In the JournalsPerspective

Bone erosions detected in 44% of patients with gout

Researchers using ultrasound were able to detect bone erosions in 44% of patients with gout, with 78.4% of erosions occurring at the first metatarsophalangeal joints, according to data published in Arthritis Care & Research.

“Few studies have focused on bone erosion in patients with gout,” Mian Wu, MD, of the Shanghai Jiao Tong University Affiliated Sixth People's Hospital, and colleagues wrote. “The sample sizes of these studies were quite small, so further clinical studies in a larger cohort of patients are warranted to confirm these findings and to explore the prevalence and distribution of bone erosion in patients with gout.”

To analyze the prevalence, distribution and factors associated with bone erosion, as detected through ultrasound, among patients with gout, Wu and colleagues conducted a retrospective cohort study of 980 participants recruited from the Shanghai Jiao Tong University Affiliated Sixth People's Hospital. Eligibility included a history of gout based on the 2015 ACR/EULAR criteria to undergo imaging investigations. All participants completed a questionnaire at enrollment documenting age, sex, disease duration, comorbidities, medications, flare frequency, pain score and various clinical data.

 
Researchers using ultrasound were able to detect bone erosions in 44% of patients with gout, according to data.
Source: Shutterstock

All participants underwent ultrasound examinations, performed by three experienced sonographers. The researchers calculated the prevalence and distribution of bone erosion, including both clinical variables and ultrasound signs into a multivariate logistic analysis to clarify associated factors.

According to Wu and colleagues, bone erosions were found in 44% of participants, with 78.4% of all erosions detected in the first metatarsophalangeal joint. A multivariate logistic regression analysis found that age, duration of gout, the existence of tophi, ultrasound-detected synovial hypertrophy and joint effusion were independently associated with bone erosion. In addition, a tophus was the most significant factor linked to bone erosion, (OR = 4.218; 95% CI, 3.092-5.731).

The researchers also found that the risk for bone erosion increased as the number of tophi increased (P < .001). However, after stratifying the size of tophi, the odds ratios did not significantly increase (P = .206).

“This study has shown that bone erosion is a common complication of gout,” Wu and colleagues wrote. “Age, duration of gout, tophi, synovial hypertrophy and joint effusion were independently associated with bone erosion, shedding further light on the links between crystal deposition and joint damage in patients with gout. These results suggest that an early diagnosis of gout, controlling the urate level and decreasing local urate crystal deposition may be the most effective way to prevent bone erosion in patients with gout.” – by Jason Laday

Disclosure: Wu reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

Researchers using ultrasound were able to detect bone erosions in 44% of patients with gout, with 78.4% of erosions occurring at the first metatarsophalangeal joints, according to data published in Arthritis Care & Research.

“Few studies have focused on bone erosion in patients with gout,” Mian Wu, MD, of the Shanghai Jiao Tong University Affiliated Sixth People's Hospital, and colleagues wrote. “The sample sizes of these studies were quite small, so further clinical studies in a larger cohort of patients are warranted to confirm these findings and to explore the prevalence and distribution of bone erosion in patients with gout.”

To analyze the prevalence, distribution and factors associated with bone erosion, as detected through ultrasound, among patients with gout, Wu and colleagues conducted a retrospective cohort study of 980 participants recruited from the Shanghai Jiao Tong University Affiliated Sixth People's Hospital. Eligibility included a history of gout based on the 2015 ACR/EULAR criteria to undergo imaging investigations. All participants completed a questionnaire at enrollment documenting age, sex, disease duration, comorbidities, medications, flare frequency, pain score and various clinical data.

 
Researchers using ultrasound were able to detect bone erosions in 44% of patients with gout, according to data.
Source: Shutterstock

All participants underwent ultrasound examinations, performed by three experienced sonographers. The researchers calculated the prevalence and distribution of bone erosion, including both clinical variables and ultrasound signs into a multivariate logistic analysis to clarify associated factors.

According to Wu and colleagues, bone erosions were found in 44% of participants, with 78.4% of all erosions detected in the first metatarsophalangeal joint. A multivariate logistic regression analysis found that age, duration of gout, the existence of tophi, ultrasound-detected synovial hypertrophy and joint effusion were independently associated with bone erosion. In addition, a tophus was the most significant factor linked to bone erosion, (OR = 4.218; 95% CI, 3.092-5.731).

The researchers also found that the risk for bone erosion increased as the number of tophi increased (P < .001). However, after stratifying the size of tophi, the odds ratios did not significantly increase (P = .206).

“This study has shown that bone erosion is a common complication of gout,” Wu and colleagues wrote. “Age, duration of gout, tophi, synovial hypertrophy and joint effusion were independently associated with bone erosion, shedding further light on the links between crystal deposition and joint damage in patients with gout. These results suggest that an early diagnosis of gout, controlling the urate level and decreasing local urate crystal deposition may be the most effective way to prevent bone erosion in patients with gout.” – by Jason Laday

Disclosure: Wu reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

    Perspective
    Herbert S. B. Baraf

    Herbert S. B. Baraf

    In their study of the prevalence of ultrasound-detected bone erosion in a population of gout patients, Wu and colleagues have shown that almost half of patients with gout, as diagnosed by ACR/EULAR criteria, have evidence of anatomic alteration of bone. It should come as no surprise to rheumatologists that their key finding — 44% of patients show bony erosion by ultrasound (US) — reinforces the notion of the utility of US as a diagnostic tool in the rheumatology outpatient setting, but also the destructive nature of gouty arthritis.

    From this practitioner’s perspective, one informed by a 40-plus year obsession with the clinical and therapeutic aspects of gout, this study confirms the very sensitive nature of US examination relative to conventional radiographs. I have long been accustomed to performing radiographs of the feet of new gout patients to look for erosive disease. Although the addition of digital X-ray has helped to more readily identify tophaceous deposits in the soft tissues and has made it easier to detect erosions in joints affected by gout than before, X-ray is still a relatively insensitive diagnostic tool.

    Rheumatologists using US are familiar with the other signature findings in acute and chronic gout, including the presence of color power Doppler (CPD) signal indicating active inflammation, synovial thickening, a “snow storm” pattern (indicative of urate deposits within the joint), the very characteristic “double contour” sign and the presence of discrete tophi. For rheumatologists not performing US in their clinics, this should be clarion call to get on board.

    The second “takeaway” for me from this article is that gout is a more destructive disorder than we have thought. Though obsessed with erosions developing in rheumatoid arthritis, rheumatologists don’t think of gout in the same way. Although disease modification is a basic tenet of management in rheumatoid arthritis, the disease-modifying benefit of potent urate-lowering therapy in gout patients is not thought of in the same vein.

    Patients with gout who are more than 60 years old are almost three times more likely to have US-detected erosions than patients under 40 years. If gout has caused erosive changes in 44% of patients in this cohort, and erosions — as shown by the authors — are a function of duration of disease, we should be intervening sooner with urate-lowering therapies to prevent disease progression and possibly even reverse radiographic changes.

    • Herbert S. B. Baraf, MD, FACP, MACR
    • Managing Partner, Arthritis and Rheumatism Associates
      Founding Medical Director
      The Center for Rheumatology and Bone Research
      Clinical professor of medicine
      The George Washington University School of Medicine and Health Sciences
      Member, Medical Policy Committee
      United Rheumatology

    Disclosures: Baraf reports no relevant financial disclosures.

    Perspective
    Vickie L. Sayles

    Vickie L. Sayles

    Gout is a common and complex form of arthritis that occurs in response to monosodium urate crystals building up in joints, bones and soft tissues. Several interacting processes may cause this debilitating disease, including metabolic disorders, genetic factors and diet, all of which result in hyperuricemia. As one of the most common crystal-induced arthropathies, gout can manifest in self-limited attacks or chronic hyperuricemia with ongoing inflammation and joint destruction.

    In the study by Wu and colleagues, the most common area for gout to attack is the first metatarsophalangeal joint or the joint at the base of the big toe. It is characterized by sudden severe pain, swelling, heat, and redness in the affected joint. When crystals form in and around the joints, bone erosion ensues causing anatomical damage, which is associated with functional disability, joint deformity and ongoing pain.

    Few past studies have focused on bone erosion among gout patients. This study found that ultrasound imaging is superior to other types of imaging techniques for detecting early bone destruction; additionally, controlling urate levels and deposition may be the most effective way to decrease disability associated with this disease.

    • Vickie L. Sayles, BSN, CRNI, RN-BC
    • Treasurer, Rheumatology Nurses Society
      Clinical nurse manager
      Department of Rheumatic and Immunologic Diseases
      The Cleveland Clinic Foundation

    Disclosures: Sayles reports speaking fees from Kevzara and Sanofi Genzyme.