A recently developed MRI scoring system for hand osteoarthritis: its application in a clinical setting

This study aimed to apply the recently proposed Oslo hand osteoarthritis magnetic resonance imaging (MRI) scoring system to evaluate MRI findings in a cohort of patients affected by long-standing erosive hand osteoarthritis (EHOA). Eleven female EHOA patients (median 59 [interquartile range 62-52] years, disease duration 9.5 [interquartile range 13-3.75] years) underwent MRI (1.5 T) of the dominant hand, and synovitis, bone marrow lesions (BMLs), joint space narrowing, osteophytes, cysts, malalignment, and erosions were scored using the Oslo scoring system. Intra- and inter-reader reliability were assessed. The patients also underwent X-ray examination, and bone features were evaluated using the same scoring system. Pain and tenderness were assessed during a physical examination. Spearman's non-parametric test was used to analyze the correlations between variables. MRI intra- and inter-reader reliability were found between good and moderate for many features. No statistical differences were found between the radiographs and MRI with regard to detection of JSN, malalignment, and bone erosions. Synovitis was detected in 39.8 % of the 80 joints examined (in a mild form in 80 %), erosions were found in 51.1 %, and BMLs were identified in 20.5 and 23.9 % at the distal and the proximal side, respectively. BMLs at both the proximal and distal ends were correlated with tender joints (BML distal p = 0.0013, BML proximal p = 0.012). The presence of synovitis was correlated with tenderness (p = 0.004) and erosions at both the distal and proximal joints (p = 0.004). The presence of erosions correlated with tender joints (p < 0.01) and the mean visual analog scale (VAS) score (distal p = 0.03, proximal p = 0.01). Synovitis and BMLs were correlated with clinical symptoms in our patients affected with long-standing EHOA.

Methotrexate treatment in hand osteoarthritis refractory to usual treatments: A randomised, double-blind, placebo-controlled trial

OBJECTIVE

To examine the effect of methotrexate (MTX) on pain and structural progression in symptomatic erosive hand osteoarthritis (HOA).

METHODS

This 1-year prospective, single-centre, randomised, double-blind, placebo-controlled study (www.ClinicalTrial.gov, NCT01068405) followed up patients with symptomatic erosive HOA. Patients were randomised into two groups based on the drug that was administered: 10 mg methotrexate (MTX) per week or a placebo. The primary endpoint was the change in pain (determined using a visual analogue scale [VAS]) from baseline to 3 months. The secondary endpoints were pain VAS score at 12 months, clinical features (pain VAS score and function), radiographic features (the anatomical radiographic Verbruggen-Veys [VV] score and Gent University Score System), and magnetic resonance imaging (MRI) at 12 months.

RESULTS

Sixty-four patients with HOA were randomised into either the placebo or MTX group. At 3 months, there was no significant difference in the mean decrease in the pain VAS score (mm) (MTX: 21.1 [standard deviation, 27.4], placebo: 11.7 [24.3]; p = 0.2). At 12 months, according to the VV score, erosive joints progressed significantly more to a remodelling phase in the MTX group than in the placebo group (27% vs 15%; p = 0.03). Joints with space loss appeared to be eroding less in the MTX group compared to the placebo group (8% vs 29%; p = 0.2). Synovitis on MRI at baseline could be associated with the erosive structural evolution of non-erosive joints (p = 0.02).

CONCLUSIONS

Weekly doses of 10-mg MTX showed no superiority over the placebo in terms of pain relief at 3 or 12 months.

CLINICAL TRIAL REGISTRATION NUMBER

This study was registered at www.ClinicalTrial.gov (NCT01068405).

Impact of thumb osteoarthritis on pain, function, and quality of life: a comparative study between erosive and non-erosive hand osteoarthritis

OBJECTIVE

The study was aimed to compare the impact of thumb base osteoarthritis (TBOA) on pain, function, and quality of life in patients with erosive or non-erosive hand osteoarthritis (HOA).

METHODS

This observational retrospective study included 232 patients: 64 with erosive HOA (EHOA) and concomitant TBOA, 36 with isolated EHOA, 97 with non-erosive HOA (non-EHOA) and TBOA, and 35 with isolated non-EHOA. Hand pain by a visual analogue scale (VAS), Functional Index for Hand Osteoarthritis (FIHOA) score, Health Assessment Questionnaire (HAQ), the Medical Outcomes Study 36-Item Short Form (SF-36), and the possible correlations between VAS and FIHOA with radiological score were assessed.

RESULTS

No differences were found between EHOA with TBOA and isolated EHOA in VAS and FIHOA scores; opposite, there was a significant difference in VAS (p < 0.01) and FIHOA (p < 0.001) between subjects with non-EHOA and TBOA and patients with only non-EHOA. VAS and FIHOA values resulted slightly higher in patients with EHOA and TBOA vs non-EHOA and TBOA; they were significantly more elevated in EHOA and TBOA group compared to isolated non-EHOA (p ≤ 0.001) and in isolated EHOA vs isolated non-EHOA (p < 0.01 and p < 0.001, respectively). HAQ, SF-36 resulted significantly better in isolated non-EHOA patients compared to the other groups. Finally, we observed a significant correlation between FIHOA and all the Kallman scales in EHOA patients with TBOA and between FIHOA and Kallman's thumb score in non-EHOA-TBOA group.

CONCLUSIONS

EHOA has a more severe clinical burden than non-EHOA; the presence of TBOA appeared an important determinant of pain and disability in non-EHOA.Key Points• Each subset of HOA can have a different impact on pain and functionality, with EHOA determining more severe effects on hand symptoms and disability than non-EHOA.• The presence of TBOA appeared an important determinant of pain and disability in non-EHOA, but not in EHOA.• Our findings support the need for an individualized therapy for each phenotype of hand osteoarthritis.

The DIGICOD cohort: A hospital-based observational prospective cohort of patients with hand osteoarthritis - methodology and baseline characteristics of the population

OBJECTIVE

Despite its prevalence, there are few worldwide hand osteoarthritis (HOA) cohorts. The main objective of DIGItal COhort Design (DIGICOD) cohort is to investigate prognostic clinical, biological, genetic and imaging factors of clinical worsening after 6years follow-up.

METHODS

DIGICOD is a hospital-based prospective cohort including patients>35years-old with symptomatic HOA fulfilling: (i) ACR criteria for HOA with≥2 symptomatic joints among proximal/distal interphalangeal joints or 1st interphalangeal joint with Kellgren-Lawrence (KL)≥2; or (ii) symptomatic thumb base OA with KL≥2. Main exclusion criteria were inflammatory arthritis and crystal arthropathies. Annual clinical evaluations were scheduled with imaging (X-rays of the hands and of other OA symptomatic joints) and biological sampling every 3years. Hand radiographs are scored using KL and anatomical Verbruggen-Veys scores. Follow-up visits are ongoing. Cohort methodology and baseline characteristics are presented.

RESULTS

Between April 2013 and June 2017, from the 436 HOA included patients, 426 have been analysed of whom 357 (84%) are women. Mean age±standard deviation was 66.7±7.3years and mean disease duration was 12.6±9.6years. Metabolic syndrome affected 151 (36.5%) patients. Mean Visual Analog Scale (VAS) hand pain (0-100mm) was 44.4±26.7mm at activity. Mean FIHOA (0-100) was 19.9±18.6. Elevated serum CRP level (≥5mg/L) involved 10% patients. Mean KL score (0-128) was 46.7±18 and the mean number of joint with KL≥2 was 15.1±6.3. Erosive HOA (defined as≥1 Erosive or Remodeling phase joint according to Verbruggen-Veys score) involved 195/426 (45.8%) patients and the median number (interquartile range) of erosive joints in erosive patients was 3.0 (1.0-5.0).

CONCLUSION

DIGICOD is a unique prospective HOA cohort with a long-term 6years standardized assessment and has included severe radiologically HOA patients with a high prevalence of erosive disease.

Serum Tryptophan Metabolites are Associated with Erosive Hand Osteoarthritis and Pain: Results from the DIGICOD Cohort

OBJECTIVE

To investigate host and gut-microbiota related Tryptophan metabolism in hand osteoarthritis (HOA).

METHODS

The baseline serum concentration of 20 Tryptophan metabolites was measured in 416 HOA patients in a cross-sectional analysis of the DIGICOD cohort. Tryptophan metabolites levels, metabolite-ratios and metabolism pathway activation were compared between erosive (N=141) and non-erosive HOA (N=275) by multiple logistic regressions adjusted on age, BMI and sex. The association between Tryptophan metabolite levels and HOA symptoms was investigated by a Spearman's rank correlation analysis.

RESULTS

Four serum Tryptophan metabolites, eight metabolite ratios and one metabolism pathway were associated with erosive HOA. Erosive HOA was negatively associated with Tryptophan (odds ratio (OR)=0.41, 95% confidence interval [0.24-0.70]), indole-3-aldehyde (OR=0.67 [0.51-0.90]) and 3-OH-anthranilic acid (OR=1.32 [1.13-1.54]) and positively with 5-OH-Tryptophan levels (OR=1.41 [1.13-1.77]). The pro-inflammatory kynurenine-indoleamine 2,3-dioxygenase pathway was upregulated in erosive HOA (OR=1.60 [1.11-2.29]). Eleven metabolites were correlated with HOA symptoms and were mostly pain-related. Serotonin and N-acetyl serotonin levels were negatively correlated with number of tender joints. Indole-3-aldehyde level was negatively correlated and 3-OH-anthranilic acid, 3-OH-kynurenine and 5-OH-Tryptophan levels were positively correlated with number of patients-reported painful joints. Quinolinic acid and 3-OH-kynurenine levels correlated positively with AUSCAN pain.

CONCLUSIONS

Tryptophan metabolites disturbance is associated with erosive HOA and pain and emphasize the role of low-grade inflammation and gut dysbiosis in HOA.

Erosive osteoarthritis, psoriatic arthritis and pseudogout; a casual association?

According to recent hypothesis, the inflammation has a pivotal role in the onset and progression of erosive hand osteoarthritis (EHOA), psoriatic arthritis (PsA) and chondrocalcinosis (CC)/pseudogout. Albeit, it has been recognised for years as an association between EHOA and radiographic evidence of CC, but there are few reports of coexistence of microcrystalline arthritis and PsA. This is the first report that described a clinical experience concerning two consecutive cases of patients presented with EHOA, PsA and pseudogout. Two Caucasian women of 71 and 85 years old with a history of OA and mild psoriasis are presented with tenderness and swelling of first interphalangeal (IP) and wrist joint, respectively. Arthrocentesis performed at the first IP and wrist joint, respectively, showed an inflammatory synovial fluid with presence of calcium pyrophosphate dehydrate crystals. X-rays of hands, feet and knees showed characteristic features of EHOA, PsA and CC. Furthermore, HLA typing evinces the presence of HLA C*06; DRB*01 07 and HLA C*07; DRB*01 *11 alleles, respectively, predisposing factors of these inflammatory diseases. The relationship between these aggressive rheumatic diseases along with their clinical, radiographic, laboratory and genetic features is discussed.

Radiological and histological analysis of two replaced interphalangeal joints with active subchondral bone resorption in erosive hand osteoarthritis: a novel mechanism?

The aim of this study was to describe the histological features of erosive hand osteoarthritis (EHOA), which is considered an aggressive subset of hand osteoarthritis (OA) characterized by severe local inflammation and degeneration of the distal and proximal interphalangeal joints. Two patients with EHOA underwent replacement with a cement-free press fit ceramic prosthesis of a proximal interphalangeal joint (PIPJ). Clinical and radiological data were collected and histological examination was performed. Radiological examination with histological correlation showed complete erosion of the articular cartilage with focal presence of peripheral fibrocartilaginous resurfacing, sclerosis, and remodeling of the exposed bone, osteoclastic activity with resorptive lacunae in the subchondral bone and around degenerative fibromyxoid pseudocysts, coarse trabeculation of the cancellous bone, and marginal osteophytes. The synovial membrane showed non-specific mild hypertrophy and mildly cellular fibromyxoid stroma. The histological findings in patients with EHOA suggest a pathogenesis of cartilage resorption from the subchondral bone, via osteoclastic-mediated activity and formation of periarticular reactive fibrocartilaginous proliferation with partial resurfacing of the articular surface.

Erosive Hand OsteoArthritis (EHOA): analysis of consecutive patients presenting with EHOA in a hospital-based rheumatology practice and its implications for an upcoming interventional study

INTRODUCTION

Erosive Hand OsteoArthritis (EHOA) is a common rheumatological problem. We aim to determine characteristics of EHOA patients: comorbidities, radiographic erosivity and pain experienced after being diagnosed, in order to find which of these are potentially relevant in upcoming interventional trials.

METHOD

Retrospective analysis of EHOA patients within the electronic database in one centre, with a telephone interview on pain as experienced even exceeding 12 months after being diagnosed.

RESULTS

Eighty-four non-academic EHOA patients were found: 89% females (median age 69 years), 11% males (similar age distribution). Kellgren-Lawrence (KL) erosivity scores in both sexes were comparable; DIPs scored higher than PIP's. Comorbid conditions were crystal-induced arthritis, rheumatoid arthritis (RA) and psoriatic arthritis (PsA) in 8%, 5% and 1%, respectively; seropositivity for rheumatoid factor and anti-citrullinated protein antibodies in 8% and 1% respectively. Pain worst experienced often exceeded a visual analogue score of 5.0, but was unrelated to the total KL score. Some pain reduction was reached with non-steroidals (perorally/transcutaneously) as deduced from continued use in 1 in 3.

CONCLUSIONS

In many EHOA patients, there is an unmet need regarding the treatment of pain, which per se was not directly correlated with erosivity score. Future studies may be designed considering the aforementioned characteristics, acting on the inflammatory process resulting in PIP/DIP erosions, with the exclusion of RA and PsA in order to get a clean study on EHOA. Several studies with monoclonal antibodies have been performed but demonstrated ineffectivity on the outcome of pain. Hope glooms with the arrival of innovative small molecules that may reach EHOA target cells. Key Points • Erosive handOA is a common problem in non-academic rheumatology; it is often associated with significant pain in both sexes exceeding a VASpain of 5.0 even years after being diagnosed; 1 in 3 found some relief in non-steroidals perorally/transcutaneously. • Future studies will have to focus on (episodic) inflammatory hand OA resulting in proven erosivity (EHOA) located in PIP plus DIP joints and may have to exclude comorbid active crystal-induced arthritis as well as rheumatoid/psoriatic arthritis and possibly even RF/ACPA seropositivity in order to get a clean study on EHOA. • As several big monoclonals have failed in EHOA, we may have to search for promising new drugs within the group of small molecules. These will have to show a significant pain-reducing effect and preferably also a disease-modifying osteoarthritis drug (DMOAD) effect.

Prescription-grade crystalline glucosamine sulfate as an add-on therapy to conventional treatments in erosive osteoarthritis of the hand: results from a 6-month observational retrospective study

Objective

To evaluate the efficacy of prescription-grade Crystalline Glucosamine Sulfate (pCGS) as an add-on treatment to conventional therapy, compared to usual therapy alone, in patients with erosive osteoarthritis of the hand (EHOA).

Methods

This 6-month retrospective case–control study included patients with concomitant knee osteoarthritis and symptomatic EHOA. Participants were stratified into two groups based on whether or not pCGS (1500 mg/day) was added to the conventional therapy (education and training in ergonomic principles, exercise and use on-demand of symptomatic drugs) for hand osteoarthritis. Patients were evaluated at baseline, after 3 and 6 months. Primary outcomes were the change from baseline to month 6 in Visual Analogue Scale (VAS) hand pain and in Functional Index for Hand Osteoarthritis (FIHOA) score. A set of secondary parameters was also evaluated.

Results

123 patients were included as follows: 67 treated with pCGS in addition to conventional therapy (pCGS Group) and 56 with conventional therapy alone (Control Group). After 6 months a significant difference in VAS and in FIHOA score (p < 0.01 and p < 0.001, respectively) was observed in favor of pCGS Group. Similar results were found for morning stiffness duration (p < 0.05), health assessment questionnaire (p < 0.01) and physical and mental component score of 36-item short form (p < 0.05 and p < 0.001, respectively). A significant reduction of symptomatic drug consumption at 3 and 6 months was reported in the pCGS Group (p < 0.001). No serious adverse event was recorded in both groups.

Conclusions

Despite all the limitations inherent to an observational study, our results suggest the potential effectiveness of pCGS, when used in combination with conventional therapy in EHOA. Further randomized placebo-controlled trials are needed to confirm these positive findings.

Trial Registration

ClinicalTrials.gov, http://www.clinicaltrials.gov, date of registration: February 2, 2022, NCT05237596. The present trial was retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-022-02151-7.

Erosive Hand Osteoarthritis: Recent Advances and Future Treatments

PURPOSE OF THE REVIEW

Erosive hand osteoarthritis (EHOA) is an aggressive form of hand osteoarthritis that leads to significant disability, and recent data suggests that it is increasing in prevalence. This review provides an update of our current understanding of epidemiology, genetic associations, biomarkers, pathogenesis, and treatment of EHOA, with particular focus on studies published within the last 5 years.

RECENT FINDINGS

New studies of EHOA have identified new genetic loci associated with disease, including variants in genes involved in inflammation and bone remodeling. Preclinical studies implicate pathways of innate immunity, including some that may be causal in the condition. Recent novel studies showed that inflammatory features identified by ultrasound and MRI are associated with development of erosive lesions over time on conventional radiography. In the future, these imaging modalities may be useful in identifying patients at risk of adverse outcomes. Promising new findings in genetics, biomarkers, and treatment targets will hopefully allow for future therapeutic options for this debilitating condition.

Serum intestinal permeability biomarkers are associated with erosive hand osteoarthritis and radiographic severity: results from the DIGICOD cohort

OBJECTIVE

To investigate the association between intestinal permeability alteration and erosive hand osteoarthritis (EHOA).

METHODS

Serum concentrations of four intestinal permeability biomarkers (lipopolysaccharide binding protein (LBP), FABP2, sCD14, Zonulin-related proteins (ZRP) along with calprotectin, and high-sensitivity C-Reactive Protein (hs-CRP) were assessed in 410 patients of the DIGICOD cohort. The study compared patients with EHOA (≥ 2 erosion in Verbruggen score N=140) to those without EHOA (N=270) using the Mann-Whitney U test. Logistic regression was performed to adjust for potential covariates. The Spearman rank test was used to investigate the correlation between intestinal permeability biomarkers and seven clinical variables associated with HOA clinical and radiographic severity.

RESULTS

Serum levels of LBP and ZRP were found to be higher in patients with EHOA compared to those without EHOA (p=0.001, p=0.04). Additionally, LBP and ZRP remained associated with EHOA in a logistic regression model adjusted for age, body mass index, and sex (p=0.017, p=0.005). ZRP was positively correlated with Verbruggen score and Kellgren-Lawrence sum score of both hands (r=0.14 p=0.005, r=0.12 p=0.023). LBP was positively correlated with the number of erosive joints (r=0.14 p=0.0006). Hs-CRP and LBP were positively correlated with AUSCAN pain (r=0.14 p=0.008, r=0.10 p=0.042).

CONCLUSIONS

LBP and ZRP were associated with EHOA with clinical and radiographic severity in HOA. These results overall support the role of intestinal permeability in both symptoms and structural alteration in HOA.

Associations of inflammatory and metabolic biomarkers with incident erosive hand osteoarthritis in the osteoarthritis initiative cohort

OBJECTIVE

Erosive hand osteoarthritis (eHOA) is a subtype of hand osteoarthritis (OA) that develops in finger joints with pre-existing OA and is differentiated by clinical characteristics (hand pain/disability, inflammation, and erosions) that suggest inflammatory or metabolic processes.

METHOD

This was a longitudinal nested case-cohort design among Osteoarthritis Initiative participants who had hand radiographs at baseline and 48-months, and biospecimens collected at baseline. We classified incident radiographic eHOA in individuals with ≥1 joint with Kellgren-Lawrence ≥2 and a central erosion present at 48-months but not at baseline. We used a random representative sample (n = 1282) for comparison. We measured serum biomarkers of inflammation, insulin resistance and dysglycemia, and adipokines using immunoassays and enzymatic colorimetric procedures, blinded to case status.

RESULTS

Eighty-six participants developed incident radiographic eHOA. In the multivariate analyses adjusted for age, gender, race, smoking, and body mass index, and after adjustment for multiple analyses, incident radiographic eHOA was associated with elevated levels of interleukin-7 (risk ratio (RR) per SD = 1.30 [95% confidence interval (CI) 1.09, 1.55] p trend 0.01).

CONCLUSION

This exploratory study suggests an association of elevated interleukin-7, an inflammatory cytokine, with incident eHOA, while other cytokines or biomarkers of metabolic inflammation were not associated. Interleukin-7 may mediate inflammation and tissue damage in susceptible osteoarthritic finger joints and participate in erosive progression.

The natural history of marginal erosions in hands with and without osteoarthritis

INTRODUCTION/OBJECTIVES

Among people with or without hand osteoarthritis, we aimed to identify characteristics of people (e.g., age and gender) with marginal erosions (MEs). We also examined changes in MEs during 48 months. We described radiographic severity and progression among joints with MEs, changes in MEs, or central erosions (CEs).

DESIGN

We studied participants from the Osteoarthritis Initiative with baseline and 48-month hand radiographs. A radiologist and rheumatologist evaluated the radiographs for disease severity (Kellgren-Lawrence grades) and erosions (central or marginal), respectively. We used descriptive statistics to characterize participants and calculated frequencies at the joint level.

RESULTS

Of the 3558 participants, 89 had a ME at baseline. People with MEs were more often male, older, and ever (former and current) smokers than those without a ME. There was no difference in inflammatory biomarkers or the presence of hand pain between individuals with and without a baseline ME. Almost all hands had only one ME (80%), whereas only 50% of individuals with CEs had only one CE at baseline. Compared to CEs, MEs appeared more frequently in joints without osteoarthritis (54% vs. < 1%). Approximately 18% of joints with an ME progressed in Kellgren-Lawrence grade versus 4% without ME. Among the joints with an ME at baseline, 10% resolved by 48 months. Less than 0.1% of joints developed a new ME.

CONCLUSION

MEs appear to be distinct from CEs. MEs are predominantly present in males, isolated to one specific joint without osteoarthritis within a hand, and possibly predictive of radiographic progression. Key Points • Marginal erosions appear to be distinct from central erosions. • Most marginal erosions occur in joints without radiographic osteoarthritis. • Radiographic progression but not hand pain is more common in joints with a marginal erosion than without one.

Protocol for the MERINO study: A randomized placebo-controlled trial assessing the efficacy, safety, and cost-effectiveness of methotrexate in people with erosive hand osteoarthritis

Objective

Previous studies on the efficacy of methotrexate in people with hand osteoarthritis (OA) have shown conflicting results. The MERINO trial aims to investigate the efficacy and safety of methotrexate in people with painful inflammatory erosive hand OA.

Design

In total 163 participants with erosive hand OA, synovitis by ultrasound, and finger joint pain of 40-80 ​mm on a visual analogue scale (VAS) will be recruited from a rheumatology outpatient clinic. Participants are randomized 1:1 to receive either encapsulated oral methotrexate 20 ​mg/week or placebo for 12 months in a double-blind manner. The primary endpoint is VAS finger joint pain at 6 months. Key secondary outcomes are hand function by the Australian/Canadian hand index (AUSCAN) at 6 months and radiographic progression by the Verbruggen-Veys anatomical phase scoring system at 12 months. Other secondary endpoints include hand stiffness, disease activity, health-related quality of life, grip strength, clinical joint counts, synovitis by ultrasound and MRI, bone marrow lesions by MRI, cost-effectiveness, and symptoms in knees and hips. Adverse events will be recorded. The primary analysis will be performed on full analysis set.

Conclusions

The findings of this trial will be clinically relevant for patients with erosive hand OA and may influence future treatment recommendations.

Clinical trial registration

EU CT number: 2023-510523-30-00, NCT04579848.

Presence of erosions is not a risk factor for the development of knee OA in a hand OA population: Results from the Framingham OA study

Objective

This study aimed to investigate whether there is a difference in risk of knee OA between individuals with erosive hand osteoarthritis (OA) compared to non-erosive hand OA, and to identify other risk factors for knee OA presence and development in hand OA patients.

Methods

Subjects were selected from the Framingham OA study's Offspring and Community cohorts. Bilateral knee and hand radiographs were scored. Generalized linear models compared knee OA prevalence and incidence rates among hand OA-free, non-erosive and erosive hand OA. Multivariable logistic regression identified risk factors for symptomatic knee OA (presence of hand OA, anatomical location, erosions, number of affected finger joints, radiographic grade changes), adjusted for age, sex and BMI.

Results

In total, 2367 participants were studied. Hand classification (hand OA-free, non-erosive and erosive hand OA) significantly impacted the prevalence of knee OA (P ​< ​0.0001). Prevalence rates at baseline were 6.3 ​%, 17.9 ​% and 26.8 ​% for radiographic knee OA and 2.9 ​%, 9.7 ​% and 12.7 ​% for symptomatic knee OA for hand OA-free, non-erosive and erosive hand OA respectively. Post hoc analysis indicated differences were primarily between hand OA-free and hand OA groups (p ​< ​0.001), with no significant differences between erosive and non-erosive hand OA (p ​= ​0.7 and p ​= ​0.8). Overall, hand OA was identified as a risk factor for knee OA development. Presence of erosions did not increase risk, but the number of affected finger joints and changes in Kellgren-Lawrence grade did.

Conclusion

Hand OA is associated with knee OA presence and incidence with no difference in the risk of knee OA between those with non-erosive vs erosive hand OA.