Dynamic load at baseline can predict radiographic disease progression in medial compartment knee osteoarthritis

OBJECTIVE: To test the hypothesis that dynamic load at baseline can predict radiographic disease progression in patients with medial compartment knee osteoarthritis (OA). METHODS: During 1991-93 baseline data were collected by assessment of pain, radiography, and gait analysis in 106 patients referred to hospital with medial compartment knee OA. At the six year follow up, 74 patients were again examined to assess radiographic changes. Radiographic disease progression was defined as more than one grade narrowing of minimum joint space of the medial compartment. RESULTS: In the 32 patients showing disease progression, pain was more severe and adduction moment was higher at baseline than in those without disease progression (n=42). Joint space narrowing of the medial compartment during the six year period correlated significantly with the adduction moment at entry. Adduction moment correlated significantly with mechanical axis (varus alignment) and negatively with joint space width and pain score. Logistic regression analysis showed that the risk of progression of knee OA increased 6.46 times with a 1% increase in adduction moment. CONCLUSIONS: The results suggest that the baseline adduction moment of the knee, which reflects the dynamic load on the medial compartment, can predict radiographic OA progression at the six year follow up in patients with medial compartment knee OA.     

Absence of a relationship between joint space narrowing and osteophyte formation in early knee osteoarthritis among Japanese community-dwelling elderly individuals: A cross-sectional study

Objectives: Joint space narrowing and osteophyte formation, radiographic features of knee osteoarthritis (OA), are not necessarily synchronous processes. We evaluated the relationship between medial minimum joint space width (mJSW) and osteophyte formation.

Methods: We conducted a retrospective study of 1050 individuals (424 males; 626 females; mean age 64.9 years) who underwent knee radiography as part of a health screening program, between 2011 and 2013. mJSW and tibial osteophyte area (OF) were quantified using automated software. The mJSW range was subdivided into tertiles, and OF, mJSW, and quality of life (QOL) were compared among them. Correlation between OF and mJSW was evaluated.

Results: In females, OF was largest and correlated with mJSW only in the lowest tertile group. Patients in the lowest mJSW tertile group had a lower QOL and higher pain than those in the other two groups. Based on our generalized additive models and a receiver operating characteristic curve analysis, an mJSW cutoff point of 3.5?mm was apparent in females, with no significant cutoff identified in males.

Conclusions: OF correlates with mJSW below a cutoff value of about 3.5?mm in females. OA symptoms, namely physical function impairment and pain, increases significantly as mJSW decreases below the cutoff.     

Gait changes in patients with knee osteoarthritis are replicated by experimental knee pain

Objective

Medial knee osteoarthritis (OA) is characterized by pain and associated with abnormal knee moments during walking. The relationship between knee OA pain and gait changes remains to be clarified, and a better understanding of this link could advance the treatment and prevention of disease progression. This study investigated changes in knee moments during walking following experimental knee pain in healthy volunteers, and whether these changes replicated the joint moments observed in medial knee OA patients.

Methods

In a crossover study, 34 healthy subjects were tested on 3 different days; gait analyses were conducted before, during, and after pain induced by hypertonic saline injections (0.75 ml) into the infrapatellar fat pad. Isotonic saline and sham injections were used as control conditions. Peak moments in frontal and sagittal planes were analyzed. The results were compared with data from 161 medial knee OA patients. The patients were divided into less severe OA and severe OA categories, which was based on radiographic disease severity of the medial compartment.

Results

Experimental knee pain led to reduced peak moments in the frontal and sagittal planes in the healthy subjects, which were similar to the patterns observed in less severe OA patients while walking at the same speed.

Conclusion

In healthy subjects, pain was associated with reductions in knee joint moments during walking in a manner similar to less severe knee OA patients. The experimental model may be used to study mechanically‐driven knee OA progression and preventive measures against abnormal joint loading in knee OA.     

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.

     

Safety and efficacy of long‐term intraarticular steroid injections in osteoarthritis of the knee: A randomized,double‐blind,placebo‐controlled trial

Objective

To evaluate the safety and efficacy of long‐term intraarticular (IA) steroid injections for knee pain related to osteoarthritis (OA).

Methods

In a randomized, double‐blind trial, 68 patients with OA of the knee received IA injections of triamcinolone acetonide 40 mg (34 patients) or saline (34 patients) into the study knee every 3 months for up to 2 years. The primary outcome variable was radiologic progression of joint space narrowing of the injected knee after 2 years. Measurements of minimum joint space width were performed by an automated computerized method on standardized fluoroscopically guided radiographs taken with the patient standing and with the knee in a semiflexed position. The clinical efficacy measure of primary interest was the pain subscale from the Western Ontario and McMaster Universities OA Index (WOMAC). Efficacy measures of secondary interest were the total score on the WOMAC, physician's global assessment, patient's global assessment, patient's assessment of pain, range of motion (ROM) of the affected knee, and 50‐foot walking time. Clinical symptoms were assessed just before each injection.

Results

At the 1‐year and 2‐year followup evaluations, no difference was noted between the two treatment groups with respect to loss of joint space over time. The steroid‐injected knees showed a trend toward greater symptom improvement, especially at 1 year, for the WOMAC pain subscale, night pain, and ROM values (P = 0.05) compared with the saline‐injected knees. Using area under the curve analyses, knee pain and stiffness were significantly improved throughout the 2‐year study by repeated injections of triamcinolone acetonide, but not saline (P < 0.05).

Conclusion

Our findings support the long‐term safety of IA steroid injections for patients with symptomatic knee OA. No deleterious effects of the long‐term administration of IA steroids on the anatomical structure of the knee were noted. Moreover, long‐term treatment of knee OA with repeated steroid injections appears to be clinically effective for the relief of symptoms of the disease.

     

Serum hyaluronic acid level as a predictor of disease progression in osteoarthritis of the knee

Objective. To investigate the prognostic value of serum hyaluronic acid (HA) and keratan sulfate (KS) levels in relation to tibiofemoral osteoarthritis (OA) of the knee. Methods. Clinical and demographic data were collected on 94 patients. Radiographs were obtained at study entry and at 5-year followup. Disease progression was defined as 2 mm of joint space narrowing of any tibiofemoral compartment, and/or knee joint surgery during the study period. Serum HA and KS were measured and levels were correlated with entry data and disease progression. Results. At entry, HA levels were significantly related to disease duration (P = 0.036), minimum joint space (P = 0.049), and previous surgery (P = 0.001). After these variables were taken into account, patients whose disease had progressed were shown to have had significantly higher levels of HA at baseline compared with those whose disease had not progressed (P = 0.019). However, there were no significant differences in levels of serum KS between those with and those without disease progression, at entry (P = 0.779) or at subsequent visits. Conclusion. These results suggest that serum HA levels predict disease outcome in OA of the knee and confirm that a single measurement of the serum level of KS is not useful as a prognostic marker in OA.     

Individual magnetic resonance imaging and radiographic features of knee osteoarthritis in subjects with unilateral knee pain: The Health,Aging, and Body Composition Study

Objective

Strong associations between radiographic features of knee osteoarthritis (OA) and pain have been demonstrated in persons with unilateral knee symptoms. This study was undertaken to compare radiographic and magnetic resonance imaging (MRI) features of knee OA and assess their ability to discriminate between painful and nonpainful knees in persons with unilateral symptoms.

Methods

The study population included 283 individuals ages 70–79 years with unilateral knee pain who were enrolled in the Health, Aging, and Body Composition Study, a study of weight‐related diseases and mobility. Radiographs of both knees were read for Kellgren/Lawrence (K/L) grade and individual radiographic features, and 1.5T MRIs were assessed using the Whole‐Organ Magnetic Resonance Imaging Score. The association between structural features and pain was assessed using a within‐person case–control design and conditional logistic regression. Receiver operating characteristic (ROC) analysis was then used to test the discriminatory performance of structural features.

Results

In conditional logistic analyses, knee pain was significantly associated with both radiographic features (any joint space narrowing grade ≥1) (odds ratio 3.20 [95% confidence interval 1.79–5.71]) and MRI features (any cartilage defect scored ≥2) (odds ratio 3.67 [95% confidence interval 1.49–9.04]). However, in most subjects, MRI revealed osteophytes and cartilage and bone marrow lesions in both knees, and using ROC analysis, no individual structural feature discriminated well between painful and nonpainful knees. The best‐performing MRI feature (synovitis/effusion) was not significantly more informative than K/L grade ≥2 (P = 0.42).

Conclusion

In persons with unilateral knee pain, MRI and radiographic features were associated with knee pain, confirming that structural abnormalities in the knee have an important role in the etiology of pain. However, no single MRI or radiographic finding performed well in discriminating between painful and nonpainful knees. Further work is needed to examine how structural and nonstructural factors influence knee pain.

     

Changes in knee joint destruction patterns among patients with rheumatoid arthritis undergoing total knee arthroplasty in recent decades

Objectives

This study aimed to investigate the trend of joint destruction patterns on knee radiographs of patients with rheumatoid arthritis (RA) undergoing total knee arthroplasty (TKA) over the past 16 years.

Method

Medial joint space, lateral joint space, medial spur area, lateral spur area (L-spur), and femoro-tibial angle were obtained from 831 preoperative knee radiographs of patients with RA who underwent TKA between 2006 and 2021 using software capable of automatic measurements. Non-hierarchical clustering was performed based on these five parameters. Trends in the five individual radiographic parameters and the ratio of each cluster were investigated during the target period. Moreover, clinical data from 244 cases were compared among clusters to identify factors associated with this trend.

Results

All parameters, except for L-spur, showed significant increasing trends from 2006 to 2021. The radiographs were clustered into groups according to the characteristic pattern of radiographic findings: cluster 1 (conventional RA type), with bicompartmental joint space narrowing (JSN), less spur formation, and valgus alignment; cluster 2 (osteoarthritis type), with medial JSN, medial osteophytes, and varus alignment; and cluster 3 (less destructive type), with mild bicompartmental JSN, less spur formation, and valgus alignment. The ratio of cluster 1 showed a significantly decreasing trend contrary to the significantly increasing trend in clusters 2 and 3. The DAS28-CRP of cluster 3 was higher than those of clusters 1 and 2.

Conclusions

Radiographs of TKA recipients with RA are increasingly presenting osteoarthritic features in recent decades.

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.

     

Quality of life and self-reported disability in patients with knee osteoarthritis

Abstract

Objectives Osteoarthritis (OA) is the most common degenerative joint disorder and a major public health problem throughout the world. The aims of this study are to assess quality of life (QoL) in patients with knee OA using the generic instrument Short Form-36 (SF-36) and to determine its relationships with conventional clinical measures and self-reported disability.

Methods Patients with knee OA (n = 112) with median age of 60 (45–76) years and 40 sex- and age-matched healthy controls were included in the study. Age, sex, body mass index (BMI), symptom duration, and Kellgren–Lawrence scores were recorded. QoL, disability, and pain were assessed using the SF-36, the Western Ontario and McMaster (WOMAC) index, the Lequesne index, and a visual analog scale (VAS) in patients. Also, QoL was assessed using the SF-36 in controls.

Results Patients with knee OA had lower scores in all subgroups of SF-36 compared with controls. In patients, the SF-36 physical function (PF) and pain areas significantly correlated with effusion, VAS pain, and Lequesne and WOMAC subgroup scores (p < 0.05). The pain area of QoL did not show correlation with comorbidity with knee OA. We found that SF-36 and WOMAC pain scores were more severe in female patients.

Conclusions Patients with knee OA had significantly poorer QoL compared with healthy controls. SF-36 is related to the clinical status and functional ability of patients with OA and can be used as a sensitive health status measure for clinical evaluation. Also WOMAC can be used as a sensitive measure for disability of patients with knee OA.     

Radiographic assessment of symptomatic knee osteoarthritis in the community: definitions and normal joint space

OBJECTIVE—To evaluate radiographic features of osteoarthritis (OA) to determine which is more closely associated with knee pain and hence might be used as a radiographic definition of OA in the community. To evaluate joint space width in normal subjects.METHODS—452 subjects from a case-control community study of knee pain (294 women, 158 men, mean age 62 years, range 40-80) underwent AP standing and mid-flexion skyline radiographs. Joint space width, measured by metered calliper to 0.1 mm, and graded individual features of OA (osteophyte 0-3, narrowing 0-3, sclerosis 0-1, cysts 0-1) were assessed in all three compartments independently by two observers who were blind to clinical status. Subjects were categorised as having knee pain by a positive response to both parts of the question "Have you ever had pain in or around the knee on most days for at least a month? If so, have you experienced any pain during the last year?"RESULTS—Intraobserver reproducibility for joint space width measurements was to within ±0.4 mm (95% CI for limits of agreement); κ values for grading were >0.7. One hundred and twenty five subjects were without knee pain or osteophyte. In these radiographically normal knees, mean joint space width varied according to sex but did not decrease with age. A definition based on the presence of osteophyte ?grade 1 in any compartment was more efficient at predicting pain than definitions based on either measurement or grading of joint space; there was no clear threshold of joint space loss at which the likelihood of pain substantially increased. The presence of osteophyte at the patellofemoral joint (PFJ) was more sensitive but less specific than at the tibiofemoral joint (TFJ); the addition of PFJ assessment improved sensitivity from 38.1% to 62.3% with a reduction in specificity from 82.7% to 58.7% for the presence of knee pain.CONCLUSION—Among men and women in the community, osteophyte is the radiographic feature that associates best with knee pain. Radiographic assessment of both TFJ and PFJ should be included in all community studies. Joint space loss is not a feature of asymptomatic aging, and there is not a biological cut off for joint space width below which the likelihood of knee pain markedly increases.     

Knee laxity after staircase exercise predicts radiographic disease progression in medial compartment knee osteoarthritis

Objective

To evaluate whether increased laxity of the knee during daily physical activities such as stair climbing is associated with progression of knee joint osteoarthritis (OA).

Methods

During the years 2001–2003, 136 patients with bilateral primary medial compartment knee joint OA were enrolled in this prospective study. Baseline data collected were body mass index (BMI), muscle power, radiographic joint space width, mechanical axis on standing radiography, and anteroposterior (AP) knee laxity before and after physical exercise. After 8 years of followup, 84 patients were reexamined to assess radiographic changes. Radiographic disease progression was defined as progression of >1 grade on the Kellgren/Lawrence scale.

Results

AP knee laxity increased significantly after stair climbing. Patients with OA progression and those without progression did not differ significantly in age, sex, baseline quadriceps muscle strength, mechanical axis, joint space width, and AP knee laxity before exercise. The 2 groups of patients did, however, differ significantly in baseline BMI and change in AP knee laxity due to exercise. The risk of progression of knee OA increased 4.15‐fold with each millimeter of increase in the change in AP knee laxity due to exercise and 1.24‐fold with each point increase in the BMI.

Conclusion

Our results indicate that patients with OA progression have significantly greater changes in knee joint laxity during physical activities and a higher BMI than patients without OA progression. These findings suggest that larger changes in knee laxity during repetitive physical activities and a higher BMI play significant roles in the progression of knee OA.

     

Safety and efficacy of long-term intraarticular steroid injections in osteoarthritis of the knee: a randomized,double-blind,placebo-controlled trial

OBJECTIVE: To evaluate the safety and efficacy of long-term intraarticular (IA) steroid injections for knee pain related to osteoarthritis (OA). METHODS: In a randomized, double-blind trial, 68 patients with OA of the knee received IA injections of triamcinolone acetonide 40 mg (34 patients) or saline (34 patients) into the study knee every 3 months for up to 2 years. The primary outcome variable was radiologic progression of joint space narrowing of the injected knee after 2 years. Measurements of minimum joint space width were performed by an automated computerized method on standardized fluoroscopically guided radiographs taken with the patient standing and with the knee in a semiflexed position. The clinical efficacy measure of primary interest was the pain subscale from the Western Ontario and McMaster Universities OA Index (WOMAC). Efficacy measures of secondary interest were the total score on the WOMAC, physician's global assessment, patient's global assessment, patient's assessment of pain, range of motion (ROM) of the affected knee, and 50-foot walking time. Clinical symptoms were assessed just before each injection. RESULTS: At the 1-year and 2-year followup evaluations, no difference was noted between the two treatment groups with respect to loss of joint space over time. The steroid-injected knees showed a trend toward greater symptom improvement, especially at 1 year, for the WOMAC pain subscale, night pain, and ROM values (P = 0.05) compared with the saline-injected knees. Using area under the curve analyses, knee pain and stiffness were significantly improved throughout the 2-year study by repeated injections of triamcinolone acetonide, but not saline (P < 0.05). CONCLUSION: Our findings support the long-term safety of IA steroid injections for patients with symptomatic knee OA. No deleterious effects of the long-term administration of IA steroids on the anatomical structure of the knee were noted. Moreover, long-term treatment of knee OA with repeated steroid injections appears to be clinically effective for the relief of symptoms of the disease.     

A prospective, randomized, double-blind, placebo controlled study to evaluate the efficacy of intraarticular hyaluronic acid for osteoarthritis of the knee

OBJECTIVE: To assess the efficacy of intraarticular (IA) injections of hyaluronic acid (HA) compared to placebo in patients with osteoarthritis (OA) of the knee; and to assess patient satisfaction with treatment relative to placebo, and whether there is a difference between a series of 3 versus 6 consecutive IA injections. METHODS: We conducted a randomized, double-blind, placebo controlled, 2-arm parallel design trial of 106 patients with radiologically confirmed knee OA. Two-milliliter IA injections using 20 mg/ml HA sodium salt or saline placebo were administered once weekly over 3 weeks (HA and placebo groups), followed by once weekly IA injection with 2.0 ml (20 mg/ml) HA for a further 3 consecutive weeks. The primary efficacy assessment included Western Ontario and McMaster Universities osteoarthritis index (WOMAC) score for knee pain (Week 3 score). Secondary efficacy assessments included WOMAC scores for knee pain at Weeks 6 and 12 (followup), as well as WOMAC stiffness, physical function and quality of life scores, visual analog scale (VAS) scores for pain at rest and following walking and stepping activity, range of knee joint motion, and global patient satisfaction with treatment and quality of life using the SF-36. RESULTS: After 3 weeks of study treatment, both treatment groups showed improvements in knee function, the HA group showing a greater improvement compared to placebo in WOMAC knee pain score (p < 0.01). The HA group showed greater (p < 0.05) improvement in the overall WOMAC score and VAS pain following walking and stepping activity at Week 3. Results from all other secondary efficacy assessments at Weeks 6 and 12 including patient satisfaction were similar and were not statistically significant between treatment groups, and there were no significant differences between groups for adverse events. CONCLUSION: Intraarticular HA was superior to placebo in improving knee pain and function, with no difference between 3 or 6 consecutive injections for the primary efficacy assessment.     

Knee osteoarthritis in obese women with cardiometabolic clustering

Objective

To assess the role of obesity and metabolic dysfunctionality with knee osteoarthritis (OA), knee joint pain, and physical functioning performance, adjusted for joint space width (JSW) asymmetry.

Methods

Knee OA was defined as a Kellgren/Lawrence score ≥2 on weight‐bearing radiographs. Obesity was defined as a body mass index ≥30 kg/m². Cardiometabolic clustering classification was based on having ≥2 of the following factors: low levels of high‐density lipoprotein cholesterol; elevated levels of low‐density lipoprotein cholesterol, triglycerides, blood pressure, C‐reactive protein, waist:hip ratio, or glucose; or diabetes mellitus. The difference between lateral and medial knee JSW was used to determine joint space asymmetry.

Results

In a sample of women (n = 482, mean age 47 years), prevalences of knee OA and persistent knee pain were 11% and 30%, respectively. The knee OA prevalence in nonobese women without cardiometabolic clustering was 4.7%, compared with 12.8% in obese women without cardiometabolic clustering and 23.2% in obese women with cardiometabolic clustering. Nonobese women without cardiometabolic clustering were less likely to perceive themselves as limited compared with women in all other obesity/cardiometabolic groups (P < 0.05). Similar associations were seen with knee pain and physical functioning measures. The inclusion of a joint space asymmetry measure was associated with knee OA but not with knee pain or physical functioning.

Conclusion

Knee OA was twice as frequent in obese women with cardiometabolic clustering compared with those without, even when considering age and joint asymmetry. Obesity/cardiometabolic clustering was also associated with persistent knee pain and impaired physical functioning.     

The incidence and natural history of knee osteoarthritis in the elderly,the framingham osteoarthritis study

Objective. To determine the incidence of radiographic knee osteoarthritis (OA) and symptomatic OA (symptoms plus radiographic OA), as well as the rate of progression of preexisting radiographic OA in a population-based sample of elderly persons. Methods. Framingham Osteoarthritis Study subjects who had knee radiographs and had answered questions about knee symptoms in 1983–1985 were reexamined in 1992–1993 (mean 8.1-year interval) using the same protocol. Subjects were defined as having new (incident) radiographic OA if they developed grade ≤2 OA (at least definite osteophytes or definite joint space narrowing). New symptomatic OA was present if subjects developed a combination of knee symptoms and grade ≤2 OA. Progressive OA was diagnosed when radiographs showing grade 2 disease at baseline showed grade ≤3 disease on followup. Results. Of 1,438 participants in the original study, 387 (26.9%) died prior to followup. Of the 1,051 surviving subjects, 869 (82.7%) participated in the followup study (mean ± SD age 70.8 ± 5.0 at baseline). Rates of incident disease were 1.7 times higher in women than in men (95% confidence interval [CI] 1.0–2.7), and progressive disease occurred slightly more often in women (relative risk = 1.4; 95% CI 0.8–2.5) but rates did not vary by age in this sample. Among women, approximately 2% per year developed incident radiographic disease, 1% per year developed symptomatic knee OA, and about 4% per year experienced progres- sive knee OA. Conclusion. In elderly persons, the new onset of knee OA is frequent and is more common in women than men. However, among the elederly, age may not affect new disease occurrence or progression.     

The effects of impaired joint position sense on the development and progression of pain and structural damage in knee osteoarthritis

Objective

Although cross‐sectional studies have reported impaired proprioceptive acuity in people with osteoarthritis (OA), there have been no longitudinal studies to evaluate whether those with such impairments increase the risk of OA or its worsening.

Methods

We studied subjects from the Multicenter Osteoarthritis Study study, a longitudinal study of people with or at high risk of knee OA. At baseline, we quantified acuity as the amount of a subject's error when attempting to reproduce a test knee flexion angle (a measure of joint position sense). We tested proprioception 10 times in the right leg and used a person's worst score as their proprioceptive acuity. At baseline and the 30‐month followup, we assessed the presence of frequent pain, obtained Western Ontario and McMasters Universities OA Index (WOMAC) scores, and acquired posteroanterior and lateral weight‐bearing knee radiographs read for Kellgren/Lawrence grade and individual radiographic features. We examined the relation of baseline proprioceptive acuity in quartiles with baseline knee pain (frequent pain yes/no), WOMAC pain score, self‐reported physical function, and radiographic OA, and with changes from baseline in pain, physical function, and radiographic OA adjusted for age, sex, body mass index, and quadriceps strength.

Results

At baseline, proprioceptive acuity was associated with the presence and severity of knee pain but not with the presence of radiographic OA. However, among the 2,243 subjects with baseline acuity assessments and 30‐month followup, there were no strong associations between proprioceptive acuity and development of adverse OA outcomes. Acuity was not significantly associated with the new onset of frequent knee pain. Those with the worst acuity at baseline had slightly greater worsening of WOMAC pain scores (0.47 on a 20‐point scale) and physical function scores (by 1.5 points on a 0–68‐point scale) compared with those with the best proprioceptive acuity, whose pain and physical function score deteriorated less (for pain P = 0.05; for physical function P = 0.02). Radiographic worsening was not significantly associated with proprioceptive acuity.

Conclusion

Proprioceptive acuity as assessed by the accuracy of reproduction of the angle of knee flexion had modest effects on the trajectory of pain and physical functional limitation in knee OA.     

Associations of dietary and serum magnesium with serum high-sensitivity C-reactive protein in early radiographic knee osteoarthritis patients

Introduction: This study aimed to examine the associations of dietary magnesium (Mg) intake and serum Mg concentration with the high-sensitivity C-reactive protein (hsCRP) level in early radiographic knee osteoarthritis (OA) patients.

Methods: Multivariable logistic regression was used to test the associations of dietary and serum Mg with the serum hsCRP in early radiographic knee OA patients after adjustment of a number of potential confounding factors.

Results: A total of 936 early radiographic knee OA patients were included. A significant association between dietary Mg intake and hsCRP was observed. The multivariable-adjusted odds ratio (OR) (95% CI) for elevated hsCRP (≥3.0?mg/l) in the second, third, fourth, and fifth dietary Mg intake quintile were 0.44 (95% CI: 0.24–0.82), 0.58 (95% CI: 0.31–1.10), 0.34 (95% CI: 0.15–0.77), and 0.19 (95% CI: 0.06–0.57), respectively, compared with the lowest (first) quintile, and p for trend was 0.01. A significant association between serum Mg concentration and hsCRP was observed. The multivariable-adjusted OR (95% CI) for elevated hsCRP in the second, third, fourth, and fifth serum Mg concentration quintile were 0.63 (95% CI: 0.35–1.12), 0.83 (95% CI: 0.50–1.39), 0.53 (95% CI: 0.31–0.91), and 0.46 (95% CI: 0.25–0.85), respectively, compared with the lowest quintile, and p for trend was 0.01.

Conclusion: The present study indicated that both dietary and serum Mg were inversely associated with serum hsCRP in early radiographic knee OA patients.     

Association of magnetic resonance imaging-based knee cartilage T2 measurements and focal knee lesions with knee pain: data from the Osteoarthritis Initiative

Objective

To evaluate the association of magnetic resonance imaging (MRI)–based knee cartilage T2 measurements and focal knee lesions with knee pain in knees without radiographic osteoarthritis (OA) among subjects with OA risk factors.

Methods

We studied the right knees of 126 subjects from the Osteoarthritis Initiative database. We randomly selected 42 subjects ages 45–55 years with OA risk factors, right knee pain (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] pain score ≥5), no left knee pain (WOMAC pain score 0), and no radiographic OA (Kellgren/Lawrence [K/L] score ≤1) in the right knee. We also selected 2 comparison groups: 42 subjects without knee pain in either knee and 42 with bilateral knee pain. Both groups were frequency matched to subjects with right knee pain only by sex, age, body mass index, and K/L score. All of the subjects underwent 3T MRI of the right knee. Focal knee lesions were assessed and cartilage T2 measurements were performed.

Results

Prevalences of meniscal, bone marrow, and ligamentous lesions and joint effusion were not significantly different between the groups (P > 0.05), while cartilage lesions were more frequent in subjects with right knee pain only compared to subjects without knee pain (P < 0.05). T2 values averaged over all of the compartments were similar in subjects with right knee pain only (mean ± SD 34.4 ± 1.8 msec) and in subjects with bilateral knee pain (mean ± SD 34.7 ± 4.7 msec), but were significantly higher compared to subjects without knee pain (mean ± SD 32.4 ± 1.8 msec; P < 0.05).

Conclusion

These results suggest that elevated cartilage T2 values are associated with findings of pain in the early phase of OA, whereas among morphologic knee abnormalities only knee cartilage lesions are significantly associated with knee pain status.     

A new marker for osteoarthritis: Cross‐sectional and longitudinal approach

Objective

To investigate the association between urinary concentrations of C‐telopeptide fragments of type II collagen (CTX‐II) and the prevalence and progression of radiographic osteoarthritis (OA) of the knee and hip.

Methods

The study population consisted of a sample of 1,235 men and women ages ≥55 years who were enrolled in the Rotterdam Study (a population‐based cohort study) and who were followed up for a mean of 6.6 years. Prevalent radiographic OA was defined as a Kellgren/Lawrence score ≥2; progression of radiographic OA was defined as a decrease in joint space width.

Results

Subjects with a CTX‐II level in the highest quartile had a 4.2‐fold increased risk of having radiographic OA of the knee (95% confidence interval [95% CI] 2.5–7.0) and of the hip (95% CI 2.2–7.8) compared with subjects with a CTX‐II level in the lowest quartile. We observed a substantially stronger association between CTX‐II levels and radiographic OA for subjects with hip pain (odds ratio [OR] 20.4, 95% CI 2.3–185.2) than for those without hip pain (OR 3.0, 95% CI 1.5–6.0). Subjects with a CTX‐II level in the highest quartile had a 6.0‐fold increased risk for progression of radiographic OA at the knee (95% CI 1.2–30.8) and an 8.4‐fold increased risk for progression of radiographic OA at the hip (95% CI 1.0–72.9). All of these associations were found to be independent of known risk factors for OA, such as age, sex, and body mass index.

Conclusion

This study shows that CTX‐II is associated with both the prevalence and the progression of radiographic OA at the knee and hip. Importantly, this association is independent of known clinical risk factors for OA and seems stronger in subjects with joint pain.