Bone mineral density in patients with hand osteoarthritis compared to population controls and patients with rheumatoid arthritis

Three-Dimensional Analysis of the Trapezium Subchondral Bone and its Association with Trapeziometacarpal Joint Osteoarthritis

Subchondral bone properties are associated with the pathogenesis of osteoarthritis (OA), but this relationship has not been confirmed in the trapeziometacarpal joint (TMCJ). We aimed to evaluate the thickness (SBT) and density (SBD) of three-dimensional (3D) trapezium subchondral bone models derived from computed tomography (CT) images, and their relationships with early-stage TMCJ OA. We reviewed patients with a distal radius fracture who underwent conventional CT scans and such osteoporosis evaluations as bone mineral density (BMD) and bone turnover markers (BTMs). From 3D trapezium subchondral bone models, we measured SBT and SBD according to the OA stage and performed multivariate analyses to evaluate their associations with age, sex, body mass index, BMD, and BTMs. As results, a total of 156 patients (78 men and 78 age-matched women; mean age, 67 ± 10 years) were analyzed. There were 30 (19%) with grade 0, 71 (45%) with grade 1, 13 (8%) with grade 2, and 42 (27%) with grade 3 TMCJ OA. SBT was significantly lower in patients with grade 1 OA than those with grade 0 or grade 3 OA, but SBD generally increased according to the OA severity. Low SBT was associated with low BMD, and low SBD with low BMD, high osteocalcin levels, and severe OA grades. In conclusion, patients with early-stage radiographic TMCJ OA have a lower SBT at the trapezium, which may support the potential role of subchondral bone in OA pathogenesis. This study also shows that subchondral bone properties are associated with BMD and osteocalcin levels.

The prevalence of osteoporosis in rheumatoid arthritis patient: a systematic review and meta-analysis

Osteoporosis (OP) is one of the most commonly known extra-articular complications of rheumatoid arthritis (RA). Since the prevalence of OP is diverse in different studies and there is no general consensus about it, in this systematic review, we aimed to investigate the global prevalence of OP among RA patients. In this review, three databases including Medline via PubMed, Scopus, and Web of Science (Clarivate analytics) were searched by various keywords. After screening of retrieved papers, the related data of included papers were extracted and analyzed. To assess the risk of methodological bias of included studies, quality assessment checklist for prevalence studies was used. Because of heterogeneity among studies, random-effect model was used to pooled the results of primary studies. In this review, the results of 57 studies were summarized and the total included sample size was 227,812 cases of RA with 64,290 cases of OP. The summary point prevalence of OP among RA was estimated as 27.6% (95%CI 23.9-31.3%). Despite significant advances in prevention, treatment and diagnostic methods in these patients, it still seems that the prevalence of OP in these patients is high and requires better and more timely interventions.

Prevalence of osteoporosis in osteoarthritis: a systematic review and meta-analysis

Data are contradictory regarding the relationship between osteoarthritis (OA) and osteoporosis (OP) with some studies showing the increased risk of OP in OA. The study was conducted to determine whether OP prevalence is increased in patients with OA, compared to age and sex-matched population. MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane Library (inception-2019) were searched for studies reporting the frequency, rate, prevalence, incidence, risk, or excess risk of OP in patients with OA compared to age and sex-matched population. Estimates were combined using a random effects model. Consistency was evaluated using the I² statistic. Articles with fewer than 200 participants were excluded. Of 2772 articles, 49 had full article screening, and 8 articles met the inclusion criteria. Other articles reporting mean BMD and not OP were excluded. In women, 998 participants with OA were compared with 1903 controls. The pooled estimate of the odds ratio for prevalence of OP vs general matched population was not statistically different. In men, 136 participants with OA were compared with 682 controls. The results did not show a statistically significant difference in the frequency of OP in OA in men. According to the site of bone mineral density measurement, a higher prevalence of OP at lumbar spine was found in both men and women. The frequency of OP overall in participants with OA was not different, except for a higher prevalence of OP in lumbar spine in both men and women compared to the matched controls.

An in-depth study of the associations between osteoarthritis- and osteoporosis-related phenotypes at different skeletal locations

The relationship between OA and osteoporosis characteristics remains controversial. This study revealed that age-adjusted hand OA is associated with lower hand/arm BMD levels. Wrist fracture occurrence is associated with increased OA hand scores and low arm BMD. Conversely, age-adjusted knee and spine OA is associated with high spine, hip, and total BMDs.

INTRODUCTION

Osteoarthritis (OA) and osteoporosis are two common musculoskeletal diseases which contribute a high burden of disability, yet assessments of their relationship remains controversial. The aim of this study was to clarify the association between bone mineral densities (BMD) of the hand, arm, spine, hip, and total body, and OA of the hand and knee and lumbar disc degeneration in two different ethnic groups.

METHODS

Radiographic assessments of the hand, knee, and spine were collected and coded for joint space narrowing, osteophytes, and the Kellgren-Lawrence score from Chuvashian (n = 1504) and British (n = 2280) individuals. BMD measurements of standard skeletal sites were estimated by dual X-ray absorptiometry. Age- and familial-adjusted regression analyses were conducted to determine associations.

RESULTS

Knee OA affection was positively associated with elevated hip, spine, and total body BMD levels (p < 0.001). Additionally, disc degeneration phenotypes showed significant positive associations with the hip, spine, and total BMD (p < 0.001). However, increased hand OA scores was significantly negatively correlated with arm and hand BMD measurements in males and females in both samples (p < 0.001). Additionally, higher hand OA scores were significantly associated with wrist fracture.

CONCLUSIONS

We discovered a clear pattern of association between hand OA and low hand and arm BMD, with increased risk of wrist fracture, as well as reproducing previous associations between knee and spine OA and elevated spine, hip, and total body BMD. It appears that hand OA manifests differently in comparison to hip and knee OA.

Longitudinal changes in bone mineral density and trabecular bone score in Korean adults: a community-based prospective study

The bone mineral densities (BMDs) of the femoral neck and total hip, and the lumbar spine trabecular bone score (TBS), tended to decrease with age in both men and women, whereas the lumbar spine BMD tended to increase. Lumbar spine BMD is thus inappropriate for evaluating longitudinal changes in bone loss; the lumbar spine TBS is an alternative measure.

PURPOSE

Aging is associated with a decrease in bone mass and quality. This community-based prospective cohort study investigated longitudinal changes in bone phenotype in Korean adults.

METHODS

We analyzed data from a prospective community-based cohort study, the Korean Genome and Epidemiology Study. Postmenopausal women and men who underwent dual-energy X-ray absorptiometry at least twice from 2007 to 2014 were included. Longitudinal changes in bone mineral density (BMD) and trabecular bone score (TBS) over 6 years were analyzed by sex, age, and body mass index.

RESULTS

A total of 1895 subjects were enrolled (men 965; postmenopausal women 929). The femoral neck (FN) BMD, total hip (TH) BMD, and lumbar spine (LS) TBS decreased significantly over time, but the LS BMD increased significantly. In men, the average annual changes were 0.3% in LS BMD (p < 0.001), - 0.33% in FN BMD (p < 0.001), - 0.26% in TH BMD (p = 0.001), and - 0.27% in LS TBS (p < 0.001). In women, the average annual changes were 0.27% in LS BMD (p < 0.001), - 0.67% in FN BMD (p < 0.001), - 0.66% in TH BMD (p < 0.001), and - 0.27% in LS TBS (p < 0.001). The longitudinal decrease in TH BMD over time was significantly greater in women (versus men) and those who were older (versus younger).

CONCLUSION

The FN and TH BMDs decreased with aging. But, the LS BMD was inappropriate to evaluate longitudinal changes of bone loss. The LS TBS could be alterative.

Unknown osteoporosis in older patients admitted to post-acute rehabilitation

BACKGROUND

Osteoporotic fractures are associated with increased morbidity, mortality, and increased health care use. As the number of older adults increases, identifying those at increased risk for osteoporotic fractures has become of utmost importance to providing them with preventive and therapeutic interventions.

AIMS

To determine the prevalence of unknown clinical and densitometric osteoporosis and to investigate the performance of different diagnostic strategies for osteoporosis in elderly patients admitted to rehabilitation.

METHOD

This is an observational study. Eligible participants were older adults admitted to rehabilitation in an academic hospital in Switzerland over an 11-month period. Patients with previously unknown osteoporosis underwent dual-energy X-ray absorptiometry (DXA), vertebral fracture assessment (VFA), and history review for past fractures.

RESULTS

Complete assessment was available for 252 patients. Previously undiagnosed osteoporosis was identified in 62.3% of these patients, a proportion that was higher among women (71.5%) than men (44.8%). DXA proved most sensitive, followed by VFA and history review. Results differed across gender: DXA remained the most sensitive single test among women, but VFA proved most sensitive in men. The best test to combine with history review was DXA in women (detection increasing from 47.5 to 93.2%) and VFA in men (detection increasing from 35.9 to 84.6%).

CONCLUSIONS

Prevalence of previously unknown osteoporosis appears very high in elderly patients admitted to post-acute rehabilitation. The combination of history review of previous fractures with DXA in women and with VFA in men appears the best two-step strategy to improving detection of osteoporosis in this population.

Surface damage of bovine articular cartilage-off-bone: the effect of variations in underlying substrate and frequency

BACKGROUND

Changes in bone mineral density have been implicated with the onset of osteoarthritis, but its role in inducing failure of articular cartilage mechanically is unclear. This study aimed to determine the effect of substrate density, as the underlying bone, on the surface damage of cartilage-off-bone, at frequencies associated with gait, and above.

METHODS

Bovine articular cartilage samples were tested off-bone to assess induced damage with an indenter under a compressive sinusoidal load range of 5-50 N at frequencies of 1, 10 and 50 Hz, corresponding to normal and above normal gait respectively, for up to 10,000 cycles. Cartilage samples were tested on four underlying substrates with densities of 0.1556, 0.3222, 0.5667 and 0.6000 g/cm3. India ink was applied to identify damage as cracks, measured across their length using ImageJ software. Linear regression was performed to identify if statistical significance existed between substrate density, and surface damage of articular cartilage-off-bone, at all three frequencies investigated (p < 0.05).

RESULTS

Surface damage significantly increased (p < 0.05) with substrate density at 10 Hz of applied frequency. Crack length at this frequency reached the maximum of 10.95 ± 9.12 mm (mean ± standard deviation), across all four substrates tested. Frequencies applied at 1 and 50 Hz failed to show a significant increase (p > 0.05) in surface damage with an increase in substrate density, at which the maximum mean crack length were 3.01 ± 3.41 mm and 5.65 ± 6.54 mm, respectively. Crack formation at all frequencies tended to form at the periphery of the cartilage specimen, with multiple straight-line cracking observed at 10 Hz, in comparison to single straight-line configurations produced at 1 and 50 Hz.

CONCLUSIONS

The effect of substrate density on the surface damage of articular cartilage-off-bone is multi-factorial, with an above-normal gait frequency. At 1 Hz cartilage damage is not associated with substrate density, however at 10 Hz, it is. This study has implications on the effects of the factors that contribute to the onset of osteoarthritis.

Trabecular bone texture detected by plain radiography is associated with MRI-defined osteophytes in finger joints of women without radiographic osteoarthritis

OBJECTIVE

To examine associations between trabecular bone (TB) texture and magnetic resonance imaging (MRI)-defined osteophytes in finger joints without radiographic osteoarthritis (OA) using an augmented variance orientation transform (AVOT) method.

DESIGN

In a cross-sectional study, associations of the TB texture and osteophytes were examined in 21 women with mean (standard deviation) age of 69.9 (5.3) from the Oslo Hand OA cohort. The AVOT was applied to distal and proximal TB regions selected on hand radiographs of the subjects. The regions were adjacent to 57 finger joints (24 distal and 33 proximal interphalangeal) without radiographic OA (Kellgren-Lawrence [KL] grade 0), without MRI-defined joint space narrowing (JSN), bone marrow lesions (BMLs), attrition, erosion, cysts, sclerosis, malalignment (all MRI grades 0) and without or only with mild synovitis (MRI grade 0 or 1). Bone texture parameters were calculated: mean fractal dimension (FD_MEAN), FDs in the horizontal (FD_H) and vertical (FD_V) directions, and along the roughest part (FD_Sta). Associations between the parameters categorized into groups using tertiles and osteophytes were evaluated using logistic regression adjusted for age.

RESULTS

Lower FD_Sta and FD_V in the distal TB regions were associated with increased odds of MRI-defined osteophytes (P < 0.037 for linear trend). No statistically significant associations were found for the proximal regions.

CONCLUSIONS

Lower mean roughness and lower roughness in vertical and roughest directions of the proximal TB texture are associated with MRI-defined osteophytes in finger joints without radiographic OA. These findings suggest that TB texture may be a useful marker for detecting early hand OA.

Trapezium Bone Density-A Comparison of Measurements by DXA and CT

Bone density may influence the primary fixation of cementless implants, and poor bone density may increase the risk of implant failure. Before deciding on using total joint replacement as treatment in osteoarthritis of the trapeziometacarpal joint, it is valuable to determine the trapezium bone density. The aim of this study was to: (1) determine the correlation between measurements of bone mineral density of the trapezium obtained by dual-energy X-ray absorptiometry (DXA) scans by a circumference method and a new inner-ellipse method; and (2) to compare those to measurements of bone density obtained by computerized tomography (CT)-scans in Hounsfield units (HU). We included 71 hands from 59 patients with a mean age of 59 years (43–77). All patients had Eaton–Glickel stage II–IV trapeziometacarpal (TM) joint osteoarthritis, were under evaluation for trapeziometacarpal total joint replacement, and underwent DXA and CT wrist scans. There was an excellent correlation (r = 0.94) between DXA bone mineral density measures using the circumference and the inner-ellipse method. There was a moderate correlation between bone density measures obtained by DXA- and CT-scans with (r = 0.49) for the circumference method, and (r = 0.55) for the inner-ellipse method. DXA may be used in pre-operative evaluation of the trapezium bone quality, and the simpler DXA inner-ellipse measurement method can replace the DXA circumference method in estimation of bone density of the trapezium.

The Prevalence, Incidence, and Progression of Hand Osteoarthritis in Relation to Body Mass Index, Smoking, and Alcohol Consumption

OBJECTIVE

To estimate the extent that overweight/obesity, smoking, and alcohol are associated with prevalence and longitudinal changes of radiographic hand osteoarthritis (OA).

METHODS

Participants from the Osteoarthritis Initiative (n = 1232) were included, of whom 994 had 4-year followup data. In analyses on incident hand OA, only persons without hand OA at baseline were included (n = 406). Our exposure variables were overweight/obesity [body mass index (BMI), waist circumference], smoking (current/former, smoking pack-yrs), and alcohol consumption (drinks/week). Using linear and logistic regression analyses, we analyzed possible associations between baseline exposure variables and radiographic hand OA severity, erosive hand OA, incidence of hand OA, and radiographic changes. Analyses were adjusted for age, sex, and education.

RESULTS

Neither overweight nor obesity were associated with hand OA. Current smoking was associated with less hand OA in cross-sectional analyses, whereas longitudinal analyses suggested higher odds of incident hand OA in current smokers (OR 2.20, 95% CI 1.02-4.77). Moderate alcohol consumption was associated with higher Kellgren-Lawrence sum score at baseline (1-3 drinks: 1.55, 95% CI 0.43-2.67) and increasing sum score during 4-year followup (4-7 drinks: 0.33, 95% CI 0.01-0.64). Moderate alcohol consumption (1-7 drinks/week) was associated with 2-fold higher odds of erosive hand OA, which was statistically significant. Additional adjustment for BMI gave similar strengths of associations.

CONCLUSION

Overweight/obesity were not associated with hand OA. Contrasting results were observed for smoking and hand OA, suggesting lack of association. Moderate alcohol consumption was associated with hand OA severity, radiographic changes, and erosive hand OA, warranting further investigation.

The lumbar spine age-related degenerative disease influences the BMD not the TBS: the Osteolaus cohort

We evaluated the influence of degenerative disease and fractured vertebra on lumbar spine bone mineral density (BMD) and trabecular bone score (TBS) in 1500 women aged 50-80 years. TBS was not affected by a degenerative disease. While BMD increases after 62.5 years, TBS continues to decline. TBS should play a leading role in lumbar spine evaluation.

INTRODUCTION

After menopause, lumbar spine (LS) BMD and TBS values decrease. Degenerative disease (DD) increases with age and affect LS BMD. The aim of this study was to measure changes in LS BMD and TBS in women 50 to 80 years old, taking into account the impact of fractured vertebrae and DD.

METHODS

LS BMD, TBS, and vertebral fracture assessment were evaluated in the OsteoLaus cohort (1500 women, 50-80 years old). The exams were analyzed following ISCD guidelines to identify vertebrae with fractures or DD (Vex).

RESULTS

1443 women were enrolled: mean age 66.7 ± 11.7 years, BMI 25.7 ± 4.4. LS BMD and TBS were weakly correlated (r2 = 0.16). The correlation (Vex excluded) between age and BMD was +0.03, between age and TBS -0.34. According to age group, LS BMD was 1.2 to 3.2% higher before excluding Vex (p < 0.001). TBS had an insignificant change of <1% after excluding Vex. LS BMD (Vex) decreased by 4.6% between 52.5 and 62.5 years, and increased by 2.6% between 62.5 and 77.5 years. TBS (Vex excluded) values decreased steadily with age with an overall loss of 8.99% between 52.5 and 77.5 years. Spine TBS, femoral neck, and total hip BMD gradually decreased with age, reaching one SD between the oldest and youngest group.

CONCLUSIONS

TBS is not affected by DD. While BMD increases after 62.5 years, TBS continues to decline. For lumbar spine evaluation, in view of its independence from DD, TBS should play a leading role in the diagnosis in complement to BMD.

Fragility Fractures in Patients with Rheumatoid Arthritis and Osteoarthritis Compared with the General Population

Objective.

To determine the rate ratios of hip and distal radius fractures in patients with rheumatoid arthritis (RA), hip osteoarthritis (OA), and knee OA.

Methods.

Cohort study using healthcare data (1998–2012) covering the entire population of the Skåne region of Sweden.

Results.

We found an increased rate of hip fracture in both female [standardized fracture rate ratio (SFR) 1.54, 95% CI 1.40–1.70] and male patients with RA (SFR 1.81, 95% CI 1.51–2.17). The hip fracture rate in female OA was reduced by 10–20%, and trochanteric fracture tended to have a higher rate ratio compared with the cervical.

Conclusion.

The 50–80% increased rate of hip fracture adds to the total burden of RA while the shifted distribution of cervical/trochanteric fractures in OA is in support of subchondral bone alterations.

Osteoarthritis of the Distal Interphalangeal and First Carpometacarpal Joints is Associated with High Bone Mass in Women and Small Bone Size and Low Lean Mass in Men

Objective:

To determine if primary hand osteoarthritis (OA) is associated with abnormal bone and anthropometric traits.

Methods:

We used DXA to measure total body bone mineral density (BMD), femoral neck width (bone size) and total body lean and fat mass in 39 subjects with hand OA (primary DIP and/or CMC I) and 164 controls. Data are presented as mean Z-scores or Odds Ratios (OR) with 95% confidence intervals.

Results:

Women with hand OA had (compared to controls) higher BMD (0.5(0.1,0.9)) but similar bone size (-0.3(-0.8,0.2)), lean mass (0.3(-0.3,0.9)), fat mass (-0.1(-0.6,0.5)) and BMI (0.0(-0.6,0.6)). Men with hand OA had (compared to controls) similar BMD (-0.1(-0.7,0.6)), smaller bone size (-0.5(-1.1,-0.01)), lower lean mass (-0.6(-1.1,-0.04)), and similar fat mass (-0.2(-0.7,0.4)) and BMI -0.1(-0.6,0.6). In women, each SD higher BMD was associated with an OR of 1.8 (1.03, 3.3) for having hand OA. In men each SD smaller bone size was associated with an OR of 1.8 (1.02, 3.1) and each SD lower proportion of lean body mass with an OR of 1.9 (1.1, 3.3) for having hand OA.

Conclusion:

Women with primary DIP finger joint and/or CMC I joint OA have a phenotype with higher BMD while men with the disease have a smaller bone size and lower lean body mass.

Osteoarthritis and bone mineral density: are strong bones bad for joints?

Osteoarthritis (OA) is a common and disabling joint disorder affecting millions of people worldwide. In OA, pathological changes are seen in all of the joint tissues including bone. Although both cross-sectional and longitudinal epidemiological studies have consistently demonstrated an association between higher bone mineral density (BMD) and OA, suggesting that increased BMD is a risk factor for OA, the mechanisms underlying this observation remain unclear. Recently, novel approaches to examining the BMD-OA relationship have included studying the disease in individuals with extreme high bone mass, and analyses searching for genetic variants associated with both BMD variation and OA, suggesting possible pleiotropic effects on bone mass and OA risk. These studies have yielded valuable insights into potentially relevant pathways that might one day be exploited therapeutically. Although animal models have suggested that drugs reducing bone turnover (antiresorptives) may retard OA progression, it remains to be seen whether this approach will prove to be useful in human OA. Identifying individuals with a phenotype of OA predominantly driven by increased bone formation could help improve the overall response to these treatments. This review aims to summarise current knowledge regarding the complex relationship between BMD and OA.

Patients with knee osteoarthritis have a phenotype with higher bone mass, higher fat mass, and lower lean body mass

BACKGROUND

Although knee osteoarthritis (OA) is common, its etiology is poorly understood. Specifically, it is not known whether knee OA is associated with abnormal anthropometric and musculoskeletal characteristics known to be associated with OA in general. We recently studied this topic for patients with hip arthritis; however, it is important to evaluate it for knee OA separately, because there are reports indicating that patients with primary OA in different joints may have a different phenotype.

QUESTIONS/PURPOSES

Do patients with primary knee OA have a phenotype with higher bone mineral density (BMD), higher body mass index (BMI), larger skeletal size, lower lean body mass, and higher fat content?

METHODS

We included 38 women and 74 men (mean age, 61 years; range, 34-85 years) with primary knee OA and 122 women and 121 men as control subjects. We used dual-energy x-ray absorptiometry to measure total body BMD (g/cm2), femoral neck width (cm), fat and lean mass (%), and BMI (kg/m2). Z scores were calculated for each individual. Data are presented as means with 95% confidence intervals.

RESULTS

Women with knee OA had the following Z scores: total body BMD 0.8 (0.5-1.0); BMI 1.6 (1.1-2.0); femoral neck width 0.1 (-0.3 to 0.4); proportion of lean mass -1.0 (-1.5 to -0.6); and proportion of fat mass 1.0 (0.6-1.4). Men with knee OA had the following Z scores: total body BMD 0.5 (0.3-0.7); BMI 0.9 (0.6-1.1); femoral neck width 0.3 (0.1-0.7); proportion of lean mass -0.9 (-1.1 to -0.8); and proportion of fat mass 0.7 (0.5-0.9).

CONCLUSIONS

Women and men with idiopathic knee OA have a phenotype with higher BMD, higher BMI, proportionally higher fat mass, and proportionally lower lean body mass. Men also have a larger skeletal size.

CLINICAL RELEVANCE

A higher BMD may lead to stiffer bone, a higher BMI to a greater joint load, and a proportionally lower lean body (muscle) mass to lower joint-protective ability, and all trait deviations probably predispose for knee OA.

Individuals with primary osteoarthritis have different phenotypes depending on the affected joint - a case control study from southern sweden including 514 participants

Objective:

The aim of this study was to evaluate whether primary osteoarthritis (OA), independent of affected joint, is associated with a phenotype that is different from the phenotype in a normative cohort. Material and

Methods:

We included 274 patients with primary OA, 30 women and 32 men (mean age 66 years, range 42-84) with primary hip OA, 38 women and 74 men (mean age 61 years; range 34-85) with primary knee OA, 42 women and 19 men (men age 64 years, range 42-87) with primary ankle or foot OA and 20 women and 19 men (mean age 66 years, range 47-88) with primary hand or finger OA. Of all patients included with OA, 23% had hip OA, 41% knee OA, 22% ankle or foot OA and 14% hand or finger OA. Serving as references were 122 women and 118 men of the same ages who were population-based, included as a control cohort. We measured total body BMD (g/cm2) and proportion of fat and lean mass (%) with dual energy X-ray absorptiometry. Height, weight and BMI (kg/m2) were also assessed. We then calculated Z-scores (number of standard deviations difference from the mean value of the control cohort) in the OA patients and compared these between the groups.

Results:

Individuals with hand OA and controls had similar phenotype. Individuals with lower extremity OA, irrespective of the affected joint, had similar weight, BMI and BMD, but higher than in individuals with hand OA and controls (all p<0.05). Individuals with lower extremity OA had higher fat and lower lean mass than individuals with hand OA and controls (all p<0.001).

Conclusion:

Individuals with primary OA in the lower extremity have a phenotype with higher BMD, higher BMI, proportionally higher fat content and lower lean body mass content. The different skeletal phenotypes in our patients with OA in the lower extremity and patients with hand OA indicate that separate pathophysiologic pathways may be responsible for primary OA in different joints

Patients with Osteoarthritis in all Three Knee Compartments and Patients with Medial Knee Osteoarthritis Have a Phenotype with High Bone Mass and High Fat Mass but Proportionally Low Lean Mass

BACKGROUND AND PURPOSE

Cross-sectional studies have shown that patients with primary hip osteoarthritis (OA) have higher bone mineral density (BMD), higher BMI, lower lean body mass, and higher fat content. But it is unknown if this phenotype is found also in patients with knee OA and if it precedes OA or manifests as a result of the disease.

PATIENTS AND METHODS

We included 21 women and 18 men (mean age, 71 years; range, 48-85 years) with primary OA in all three knee compartments, 17 women and 56 men (mean age, 55 years; range, 34-74 years) with primary medial knee OA and 122 women and 121 men without OA as controls. We measured total body BMD (g/cm(2)), fat and lean mass (%) by dual energy X-ray absorptiometry and also registered height and weight to calculate BMI (kg/m(2)). Z-scores were calculated for each individual. Data are presented as means with 95% confidence intervals within brackets.

RESULTS

Individuals with primary OA in all three knee compartments had the following Z-scores: total body BMD 0.4 (0.0, 0.9); BMI 1.2 (0.7, 1.6); proportion of lean mass -0.6 (-1.1, -0.1); proportion of fat mass 0.4 (0.0, 1.8). Individuals with medial knee OA had the following Z-scores: total body BMD 0.4 (0.3, 0.6); BMI 1.1 (0.8, 1.4); proportion of lean mass -0.8 (-1.3, -0.9); proportion of fat mass 0.9 (0.7, 1.1).

INTERPRETATIONS

A phenotype with higher BMD, higher BMI, higher fat mass, and proportionally lower lean body mass is evident in individuals with primary OA in all three knee compartments and in patients with only medial knee OA.

Patients with hip osteoarthritis have a phenotype with high bone mass and low lean body mass

BACKGROUND

Although hip osteoarthritis (OA) is common, its etiology is poorly understood. Specifically, it is not known whether hip OA is associated with abnormal relationships among the anthropometric and musculoskeletal characteristics that are associated with OA in general.

QUESTIONS

We asked whether patients with primary hip OA have a phenotype with higher bone mineral density (BMD), higher BMI, larger skeletal size, lower lean body mass, and higher fat content.

MATERIAL AND METHODS

We included 30 women and 32 men (mean age, 66 years; range, 42-84 years) with primary hip OA and 96 women and 91 men as control subjects. Dual energy x-ray absorptiometry was used to measure total body BMD (g/cm(2)), femoral neck width (cm), fat and lean mass (%), and BMI (kg/m(2)). Z scores were calculated for each individual. Data are presented as means with 95% CI.

RESULTS

Women with hip OA had the following Z scores: total body BMD 0.6 (0.3, 1.0); BMI 0.6 (0.2, 1.0); femoral neck width 0.2 (-0.6, 1.0); percent total body lean mass -0.9 (-1.2, -0.5); and percent total body fat mass 0.6 (0.2, 0.9). Men with hip OA had the following mean Z scores: total body BMD 0.5 (0.0, 1.0); BMI 0.8 (0.3, 1.3); femoral neck width 0.4 (0.01, 0.9); percent total body lean mass -0.8 (-1.1, -0.5); and percent total body fat mass 0.5 (0.2, 0.8).

CONCLUSIONS

Women and men with idiopathic hip OA have a phenotype with higher BMD, higher BMI, proportionally higher fat mass, and proportionally lower lean body mass. Men also have a larger skeletal size.

CLINICAL RELEVANCE

A higher BMD may lead to a stiffer bone and a proportionally lower lean body mass to lower joint-protective ability, both traits probably predisposing for hip OA.

Bone mass and anthropometry in patients with osteoarthritis of the foot and ankle

BACKGROUND

Patients with hip and knee osteoarthritis (OA) have high bone mineral density (BMD) and high BMI. If the same accounts for patients with foot or ankle OA is unknown.

METHODS

We measured BMD and femoral neck (FN) width by dual-energy X-ray absorptiometry in 42 women and 19 men with idiopathic OA in the foot or ankle, and in 99 women and 82 men as controls.

RESULTS

Women with OA had significant higher BMI than controls. Women with OA had higher BMI-adjusted BMD (p<0.01) and smaller BMI-adjusted FN width (p<0.01) than controls. Men with OA had higher BMI adjusted-BMD (p<0.05) and smaller BMI-adjusted FN width (p<0.01) than controls.

CONCLUSION

Patients with OA in the foot or ankle have higher BMD and smaller bone size than being expected by their BMI. This phenotype may provide unfavourable forces across the joint and is hypothetically important for development of OA.

Bone mineral density of the trapezium in osteoarthritic trapeziometacarpal joints

The aim of this study was to test the precision and reliability of measurements of the bone mineral density (BMD) of the trapezium in patients with osteoarthritic trapeziometacarpal joints using dual-energy X-ray absorptiometry scans and to assess whether there is an acceptable correlation between the BMD of the trapezium and that of the distal radius, for which normative data exist. We included 66 patients (52 women, 14 men) diagnosed with Eaton-Glickel stage II-IV osteoarthritis and a mean age of 59 years (range 40-77) in a prospective study. We found good intra- and inter-observer agreement of BMD measurements. Reliability was also good in repeated measurements. There was an indication of an increase in BMD with progression in the Eaton-Glickel stage. There was only a moderate correlation between the BMD of the trapezium and that of the radius.

The association between erosive hand osteoarthritis and subchondral bone attrition of the knee: the Framingham Osteoarthritis Study

OBJECTIVE

To examine whether erosive hand osteoarthritis (OA) is associated with knee subchondral bone attrition (SBA) and systemic bone mineral density (BMD).

METHODS

Associations of MRI-defined knee SBA with radiographic erosive hand OA were evaluated in 1253 Framingham participants using logistic regression with generalised estimating equations. We also examined the association between the number of erosive OA finger joints and SBA adjusted for the number of non-erosive OA finger joints. Associations between erosive hand OA and femoral neck BMD were explored in 2236 participants with linear regression. Analyses were adjusted for age, sex and body mass index.

RESULTS

Participants with erosive hand OA had increased odds of knee SBA (OR=1.60, 95% CI 1.07 to 2.38). The relation between the number of erosive OA finger joints and SBA became non-significant when adjusted for the number of non-erosive OA joints as a proxy for the burden of disease. There was a non-significant trend towards higher BMD in erosive hand OA compared with participants without hand OA.

CONCLUSIONS

Erosive hand OA was associated with knee SBA, but the relation might be best explained by a heightened burden of disease. No significant relation of erosive hand OA with BMD was found.

Hand osteoarthritis--a heterogeneous disorder

Hand osteoarthritis (OA) is a prevalent disorder. Hand OA is not one single disease, but a heterogeneous group of disorders. Radiographic signs of hand OA, such as osteophytes or joint space narrowing, can be found in up to 81% of the elderly population. Several hand OA subsets--such as nodal interphalangeal OA, thumb base OA and erosive OA--can be discriminated. Furthermore, the experience of symptoms and the course of the disease differ between patients. Studies that used well-defined study populations with longitudinal follow-up have shown that similarities and differences can be observed in the pathogenesis, epidemiology and risk factors of the various hand OA subsets. Erosive OA in particular, characterized by erosive lesions on radiographical images, has a higher clinical burden and worse outcome than nonerosive hand OA. Imaging modalities (such as ultrasonography) have increased our knowledge of the role of inflammation of the disease. Our understanding of the heterogeneous nature of hand OA can eventually lead to increased knowledge of the pathogenesis of, and ultimately new treatment modalities for, this complex disease.

Associations with subregional BMD-measurements in patients with rheumatoid arthritis

Patients with rheumatoid arthritis (RA) have bone loss to various degrees at different skeletal sites. The subregional bone mineral density (BMD) of the hand and the correlation of BMD to other regional bone losses, parameters of inflammation or bone resorption was evaluated in 421 patients with RA and controls. RA patients had significantly (P<0.01) lower BMD values in the carpus (0.405+/-0.004 g/cm2), metacarpal joint II (0.318+/-0.036 g/cm2) and metacarpal joint III (0.326+/-0.022 g/cm2) compared to controls. There was no difference in bone density at the lumbar spine or hip. Significant (P<0.001) correlations were found between BMD total of the hand, its subregions, the forearm and hip. Parameters of inflammation correlated significantly (P<0.001) with pyridinolines (r=0.378), desoxypyridinolines (r=0.183), forearm (r=-10, P<0.05), MCP II (r=-0.190, P<0.001), MCP III (r=0.204, P<0.001) and carpus (r=0.191, P<0.001).