Subchondral bone and cartilage damage: A prospective study in older adults

Objective

There is limited longitudinal evidence relating subchondral bone changes to cartilage damage and loss. The aim of this study was to describe the association between baseline tibial bone area and tibial subchondral bone mineral density (BMD) with tibial cartilage defect development and cartilage volume loss.

Methods

A total of 341 subjects (mean age 63 years, range 52–79 years) underwent measurement at baseline and ∼2.7 years later. Tibial knee cartilage volume, cartilage defects (graded on a scale of 0–4), and bone area were determined using T1‐weighted fat suppression magnetic resonance imaging. Tibial subchondral BMD was determined using dual x‐ray absorptiometry.

Results

In multivariable analysis, baseline bone area positively predicted cartilage defect development at the medial and lateral tibial sites (odds ratio [OR] 1.6 per 1 SD increase, 95% confidence interval [95% CI] 1.0, 2.6, and OR 2.4 per 1 SD increase, 95% CI 1.4, 4.0, respectively) and cartilage volume loss at the medial tibial site (β = −34.9 per 1 SD increase, 95% CI −49.8, −20.1). In contrast, baseline subchondral BMD positively predicted cartilage defect development at the medial tibial site only (OR 1.6 per 1 SD increase, 95% CI 1.2, 2.1) and was not associated with cartilage loss.

Conclusion

The results of this study demonstrated that bone area predicted medial and lateral cartilage defect development and medial cartilage volume loss, while subchondral BMD predicted medial defect development but not cartilage loss. These associations were independent of each other, indicating there are multiple mechanisms by which subchondral bone changes may lead to cartilage damage.

     

Serum levels of vitamin D,sunlight exposure,and knee cartilage loss in older adults: The Tasmanian older adult cohort study

Objective

To determine the associations between serum levels of vitamin D, sunlight exposure, and knee cartilage loss cross‐sectionally and longitudinally in older adults.

Methods

A total of 880 randomly selected subjects (mean age 61 years [range 51–79 years], 50% women) were studied at baseline, and 353 of these subjects were studied 2.9 years later. Serum levels of 25‐hydroxyvitamin D (25[OH]D) were assessed by radioimmunoassay, and sunlight exposure was assessed by questionnaire. T1‐weighted fat‐suppressed magnetic resonance imaging (MRI) of the right knee was performed to determine knee cartilage volume and defects. Knee radiographic osteoarthritis (OA) and knee pain were also assessed.

Results

The mean 25(OH)D serum level was 52.8 nmoles/liter at baseline (range 13–119 nmoles/liter). Winter sunlight exposure and serum 25(OH)D level were both positively associated with medial and lateral tibial cartilage volume, and a serum 25(OH)D level <50 nmoles/liter was associated with increased medial tibiofemoral joint space narrowing (all P < 0.05). Longitudinally, baseline serum 25(OH)D level predicted change in both medial and lateral tibial cartilage volume (β = +0.04% per annum per nmole/liter for both; P < 0.05), and change in serum 25(OH)D level was positively associated with change in medial tibial cartilage volume. These associations were consistent in subjects with radiographic OA and knee pain and/or in women, but not in men or in subjects without radiographic OA or knee pain.

Conclusion

Sunlight exposure and serum 25(OH)D levels are both associated with decreased knee cartilage loss (assessed by radiograph or MRI). This is best observed using the whole range of 25(OH)D levels rather than predefined cut points and implies that achieving vitamin D sufficiency may prevent and/or retard cartilage loss in knee OA.

     

Association of cartilage defects with loss of knee cartilage in healthy,middle‐age adults: A prospective study

Objective

The significance of asymptomatic knee cartilage defects in healthy individuals is not known. The aim of this study was to examine the association between cartilage defects in the knee and cartilage volume both cross‐sectionally and longitudinally in healthy, middle‐age adults.

Methods

Eighty‐six healthy men and women (mean ± SD age 53.8 ± 8.8 years) underwent T1‐weighted fat‐suppressed magnetic resonance imaging of their dominant knees at baseline and at the 2‐year followup visit. Knee cartilage volume was measured. Cartilage defects were scored according to a grading system (0–4) and as present (a defect score of ≥2) or absent in the medial and lateral tibiofemoral compartments.

Results

Cartilage defects in the medial and lateral tibiofemoral compartments were very common (in 61% and 43% of subjects, respectively). Those with cartilage defects had a 25% reduction in medial tibial cartilage volume, a 15% reduction in lateral tibial cartilage volume, and a 19% reduction in total femoral cartilage volume relative to those with no cartilage defects in cross‐sectional analyses (all P < 0.05). In the medial tibiofemoral compartment, the annual loss of tibial cartilage in those with cartilage defects was 2.5% (95% confidence interval [95% CI] 2.2%, 3.1%) compared with an annual loss of tibial cartilage of 1.3% (95% CI 0.5%, 2.0%) in those with no defects (P = 0.028), independent of other known risk factors for osteoarthritis (OA).

Conclusion

These data suggest that the presence of asymptomatic, non–full‐thickness medial tibiofemoral cartilage defects identifies healthy individuals most likely to lose knee cartilage in the absence of radiographic knee OA. Thus, interventions aimed at reducing or reversing cartilage defects may reduce the risk of subsequent knee OA.

     

Quadriceps strength and the risk of cartilage loss and symptom progression in knee osteoarthritis

Objective

To determine the effect of quadriceps strength in individuals with knee osteoarthritis (OA) on loss of cartilage at the tibiofemoral and patellofemoral joints (assessed by magnetic resonance imaging [MRI]) and on knee pain and function.

Methods

We studied 265 subjects (154 men and 111 women, mean ± SD age 67 ± 9 years) who met the American College of Rheumatology criteria for symptomatic knee OA and who were participating in a prospective, 30‐month natural history study of knee OA. Quadriceps strength was measured at baseline, isokinetically, during concentric knee extension. MRI of the knee at baseline and at 15 and 30 months was used to assess cartilage loss at the tibiofemoral and patellofemoral joints, with medial and lateral compartments assessed separately. At baseline and at followup visits, knee pain was assessed using a visual analog scale, and physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index.

Results

There was no association between quadriceps strength and cartilage loss at the tibiofemoral joint. Results were similar in malaligned knees. However, greater quadriceps strength was protective against cartilage loss at the lateral compartment of the patellofemoral joint (for highest versus lowest tertile of strength, odds ratio 0.4 [95% confidence interval 0.2, 0.9]). Those with greater quadriceps strength had less knee pain and better physical function over followup (P < 0.001).

Conclusion

Greater quadriceps strength had no influence on cartilage loss at the tibiofemoral joint, including in malaligned knees. We report for the first time that greater quadriceps strength protected against cartilage loss at the lateral compartment of the patellofemoral joint, a finding that requires confirmation. Subjects with greater quadriceps strength also had less knee pain and better physical function over followup.

     

Varus–valgus alignment: Reduced risk of subsequent cartilage loss in the less loaded compartment

Objective

Varus–valgus alignment has been linked to subsequent progression of osteoarthritis (OA) within the mechanically stressed (medial for varus, lateral for valgus) tibiofemoral compartment. Cartilage data from the off‐loaded compartment are sparse. The purpose of this study was to examine our hypotheses that neutral and valgus (versus varus) knees each have reduced odds of cartilage loss in the medial subregions and that neutral and varus (versus valgus) knees each have reduced odds of cartilage loss in the lateral subregions.

Methods

Patients with knee OA underwent knee magnetic resonance imaging at baseline and 2 years. The mean cartilage thickness was quantified within 5 tibial and 3 femoral subregions. We used logistic regression with generalized estimating equations to analyze the relationship between baseline alignment and subregional cartilage loss at 2 years, adjusting for age, sex, body mass index, and disease severity.

Results

A reduced risk of cartilage loss in the medial subregions was associated with neutral (versus varus) alignment (external tibial, central femoral, external femoral) and with valgus (versus varus) alignment (central tibial, external tibial, central femoral, external femoral). A reduced risk of cartilage loss in the lateral subregions was associated with neutral (versus valgus) alignment (central tibial, internal tibial, posterior tibial) and with varus (versus valgus) alignment (central tibial, external tibial, posterior tibial, external femoral).

Conclusion

Neutral and valgus alignment were each associated with a reduction in the risk of subsequent cartilage loss in certain medial subregions and neutral and varus alignment with a reduction in the risk of cartilage loss in certain lateral subregions. These results support load redistribution as an in vivo mechanism of the long‐term alignment effects on cartilage loss in knee OA.

     

Denuded subchondral bone and knee pain in persons with knee osteoarthritis

Objective

It is unclear how articular cartilage loss contributes to pain in patients with knee osteoarthritis (OA). Full‐thickness cartilage defects expose the subchondral bone plate. The relationship between denuded bone and pain has not been examined. The aim of this study was to investigate whether the percent of denuded bone is associated with moderate‐to‐severe knee pain or frequent knee pain and longitudinally with frequent knee pain 2 years after the baseline evaluation.

Methods

We studied 182 persons with knee OA (305 knees). Applying specialized magnetic resonance imaging techniques, manual segmentation was used to compute cartilage‐covered and denuded bone areas for each surface. Moderate‐to‐severe knee pain was defined as a score of ≥40 mm on a knee‐specific 100‐mm visual analog scale, and frequent knee pain was defined as pain on most days during the past month. Logistic regression and generalized estimating equations were used in analyses, adjusting for age, sex, body mass index, and bone marrow lesions.

Results

Cross‐sectional analyses revealed that moderate‐to‐severe knee pain was associated with percent denuded bone in the medial compartment (adjusted odds ratio [OR] 3.90, 95% confidence interval [95% CI] 1.33–11.47), in the medial and patellar surfaces together, and in the lateral and patellar surfaces. Frequent knee pain was associated with percent denuded bone in the patellar surface (adjusted OR 3.11, 95% CI 1.24–7.81), in the medial and patellar surfaces, and in the lateral and patellar surfaces. Longitudinal analyses (in 168 knees without frequent knee pain at baseline) revealed that percent denuded bone in the medial and patellar surfaces was associated with frequent incident knee pain (adjusted OR 4.19, 95% CI 1.56–11.22).

Conclusion

These results support a relationship between subchondral bone plate exposure and prevalent and incident knee pain in patients with knee OA.

     

Positive effects of moderate exercise on glycosaminoglycan content in knee cartilage: A four‐month,randomized, controlled trial in patients at risk of osteoarthritis

Objective

To evaluate the effects of moderate exercise on glycosaminoglycan (GAG) content in knee cartilage in subjects at high risk of knee osteoarthritis (OA).

Methods

Forty‐five subjects (16 women, mean age 46 years, mean body mass index 26.6 kg/m²) who underwent partial medial meniscus resection 3–5 years previously were randomized to undergo a regimen of supervised exercise 3 times weekly for 4 months or to a nonintervention control group. Cartilage GAG content, an important aspect of the biomechanical properties of cartilage, was estimated by delayed gadolinium‐enhanced magnetic resonance imaging of cartilage (dGEMRIC), with results expressed as the change in the T1 relaxation time in the presence of Gd‐DTPA (T1[Gd]).

Results

Thirty of 45 patients were examined by dGEMRIC at baseline and followup. The exercise group (n = 16) showed an improvement in the T1(Gd) compared with the control group (n = 14) (15 msec versus −15 msec; P = 0.036). To study the dose response, change in the T1(Gd) was assessed for correlation with self‐reported change in physical activity level, and a strong correlation was found in the exercise group (n = 16, r_S = 0.70, 95% confidence interval [95% CI] 0.31–0.89) and in the pooled group of all subjects (n = 30, r_S = 0.74, 95% CI 0.52–0.87).

Conclusion

This in vivo cartilage monitoring study in patients at risk of knee OA who begin exercising indicates that adult human articular cartilage has a potential to adapt to loading change. Moderate exercise may be a good treatment not only to improve joint symptoms and function, but also to improve the knee cartilage GAG content in patients at high risk of developing OA.

     

The effect of estrogen plus progestin on knee symptoms and related disability in postmenopausal women: The heart and estrogen/progestin replacement study,a randomized,double‐blind,placebo‐controlled trial

Objective

Most observational studies suggest that postmenopausal women taking hormone replacement therapy have a reduced risk of radiographic knee and hip osteoarthritis (OA). There are no randomized trial data on the association of hormone treatment with knee or hip OA, and no studies have been published regarding the relationship of hormone treatment to knee or hip symptoms. This study examined the association of hormone treatment with prevalent knee symptoms and disability related to knee pain as assessed at the final visit of the Heart and Estrogen/Progestin Replacement Study (HERS).

Methods

The HERS was a 4‐year randomized, double‐blind, placebo‐controlled trial of estrogen plus medroxy progesterone acetate for prevention of coronary heart disease in postmenopausal women with documented coronary disease. Participants in this substudy on knee pain were 969 postmenopausal women, with a mean age of 66 years and mean body mass index of 28.6 kg/m², attending the final visit at 9 clinical centers. Frequent knee symptoms were assessed by interview and the severity of knee pain and disability related to knee pain were determined using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Knee symptoms and disability were compared between women assigned to receive hormones and those assigned to receive placebo.

Results

Frequent knee pain was reported in 24.1% of women assigned to receive hormone therapy versus 26.1% of those assigned to the placebo group, a difference of −2.0% (95% confidence interval [95% CI] −7.4% to 3.5%). Among women with knee pain, there were no differences in the severity of pain (score difference −0.2, 95% CI −1.2 to 0.8) or disability (score difference −0.7, 95% CI −3.8 to 2.4) as assessed on the WOMAC. All results were similar for women whose body mass index was either above or below the median.

Conclusion

In a group of older, postmenopausal women with cardiac disease, we found no significant effect of 4 years of estrogen plus progestin therapy compared with placebo on knee pain and related disability. Our findings may not apply to other groups of women or to the effect of hormone therapy on the structural changes of knee OA.

     

Magnetic resonance imaging–based assessment of cartilage loss in severe osteoarthritis: Accuracy,precision, and diagnostic value

Objective

To examine the in vivo accuracy and precision of magnetic resonance imaging (MRI)–based assessment of cartilage loss in patients with severe osteoarthritis (OA) of the knee.

Methods

High‐resolution MRI images of the tibial cartilage were obtained in 8 patients prior to total knee arthroplasty, using a water‐excitation gradient‐echo MRI sequence (acquisition time 6 minutes 19 seconds; spatial resolution 1.2 × 0.31 × 0.31 mm³). The MRI measurements were repeated after joint repositioning. The precision of the cartilage volume and thickness computations was determined after 3dimensional reconstruction. During surgery, the tibial plateaus were resected, and the MRI data were compared with water displacement of surgically retrieved cartilage.

Results

The standard deviation (coefficient of variation) of repeated tibial cartilage volume measurements was 56 mm³ (5.5%) medially and 59 mm³ (3.8%) laterally. The deviation from surgically removed tissue was −13%, on average, with a high linear correlation between both methods (r = 0.98). In patients with varus OA, the tissue loss was estimated to be 1,290 mm³ in the medial tibia and 1,150 mm³ in the lateral tibia, compared with the data in healthy volunteers.

Conclusion

Noninvasive quantitative MRI‐based analysis of cartilage morphometry in severe OA is accurate, precise, and displays high potential diagnostic value.

     

Trabecular morphometry by fractal signature analysis is a novel marker of osteoarthritis progression

Objective

To evaluate the effectiveness of using subchondral bone texture observed on a radiograph taken at baseline to predict progression of knee osteoarthritis (OA) over a 3‐year period.

Methods

A total of 138 participants in the Prediction of Osteoarthritis Progression study were evaluated at baseline and after 3 years. Fractal signature analysis (FSA) of the medial subchondral tibial plateau was performed on fixed flexion radiographs of 248 nonreplaced knees, using a commercially available software tool. OA progression was defined as a change in joint space narrowing (JSN) or osteophyte formation of 1 grade according to a standardized knee atlas. Statistical analysis of fractal signatures was performed using a new model based on correlating the overall shape of a fractal dimension curve with radius.

Results

Fractal signature of the medial tibial plateau at baseline was predictive of medial knee JSN progression (area under the curve [AUC] 0.75, of a receiver operating characteristic curve) but was not predictive of osteophyte formation or progression of JSN in the lateral compartment. Traditional covariates (age, sex, body mass index, knee pain), general bone mineral content, and joint space width at baseline were no more effective than random variables for predicting OA progression (AUC 0.52–0.58). The predictive model with maximum effectiveness combined fractal signature at baseline, knee alignment, traditional covariates, and bone mineral content (AUC 0.79).

Conclusion

We identified a prognostic marker of OA that is readily extracted from a plain radiograph using FSA. Although the method needs to be validated in a second cohort, our results indicate that the global shape approach to analyzing these data is a potentially efficient means of identifying individuals at risk of knee OA progression.

     

Greater rates of cartilage loss in painful knees than in pain‐free knees after adjustment for radiographic disease stage: Data from the Osteoarthritis Initiative

Objective

To investigate whether rates of cartilage loss differ in knees with frequent baseline pain versus those without pain, after adjustment for radiographic osteoarthritis (OA) stage.

Methods

One knee in each of 718 Osteoarthritis Initiative participants was examined: 310 with calculated Kellgren/Lawrence (K/L) grade 2, 299 with calculated K/L grade 3, and 109 with calculated K/L grade 4. Twelve‐month change in (subregional) cartilage thickness was assessed by magnetic resonance imaging. Change in cartilage thickness in the central subregion of the weight‐bearing medial femoral condyle and ordered value 1 (OV1) were selected as primary end points. Frequent knee symptoms were defined as pain, aching, or stiffness on most days of at least 1 month during the previous year.

Results

The mean 12‐month rate of change in cartilage thickness in the central subregion of the medial femoral condyle was −12 μm (standardized response mean [SRM] −0.15) in knees without pain (n = 146), −27 μm (SRM −0.25) in those with infrequent pain (n = 255), and −54 μm (SRM −0.32) in those with frequent pain (n = 317). Rates differed significantly between frequently painful knees and pain‐free knees after adjustment for age, sex, body mass index, and calculated K/L grade (P = 0.011, R² = 2.6%, partial R² for frequent pain = 1.4%). Similar results were found in stratified samples of calculated K/L grade 2/calculated K/L grade 3 knees, and in analyses restricted to knees with consistent pain frequency between baseline and followup. OV1 results showed similar trends but were not significant.

Conclusion

Knees with frequent pain display greater rates of medial cartilage loss longitudinally than knees without pain, with or without adjustment or stratification for radiographic disease stage. Enrollment of participants with frequent knee pain in clinical trials can increase the observed rate of structural progression (i.e., cartilage loss) and sensitivity to change.

     

Age‐related changes in the morphology and deformational behavior of knee joint cartilage

Objective

Alterations of cartilage morphology and mechanical properties occur in osteoarthritis, but it is unclear whether similar changes also take place physiologically during aging, in the absence of disease. In this in vivo study, we tested the hypothesis that thinning of knee joint cartilage occurs with aging and that elderly subjects display a different amount of cartilage deformation than do young subjects.

Methods

We evaluated 30 asymptomatic subjects ages 50–78 years. Morphologic parameters for the knee cartilage (mean and maximum thickness, surface area) were computed from magnetic resonance imaging data. Results were compared with those in 95 young asymptomatic subjects ages 20–30 years. Deformation of the patellar cartilage was determined after the subjects performed 30 knee bends.

Results

There was a significant reduction of patellar cartilage thickness in elderly women (−12%; P < 0.05), but not in elderly men (−6%). Femoral cartilage was significantly thinner in both sexes (−21% in women, −13% in men; P < 0.01), whereas tibial cartilage thickness displayed only nonsignificant trends (−10% in women, −7% in men). Patellar cartilage deformation was −2.6% in elderly women and −2.2% in elderly men. These values were significantly lower (P < 0.05) than those in young subjects.

Conclusion

We confirmed the hypothesis that knee cartilage becomes thinner during aging, in the absence of cartilage disease, but that the amount of reduction differs between sexes and between compartments of the knee joint. We show that under in vivo loading conditions, elderly subjects display a lower level of cartilage deformation than do healthy young subjects.

     

Is there an association between the use of different types of nonsteroidal antiinflammatory drugs and radiologic progression of osteoarthritis?: The rotterdam study

Objective

To investigate the influence of the use of various types of nonsteroidal antiinflammatory drugs (NSAIDs) on progression of osteoarthritis (OA) of the hip and knee.

Methods

In 1,695 subjects (2,514 hips) and 635 subjects (874 knees) ages 55 years and older from the Rotterdam Study, radiographs of the hip and knee at baseline and followup (mean followup time 6.6 years) were evaluated. Radiologic OA (ROA) progression was defined as a minimum increase of 1 in the Kellgren/Lawrence grade or incident joint replacement at followup. The associations between the different types of NSAIDs and progression of ROA were assessed using multivariate logistic regression analysis.

Results

Those subjects who were receiving diclofenac >180 days had a 2.4‐fold increased risk (95% confidence interval [95% CI] 1.0–6.2) of progression of hip ROA and a 3.2‐fold increased risk (95% CI 1.0–9.9) of knee ROA, compared with those considered short‐term users (diclofenac for 1–30 days). These associations were adjusted for age, sex, body mass index, baseline ROA, followup time, and defined daily dosage.

Conclusion

These data suggest that diclofenac may induce accelerated progression of hip and knee ROA. Whether this occurs because of a true deleterious effect on cartilage or because of excessive mechanical loading on a hip following pain relief remains to be investigated.

     

Biomarkers of incident radiographic knee osteoarthritis: Do they vary by chronic knee symptoms?

Objective

To explore the ability of osteoarthritis (OA)–related biomarkers to predict incident radiographic knee OA in a large sample of African American and Caucasian men and women.

Methods

Baseline levels of serum cartilage oligomeric matrix protein (COMP), hyaluronan (HA), high‐sensitivity C‐reactive protein (hsCRP), and keratan sulfate (KS) and baseline and followup radiographs were available for 353 knees without baseline osteophyte formation and for 446 knees without baseline joint space narrowing (JSN). Cox models estimated the hazard ratio (HR) and 95% confidence interval (95% CI) for incident knee OA for a 1‐unit increase in the ln of each biomarker, with adjustment for age, race, sex, body mass index, and knee OA of the contralateral limb. Report of chronic knee symptoms was explored as a modifier of the association.

Results

The hazard of incident knee osteophytes (HR 2.16 [95% CI 1.39–3.37]) and incident JSN (HR 1.82 [95% CI 1.15–2.89]) increased with higher baseline ln(COMP) levels. The hazard of incident knee JSN increased with higher ln(HA) levels (HR 1.46 [95% CI 1.14–1.87]). Baseline ln(hsCRP) and ln(KS) did not predict incident knee outcomes. HRs per unit increase in ln(COMP), ln(HA), and ln(KS) were higher among knees with chronic symptoms than among those without symptoms.

Conclusion

Higher baseline ln(COMP) and ln(HA) levels were associated with incident knee OA over an average followup period of 6.3 years. These results represent detection of a molecular stage of OA prior to radiographic manifestations. Further exploration is needed to determine how chronic knee symptoms modify the biomarker–incident knee OA association.

     

The relationship between body composition and knee cartilage volume in healthy,middle‐aged subjects

Objective

Although obesity is widely accepted as a risk factor for knee osteoarthritis, it is not clear whether individual components of body composition, such as the mass and distribution of muscle and fat, are associated with development of the disease. This study examined the effect of measures of body composition on the longitudinal change in tibial cartilage volume.

Methods

Body composition, assessed via dual x‐ray absorptiometry, and tibial cartilage volume, assessed via magnetic resonance imaging, were measured in 86 healthy men and women who were mid‐life in age. Change in tibial cartilage volume was assessed by imaging each knee 2 years after the baseline measurement and determining the difference from baseline in tibial cartilage volume. Correlations were determined between the muscle and fat mass of the arm, leg, and total body and the volume of the lateral‐ and medial‐tibial cartilage, as well as the change in tibial cartilage volume over 2 years, after adjusting for confounders.

Results

There was a significant association between muscle mass and the medial‐tibial cartilage volume, independent of age, sex, body mass index, tibial bone area, and level of physical activity. Although there was a positive association between muscle mass and the lateral‐tibial cartilage volume, this did not persist after adjustment for confounders. Loss of muscle mass was associated with an increased loss of medial‐ and lateral‐tibial cartilage over 2 years, after adjusting for confounders. No relationship was apparent between fat mass and either medial‐ or lateral‐tibial cartilage volume, or between fat mass and change in either medial‐ or lateral‐tibial cartilage volume over 2 years, after adjusting for confounders.

Conclusion

Muscle mass is an independent predictor of medial‐tibial cartilage volume in healthy people in mid‐life and is associated with a reduction in the rate of loss of tibial cartilage. This suggests that increased muscle mass may be protective against the onset of osteoarthritis.

     

The effectiveness of pulsed electrical stimulation in the management of osteoarthritis of the knee: Results of a double‐blind,randomized, placebo‐controlled,repeated‐measures trial

Objective

To determine the effectiveness of subsensory, pulsed electrical stimulation (PES) in the symptomatic management of osteoarthritis (OA) of the knee.

Methods

This was a double‐blind, randomized, placebo‐controlled, repeated‐measures trial in 70 participants with clinical and radiographically diagnosed OA of the knee who were randomized to either PES or placebo. The primary outcome was change in pain score over 26 weeks measured on a 100‐mm visual analog scale (VAS). Other measures included pain on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), function on the WOMAC, patient's global assessment of disease activity (on a 100‐mm VAS), joint stiffness on the WOMAC, quality of life on the Medical Outcomes Study Short‐Form 36 (SF‐36) health survey, physical activity (using the Human Activity Profile and an accelerometer), and global perceived effect (on an 11‐point scale).

Results

Thirty‐four participants were randomized to PES and 36 to placebo. Intent‐to‐treat analysis showed a statistically significant improvement in VAS pain score over 26 weeks in both groups, but no difference between groups (mean change difference 0.9 mm [95% confidence interval −11.7, 13.4]). Similarly, there were no differences between groups for changes in WOMAC pain, function, and stiffness scores (−5.6 [95% confidence interval −14.9, 3.6], −1.9 [95% confidence interval −9.7, 5.9], and 3.7 [95% confidence interval −6.0, 13.5], respectively), SF‐36 physical and mental component summary scores (1.7 [95% confidence interval −1.5, 4.8] and 1.2 [95% confidence interval −2.9, 5.4], respectively), patient's global assessment of disease activity (−2.8 [95% confidence interval −13.9, 8.4]), or activity measures. Fifty‐six percent of the PES‐treated group achieved a clinically relevant 20‐mm improvement in VAS pain score at 26 weeks compared with 44% of controls (12% [95% confidence interval −11%, 33%]).

Conclusion

In this sample of subjects with mild‐to‐moderate symptoms and moderate‐to‐severe radiographic OA of the knee, 26 weeks of PES was no more effective than placebo.

     

Longitudinal performance evaluation and validation of fixed‐flexion radiography of the knee for detection of joint space loss

Objective

The ability of nonfluoroscopically guided radiography of the knee to assess joint space loss is an important issue in studies of progression and treatment of knee osteoarthritis (OA), given the practical limitations of protocols involving fluoroscopically guided radiography of the knee. We evaluated the ability of the nonfluoroscopically guided fixed‐flexion radiography protocol to detect knee joint space loss over 3 years.

Methods

We assessed the same‐day test–retest precision for measuring minimum joint space width (JSW), the sensitivity for detection of joint space loss using serial films obtained a median of 37 months (range 23–47 months) apart, and the relationship of joint space loss to radiographic and magnetic resonance imaging (MRI) measures of knee OA. Participants were men and women (ages 70–79 years) with knee pain who were participating in the Health, Aging, and Body Composition Study. We assessed baseline radiographic OA and measured JSW using a computerized algorithm. Serial knee MRIs obtained over the same interval were evaluated for cartilage lesions.

Results

A total of 153 knees were studied, 35% of which had radiographic OA at baseline. The mean ± SD joint space loss for all knees over 3 years was 0.24 ± 0.59 mm (P < 0.001 for change). In knees with OA at baseline, the mean ± SD joint space loss over 3 years was 0.43 ± 0.66 mm (P < 0.001), and in knees with joint space narrowing at baseline, joint space loss was 0.50 ± 0.67 mm (P < 0.001). Joint space loss and its standardized response mean increased with the severity of baseline joint space narrowing and with the presence of cartilage lesions at baseline and worsening during followup.

Conclusion

Radiography of the knee in the fixed‐flexion view provides a sensitive and valid measure of joint space loss in multiyear longitudinal studies of knee OA, without the use of fluoroscopy to aid knee positioning.

     

Does hand osteoarthritis predict future hip or knee osteoarthritis?

Objective

To evaluate the risk of future hip or knee osteoarthritis (OA) in subjects with hand OA at baseline and to evaluate whether the concurrent presence of hand OA, other risk factors for OA, or an OA biomarker (type II collagen C‐telopeptide degradation product [CTX‐II]) further increases the risk.

Methods

Radiographs of the hands (baseline) and the hips and knees (baseline and 6.6 years later) were obtained in a randomly selected subset of participants in the Rotterdam Study who were ages 55 years and older. Radiographs were scored for the presence of OA using the Kellgren/Lawrence (K/L) system. A total of 1,235 subjects without OA of the hip/knee (K/L score 0–1) at baseline were included in the study. CTX‐II levels were measured at baseline. The independent risk of future hip/knee OA in subjects with hand OA at baseline was assessed by logistic regression, as stratified for age, sex, body mass index, family history of OA, and heavy workload.

Results

Overall 12.1% of the participants (19.7% of those with hand OA versus 10.0% of those without) developed hip or knee OA (odds ratio [OR] 2.1 [95% confidence interval (95% CI) 1.3–3.1]). Subjects with hand OA had an increased risk of future hip OA (OR 3.0 [95% CI 1.6–5.4]), which was further increased in those with a family history of OA. Subjects with hand OA had an OR of 1.6 [95% CI 1.0–2.8) for the future development of knee OA, which was further increased in those who were overweight. Concurrent hand OA and high levels of CTX‐II further increased the risk of having hip or knee OA at followup (OR 4.2 [95% CI 2.3–7.8]).

Conclusion

The presence of hand OA at baseline showed an increased risk of future hip/knee OA (higher for hip OA than for knee OA). The concurrent presence of hand OA and other OA risk factors or high CTX‐II levels further increased the risk of future hip/knee OA.

     

Association of weight gain with incident knee pain,stiffness, and functional difficulties: A longitudinal study

Objective

To examine the longitudinal association between significant weight change and change in knee symptoms (pain, stiffness, and function), and to determine whether the effects differ in those who are obese and those with osteoarthritis (OA).

Methods

Two hundred fifty subjects ranging from normal weight to obese (body mass index range 16.9–59.1 kg/m²) and no significant musculoskeletal disease were recruited from the general community and weight loss clinics and organizations. Seventy‐eight percent were followed at ～2 years. Weight, height, and knee symptoms (using the Western Ontario and McMaster Universities Osteoarthritis Index) were assessed at baseline and followup. Any weight loss methods were recorded.

Results

Thirty percent of subjects lost ≥5% of baseline weight, 56% of subjects' weight remained stable (loss or gain of <5% of baseline weight), and 14% of subjects gained ≥5% of baseline weight. Using estimated marginal means, weight gain was associated with worsening pain (mean 27.1 mm; 95% confidence interval [95% CI] ?1.1, 55.2), stiffness (mean 18.4 mm; 95% CI 1.5, 35.3), and function (mean 99.3 mm; 95% CI 4.0, 194.6) compared to stable weight. Weight loss was associated with reduced pain (mean ?22.4 mm; 95% CI ?44.4, ?0.3), stiffness (mean ?15.3 mm; 95% CI ?28.50, ?2.0), and function (mean ?73.2 mm; 95% CI ?147.9, 1.3) compared to stable weight.

Conclusion

Weight gain was associated with adverse effects on knee symptoms, particularly in those who are obese and who have OA. Although losing weight is potentially beneficial for symptom improvement, the effects were more modest. Avoiding weight gain is important in managing knee symptoms.

     

When it hurts,a positive attitude may help: association of positive affect with daily walking in knee osteoarthritis. Results from a multicenter longitudinal cohort study

Objective

While depressive symptoms and knee pain are independently known to impede daily walking in older adults, it is unknown whether positive affect promotes daily walking. This study investigated this association among adults with knee osteoarthritis (OA) and examined whether knee pain modified this association.

Methods

This study is a cross‐sectional analysis of the Multicenter Osteoarthritis Study. We included 1,018 participants (mean ± SD age 63.1 ± 7.8 years, 60% women) who had radiographic knee OA and had worn a StepWatch monitor to record their number of steps per day. High and low positive affect and depressive symptoms were based on the Center for Epidemiologic Studies Depression Scale. Knee pain was categorized as present in respondents who reported pain on most days at both a clinic visit and a telephone screening.

Results

Compared to respondents with low positive affect (27% of all respondents), those with high positive affect (63%) walked a similar number of steps per day, while those with depressive symptoms (10%) walked less (adjusted β ?32.6 [95% confidence interval (95% CI) ?458.9, 393.8] and ?579.1 [95% CI ?1,274.9, 116.7], respectively). There was a statistically significant interaction of positive affect by knee pain (P = 0.0045). Among the respondents with knee pain (39%), those with high positive affect walked significantly more steps per day (adjusted β 711.0 [95% CI 55.1, 1,366.9]) than those with low positive affect.

Conclusion

High positive affect was associated with more daily walking among adults with painful knee OA. Positive affect may be an important psychological factor to consider for promoting physical activity among people with painful knee OA.