Subluxation of the first carpometacarpal joint and age are important factors in reduced hand strength in patients with hand osteoarthritis.

OBJECTIVE: To investigate the determinants of hand strength in patients with hand osteoarthritis (OA). METHOD: Pinch and cylinder grip strength were measured in 527 patients with hand OA diagnosed by their treating rheumatologist from the Hand OSTeoArthritis in Secondary care (HOSTAS) study. Radiographs of hands (22 joints) were scored 0-3 (scaphotrapeziotrapezoid and first interphalangeal joints 0-1) on osteophytes and joint space narrowing following the Osteoarthritis Research Society International atlas. The first carpometacarpal joint (CMC1) was scored 0-1 for subluxation. Pain was assessed with the Australian/Canadian Hand Osteoarthritis Index pain subscale, and health-related quality of life with the Short Form-36. Regression analysis served to investigate associations of hand strength with patient, disease, and radiographic features. RESULTS: Hand strength was negatively associated with female sex, age, and pain. Reduced hand strength was associated with reduced quality of life, although less after adjusting for pain. Radiographic features of hand OA were associated with reduced grip strength when solely adjusted for sex and body mass index, but only CMC1 subluxation in the dominant hand remained significantly associated with pinch grip adjusted additionally for age (-0.511 kg, 95% confidence interval -0.975; -0.046). Mediation analysis showed low and not significant percentages of mediation of hand OA in the association between age and grip strength. CONCLUSIONS: Subluxation of CMC1 is associated with reduced grip strength, whereas associations with other radiographic features seem to be confounded by age. In the relationship between age and hand strength, radiographic hand OA severity is not an important mediator.

In finger osteoarthritis, change in synovitis is associated with change in pain on a joint-level; a longitudinal magnetic resonance imaging study.

OBJECTIVE: To investigate determinants of decrease and increase in joint pain in symptomatic finger osteoarthritis (OA) on magnetic resonance (MR) imaging over 2 years. DESIGN: Eighty-five patients (81.2% women, mean age 59.2 years) with primary hand OA (89.4% fulfilling American College of Rheumatology (ACR) classification criteria) from a rheumatology outpatient clinic received contrast-enhanced MR imaging (1.5T) and physical examination of the right interphalangeal finger joints 2-5 at baseline and at follow-up 2 years later. MR images were scored paired in unknown time order, following the Hand OA MRI scoring system (HOAMRIS). Joint pain upon palpation was assessed by research nurses. Odds ratios (ORs; 95% confidence intervals) were estimated on joint level (n = 680), using generalized estimating equations (GEE) to account for the within patient effects. Additional adjustments were made for change in MR-defined osteophytes, synovitis, and bone marrow lesions (BMLs). RESULTS: Of 116 painful joints at baseline, at follow-up: 76 had less pain, 21 less synovitis, and 13 less BMLs. A decrease in synovitis (OR = 5.9; 1.12─31.0), but not in BMLs (OR = 0.39; 0.10─1.50), was associated with less pain. Of 678 joints without maximum baseline pain, at follow-up: 115 had increased pain, 132 increased synovitis, 96 increased BMLs, and 44 increased osteophytes. Increased synovitis (OR = 1.81; 1.11─2.94), osteophytes (OR = 2.75; 1.59─4.8), but not BMLs (OR = 1.14; 0.81─1.60), was associated with increased pain. Through stratification it became apparent that BMLs were mainly acting as effect modifier of the synovitis-pain association. CONCLUSION: Decrease in MR-defined synovitis is associated with reduced joint pain, identifying synovitis as a possible target for treatment of finger OA.

Assessment of osteoarthritic features in the thumb base with the newly developed OMERACT magnetic resonance imaging scoring system is a valid addition to standard radiography.

OBJECTIVE: To investigate the construct validity of the new thumb base OA magnetic resonance imaging (MRI) scoring system (TOMS) by comparing TOMS scores with radiographic scores in patients with primary hand OA. DESIGN: In 200 patients (83.5% women, mean (SD) age 61.0 (8.4) years), postero-anterior radiographs and MR scans (1.5 T) of the right first carpometacarpal (CMC-1) and scaphotrapeziotrapezoid (STT) joints, were scored using the OARSI atlas and TOMS, respectively. The distributions of the TOMS scores (specified in results section) were stratified for the OARSI scores of corresponding radiographic features and investigated using boxplots and non-parametric tests. Furthermore, Spearman's rank or Phi correlation coefficients (ρ/φ) were calculated. RESULTS: For all features, especially for erosions and osteophytes, the prevalence found with MRI was higher than with radiography. TOMS osteophyte and cartilage loss scores differed statistically significant between corresponding OARSI scores in CMC-1 (0 vs 1; 1 vs 2). TOMS scores were positively correlated with radiographic scores in CMC-1 for osteophytes (coefficient [95% confidence interval], ρ = 0.75 [0.69; 0.81]), cartilage loss/joint space narrowing (ρ = 0.70 [0.62; 0.76]), subchondral bone defects (SBDs)/erosion-cyst (ρ = 0.41 [0.29; 0.52]), bone marrow lesions (BMLs)/subchondral sclerosis (ρ = 0.65 [0.56; 0.73]) and subluxation (φ = 0.65 [0.57; 0.73]); and in STT for osteophytes (ρ = 0.30 [0.17; 0.42]) and cartilage loss/joint space narrowing (ρ = 0.53 [0.42; 0.62]). CONCLUSIONS: In patients with hand OA, TOMS scores positively correlated with radiographic scores, indicating good construct validity. However, the prevalence of features on MR images was higher compared to radiographs, suggesting that TOMS might be more sensitive than radiography. The clinical meaning of these extra MR detected cases is currently still unknown.

Performance of the Michigan Hand Outcomes Questionnaire in hand osteoarthritis.

OBJECTIVE: To investigate the performance of the Michigan Hand Outcomes Questionnaire (MHQ) in hand osteoarthritis (OA) by evaluating truth, discrimination and feasibility. DESIGN: Symptomatic hand OA patients from the Hand Osteoarthritis in Secondary Care (HOSTAS) cohort completed questionnaires (demographics, MHQ, Australian/Canadian Hand Osteoarthritis Index [AUSCAN], Functional Index for Hand Osteoarthritis [FIHOA] and visual analogue scale [VAS] pain) at baseline (n = 383), 1- and 2-year follow-up (n = 312, n = 293). Anchor questions at follow-up assessed whether pain/function levels were (un)acceptable and had changed compared to baseline. Correlations between MHQ and other pain/function questionnaires were calculated. Validity of unique MHQ domains (work performance, aesthetics, satisfaction), discrimination across disease stages, and responsiveness were assessed by categorizing patients by external anchors (employment, joint deformities, erosions, and anchor questions). Between-group differences were assessed with linear regression, probability plots and comparison of medians. RESULTS: MHQ pain and function subscales correlated moderately-to-good with other instruments (rs 0.63-0.81). Work performance scores were worse in patients with reduced working capacity than in employed patients. Aesthetics scores were worse in patients with more deformities. Patients with unacceptable complaints had worse satisfaction scores. All pain/function instruments discriminated between patients with acceptable vs unacceptable pain/function, while only MHQ activities of daily living (ADL), FIHOA, and MHQ aesthetics could discriminate between erosive and non-erosive disease. MHQ and AUSCAN were most responsive. CONCLUSIONS: MHQ has several unique aspects and advantages justifying its use in hand OA, including the unique assessment of work performance, aesthetics, and satisfaction. However, MHQ, AUSCAN and FIHOA appear to measure different aspects of pain and function.

Comparison of histological and morphometrical changes underlying subchondral bone abnormalities in inflammatory and degenerative musculoskeletal disorders: a systematic review.

OBJECTIVE: Subchondral bone abnormalities (SBAs) on magnetic resonance imaging (MRI) are observed frequently and associated with disease course in various musculoskeletal disorders. This review aims to map the existing knowledge of their underlying histological features, and to identify needs for future research. DESIGN: We conducted a systematic review following PRISMA guidelines until September 2017, including all studies correlating histological features to on MRI defined SBAs in patients with osteoarthritis (OA), rheumatoid arthritis (RA), spondyloarthritis (SpA) and degenerative disc disease (DDD). Two authors independently retrieved articles and assessed study quality. RESULTS: A total of 21 studies (466 patients) correlated histological features to SBAs in OA (n = 13), RA (n = 3), ankylosing spondylitis (AS) (n = 1) and DDD (n = 4). Reported changes in OA were substitution of normal subchondral bone with fibrosis and necrosis, and increased bone remodeling. In contrast, in RA, AS or DDD fibrosis was not reported and SBAs correlated to an increase in inflammatory cell number. In DDD necrosis was observed. Similar to OA, increased bone remodeling was shown in RA and DDD. The risk of bias assessment showed a lack in described patient criteria, blinding and/or adequate topographic correlation in approximately half of studies. There was heterogeneity regarding the investigated histological features between the different disorders. CONCLUSIONS: Current studies suggest that SBAs correlate to various histological features, including fibrosis, cell death, inflammation and bone remodeling. In the majority of studies most quality criteria were not met. Future studies should aim for high quality research, and consistency in investigated features between different disorders.

In thumb base osteoarthritis structural damage is more strongly associated with pain than synovitis.

OBJECTIVE: Osteoarthritis in thumb base joints (first carpometacarpal (CMC-1), scaphotrapeziotrapezoid (STT)) is prevalent and disabling, yet focussed studies are scarce. Our aim was to investigate associations between ultrasonographic and magnetic resonance imaging (MRI) inflammatory features, radiographic osteophytes, and thumb base pain in hand osteoarthritis patients. DESIGN: Cross-sectional analyses were performed in cohorts with MRI (n = 202) and ultrasound measurements (n = 87). Pain upon thumb base palpation was assessed. Radiographs were scored for CMC-1/STT osteophytes. Synovial thickening, effusion and power Doppler signal in CMC-1 joints were assessed with ultrasound. MRIs were scored for synovitis and bone marrow lesions (BMLs) in CMC-1 and STT joints using OMERACT-TOMS. Associations between ultrasound/MRI features, osteophytes, and thumb base pain were assessed. Interaction between MRI features and osteophytes was explored. RESULTS: In 289 patients (mean age 60.2, 83% women) 139/376 thumb bases were painful. Osteophyte presence was associated with pain (MRI cohort: odds ratio (OR) 5.1 (2.7-9.8)). Ultrasound features were present in 25-33% of CMC-1 joints, though no associations were seen with pain. MRI-synovitis and BMLs grade ≥2 were scored in 25% and 43% of thumb bases, and positively associated with pain (OR 3.6 (95% CI 1.7-7.6) and 3.0 (1.6-5.5)). Associations attenuated after adjustment for osteophyte presence. Combined presence of osteophytes and MRI-synovitis had an additive effect. CONCLUSIONS: Ultrasonographic and MRI inflammatory features were often present in the thumb base. Osteophytes were more strongly associated with thumb base pain than inflammatory features, in contrast to findings in finger OA studies, supporting thumb base osteoarthritis as a distinct phenotype.