Knee effusions, popliteal cysts, and synovial thickening: association with knee pain in osteoarthritis.

OBJECTIVE: To evaluate the association of effusions, popliteal cysts, and synovial thickening with knee symptoms in older persons with and without radiographic (XR) osteoarthritis (OA), using magnetic resonance imaging (MRI). METHODS: Subjects with and without knee symptoms were recruited from Veterans Affairs and community sources. All had weight-bearing knee radiographs. Subjects were divided into 3 groups: Knee pain/XROA group had knee symptoms and radiographic OA; No knee pain/XROA group had no knee symptoms and radiographic OA; and No knee pain/no XROA group had no knee symptoms and a normal radiograph. A single knee was imaged using a 1.5 T MR scanner using T1 and T2 weighted and proton density SE imaging sequences. MRI were read for effusion, popliteal cysts, and synovial thickening. RESULTS: The mean age of subjects was 67.0 years (66.6% male). We studied 381 subjects with Knee pain/XROA, 52 with No knee pain/XROA, and 25 with No knee pain/no XROA. The prevalence of moderate or larger effusions was: Knee pain/XROA 54.6%, No knee pain/XROA 15.6%, and No knee pain/no XROA 11.1%. Popliteal cysts were present in 33.0% of Knee pain/XROA subjects, 28.0% No knee pain/XROA, and 9.1% No knee pain/no XROA. After adjusting for the severity of radiographic OA, there was a difference between those with and without knee pain in prevalence of moderate or larger effusions (p < 0.001) and synovial thickening, independent of effusion (p < 0.001), but not in the prevalence of popliteal cysts. Further, among those in Knee pain/OA group, synovial thickening was associated with the severity of knee pain. CONCLUSION: Effusions and popliteal cysts are common in middle aged and elderly people. After adjusting for the degree of radiographic OA, moderate or large effusions and synovial thickening were more frequent among those with knee pain than those without pain, suggesting these features are associated with the pain of knee OA. In those with knee symptoms, synovial thickening is uniquely associated with the severity of knee pain.     

Synovitis detected on magnetic resonance imaging and its relation to pain and cartilage loss in knee osteoarthritis

Objective

To examine the relationship between longitudinal fluctuations in synovitis with change in pain and cartilage in knee osteoarthritis.

Methods

Study subjects were patients 45 years of age and older with symptomatic knee osteoarthritis from the Boston Osteoarthritis of the Knee Study. Baseline and follow‐up assessments at 15 and 30 months included knee magnetic resonance imaging (MRI), BMI and pain assessment (VAS) over the last week. Synovitis was scored at 3 locations (infrapatellar fat pad, suprapatellar and intercondylar regions) using a semiquantitative scale (0–3) at all 3 time points on MRI. Scores at each site were added to give a summary synovitis score (0–9).

Results

We assessed 270 subjects whose mean (SD) age was 66.7 (9.2) years, BMI 31.5 (5.7) kg/m²; 42% were female. There was no correlation of baseline synovitis with baseline pain score (r = 0.09, p = 0.17). The change in summary synovitis score was correlated with the change in pain (r = 0.21, p = 0.0003). An increase of one unit in summary synovitis score resulted in a 3.15‐mm increase in VAS pain score (0–100 scale). Effusion change was not associated with pain change. Of the 3 locations for synovitis, changes in the infrapatellar fat pad were most strongly related to pain change. Despite cartilage loss occurring in over 50% of knees, synovitis was not associated with cartilage loss in either tibiofemoral or patellofemoral compartment.

Conclusions

Change in synovitis was correlated with change in knee pain, but not loss of cartilage. Treatment of pain in knee osteoarthritis (OA) needs to consider treatment of synovitis.The cause of pain in knee osteoarthritis remains elusive as the primary site of pathology in OA, cartilage, has no pain fibres.¹ Many other structures around the knee such as the periosteum, subchondral bone, the fat pad, capsule and, inconsistently, the synovium have been shown to contain nociceptive fibres.¹ In addition, inflammation itself appears to play a role in increasing input from peripheral nociceptors.² Biopsies of patients with both early and late knee OA have shown low‐grade chronic synovitis with production of pro‐inflammatory cytokines.^3,4Magnetic resonance imaging (MRI) allows evaluation of multiple structures within the knee, including synovium, cartilage, menisci, bone marrow lesions and effusion. In cross‐sectional studies of MRI in knee osteoarthritis (OA), bone‐marrow lesions, periarticular lesions, knee effusions and synovitis have been shown to be more often present in persons with knee pain than in persons with a comparable amount of radiographic knee osteoarthritis but without pain.^5,6,7,8 Fernandez‐Madrid et al demonstrated that synovial thickening seen on non‐contrast enhanced MRI in the infrapatellar region of knees with OA showed low‐grade synovial inflammation on biopsy. This feature was present in 73% of knees with early OA.⁹We have previously shown that this synovial thickening is present in persons with knee pain and OA much more often than in persons with OA but without pain.⁷ Among those with pain, the presence of MRI synovial thickening identified those with more severe pain. While this evidence suggests that synovial thickening may affect pain, these data are cross‐sectional, making it impossible to evaluate the temporal relation of pain with synovial thickening. More persuasive evidence would emanate from a longitudinal study in which fluctuations in synovial thickening could be tied to fluctuations in the severity of knee pain. Herein, we provide such evidence. Our aims were to study the association between baseline and longitudinal changes in MRI‐detected synovitis and changes in knee pain, and also to study the association between baseline and longitudinal changes in synovitis and cartilage loss in patients with symptomatic knee OA.     

Ultrasonography is superior to clinical examination in the detection and localization of knee joint effusion in rheumatoid arthritis

OBJECTIVE: Musculoskeletal ultrasonography allows real-time imaging of joint structures and may be used to complement clinical examination in rheumatological practice. We compared ultrasonography (US) with clinical examination (CE) in the detection of effusion, suprapatellar bursitis, and Baker's cyst of the knee in rheumatoid arthritis (RA) in order to determine whether US provided additional clinical information. METHODS: A total of 22 patients with RA (ACR criteria) underwent independent clinical and US examination of both knees for suprapatellar bursitis, knee effusion, and presence of Baker's cyst. US was performed using an ATL HDI 3000 machine with L7-4 MHz and CL10-5 MHz probes. Clinical examination was performed using standard techniques by an experienced rheumatologist. Patients with previous knee surgery were excluded from the study. RESULTS: A total of 44 knees were examined at a total of 130 sites (one patient was unable to lie prone for US of popliteal fossae). US detected soft tissue abnormality (suprapatellar bursitis, knee effusion, or Baker's cyst) at 54/130 (42%) sites, while CE detected soft tissue abnormality at 36/130 (28%) sites. US detected 17 (39%) cases of suprapatellar bursitis in 44 knees, 7 (16%) of which were detected on CE. US detected 27 (61%) knee joint effusions in 44 knees, 16 (36.36%) of which were detected on CE. US detected 10 (23.81%) Baker's cysts in 42 knees, 2 (4.76%) of which were detected on CE. Taking US of the knee as the gold standard, CE was specific but not sensitive in the detection of soft tissue abnormality of the knee in RA. CONCLUSION: US is more sensitive than CE in the detection of suprapatellar bursitis, knee effusion, and Baker's cyst in RA. CE underestimates knee inflammation in RA. This has implications for the use of CE as a component of standardized disease activity scores and in guiding knee joint aspiration.     

磁共振成像在类风湿关节炎患者膝关节病变研究中的意义

目的　初步探讨磁共振成像 (MRI)技术在类风湿关节炎 (RA)患者膝关节病变临床诊断中的应用价值。方法　对 2 0例RA患者的 34个膝关节进行多种序列成像并分析其MRI表现。结果　MRI可清晰显示RA膝关节的滑膜增生及血管翳形成、关节软骨破坏、骨质受侵、关节囊积液、半月板及韧带异常、窝囊肿形成以及皮下结节等改变 ,并能通过血管翳的信号和强化程度判断疾病是否处于活动期。结论　与X线相比 ,MRI对RA的骨质侵蚀破坏更为敏感 (P <0 0 1)。MRI能直接显示RA患者膝关节不同时期的各种改变 ,有助于疾病的早期诊断和临床分期     

Correlation of sonographic severity with biochemical markers of synovium and cartilage in knee osteoarthritis patients

OBJECTIVE: Ultrasonography can be used to detect soft tissue abnormalities within the joints that cannot be assessed using conventional X-rays. This study investigated the relationship between soft tissue and/or bony abnormalities on ultrasonography and the biochemical markers of the synovium and cartilage in the knee of osteoarthritis (OA) patients. METHODS: The knees from 51 OA patients who fulfilled the ACR criteria were enrolled in this study. Knee ultrasonography was performed in the affected knee joints using a 12 MHz linear probe to assess the presence of effusion, synovial proliferation, capsular distention, the length of osteophytes and the cartilage thickness. At the same time, the serum hyaluronic acid (HA) and the cartilage oligomeric protein (COMP) levels were measured by ELISA, and RIA was used to determine the serum osteocalcin levels. RESULTS: The patients with a longer medial osteophyte showed higher serum HA and COMP levels than those with a shorter one. The serum HA levels were significantly higher in those patients with a larger amount of effusion and/or synovial proliferation, which indicated inflammatory changes, than in those without. In addition, the severity of the capsular distention also correlated well with the serum HA and COMP levels. However, the length of the lateral osteophytes and the thickness of the femoral cartilage showed no correlation with the serum HA or COMP levels. In addition, the serum osteocalcin levels did not show any association with the above ultrasonographic parameters. CONCLUSION: This study demonstrated that the serum HA and COMP levels were elevated in the more severe OA patients by knee ultrasonography than in the less severe patients. This suggests that the detailed pathological changes in the soft tissue and/or bone of the OA joints on ultrasonography are directly reflected by the biochemical markers measured in the peripheral blood.     

Power Doppler sonography in the evaluation and follow-up of knee involvement in patients with juvenile idiopathic arthritis

INTRODUCTION: This study was undertaken to evaluate the role of ultrasound (US), conventional color (CD) and power Doppler (PD) in the detection and quantification of inflammatory signs of the knee in children with juvenile idiopathic arthritis (JIA) and to correlate these findings with patient history, clinical, laboratory and radiological findings. PATIENTS AND METHODS: Thirty patients with JIA who had clinical signs of knee involvement as well as 15 healthy children as a control group where subjected to full clinical examination and laboratory investigations on the same day of US examination. The knee joints were evaluated with plain radiography, US, and color Doppler in 13 patients, while the remaining 17 were assessed with power Doppler. Fourteen patients were subjected to follow-up assessment. RESULTS: A highly significant difference in synovial thickening and cartilage thickness detected by US between JIA affected knees and those of controls (p < 0.0001). Knee effusion was demonstrated in 93% of patients. Synovial vessels were detected by Doppler in 76.7% of patients. A significant correlation was detected between the degree of vascularity detected by PD and knee score (p < 0.05), and JAFAR score (P < 0.05). On comparing the findings of the follow-up with those of the initial examination, a significant positive correlation was detected between the differences in the knee score and those in synovial thickness (p < 0.05), and with the vascularity scale detected by PD (p < 0.05). CONCLUSION: This study suggests the Doppler sonography as a non-invasive, low-cost, and readily available tool for the evaluation and follow-up of articular involvement in knees of JIA patients.     

Effect of 12?months treatment with chondroitin sulfate on cartilage volume in knee osteoarthritis patients: a randomized, double-blind, placebo-controlled pilot study using MRI

This pilot study aimed to evaluate the correlation between clinical symptoms and cartilage volume through MRI in patients with knee osteoarthritis after 48?weeks of treatment with Structum?. Multicenter, double-blind, placebo-controlled, parallel-group study. Symptomatic knee osteoarthritis patients aged 50–75?years received either Structum? (500?mg twice daily; N?=?22) or placebo (N?=?21) during 48?weeks. Inclusion criteria were global pain in the target knee ≥30?mm (VAS 0–100) and radiological Kellgren-Lawrence grade 2 or 3. Clinical assessments included Lequesne index and VAS for pain on motion, at baseline, 24 and 48?weeks, and MRI at baseline and at 24 and 48?weeks. Global and compartments cartilage volume, joint cartilage abnormalities, meniscal lesions, ligaments abnormalities, synovitis, synovial effusion, osteophytes, subchondral cysts, popliteal cysts and subchondral oedema were quantified. The quantitative and qualitative reproducibility of MRI was tested by the Spearman correlation coefficient and kappa coefficients, respectively. Treatments were compared by an analysis of covariance with baseline value as covariate. Groups were comparable at baseline for demographics, disease characteristics, and cartilage volumes. A significant inter-readers correlation was seen for the assessment of cartilage volumes, number of cysts, and osteophytes (correlation coefficients from 0.951 to 0.980 within investigator and from 0.714 to 0.957). After 48?weeks, symptoms improved in both groups. The total cartilage volume increased in the Structum? group (+180?mm³?+?SD) which opposed to a loss in the placebo (?46?mm³?+?SD; NS). No statistically significant differences between groups were observed for the other MRI parameters. No correlations were evidenced between key MRI parameters changes and symptoms. The difference in the evolution of cartilage volume between the two groups could reflect a structure modifying effect of Structum?. This pilot study confirms the usefulness of quantitative and qualitative MRI as a sensitive tool to assess a structure modifying drugs in knee osteoarthritis.     

Power Doppler sonography in the evaluation and follow-up of knee involvement in patients with juvenile idiopathic arthritis

Introduction This study was undertaken to evaluate the role of ultrasound (US), conventional color (CD) and power Doppler (PD) in the detection and quantification of inflammatory signs of the knee in children with juvenile idiopathic arthritis (JIA) and to correlate these findings with patient history, clinical, laboratory and radiological findings. Patients and methods Thirty patients with JIA who had clinical signs of knee involvement as well as 15 healthy children as a control group where subjected to full clinical examination and laboratory investigations on the same day of US examination. The knee joints were evaluated with plain radiography, US, and color Doppler in 13 patients, while the remaining 17 were assessed with power Doppler. Fourteen patients were subjected to follow-up assessment. Results A highly significant difference in synovial thickening and cartilage thickness detected by US between JIA affected knees and those of controls (p<0.0001). Knee effusion was demonstrated in 93% of patients. Synovial vessles were detected by Doppler in 76.7% of patients. A significant correlation was detected between the degree of vascularity detected by PD and knee score (p<0.05), and JAFAR score (P<0.05). On comparing the findings of the follow-up with those of the initial examination, a significant positive correlation was detected between the differences in the knee score and those in synovial thickness (p<0.05), and with the vascularity scale detected by PD (p<0.05). Conclusion This study suggests the Doppler sonography as a non-invasive, low-cost, and readily available tool for the evaluation and follow-up of articular involvement in knees of JIA patients.     

Ultrasonographic evaluation of pes anserinus tendino-bursitis in patients with type 2 diabetes mellitus

OBJECTIVE: To assess musculoskeletal ultrasonographic (US) findings in patients with type 2 diabetes mellitus (DM) with and without pes anserinus (PA) tendinitis or bursitis syndrome; and to determine possible etiologic factors such as systemic diabetic microvascular disease complications in these patients. METHODS: The knee joints were examined with an ultrasound real-time scanner using a 10 MHz electronic linear transducer in 48 patients with type 2 DM and 25 controls. The presence of systemic diabetic microvascular disease complications was evaluated. RESULTS: On examination 23 (23.9%) knees of the 14 (29.1%) patients with type 2 DM were found to have PA tendinitis or bursitis syndrome. US revealed that only 4 (8.3%) of the diabetic patients with PA tendinitis or bursitis syndrome had PA tendonitis findings. There were no significant differences in the thickness of PA tendons between the diabetic patients with bilateral knee PA tendinitis or bursitis syndrome (9 patients) and controls, or between the asymptomatic and symptomatic knees in patients with unilateral PA tendinitis or bursitis syndrome (5 patients). The prevalence of morphologic changes of the medial meniscus, effusion and synovitis in the suprapatellar recess, popliteal cyst, and radiographic osteoarthritis (OA) in the diabetic patients with PA tendinitis or bursitis syndrome was found to be increased. CONCLUSION: The prevalence of PA tendinitis or bursitis syndrome is not uncommon on examination in patients with type 2 DM. However, patients with clinically diagnosed PA tendinitis or bursitis syndrome less frequently have morphologic US changes of the PA tendons. Our results also suggest that structural changes such as meniscus lesions that occur in consequence of OA might have a role in the etiology of medial knee pain in diabetic patients.     

The relationship between cartilage loss on magnetic resonance imaging and radiographic progression in men and women with knee osteoarthritis

OBJECTIVE: To determine the relationship between radiographic progression of joint space narrowing and cartilage loss on magnetic resonance imaging (MRI) in patients with symptomatic knee osteoarthritis (OA), and to investigate the location of MRI-based cartilage loss in the knee and its relation to radiographic progression. METHODS: Two hundred twenty-four men and women (mean age 66 years) were studied. Radiographs and MRI of the more symptomatic knee were obtained at baseline and at 15- and 30-month followup. Radiographs of the knee (with weight-bearing) were read for joint space narrowing (scale 0-3), with progression defined as any worsening in score. We used a semiquantitative method to score cartilage morphology in all 5 regions of the tibiofemoral joint, and defined cartilage loss as an increase in score (scale 0-4) at any region. We examined the relationship between progression of joint space narrowing on radiographic images and cartilage loss on MRI, using a generalized estimating equation proportional odds logistic regression, adjusted for baseline cartilage score, age, body mass index, and sex. The medial and lateral compartments were analyzed separately. RESULTS: In the medial compartment, 104 knees (46%) had cartilage loss detected by MRI. The adjusted odds ratio was 3.7 (95% confidence interval 2.2-6.3) for radiographic progression being predictive of cartilage loss on MRI. However, there was still a substantial proportion of knees (80 of 189 [42%]) with cartilage loss visible on MRI when no radiographic progression was apparent. Cartilage loss occurred frequently in the central regions of the femur and tibia as well as the posterior femur region, but radiographic progression was less likely to be observed when posterior femur regions showed cartilage loss. Radiographic progression appeared specific (91%) but not sensitive (23%) for cartilage loss. Overall findings were similar for the lateral compartment. CONCLUSION: While our results provide longitudinal evidence that radiographic progression of joint space narrowing is predictive of cartilage loss assessed on MRI, radiography is not a sensitive measure, and if used alone, will miss a substantial proportion of knees with cartilage loss.     

Clinical evaluation during the acute exacerbation of knee osteoarthritis: the impact of diagnostic ultrasonography

We aimed to investigate (1) the probable correlation between clinical and ultrasonographic findings in chronic painful primary knee OA patients referred with acute flare-ups and (2) the impact of diagnostic ultrasonography (US) to determine the real source of pain in these patients. We included 100 patients consecutively who were admitted to our outpatient unit with a pain complaint on a single knee with the diagnosis of primary knee OA according to the ACR criteria. The control group consisted of the patients with pain-free knees at least during the last month, who were already included in the study group. The sonographic evaluation of the knee was performed by a physician who was blinded to the clinical evaluation and/or the physical and radiological evaluations. In the present study, sonographic findings were significantly more observed on the painful knees (p < 0.001). The most commonly encountered findings on the symptomatic knees were the suprapatellar effusion (55 %), the baker cyst (25 %), and the pes anserine bursitis. The distribution of the findings on the asymptomatic knees was as follows: 22 %, the suprapatellar effusion and 5 %, the Baker cyst. Effusion was detected in 55 % of the painful knees of our patients with knee OA. This finding was statistically significant compared to the painless knees of the subjects included. The results of our study also showed that there was a significant relation between the Kellgren–Lawrence grading and the frequency of suprapatellar effusion on US examination (p = 0.026). It was concluded that in chronic, primary, painful knee osteoarthritis, US is a valuable diagnostic method in the confirmation of synovitis and/or the inflammatory episode in spite of the absence of obvious clinical parameters. In advanced osteoarthritis, when we consider that the inflammatory episodes are expected findings, the early confirmation of the inflammation on US may be particularly valuable in the clinical setting.     

Ultrasound of the knee during voluntary quadriceps contraction: A technique for detecting otherwise occult effusions

Objective

To describe 1) a technique that can detect synovial effusions not seen on static ultrasound (US) examination and 2) the characteristics of patients with knee osteoarthritis (OA) for whom this technique proved useful.

Methods

From reviewed records of 76 patients with knee OA (112 knees) that we had seen for US‐guided injections over a defined period, we found 45 knees with no detectable effusion on static US, of which 18 (14 patients) showed fluid when scanned during voluntary quadriceps contraction. For all patients, we had recorded effusion features (physical examination, presence and size on US), and success of joint entry was determined by getting synovial fluid and/or seeing an air echo or inflow of injected material.

Results

The 14 patients we studied were obese (mean ± SEM body mass index 32.7 ± 2.3 kg/m²; 3 morbidly obese), with moderate to severe OA by radiography in most (Kellgren/Lawrence class 3 or 4 in 10 of 14 knees for which radiographs were available). The suprapatellar synovial space seen by US was small (mean ± SEM depth 0.38 ± 0.04 cm). Arthrocentesis obtained 0.5–16 ml of synovial fluid (mean ± SEM 2.9 ± 0.6 ml), which correlated with the depth of effusion as seen on US with the quadriceps in maximum contraction (Spearman's ρ = 0.5597, P = 0.0157). In 4 knees where arthrocentesis failed to retrieve fluid, we observed at injection the inflow of material and a linear air echo.

Conclusion

US of the knee during voluntary quadriceps contraction can find effusions not detectable on static US. Such effusions provide targets for accurate aspiration and injection that would not be appreciated with static US.     

Value of magnetic resonance imaging for the diagnosis and follow-up of haemophilic arthropathy

An orthopaedic assessment of the joint status of seven severe haemophiliacs (mean age 12.5 y - range 8.9-15.5) on prophylactic treatment (PT) by magnetic resonance imaging (MRI) and physical examination was carried out. Median duration of PT of these patients was 84 months (range 32-107). A locally designed MRI joint score considering seven parameters (1 - joint effusion, 2 - synovial membrane thickening, 3 - haemosiderin deposits, 4 - joint cartilage injury, 5 - subchondral bone erosion, 6 - subchondral bone cysts, 7 - osteonecrosis) was used (maximum score = 13 points). MRI scans were performed in 17 joints (nine ankles, seven knees and one elbow): mean MRI scores for the affected joints was 5.1. A poor consistency between physical examination and MRI findings or the real extent of joint damage was found (Cohen kappa index 0.320). MRI is a precise non-invasive tool for the assessment of early joint cartilage and synovium pathological changes still undetectable by physical examination or conventional X-rays in the haemophilic setting.     

EULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 2: exploring decision rules for clinical utility

BACKGROUND: Synovial inflammation (as defined by hypertrophy and effusion) is common in osteoarthritis (OA) and may be important in both pain and structural progression. OBJECTIVE: To determine if decision rules can be devised from clinical findings and ultrasonography (US) to allow recognition of synovial inflammation in patients with painful knee OA. METHODS: A EULAR-ESCISIT cross sectional, multicentre study enrolled subjects with painful OA knee who had clinical, radiographic, and US evaluations. A classification and regression tree (CART) analysis was performed to find combinations of predictor variables that would provide high sensitivity and specificity for clinically detecting synovitis and effusion in individual subjects. A range of definitions for the two key US variables, synovitis and effusion (using different combinations of synovial thickness, depth, and appearance), were also included in exploratory analyses. RESULTS: 600 patients with knee OA were included in the analysis. For both knee synovitis and joint effusion, the sensitivity and specificity were poor, yielding unsatisfactory likelihood ratios (75% sensitivity, 45% specificity, and positive LR of 1.36 for knee synovitis; 71.6% sensitivity, 43.2% specificity, and positive LR of 1.26 for joint effusion). The exploratory analyses did not improve the sensitivity and specificity (demonstrating positive LRs of between 1.26 and 1.57). CONCLUSION: Although it is possible to determine clinical and radiological predictors of OA inflammation in populations, CART analysis could not be used to devise useful clinical decision rules for an individual subject. Thus sensitive imaging techniques such as US remain the most useful tool for demonstrating synovial inflammation of the knee at the individual level.     

Relationship between osteoprotegerin/osteoclastogenesis inhibitory factor concentration in synovial fluid and disease severity in individuals with osteoarthritis of the knee

We studied the relationship between osteoprotegerin (OPG)/osteoclastogenesis inhibitory factor (OCIF) concentration in synovial fluid from individuals with osteoarthritis (OA) of the knee and the severity of this condition. The study population included 111 Japanese women with knee OA (153 knees) and 23 normal controls. Osteoarthritic changes were graded according to the system of Kellgren and Lawrence. The concentration of OPG/OCIF in synovial fluid increased with severity of knee OA and was significantly higher in individuals with OA of grade IV than in those with OA of grade 0 or grade 1. It has been shown in a previous study that administration of OPG/OCIF prevents cartilage destruction in adjuvant-induced arthritis in rats. The increase in the concentration OPG/OCIF in synovial fluid of individuals with knee OA might thus reflect a compensatory response to degeneration of articular cartilage and serve to protect cartilage rather than be a cause of OA.     

Rates of change and sensitivity to change in cartilage morphology in healthy knees and in knees with mild, moderate, and end-stage radiographic osteoarthritis: results from 831 participants from the Osteoarthritis Initiative

Objective

To study the longitudinal rate of (and sensitivity to) change of knee cartilage thickness across defined stages of radiographic osteoarthritis (OA), specifically healthy knees and knees with end‐stage radiographic OA.

Methods

One knee of 831 Osteoarthritis Initiative participants was examined: 112 healthy knees, without radiographic OA or risk factors for knee OA, and 719 radiographic OA knees (310 calculated Kellgren/Lawrence [K/L] grade 2, 300 calculated K/L grade 3, and 109 calculated K/L grade 4). Subregional change in thickness was assessed after segmentation of weight‐bearing femorotibial cartilage at baseline and 1 year from coronal magnetic resonance imaging (MRI). Regional and ordered values (OVs) of change were compared by baseline radiographic OA status.

Results

Healthy knees displayed small changes in plates and subregions (±0.7%; standardized response mean [SRM] ±0.15), with OVs being symmetrically distributed close to zero. In calculated K/L grade 2 knees, changes in cartilage thickness were small (<1%; minimal SRM ?0.22) and not significantly different from healthy knees. Knees with calculated K/L grade 3 showed substantial loss of cartilage thickness (up to ?2.5%; minimal SRM ?0.35), with OV1 changes being significantly (P < 0.05) greater than those in healthy knees. Calculated K/L grade 4 knees displayed the largest rate of loss across radiographic OA grades (up to ?3.9%; minimal SRM ?0.51), with OV1 changes also significantly (P < 0.05) greater than in healthy knees.

Conclusion

MRI‐based cartilage thickness showed high rates of loss in knees with moderate and end‐stage radiographic OA, and small rates (indistinguishable from healthy knees) in mild radiographic OA. From the perspective of sensitivity to change, end‐stage radiographic OA knees need not be excluded from longitudinal studies using MRI cartilage morphology as an end point.

     

The rheumatoid knee before and after arthrocentesis and Prednisolone injection: Evaluation by Gd-enhanced MRI

Summary In patients with rheumatoid arthritis, intraarticular injection of corticosteroids is an accepted means of treating a symptomatic joint. It has previously been impossible to precisely quantitate the effects of these injections on synovial effusion and pannus. Magnetic resonance imaging (MRI) is a safe, effective means of evaluating joint anatomy, and the use of intravenous gadolinium (Gd)-containing contrast allows clear differentiation of fluid from abnormal synovial tissue. The current study utilized MRI with Gd-labeled diethylene-triamene pentacetic acid (Gd-DTPA) contrast to evaluate serial changes in 6 knees of 6 patients with rheumatoid arthritis, following arthrocentesis and intraarticular injection of prednisolone. One week after the corticosteroid was injected, 2 patients had reduction of pannus width to 20% and 68% of baseline measurements. In these same individuals, follow-up sagittal views showed decreases of total effusion and fluid-plus-pannus width. The other 4 patients, who were followed for 4 weeks, had minimal changes in fluid and synovium. Gd-DTPA-enhanced MRI permits precise assessment of effects of intraarticular injections on synovial fluid and pannus in the rheumatoid knee.     

Acetaminophen, like conventional NSAIDs, may reduce synovitis in osteoarthritic knees

OBJECTIVE: To determine the extent to which treatment of patients with symptomatic knee osteoarthritis (OA) with non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (ACET) reduces total effusion volume and synovial tissue volume, as quantified by magnetic resonance imaging (MRI). METHODS: Sequential pilot studies used subjects whose knee OA was treated with NSAIDs (n=10) or with ACET or=15 of 25 on the Western Ontario and McMaster Universities' pain scale underwent l.5T MRI. Effusion was quantified in axial short tau inversion recovery images; to measure synovial tissue volume, fat-suppressed T1-weighted axial images were obtained 3 min after i.v. injection of gadolinium contrast. After the initial MRI examination, patients resumed their customary pain medications until the severity of knee pain returned to baseline, when pain was again measured and the MRI was repeated. RESULTS: Pain severity after washout was similar in subjects taking ACET and NSAIDs. Reinstitution of ACET resulted in a 50% decrease in the mean of pain scores (P=1.7 x 10(-12)) that was comparable with that seen after the reinstitution of NSAID (49%, P=6.0 x 10(-7)). The mean total effusion volume measured during the flare of knee pain induced by the withdrawal of the two drugs was comparable (ACET 16.9 ml, NSAID 16.2 ml; P=0.884). Significant decreases in mean total effusion volume were observed after reinstitution of both ACET (-4.5 ml, P=0.009) and NSAID (-3.3 ml, P=0.013); the difference between drugs was not significant. Analyses of synovial volume yielded similar results. CONCLUSION: While uncontrolled and derived from small samples, these data suggest that ACET may have a significant anti-inflammatory effect in patients with knee OA, comparable with that achieved with NSAIDs, possibly through an effect on neurogenic inflammation. Joint pain is the clinical feature of OA that most often leads the affected individual to seek medical attention. Because many patients with OA improve symptomatically with the use of NSAIDs, it has been widely assumed that the pain of OA is due to synovial inflammation. However, the origins of OA pain are numerous and may vary from patient to patient and, within the same subject, from visit to visit. Although the articular cartilage is usually the site of the most obvious pathological changes in this disease, it is aneural and, therefore, is not the source of joint pain. However, in addition to the synovium, the subchondral bone, joint capsule, osteophytes, menisci, ligaments, periarticular tendons, entheses and bursae all contain nociceptive nerve endings, stimulation of which by chemical or physical mediators may be a basis for OA pain.     

EULAR report on the use of ultrasonography in painful knee osteoarthritis. Part 1: prevalence of inflammation in osteoarthritis

Objectives: To assess the prevalence of inflammation in subjects with chronic painful knee osteoarthritis (OA), as determined by the presence of synovitis or joint effusion at ultrasonography (US); and to evaluate the correlation between synovitis, effusion, and clinical parameters. Methods: A cross sectional, multicentre, European study was conducted under the umbrella of EULAR-ESCISIT. Subjects had primary chronic knee OA (ACR criteria) with pain during physical activity ?30 mm for at least 48 hours. Clinical parameters were collected by a rheumatologist and an US examination of the painful knee was performed by a radiologist or rheumatologist within 72 hours of the clinical examination. Ultrasonographic synovitis was defined as synovial thickness ?4 mm and diffuse or nodular appearance, and a joint effusion was defined as effusion depth ?4 mm. Results: 600 patients with painful knee OA were analysed. At US 16 (2.7%) had synovitis alone, 85 (14.2%) had both synovitis and effusion, 177 (29.5%) had joint effusion alone, and 322 (53.7%) had no inflammation according to the definitions employed. Multivariate analysis showed that inflammation seen by US correlated statistically with advanced radiographic disease (Kellgren-Lawrence grade ?3; odds ratio (OR) = 2.20 and 1.91 for synovitis and joint effusion, respectively), and with clinical signs and symptoms suggestive of an inflammatory "flare", such as joint effusion on clinical examination (OR = 1.97 and 2.70 for synovitis and joint effusion, respectively) or sudden aggravation of knee pain (OR = 1.77 for joint effusion). Conclusion: US can detect synovial inflammation and effusion in painful knee OA, which correlate significantly with knee synovitis, effusion, and clinical parameters suggestive of an inflammatory "flare".     

The association of meniscal pathologic changes with cartilage loss in symptomatic knee osteoarthritis

OBJECTIVE: To explore the role of meniscal tears and meniscal malposition as risk factors for subsequent cartilage loss in subjects with symptomatic osteoarthritis (OA). METHODS: Study subjects were patients with symptomatic knee OA from the Boston Osteoarthritis of the Knee Study. Baseline assessments included knee magnetic resonance imaging (MRI) with followup MRI at 15 and 30 months. Cartilage and meniscal damage were scored on MRI in the medial and lateral tibiofemoral joints using the semiquantitative whole-organ magnetic resonance imaging score. Tibiofemoral cartilage was scored on MR images of all 5 plates of each tibiofemoral joint, and the meniscal position was measured using eFilm Workstation software. A proportional odds logistic regression model with generalized estimating equations was used to assess the effect of each predictor (meniscal position factor and meniscal damage as dichotomous predictors in each model) on cartilage loss in each of the 5 plates within a compartment. Models were adjusted for age, body mass index (BMI), tibial width, and sex. RESULTS: We assessed 257 subjects whose mean +/- SD age was 66.6 +/- 9.2 years and BMI was 31.5 +/- 5.7 kg/m2; 42% of subjects were female, and 77% of knees had a Kellgren/Lawrence radiographic severity grade > or = 2. In the medial tibiofemoral joint, each measure of meniscal malposition was associated with an increased risk of cartilage loss. There was also a strong association between meniscal damage and cartilage loss. Since meniscal coverage and meniscal height diminished with subluxation, less coverage and reduced height also increased the risk of cartilage loss. CONCLUSION: This study highlights the importance of an intact and functioning meniscus in patients with symptomatic knee OA, since the findings demonstrate that loss of this function has important consequences for cartilage loss.