonda R, Rossato M. Efficacy of intra-articular corticosteroid injection in erosive hand osteoarthritis: Infrared thermal imaging. Rheumatology (Oxford). 2017 Jan;56(1):86.
6. Kloppenburg M, Ramonda R, Bobacz K, et al. Etanercept in patients with inflammatory hand osteoarthritis (EHOA): A multicentre, randomised, double-blind, placebo-controlled trial. Ann Rheum Dis. 2018 Dec;77(12):1757–1764.
7. Saviola G, Abdi-Ali L, Povino MR, et al. Intramuscular clodronate in erosive osteoarthritis of the hand is effective on pain and reduces serum COMP: A randomized pilot trial—The ER.O.D.E. study (ERosive Osteoarthritis and Disodium-clodronate Evaluation). Clin Rheumatol. 2017 Oct;36(10):2343–2350.