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.

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.

Ensemble Learning Method for the Continuous Decoding of Hand Joint Angles.

Human-machine interface technology is fundamentally constrained by the dexterity of motion decoding. Simultaneous and proportional control can greatly improve the flexibility and dexterity of smart prostheses. In this research, a new model using ensemble learning to solve the angle decoding problem is proposed. Ultimately, seven models for angle decoding from surface electromyography (sEMG) signals are designed. The kinematics of five angles of the metacarpophalangeal (MCP) joints are estimated using the sEMG recorded during functional tasks. The estimation performance was evaluated through the Pearson correlation coefficient (CC). In this research, the comprehensive model, which combines CatBoost and LightGBM, is the best model for this task, whose average CC value and RMSE are 0.897 and 7.09. The mean of the CC and the mean of the RMSE for all the test scenarios of the subjects' dataset outperform the results of the Gaussian process model, with significant differences. Moreover, the research proposed a whole pipeline that uses ensemble learning to build a high-performance angle decoding system for the hand motion recognition task. Researchers or engineers in this field can quickly find the most suitable ensemble learning model for angle decoding through this process, with fewer parameters and fewer training data requirements than traditional deep learning models. In conclusion, the proposed ensemble learning approach has the potential for simultaneous and proportional control (SPC) of future hand prostheses.

Association between hyperuricaemia and hand osteoarthritis: data from the Xiangya Osteoarthritis Study.

OBJECTIVE: The pathogenesis of hand osteoarthritis (OA) remains unknown. Hyperuricaemia, which is related to inflammation, may play a role in hand OA, but evidence is lacking. In a large population-based study, we examined the association between hyperuricaemia and hand OA. METHODS: Participants were from the Xiangya OA Study, a community-based observational study. Hyperuricaemia was defined as serum urate >416 µmol/L in men and >357 µmol/L in women. Radiographic hand OA (RHOA) was defined as presence of the modified Kellgren-Lawrence grade ≥2 in any hand joint. Symptomatic hand OA (SHOA) was defined as presence of both self-reported symptoms and RHOA in the same hand. The associations of hyperuricaemia with RHOA or SHOA were examined using generalised estimating equations. RESULTS: Among 3628 participants, the prevalence of RHOA was higher in participants with hyperuricaemia than those with normouricaemia (26.9% vs 20.9%), with an adjusted OR (aOR) of 1.34 (95% CI 1.11 to 1.61). The associations were consistent in men (aOR 1.33, 95% CI 1.01 to 1.74) and women (aOR 1.35, 95% CI 1.05 to 1.74). Hyperuricaemia was mainly associated with bilateral RHOA (aOR 1.54, 95% CI 1.18 to 2.01) but not unilateral RHOA (aOR 1.13, 95% CI 0.89 to 1.45). Prevalence of SHOA was higher, although statistically insignificant, in participants with hyperuricaemia (aOR 1.39, 95% CI 0.94 to 2.07). CONCLUSION: In this population-based study, hyperuricaemia was associated with a higher prevalence of hand OA. Future prospective studies are required to investigate the temporal relationship. TRIAL REGISTRATION NUMBER: NCT04033757.

Total joint arthroplasty versus trapeziectomy in the treatment of trapeziometacarpal joint arthritis: a randomized controlled trial.

The aim of this double anonymized, randomized controlled trial was to determine whether total joint arthroplasty has superior outcomes than trapeziectomy 1 year after surgery for trapeziometacarpal osteoarthritis. A total of 62 women aged 40 years and older, scheduled for surgery for stage II or III osteoarthritis of the trapeziometacarpal joint, were included and randomized to trapeziectomy or total joint arthroplasty. The primary outcome was the total score of the Michigan Hand Outcomes Questionnaire. Secondary outcomes were the Michigan Hand Outcomes Questionnaire subscale scores, Disability of the Arm, Shoulder and Hand Questionnaire, active range of motion, strength, return to work, patient satisfaction and complications. Data were collected at baseline and at 3 and 12 months. At 1 year, we found no superiority of total joint arthroplasty over trapeziectomy regarding the total score of the Michigan Hand Outcomes Questionnaire. The total joint arthroplasty did show a significant advantage in strength and range of motion.Level of evidence: I.

Measuring Arm and Hand Joint Kinematics to Estimate Impairment During a Functional Reach and Grasp Task after Stroke.

BACKGROUND: Current approaches to characterizing deficits in upper limb movements after stroke typically focus either on changes in a functional measure, for example, how well a patient can complete a task, or changes in impairment, for example, isolated measurements of joint range of motion. However, there can be notable dissociations between static measures of impairment versus those of function. OBJECTIVE: We develop a method to measure upper limb joint angles during performance of a functional task and use measurements to characterize joint impairment in the context of a functional task. METHODS: We developed a sensorized glove that can precisely measure select finger, hand, and arm joints while participants complete a functional reach-to-grasp task involving manipulation of a sensorized object. RESULTS: We first characterized the accuracy and precision of the glove's joint angle measurements. We then measured joint angles in neurologically intact participants (n = 4 participants, 8 limbs) to define the expected distribution of joint angle variation during task execution. These distributions were used to normalize finger, hand, and arm joint angles in stroke participants (n = 6) as they performed the task. We present a participant-specific visualization of functional joint angle variance which illustrated that stroke participants with nearly identical clinical scores exhibited unique patterns of joint angle variation. CONCLUSIONS: Overall, measuring individual joint angles in the context of a functional task may inform whether changes in functional scores over recovery or rehabilitation are driven by changes in impairment or the development of compensatory strategies, and provide a quantified path toward personalized rehabilitative therapy.

Patterns of Involvement of the Hand Joints in Classical Rheumatoid Arthritis.

BACKGROUND: Symmetrical involvement of the hand joints is described as characteristic of rheumatoid arthritis (RA). Quantitative data on specific patterns of involvement are lacking. OBJECTIVE: The Brigham Rheumatoid Arthritis Sequential Study was created for observational studies of patients with RA and afforded a unique opportunity to answer these questions. METHODS: Of 1598 subjects in the Brigham Rheumatoid Arthritis Sequential Study cohort, 535 met the following criteria: (1) disease duration of 7 years or greater, (2) seropositive, and (3) hand radiographs available. Patterns in specific hand joints based on physical examination and radiographic findings obtained at entry were identified. The level of symmetry of involvement of the metacarpophalangeal (MCP) and wrist joints was determined, as was the correlation between findings on physical examination and radiographic changes in the hand joints. RESULTS: The prevalence of joint space narrowing and/or erosions in each proximal interphalangeal (PIP) joints ranged between 11% and 18%. Joint space narrowing and/or erosions in the MCPs increased radially from the fifth to the second finger. Swelling and tenderness on physical examination of both the PIPs and MCPs also increased radially although the positive predictive value of physical examination as an indicator of joint damage decreased radially. The wrist was the most common joint involved both by physical examination (67%) and radiographically (70%). The right side was more involved radiographically. Analysis of radiographic changes in individual patients revealed that symmetrical findings in the wrists and MCPs occurred in only 67% of patients. CONCLUSIONS: The study describes the pattern of involvement of the hand joints in patients with long standing RA. Findings of interest include symmetrical involvement in only 67% of patients and a discordancy between physical findings and radiographic changes most marked in the more radial PIP joints.

Serum carboxymethyllysine concentration is associated with erosive hand osteoarthritis.

OBJECTIVE: Carboxymethyllysine (CML) and homocitrulline (HCit) are the products of two non-enzymatic post-translational modifications of protein, a process related to age. We investigated whether serum CML and HCit concentrations were associated with hand osteoarthritis (HOA), especially erosive HOA. DESIGN: Serum CML and HCit were measured by using liquid chromatography coupled with tandem mass spectrometry at inclusion in 386 patients included in the DIGItal Cohort Design (DIGICOD) cohort. We investigated whether serum CML and/or HCit concentrations were associated with erosive HOA or with HOA clinical and radiological features. Moreover, we compared the tissular concentrations of CML and HCit in OA and non-OA cartilage from proximal interphalangeal and metacarpo-phalangeal (MCP) joints from human cadaveric donors. RESULTS: Median (IQR) serum CML concentration was lower in patients with erosive HOA than those with non-erosive HOA (178.7 [157.1-208.8] vs 194.7 [168.9-217.1] µmol/mol Lys, P = 0.002), but median HCit concentration did not differ between the groups (193.9 [162.9-232.0] vs 193.9 [155.9-224.6] µmol/mol Lys). Cartilage HCit and CML concentrations were not correlated with clinical features. Serum CML concentration was higher in OA than non-OA MCPs (7.0 vs 4.0 mmol/mol Lys, P = 0.01). CONCLUSIONS: Serum CML concentration was lower in erosive HOA than non-erosive HOA, and cartilage CML concentration was higher in OA than non-OA cartilage. These results encourage further studies to test whether serum CML could be a new prognostic biomarker in HOA.

Meta-analysis of erosive hand osteoarthritis identifies four common variants that associate with relatively large effect.

OBJECTIVES: Erosive hand osteoarthritis (EHOA) is a severe subset of hand osteoarthritis (OA). It is unclear if EHOA is genetically different from other forms of OA. Sequence variants at ten loci have been associated with hand OA but none with EHOA. METHODS: We performed meta-analysis of EHOA in 1484 cases and 550 680 controls, from 5 populations. To identify causal genes, we performed eQTL and plasma pQTL analyses, and developed one zebrafish mutant. We analysed associations of variants with other traits and estimated shared genetics between EHOA and other traits. RESULTS: Four common sequence variants associated with EHOA, all with relatively high effect. Rs17013495 (SPP1/MEPE, OR=1.40, p=8.4×10-14) and rs11243284 (6p24.3, OR=1.35, p=4.2×10-11) have not been associated with OA, whereas rs11631127 (ALDH1A2, OR=1.46, p=7.1×10-18), and rs1800801 (MGP, OR=1.37, p=3.6×10-13) have previously been associated with hand OA. The association of rs1800801 (MGP) was consistent with a recessive mode of inheritance in contrast to its additive association with hand OA (OR homozygotes vs non-carriers=2.01, 95% CI 1.71 to 2.37). All four variants associated nominally with finger OA, although with substantially lower effect. We found shared genetic components between EHOA and other OA measures, grip strength, urate levels and gout, but not rheumatoid arthritis. We identified ALDH1A2, MGP and BMP6 as causal genes for EHOA, with loss-of-function Bmp6 zebrafish mutants displaying EHOA-like phenotypes. CONCLUSIONS: We report on significant genetic associations with EHOA. The results support the view of EHOA as a form of severe hand OA and partly separate it from OA in larger joints.

The role of ultrasound synovitis scores for patients who are at risk of rheumatoid arthritis.

OBJECTIVES: The development of rheumatoid arthritis (RA) has been classified into 6 phases A-F according to the present risk factors in sequence of genes, environments, autoimmunity, arthralgia and joint swelling. To clarify the ultrasound synovitis scores in at-risk patients (phases C-E) and RA (phase F). METHODS: Patients who had been experiencing hand joint symptoms for at least 6 weeks and asymptomatic patients with positive rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies were enrolled. A 40-joint ultrasonography with semiquantitative synovitis scoring for gray scale (GS) and power Doppler (PD) images was performed. RESULTS: A total of 139 patients were enrolled and classified into non-RA, phase C, phase D, phase E and phase F. Total GS scores in phases C (17.4 ± 7.0), D (16.0 ± 5.4), E (18.5 ± 7.7) and F (21.8 ± 9.1) were higher than those in non-RA (9.8 ± 4.0, P < 0.001). The total PD score in phase F (3.1 ± 4.6) was higher than that in phases C (0.2 ± 0.5), D (0.1 ± 0.4), and E (0.1 ± 0.3), as well as in non-RA (0.0 ± 0.0, P < 0.01). A total GS score ≥14 differentiated patients at risk for RA from patients with non-RA (area under curve [AUC] 0.82), while a total PD score ≥2 differentiated patients with RA from patients at risk for RA (AUC 0.71). CONCLUSION: Total GS score may differentiate patients at risk for RA from non-RA patients, while total PD score may differentiate patients with RA from those who are at risk for RA.

Analysis of Hand Joint Space Morphology in Women and Men with Hereditary Hemochromatosis.

Hereditary hemochromatosis (HH) causes unbalanced iron deposition in many organs including the joints leading to severe cartilage loss and bone damage in the metacarpophalangeal joints (MCPJ). High-resolution peripheral quantitative computed tomography (HR-pQCT) and its joint space width (JSW) quantification algorithm quantifies in vivo 3D joint morphology. We therefore aimed to (i) determine feasibility and performance of the JSW algorithm in HH, (ii) quantify joint space morphology, and (iii) investigate the relationship between morphological and clinical parameters in HH. Here, we performed an exploratory study on 24 HH patients and sex- and age-matched controls using HR-pQCT imaging of MCPJ. Mineralized bone structure was automatically segmented from the grayscale image data and periosteal surface bone masks and joint space masks were generated. Mean, minimal, and maximal joint space width (JSW; JSW.MIN; JSW.MAX), JSW heterogeneity (JSW.SD), JSW asymmetry (JSW.AS), and joint space volume (JSV) were computed. Demographics and, for HH patients, disease-specific parameters were recorded. Segmentation of JS was very good with 79.7% of MCPJs successfully segmented at first attempt and 20.3% requiring semi-manual correction. HH men showed larger JSV at all MCPs (+ 25.4% < JSV < + 41.8%, p < 0.05), larger JSW.MAX at MCP 3-4 (+ 14%, 0.006 < p < 0.062), and wider JSW (+ 13%, p = 0.043) at MCP 4 relative to HH women. Compared to controls, both HH men and HH women showed larger JSW.AS and smaller JSW.MIN at all MCP levels, reaching significance for HH men at MCP 2 and 3 (JSW.AS: + 323% < JSW.AS < + 359%, 0.020 < p < 0.043; JSW.MIN: - 216% < JSW.MIN < - 225%, p < 0.043), and for women at MCP 3 (JSW.AS: + 180%, p = 0.025; JSW.MIN: - 41.8%, p = 0.022). Time since HH diagnosis was correlated positively with MCP 4 JSW.AS and JSW.SD (0.463 < ρ < 0.499, p < 0.040), and the number of phlebotomies since diagnosis was correlated with JSW.SD at all MCPs (0.432 < ρ < 0.535, p < 0.050). HR-pQCT-based JSW quantification in MCPJ of HH patients is feasible, performs well even in narrow JS, and allows to define the microstructural joint burden of HH.

Detecting hand joint ankylosis and subluxation in radiographic images using deep learning: A step in the development of an automatic radiographic scoring system for joint destruction.

We propose a wrist joint subluxation/ankylosis classification model for an automatic radiographic scoring system for X-ray images. In managing rheumatoid arthritis, the evaluation of joint destruction is important. The modified total Sharp score (mTSS), which is conventionally used to evaluate joint destruction of the hands and feet, should ideally be automated because the required time depends on the skill of the evaluator, and there is variability between evaluators. Since joint subluxation and ankylosis are given a large score in mTSS, we aimed to estimate subluxation and ankylosis using a deep neural network as a first step in developing an automatic radiographic scoring system for joint destruction. We randomly extracted 216 hand X-ray images from an electronic medical record system for the learning experiments. These images were acquired from patients who visited the rheumatology department of Keio University Hospital in 2015. Using our newly developed annotation tool, well-trained rheumatologists and radiologists labeled the mTSS to the wrist, metacarpal phalangeal joints, and proximal interphalangeal joints included in the images. We identified 21 X-ray images containing one or more subluxation joints and 42 X-ray images with ankylosis. To predict subluxation/ankylosis, we conducted five-fold cross-validation with deep neural network models: AlexNet, ResNet, DenseNet, and Vision Transformer. The best performance on wrist subluxation/ankylosis classification was as follows: accuracy, precision, recall, F1 value, and AUC were 0.97±0.01/0.89±0.04, 0.92±0.12/0.77±0.15, 0.77±0.16/0.71±0.13, 0.82±0.11/0.72±0.09, and 0.92±0.08/0.85±0.07, respectively. The classification model based on a deep neural network was trained with a relatively small dataset; however, it showed good accuracy. In conclusion, we provided data collection and model training schemes for mTSS prediction and showed an important contribution to building an automated scoring system.

Determination and characterization of patient subgroups based on pain trajectories in hand osteoarthritis.

OBJECTIVES: To investigate pain, pain trajectories and their determinants in hand osteoarthritis (OA). METHODS: Data from the HOSTAS (Hand OSTeoArthritis in Secondary care) consisting of consecutive hand OA patients were used. Australian Canadian Osteoarthritis Hand Index (AUSCAN) pain was measured yearly for four years. Patients with complete AUSCAN at ≥2 time points were eligible for longitudinal analysis. Associations between variables of interest and baseline AUSCAN pain were investigated with linear regression. Development of pain over time was modelled using latent class growth analysis (LCGA). Associations of LCGA classes with variables of interest were analysed using multinomial logistic regression adjusted for baseline pain. RESULTS: A total of 484/538 patients [mean (s.d.) age 60.8 (8.5) years, 86% women, mean (s.d.) AUSCAN pain 9.3 (4.3)] were eligible for longitudinal analysis. Sex, marital and working status, education, disease duration and severity, anxiety and depression scores, lower health-related quality of life (HR-QoL), specific illness perceptions and coping styles were associated with baseline pain. LCGA yielded three classes, characterized by average pain levels at baseline; average pain remained stable over time within classes. Classes with more pain were positively associated with BMI, tender joint count, symptom duration, hand function scores and depression scores, negatively with physical HR-QoL, and education level. CONCLUSION: Baseline pain was associated with patient and disease characteristics, and psychosocial factors. LCGA showed three pain trajectories in hand OA patients, with different baseline pain levels and stable pain over time. Classes were distinguished by BMI, education level, disease severity, depression and HR-QoL.

Identification of Symptom Phenotypes of Hand Osteoarthritis Using Hierarchical Clustering: Results From the DIGICOD Cohort.

OBJECTIVE: We aimed to delineate phenotypes in hand osteoarthritis (HOA) based on cardinal symptoms (pain, functional limitation, stiffness, and aesthetic discomfort). METHODS: With data from the Digital Cohort Design (DIGICOD), we performed a hierarchical agglomerative clustering analysis based on Australian/Canadian Osteoarthritis Hand Index (AUSCAN) subscores for pain, physical function, stiffness, and visual analog scale for aesthetic discomfort. Kruskal-Wallis and post hoc analyses were used to assess differences between clusters. RESULTS: Among 389 patients, we identified 5 clusters: cluster 1 (n = 88) and cluster 2 (n = 91) featured low and mild symptoms; cluster 3 (n = 80) featured isolated aesthetic discomfort; cluster 4 (n = 42) featured a high level of pain, stiffness, and functional limitation; and cluster 5 (n = 88) had the same features as cluster 4 but with high aesthetic discomfort. For clusters 4 and 5, AUSCAN pain score was >41 of 100, representing only one-third of our patients. Aesthetic discomfort (clusters 3 and 5) was significantly associated with erosive HOA and a higher number of nodes. The highly symptomatic cluster 5 was associated but not significantly with metabolic syndrome, and body mass index and C-reactive protein level did not differ among clusters. Symptom intensity was significantly associated with joint destruction as well as with physical and psychological burden. Patients' main expectations differed among clusters, and function improvement was the most frequent expectation overall. CONCLUSION: The identification of distinct clinical clusters based on HOA cardinal symptoms suggests previously undescribed subtypes of this condition, warranting further study of biological characteristics of such clusters, and opening a path toward phenotype-based personalized medicine in HOA.

Folate deficiency is associated with increased radiographic severity of osteoarthritis in knee joints but not in hand joints.

OBJECTIVES: No previous studies have explored the effect of folate deficiency on the severity of osteoarthritis (OA). Therefore, we investigated the relationship between folate level and features on knee and hand radiographs in a large, population-based OA cohort. METHODS: Among 9,260 subjects enrolled in the Dong-gu study, 2,489 who had knee and hand joint radiographs were included. Of these, subjects with a history of amputation or total knee replacement were excluded. Serum folate levels were measured using blood samples collected at the time of enrolment and stored. A semi-quantitative system was used to grade the severity of hand and knee x-ray changes. Linear regression was performed to assess relationships between serum folate levels and knee and hand radiographic scores after adjusting for age, sex, body mass index, smoking, alcohol consumption, education, physical activity, occupation, vitamin D, and ferritin. RESULTS: A total of 2,322 subjects were recruited. After adjusting for confounders, participants with folate deficiency (<4 ng/mL) had higher total (p<0.001), osteophyte (p<0.001), joint space narrowing (p=0.002), tibial attrition (p<0.001), and sclerosis (p=0.005) scores for knee joint radiographs compared to participants with a normal folate level. After adjusting for confounders, the radiographic scores for hand joints did not differ between the groups. CONCLUSIONS: Folate deficiency is associated with increased radiographic severity of OA in knee joints, but not in hand joints. Further studies are needed to explore the differential effects of folate on the severity of knee and hand OA.

The biomechanics of osteoarthritis in the hand: Implications and prospects for hand therapy.

BACKGROUND: The unique anatomy of the human hand makes it possible to carefully manipulate tools, powerfully grasp objects, and even throw items with precision. These apparent contradictory functions of the hand, high mobility for manual dexterity vs high stability during forceful grasping, imply that daily activities impose a high strain on a relatively instable joint. This makes the hand susceptible to joint disorders such as osteoarthritis. Both systemic (eg, genetics, hormones) and mechanical factors (eg, joint loading) are important in the development of osteoarthritis, but the precise pathomechanism remains largely unknown. This paper focuses on the biomechanical factors in the disease process and how hand therapists can use this knowledge to improve treatment and research. CONCLUSION: Multiple factors are involved in the onset and development of osteoarthritis in the hand. Comprehension of the biomechanics helps clinicians establish best practices for orthotics intervention, exercise, and joint protection programs even in de absence of clear evidence-based guidelines. The effect and reach of hand therapy for OA patients can be expanded substantially when intervention parameters are optimized and barriers to early referrals, access reimbursement, and adherence are addressed. Close and early collaboration between hand therapists and primary care, women's health, rheumatology, and hand surgery providers upon diagnosis, and with hand surgeons pre and postoperatively, combined with advances in the supporting science and strategies to enhance adherence, appear to be a promising way forward.

Association between radiographic hand osteoarthritis and bone microarchitecture in a population-based sample.

BACKGROUND: Subchondral bone plays an important role in the pathogenesis of radiographic osteoarthritis (OA). However, the bony changes that occur in hand OA (HOA) are much less understood. This study aimed to describe the association between radiographic HOA and high-resolution peripheral quantitative computed tomography (HRpQCT) measures of the hand and radius in a population-based sample. METHODS: A total of 201 participants (mean age 72, 46% female) from the Tasmanian Older Adult Cohort (TASOAC) study underwent HRpQCT assessment of the 2nd distal and proximal interphalangeal (DIP, PIP), 1st carpometacarpal (CMC) joint, and distal radius. Radiographic HOA was assessed at the 2nd DIP, PIP joints, and the 1st CMC joint using the OARSI atlas. RESULTS: Proximal osteophyte and joint space narrowing (JSN) scores were consistently more strongly associated with HRpQCT measures compared to the distal site with positive associations for indices of bone size (total and trabecular bone area and cortical perimeter but inconsistent for cortical area) and negative associations for volumetric bone mineral density (vBMD). There was a decrease in trabecular number and bone volume fraction with increasing osteophyte and JSN score as well as an increase in trabecular separation and inhomogeneity. Osteophyte and JSN scores in the hand were not associated with HRpQCT measures at the distal radius. CONCLUSIONS: This hypothesis generating data suggests that bone size and trabecular disorganization increase with both osteophyte formation and JSN (proximal more than distal), while local vBMD decreases. This process appears to be primarily at the site of pathology rather than nearby unaffected bone.

Dorso-ventral osteophytes of interphalangeal joints correlate with cartilage damage and synovial inflammation in hand osteoarthritis: a histological/radiographical study.

OBJECTIVE: To detect dorsally located osteophytes (OP) on lateral x-ray views and to correlate their presence with the extent of structural joint damage, determined by histologic grading (cartilage damage and synovial inflammation) and radiographic scoring in hand osteoarthritis (HOA). METHODS: Distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints were obtained from post mortem specimens (n = 40). Multiplanar plain x-rays were taken (dorso/palmar (dp) and lateral views). Radiographic OA was determined by the Kellgren and Lawrence classification. Joint samples were prepared for histological analysis and cartilage damage was graded according to the Mankin scoring system. Inflammatory changes of the synovial membrane were scored using the general synovitis score (GSS). Spearman's correlation was applied to examine the relationship between histological and radiographical changes. Differences between groups were determined by Mann-Whitney test. RESULTS: Bony proliferations that were only detectable on lateral views but reminiscent of OPs on dp images were termed dorso-ventral osteophytes (dvOPs). All joints displaying dvOPs were classified as OA and the presence of dvOPs in DIP and PIP joints correlated with the extent of histological and radiographic joint damage, as well as with patient age. Joint damage in osteoarthritic DIP and PIP joints without any dvOPs was less severe compared to joints with dvOPs. Synovial inflammation was mainly present in joints displaying dvOPs and correlated with joint damage. CONCLUSION: dvOPs are associated with increasing structural alterations in DIP and PIP joints and can be seen as markers of advanced joint damage. Detecting dvOPs can facilitate the diagnosis process and improve damage estimation in HOA.