Prospective sonographic and arthroscopic evaluation of proliferative knee joint synovitis

Ultrasonography of Superficial Soft-Tissue Masses: Society of Radiologists in Ultrasound Consensus Conference Statement

The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, orthopedic surgery, and pathology to arrive at a consensus regarding the management of superficial soft-tissue masses imaged with US. The recommendations in this statement are based on analysis of current literature and common practice strategies. This statement reviews and illustrates the US features of common superficial soft-tissue lesions that may manifest as a soft-tissue mass and suggests guidelines for subsequent management.

Will rheumatologists ever pick up the arthroscope again?

Conditions prompting physicians and surgeons first adapting endoscopes to peer into joints were mainly the sort of synovial conditions that would concern today's rheumatologists. Rheumatologists were among the pre-World War II pioneers developing and documenting arthroscopy. The post-War father of modern arthroscopy, Watanabe, found rheumatologists among his early students, who took back the technique to their home countries, teaching orthopedists and rheumatologists alike. Rheumatologists described and analyzed the intra-articular features of their common diseases in the '60s and '70s. A groundswell of interest from academic rheumatologists in adapting arthroscopy grew considerably in the '90s with development of "needle scopes" that could be used in an office setting. Rheumatologists helped conduct the very trials the findings of which reduced demand for their arthroscopic services by questioning the efficacy of arthroscopic debridement in osteoarthritis (OA) and also developing biological compounds that greatly reduced the call for any resective intervention in inflammatory arthropathies. The arthroscope has proven an excellent tool for viewing and sampling synovium and continues to serve this purpose at several international research centers. While cartilage is now imaged mainly by magnetic resonance imaging, some OA features - such as a high prevalence of visible calcinosis - beg further arthroscopy-directed investigation. A new generation of "needle scopes" with far superior optics awaits future investigators, should they develop interest.

Musculoskeletal ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review

Objective

To systematically review the role of musculoskeletal US in patients suffering from PsA or psoriasis (Pso) in terms of prevalence, diagnosis, prognosis, monitoring and treatment.

Methods

A systematic literature review was conducted through medical databases (MEDLINE via PubMed, Embase) and the grey literature up to September 2015 to inform a new study of the Musculoskeletal Ultrasound Study Group of the Italian Society for Rheumatology. All articles reporting data on musculoskeletal US in PsA or Pso were included and extracted according to the underlying clinical question.

Results

A total of 86 publications were included. The prevalence of US abnormalities showed a wide range for each examined feature (e.g. 37-95% for entheses thickness of the lower limbs). The performance of US for diagnosis of disease or elementary lesions was variable across studies, but no study evaluated the overall performance of US in addition to clinical findings for diagnosing PsA. Considering US in defining PsA and Pso prognosis, several works focused on US of entheses of lower limbs in Pso, while for the monitoring of PsA activity five different scoring systems were identified. Last, the results of the role of US in guiding intra-articular interventions were controversial for the clinical outcomes, but in favour of US for accuracy.

Conclusion

despite the recognized importance of US in the management of PsA and Pso, this review clearly demonstrated the need of pivotal research in order to optimize the use of US in the diagnosis and monitoring of psoriatic disease.

Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial

IMPORTANCE

Synovitis is common and is associated with progression of structural characteristics of knee osteoarthritis. Intra-articular corticosteroids could reduce cartilage damage associated with synovitis but might have adverse effects on cartilage and periarticular bone.

OBJECTIVE

To determine the effects of intra-articular injection of 40 mg of triamcinolone acetonide every 3 months on progression of cartilage loss and knee pain.

DESIGN, SETTING, AND PARTICIPANTS

Two-year, randomized, placebo-controlled, double-blind trial of intra-articular triamcinolone vs saline for symptomatic knee osteoarthritis with ultrasonic features of synovitis in 140 patients. Mixed-effects regression models with a random intercept were used to analyze the longitudinal repeated outcome measures. Patients fulfilling the American College of Rheumatology criteria for symptomatic knee osteoarthritis, Kellgren-Lawrence grades 2 or 3, were enrolled at Tufts Medical Center beginning February 11, 2013; all patients completed the study by January 1, 2015.

INTERVENTIONS

Intra-articular triamcinolone (n = 70) or saline (n = 70) every 12 weeks for 2 years.

MAIN OUTCOMES AND MEASURES

Annual knee magnetic resonance imaging for quantitative evaluation of cartilage volume (minimal clinically important difference not yet defined), and Western Ontario and McMaster Universities Osteoarthritis index collected every 3 months (Likert pain subscale range, 0 [no pain] to 20 [extreme pain]; minimal clinically important improvement, 3.94).

RESULTS

Among 140 randomized patients (mean age, 58 [SD, 8] years, 75 women [54%]), 119 (85%) completed the study. Intra-articular triamcinolone resulted in significantly greater cartilage volume loss than did saline for a mean change in index compartment cartilage thickness of -0.21 mm vs -0.10 mm (between-group difference, -0.11 mm; 95% CI, -0.20 to -0.03 mm); and no significant difference in pain (-1.2 vs -1.9; between-group difference, -0.6; 95% CI, -1.6 to 0.3). The saline group had 3 treatment-related adverse events compared with 5 in the triamcinolone group and had a small increase in hemoglobin A1c levels (between-group difference, -0.2%; 95% CI, -0.5% to -0.007%).

CONCLUSIONS AND RELEVANCE

Among patients with symptomatic knee osteoarthritis, 2 years of intra-articular triamcinolone, compared with intra-articular saline, resulted in significantly greater cartilage volume loss and no significant difference in knee pain. These findings do not support this treatment for patients with symptomatic knee osteoarthritis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01230424.

Ultrasound evaluation of fluid in knee recesses at varying degrees of flexion

OBJECTIVE

Various methods are utilized in daily practice to obtain optimal information on effusion in the knee. Our aim is to investigate which scanning position provides the best information about synovial fluid in the knee by using ultrasound and to evaluate the magnitude of difference for measuring synovial fluid in 3 major recesses (suprapatellar, medial parapatellar, and lateral parapatellar) of the knee according to various degrees of flexion.

METHODS

Sonographers in 14 European centers documented bilateral knee joint ultrasound examinations on a total of 148 knee joints. The largest sagittal diameter of fluid was measured in scans corresponding to the 3 major recesses at different (0°, 15°, 30°, 45°, 60°, and 90°) degrees of flexion of the knee. The difference of measurement of effusion according to transducer position, knee position, and the interaction between them was investigated by analysis of variance followed by Tukey's test.

RESULTS

No correlation was noted between patient characteristics and ultrasound detection of effusion. The sagittal diameter of synovial fluid in all 3 recesses was greatest at 30° flexion. Analysis of variance and Tukey's test revealed that the suprapatellar scan and 30° flexion is the best combination for detecting effusion as confirmed by receiver operator characteristic curve analysis.

CONCLUSION

The suprapatellar scan of the knee in 30° flexion was the most sensitive position to detect fluid in knee joints. Sagittal diameter of fluid in all 3 recesses increased with the knee in the 30° flexed position as compared to the extended position.

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.

Usefulness of ultrasound imaging in detecting psoriatic arthritis of fingers and toes in patients with psoriasis

Background. Given that clinical evaluation may underestimate the joint damage and that early treatment can slow down psoriatic arthritis (PsA) progression, screening psoriasis patients with imaging tools that can depict early PsA changes would entail clear benefits. Objective. To compare the ability of X-ray and ultrasound (US) examination in detecting morphological abnormalities consistent with early PsA in patients with psoriasis, using rheumatological evaluation as the gold standard for diagnosis. Methods. Patients with chronic plaque psoriasis and no previous PsA diagnosis attending our outpatient dermatology clinic and reporting finger/toe joint and/or tendon pain underwent X-ray and US evaluation; they were subsequently referred to a rheumatologist for clinical examination and review of imaging findings. Results. Abnormal US and/or X-ray findings involving at least one finger and/or toe (joints and/or tendons) were seen in 36/52 patients: 11 had one or more X-ray abnormalities, including erosion, joint space narrowing, new bone formation, periarticular soft tissue swelling, and periarticular osteoporosis; 36 had suspicious changes on US. Conclusion. US proved valuable in detecting joint and/or tendon abnormalities in the fingers and toes of patients with suspicious changes. The dermatologist should consider US to obtain an accurate assessment of suspicious findings.

Can simple ultrasonography predict the clinical effect of intra-articular injection therapy of the knee joint?

To investigate whether ultrasonographic joint assessment can predict the clinical response to intra-articular injection therapy of the knee. Patients with persistent gonarthritis intra-articularly received in a randomized double-blinded crossover fashion radiation synovectomy or a glucocorticoid injection, both followed by clinical bed rest. Prior to treatment and 3 months afterwards, grey-scale ultrasonography (US) of the knee was performed, measuring synovial thickness and extent of effusion. The final clinical effect of these two treatments was assessed at 3 months and finally at 6 months using a composite index. Ninety-seven patients, mainly suffering from undifferentiated arthritis (40%) or rheumatoid arthritis (31%), received 165 injections (including crossovers). Clinical effect at 6 months was not related to the baseline ultrasonographic extent of effusion or synovial thickness, nor with ultrasonographic decrease of effusion after the first 3 months. Nevertheless, it was associated with ultrasonographic decrease of synovial thickness within the first 3 months. Simple baseline US measurements fail to predict the final clinical effect of intra-articular treatment of the knee at 6 months, in contrast to early US changes of synovial thickness 3 months after therapy.

Systematic Review of MRI, Ultrasound, and Scintigraphy as Outcome Measures for Structural Pathology in Interventional Therapeutic Studies of Knee Arthritis: Focus on Responsiveness

Objective.

Validated imaging outcome tools to assess response to therapies in a single joint are required. Our aim was to review the published literature to ascertain the responsiveness of novel imaging techniques as outcome measures in interventional therapeutic studies of knee arthritis.

Methods.

An Ovid Medline search was performed for original articles in English that used imaging techniques to assess response at the knee joint to therapy in osteoarthritis, rheumatoid arthritis, and psoriatic arthritis. Changes in response to therapy were assessed with regard to both internal and external responsiveness.

Results.

In the studies that presented appropriate statistical data to allow responsiveness to be assessed, MRI was generally found to be internally responsive to pathologies imaged, and externally responsive, referenced against both other imaging modalities and biochemical biomarkers of arthritis. Ultrasonography was found to demonstrate internal responsiveness with regard to synovial thickness, effusion size, and popliteal cyst size. External responsiveness was demonstrated against several referenced health status measures. Scintigraphy was found to be externally responsive in the majority of studies, with internal responsiveness demonstrated in 1 study.

Conclusion.

While the imaging techniques appear to be responsive from the data we present, further inspection reveals that interpreting the responsiveness of imaging techniques was difficult, largely because of a lack of standardization of image acquisition, definitions of pathology, and scoring systems. Refined pathological definitions and scoring systems are required to enable the development of valid and responsive tools for interventional clinical trials.

Using ultrasonography to facilitate best practice in diagnosis and management of RA

The key to successful management of rheumatoid arthritis (RA) is early objective quantification of inflammation and ongoing precise, tailored therapy to ensure long term suppression of inflammatory disease activity. Musculoskeletal ultrasonography (MSKUS) has emerged as a tool with the potential to enhance disease assessment and management in this area. This includes applications in patients with undifferentiated arthropathy attending an early inflammatory arthritis clinic, in which the diagnosis of inflammatory disease may be confirmed or refuted at an early stage, and those with treated RA where accurate measurement of outcomes, such as response to therapy, structural damage and disease remission, are extremely important. This imaging modality is safe and portable, making it ideal for outpatient and inpatient settings, and can be used to assess many joints in multiple planes and to demonstrate changes in disease activity and structural damage over time. MSKUS is gaining popularity among rheumatologists, as increasing evidence supports the added value of a physician-performed ultrasonography assessment above traditional clinical, laboratory and radiographic measures, enabling greater confidence in diagnostic and management decisions. Although additional longitudinal data are required and further applications are likely to arise, MSKUS may well possess the necessary attributes to facilitate best practice in inflammatory arthritis management.

Power Doppler and spectral Doppler measurements of knee-joint synovitis in rheumatoid arthritis patients with superficial pattern signals and in those with deep pattern signals

Power Doppler and spectral Doppler ultrasonography were used to scan 127 knee joints of 72 patients with rheumatoid arthritis (RA). Synovial effusion thickness and synovial proliferation (pannus) thickness, as well as the flow signal diameter, were measured on ultrasonogram prints of the power Doppler using digital calipers. In addition, color-flow signal grades on power Doppler and the resistance index (RI) values on spectral Doppler were evaluated. The values of these five variables were compared among 58 joints with superficial pattern flow signals and 69 joints with deep pattern flow signals. Compared with the joints with deep pattern signals, the joints with superficial pattern signals had significantly higher mean values of effusion thickness (P < 0.0001) and flow signal grades (P < 0.0001), and significantly lower mean RI (P < 0.0001). On the other hand, the joints with deep pattern signals had a significantly higher value of signal diameter (P = 0.0125) and had a trend to higher value of pannus thickness (P = 0.079) as well. Significant correlations were observed between effusion thickness and signal grades (P < 0.0001); effusion thickness and RI (P < 0.0001); signal diameter and pannus thickness (P = 0.0102); signal diameter and RI (P < 0.0001); and signal grades and RI (P < 0.0001). The ultrasonographic measurements of synovitis in RA patients provide valuable information on synovial inflammation.

Intra-articular methotrexate in the treatment of rheumatoid arthritis and psoriatic arthritis: a clinical and sonographic study

The aim of our study was to evaluate the effects of intra-articular methotrexate (MTX) in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Twenty-three consecutive patients, 10 with RA and 13 with PsA, with prevalent or unique arthritic involvement of one knee, were treated with intra-articular injections of MTX 10 mg every 7 days for 8 weeks. Before the beginning of the treatment and after 9 and 17 weeks, the patients underwent a clinical evaluation measuring maximal knee flexion angle, visual analog scale (VAS) and erythrocyte sedimentation rate (ESR). On the same days, an ultrasonographic examination of the involved knee was performed by two independent experienced operators. Synovial thickness in the suprapatellar bursa and the presence of joint effusion and Baker's cyst were assessed. An increase of the mean value of maximal knee flexion angle and a reduction of the mean values of ESR and VAS between T0, T9 and T17 were demonstrated. Ultrasonographic evaluation showed significant reduction of synovial thickness and joint effusion. No differences were detected for the presence of Baker's cyst. We may conclude that repeated intra-articular injections of MTX resulted in a decrease of local as well as systemic inflammatory signs. As far as we know, this is the first study that explores the effects of intra-articular MTX in RA and PsA both clinically and by ultrasonography.

(18)F-FDG PET imaging of rheumatoid knee synovitis correlates with dynamic magnetic resonance and sonographic assessments as well as with the serum level of metalloproteinase-3

PURPOSE

The aim of this study was to assess rheumatoid arthritis (RA) synovitis with positron emission tomography (PET) and( 18)F-fluorodeoxyglucose ((18)F-FDG) in comparison with dynamic magnetic resonance imaging (MRI) and ultrasonography (US).

METHODS

Sixteen knees in 16 patients with active RA were assessed with PET, MRI and US at baseline and 4 weeks after initiation of anti-TNF-alpha treatment. All studies were performed within 4 days. Visual and semi-quantitative (standardised uptake value, SUV) analyses of the synovial uptake of FDG were performed. The dynamic enhancement rate and the static enhancement were measured after i.v. gadolinium injection and the synovial thickness was measured in the medial, lateral patellar and suprapatellar recesses by US. Serum levels of C-reactive protein (CRP) and metalloproteinase-3 (MMP-3) were also measured.

RESULTS

PET was positive in 69% of knees while MRI and US were positive in 69% and 75%. Positivity on one imaging technique was strongly associated with positivity on the other two. PET-positive knees exhibited significantly higher SUVs, higher MRI parameters and greater synovial thickness compared with PET-negative knees, whereas serum CRP and MMP-3 levels were not significantly different. SUVs were significantly correlated with all MRI parameters, with synovial thickness and with serum CRP and MMP-3 levels at baseline. Changes in SUVs after 4 weeks were also correlated with changes in MRI parameters and in serum CRP and MMP-3 levels, but not with changes in synovial thickness.

CONCLUSION

(18)F-FDG PET is a unique imaging technique for assessing the metabolic activity of synovitis. The PET findings are correlated with MRI and US assessments of the pannus in RA, as well as with the classical serum parameter of inflammation, CRP, and the synovium-derived parameter, serum MMP-3. Further studies are warranted to establish the place of metabolic imaging of synovitis in RA.

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 >or=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 >or=4 mm and diffuse or nodular appearance, and a joint effusion was defined as effusion depth >or=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 >or=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".

Assessment of inflammatory activity in rheumatoid arthritis: a comparative study of clinical evaluation with grey scale and power Doppler ultrasonography

OBJECTIVE

To compare the clinical assessment of overall inflammatory activity in patients with rheumatoid arthritis (RA) with grey scale and power Doppler (PD) ultrasonography (US).

METHODS

Ninety four consecutive patients with RA were included. Demographic and clinical data, C reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR) were recorded for each patient. The presence of tenderness, swelling, and a subjective swelling score from 1 to 3 were independently assessed by two rheumatologists, who reached a consensus in 60 joints examined in each patient. All patients underwent a US examination by a third blinded rheumatologist, using PD. US joint effusion, synovitis, and PD signal were graded from 1 to 3 in the 60 joints. Joint count and joint index for effusion, synovitis, and PD signal were recorded. A 28 joint count for clinical and US variables was calculated. Interobserver reliability of the US examination was evaluated by a fourth blinded rheumatologist.

RESULTS

US showed significantly more joints with effusion (mean 15.2) and synovitis (mean 14.6) than clinical examination (mean 11.5, p<0.05). A significant correlation was found between joint count and joint index for swelling, US effusion, synovitis, and PD signal. The 28 joint count for effusion, synovitis, and PD signal correlated highly with the corresponding 60 joint counts. US findings correlated better with CRP and ESR than clinical measures. Interobserver reliability was better for US findings than for clinical assessment.

CONCLUSION

US is a sensitive method for assessing joint inflammatory activity in RA, complementary to clinical evaluation.

Imaging in early arthritis

Imaging can play a vital role in the evaluation of patients with early arthritis. Various imaging methods can be utilized to aid with diagnosis, predict prognosis and follow disease progression and treatment response. Previously, conventional radiography was the principal method used to evaluate and follow bone damage in patients with inflammatory arthritis. More recently the use of magnetic resonance imaging and ultrasonography has gained wider acceptance and popularity due to the ability of these multiplanar techniques to image both bone changes and soft tissue abnormalities, including synovitis. This chapter discusses the current imaging modalities used in the evaluation of patients with early arthritis, as well as the use of imaging in establishing the extent of disease, in prognosis and in monitoring disease course. Current data on imaging of patients with early arthritis due to rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis is reviewed.

Rheumatoid and psoriatic knee synovitis: clinical, grey scale, and power Doppler ultrasound assessment of the response to etanercept

OBJECTIVE

To determine the effect of tumour necrosis factor alpha (TNFalpha) blockade with etanercept in refractory knee joint synovitis (KJS) in rheumatoid and psoriatic arthritis, by local and systemic disease activity assessment and combined grey scale and power Doppler ultrasonographic monitoring.

METHODS

27 knees affected by rheumatoid KJS (n = 12) and psoriatic KJS (n = 8) were assessed before receiving treatment and at 3 and 12 months' follow up. Time dependent clinical changes in disease activity were monitored by C reactive protein, erythrocyte sedimentation rate (ESR), global health status (GHS), and Ritchie (RAI) and knee joint articular (KJAI) indices; synovial changes were monitored by ultrasonographic and power Doppler indices for grey scale synovial thickening and for distinct intrasynovial vessel power Doppler flow configurations (fluid/synovium interface (F/SI-PD) and pannus/cartilage interface (P/CI-PD)). Interobserver and intraobserver variability of grey scale and power Doppler ultrasonographic was evaluated. Response to treatment was assessed by analysis of variance for repeated measures on clinical and ultrasonographic variables.

RESULTS

Rapid (3 months) reduction in F/SI-PD flow (p<0.001), parallel to reductions of C reactive protein (p<0.05), ESR (p<0.001), KJAI (p<0.002), RAI, and GHS (p<0.001), was sustained at 12 months when it was accompanied by reduction in both synovial thickening and P/CI-PD flow (p<0.001). No differences (ANOVA) were noted at baseline or at 12 months in clinical and ultrasonographic variables between either the rheumatoid or the psoriatic KJS groups.

CONCLUSION

Grey scale and power Doppler ultrasonography are reliable measures of long term change in rheumatoid and psoriatic KJS disease activity in response to anti-TNFalpha treatment with etanercept.

Arthrofibrosis Associated with Total Knee Arthroplasty:Gray-Scale and Power Doppler Sonographic Findings

OBJECTIVE

The objective of this study was to determine gray-scale and power Doppler sonographic findings in patients with arthrofibrosis associated with total knee arthroplasty. SUBJECTS AND METHODS. From a consecutive cohort of more than 3000 mobilebearing total knee arthroplasties, 44 cases (1.5%) with arthrofibrosis were identified, of which 38 were recruited for a clinical and sonographic investigation. A control group of 38 patients with a well-functioning total knee arthroplasty was matched. Synovial hypertrophy, presence of neovascularity, patellar tendon thickness, and extent of effusion were assessed.

RESULTS

Synovial membrane thickness was significantly (p < 0.001) increased in the arthrofibrosis group (medial, 3.4 mm; lateral, 3.0 mm; suprapatellar, 3.1 mm) when compared with the control group (medial, 2.0 mm; lateral, 2.0 mm; suprapatellar, 1.9 mm). When a cutoff of 3.0 mm was used, sonography had a sensitivity of 84% and a specificity of 82% for detecting arthrofibrosis. Neovascularity (rated as grades 0-3) of the synovial membrane and Hoffa's fat pad was significantly (p <or= 0.003) more pronounced in the arthrofibrosis group (medial, 1.1; lateral, 1.2; suprapatellar, 1.0; Hoffa's fat pad, 1.1) than in the control group (medial, 0.1; lateral, 0.3; suprapatellar, 0.2; Hoffa's fat pad, 0.1). No significant difference was seen between study groups with regard to the amount of joint effusion at three locations and with regard to patellar tendon thickness.

CONCLUSION

Synovial membrane thickening and neovascularity are characteristic sonographic findings for the diagnosis of arthrofibrosis associated with total knee arthroplasty.

Validation and reproducibility of ultrasonography in the detection of synovitis in the knee: A comparison with arthroscopy and clinical examination

OBJECTIVE

Accurate detection of synovitis is important in both the diagnosis and outcome assessment of arthritis. This study was undertaken to assess the validity and reproducibility of ultrasonography (US) as a means of detecting synovitis in the knee, by comparing US findings with findings of arthroscopy and clinical examination.

METHODS

Sixty consecutive patients with knee pain due to various arthritides had a clinical examination and US of their knee performed immediately prior to arthroscopy. All 3 assessments were performed by different clinicians who were blinded to the results obtained with the other modalities. US and clinical examination were compared with arthroscopically detected synovitis as the gold standard. Data from a subset of patients were used for calculating the inter- and intrareader reproducibility of US results, using a standard dichotomous (absence/presence of synovitis) as well as a graded (absence/grade of synovitis) scoring system.

RESULTS

With the use of arthroscopy as the gold standard, US had a higher sensitivity (98% versus 85%), specificity (88% versus 25%), accuracy (97% versus 77%), positive predictive value (98% versus 88%), and negative predictive value (88% versus 20%) compared with clinical examination. The Cohen kappa values for inter- and intrareader reproducibility of US for distinguishing between presence and absence of synovitis were 0.71 and 0.85, respectively (P < 0.05 for both). The weighted kappa values for distinguishing grade of synovitis were 0.65 for inter- and 0.74 for intrareader reproducibility. The kappa value for intrareader reproducibility of arthroscopy results was 0.88.

CONCLUSION

Ultrasonography is a valid and reproducible technique for detecting synovitis in the knee, and is more accurate than clinical examination. It may be valuable as a tool in studies investigating pain, diagnosis, and treatment response in knee arthritis.

Power Doppler sonography in the assessment of synovial tissue of the knee joint in rheumatoid arthritis: a preliminary experience

OBJECTIVE

To investigate the intra-articular vascularisation of the synovial pannus in the knee of patients with rheumatoid arthritis (RA) with power Doppler ultrasonography (PDS) and an echo contrast agent and correlate the area under the time-intensity curves with the clinical findings and laboratory measures of disease activity.

METHOD

Forty two patients with RA (31 women, 11 men) with history and signs of knee arthritis, classified according to a modified index of synovitis activity (active, moderately active, and inactive), were studied. Clinical and functional assessment (number of swollen joints, intensity of pain, general health-visual analogue scale, disability index-Health Assessment Questionnaire, Ritchie articular index) and a laboratory evaluation were made on all patients. Disease activity was evaluated using the disease activity score (DAS) and the chronic arthritis systemic index (CASI) for each patient. All patients were examined with conventional ultrasonography and PDS before injection of intravenous ultrasound contrast agent (Levovist). The quantitative estimation of the vascularisation of the synovial membrane was performed with time-intensity curves and calculation of the area under the curves.

RESULTS

The mean (SD) value of the area underlying time-intensity curves was 216.2 (33.4) in patients with active synovitis, 186.8 (25.8) in patients with moderately active synovitis, and 169.6 (20.6) in those with inactive synovitis. The mean value of the areas differed significantly between the patients with active and those with inactive synovitis (p<0.01). The mean value of the area under the curve of the entire group was weakly correlated with the number of swollen joints (p=0.038), but a strong correlation was found with composite indexes of disease activity such as the DAS (p=0.006) and CASI (p=0.01). No correlation was found with age, disease duration, and other laboratory and clinical variables.

CONCLUSION

PDS may be a valuable tool to detect fractional vascular volume and to assist clinicians in distinguishing between inflammatory and non-inflammatory pannus. The transit of microbubbles of ultrasound contrast across a tissue can be used to estimate haemodynamic alterations and may have a role in assessing synovial activity and the therapeutic response to treatment of synovitis of the knee joint.

Synovial tissue of the hip at power Doppler US: correlation between vascularity and power Doppler US signal

PURPOSE

To correlate power Doppler ultrasonographic (US) findings of the vascularity of synovial tissue of the hip joint with the results of histopathologic examination of the same tissue to assess the value of power Doppler US in the visualization of synovitis.

MATERIALS AND METHODS

The hip joints of 24 patients with osteoarthritis (n = 15) or rheumatoid arthritis (n = 9) of the hip joint were examined with US before arthroplasty. The vascularity of the synovial membrane was classified qualitatively by using power Doppler US. During surgery, a section of the synovial tissue examined at power Doppler US preoperatively was resected. The vascularity of the tissue specimen was investigated and graded qualitatively by a pathologist who was not aware of the US findings. Visual qualitative grading was controlled by means of analysis of the US images and histopathologic specimens with a digital image evaluation system. Correlations between power Doppler US and histopathologic examination findings were calculated by using Spearman rank correlation and Pearson correlation tests.

RESULTS

The correlation between the qualitative power Doppler US results and the qualitative vascularity grades was 0.92 (P <.01, Spearman rho). The correlation between quantitative and qualitative results was 0.93 (P <.01, Spearman rho) for US imaging and 0.97 (P <.01, Spearman rho) for histopathologic examination.

CONCLUSION

Study results showed power Doppler US to be reliable for qualitative grading of the vascularity of synovial tissue of the hip.

Ultrasonographic evaluation of synovial effusion and synovial proliferation pattern in the knee joints of patients with rheumatoid arthritis

Abstract In the present study, 49 knee joints of 26 patients with rheumatoid arthritis and 17 knee joints of 17 healthy subjects were ultrasonographically examined. Lateral, superior, and medial aspects of the patella were scanned using an ultrasonograph with a 7.5-MHz annular array transducer to evaluate the thickness of synovial effusion and the synovial proliferation pattern. The overall mean thickness of synovial effusion (mean of all three sites) in the knee joints was 4.9 ± 3.4 mm for rheumatoid arthritis patients and 1.4 ± 0.5 mm for healthy subjects. In rheumatoid arthritis patients, the mean thickness of synovial effusion at the superior aspect of the patella (6.5 ± 4.1 mm) was significantly greater than that at the lateral aspect (4.5 ± 4.8 mm) (P < 0.05) and the medial aspect (4.0 ± 3.1 mm) (P < 0.01). Patients with the villonodular pattern of synovial proliferation had a shorter duration of disease than those with uniform thickening or an overlapping pattern.

Imaging the joints in early rheumatoid arthritis

Radiography is the most widely utilized imaging modality for early rheumatoid arthritis, determination of radiographic progression remaining a crucial part of the evaluation of therapy. Conventional radiography is, however, insensitive for showing bone damage in early disease and is totally unsuitable for assessing synovial inflammation. The recognition of these limitations has led to intense interest in the multiplanar imaging capabilities of magnetic resonance imaging in rheumatoid arthritis and to an increasing use of ultrasonography for assessing synovitis and bone damage. This chapter discusses the role of radiography in early rheumatoid arthritis and the emerging use and role of magnetic resonance imaging and ultrasonography in evaluating synovitis and bone damage. The relationship between synovitis and bone damage is also addressed in the light of recent magnetic resonance imaging observations.

Correlation of power Doppler sonography with vascularity of the synovial tissue of the knee joint in patients with osteoarthritis and rheumatoid arthritis

OBJECTIVE

To examine the significance of power Doppler sonography (PDS) in the diagnosis of synovial hypertrophy of the knee joint by verifying and comparing the PDS findings with histopathologic findings of synovial membrane vascularity.

METHODS

The knee joints of 23 patients who were undergoing arthroplasty of the knee joint because of osteoarthritis or rheumatoid arthritis were examined with ultrasound before arthroplasty. The vascularity of the synovial membrane was classified semiquantitatively using PDS. A sample of synovial tissue was obtained during the arthroplasty, and the vascularity of the synovial tissue was evaluated by immunohistochemistry (factor VIII) and was graded qualitatively by a pathologist who was unaware of the PDS findings. The visual qualitative grading by the examiner was controlled by analyzing PDS images and histologic samples using a digital image evaluation system.

RESULTS

The correlation between the qualitative PDS results and the qualitative grading of the vascularity by the pathologist was 0.89 by Spearman's rho (P < 0.01). The Pearson correlation coefficient between the digital analysis of the PDS images and the digital analysis of the tissue sections was 0.81 (P < 0.01). Digital image analysis and qualitative grading by the examiner had a correlation of 0.89 by Spearman's p (P < 0.01) for the PDS images. The correlation between the qualitative estimation of vascularity by the pathologist and the digital image analysis was 0.88 by Spearman's rho (P < 0.01).

CONCLUSION

In the present study, PDS proved to be a reliable diagnostic method for qualitative grading of the vascularity of the synovial tissue. In clinical practice, PDS allows further differentiation of the hypertrophic synovium.

Ultrasound in acute and chronic knee injury

This article presents a clinical approach to the role of ultrasound in the assessment of intra-articular and extra-articular knee pathology, including a comprehensive review of both acute and chronic conditions that may affect the tendons, ligaments, and bursae related to the knee joint. A brief review of the ultrasound findings in degenerative and inflammatory arthropathies and some of the more common tumors and masses that may be encountered around the symptomatic knee also has been included. Finally, the limited role of ultrasound in the assessment of the knee menisci and the symptomatic postarthroscopic patient is discussed.

Musculoskeletal ultrasound

Ultrasound is an extremely useful and versatile method of assessing soft tissue abnormality in rheumatological conditions. It is best performed as an extension of clinical examination. Ultrasound has the advantage of not only being able to demonstrate abnormalities but also allows transducer compression of those abnormalities to see if it reproduces the patient's characteristic symptoms. It is likely to find even greater use in the clinical setting over future years. In the near future skeletal ultrasound should develop into an essential tool for the extension of physical examination in rheumatology practise. It hopefully will become as vital to a rheumatologist as echocardiography is to a cardiologist. This will however require clinicians to be prepared to undergo sufficient training in order to avoid diagnostic errors. Probably it will only be at that time, when skeletal ultrasound has become a fundamental part of rheumatological diagnosis, that its full potential will be realized.