A Standardized, Pragmatic Approach to Knee Ultrasound for Clinical Research in Osteoarthritis: The Johnston County Osteoarthritis Project

Knee Effusion-Synovitis Is Not Associated With Self-Reported Knee Pain in Division I Female Athletes

BACKGROUND

Recent research indicates a potential link between effusion-synovitis and knee pain in athletes. This study investigates the association of knee effusion-synovitis with self-reported knee pain in elite female athletes, leveraging ultrasound imaging for effusion-synovitis assessment.

HYPOTHESIS

Presence of knee effusion-synovitis is associated with increased self-reported knee pain in Division I female athletes.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 53 NCAA Division I female athletes underwent bilateral knee ultrasound to identify effusion-synovitis. The Knee Injury and Osteoarthritis Outcome Survey (KOOS) Pain subscale assessed knee pain. A 1-way analysis of variance compared KOOS pain, symptoms, activities during daily living (ADL), and quality of life (QoL) scores across groups with no, unilateral, and bilateral effusion-synovitis.

RESULTS

Among the athletes, 49.1% showed no effusion-synovitis, 26.4% had unilateral, and 24.5% had bilateral effusion-synovitis. There were no differences in self-reported pain scores (F = 0.027; P = 0.97), ADL (F = 0.256; P = 0.78), or QoL (F = 0.120; P = 0.88) between any groups. In addition, the frequency of effusion-synovitis was as follows: for the right limb, Grade 0 = 35 (66%), Grade 1 = 15 (28%), Grade 2 = 1 (2%), and Grade 3 = 2 (4%); for the left limb, Grade 0 = 31 (58%), Grade 1 = 19 (36%), Grade 2 = 3 (6%), and Grade 3 = 0 (0%).

CONCLUSION

The presence of effusion-synovitis, irrespective of being unilateral or bilateral, was not associated with self-reported knee pain in elite female athletes. This suggests that lower grades of effusion-synovitis may not significantly impact knee pain.

CLINICAL RELEVANCE

The findings of this study challenge existing assumptions about the impact of effusion-synovitis on knee pain in athletes, contributing to the nuanced understanding of knee joint health in sports medicine.

The impact of high-heel shoes on knee joint space width in healthy young females: A real-time ultrasound study

BACKGROUND

Wearing high heel shoes is thought to increase the risk of knee osteoarthritis in females by altering knee joint alignment and increasing muscle activation. However, direct measurements of knee joint space width using ultrasound have been limited. This study aimed to investigate the effects of 8-cm high-heel shoes on knee joint articular space in healthy young females during standing.

METHODS

A cross-sectional study was conducted with 30 healthy females (age 22 ± 1.3 years). Participants' knee medial, lateral and patellofemoral joint space width were measured using an ultrasound imaging device in both barefoot and high-heel shoes conditions. A general linear model was used to compare the impact of high-heel shoes on knee joint articular space with adjusted covariates of demographic and lower limb physical measurement data.

RESULTS

Significant reductions in lateral joint space width were observed in both the dominant and non-dominant knees when wearing high-heel shoes compared with barefoot (mean difference: dominant side = 1.63 ± 3.91 mm, non-dominant side = 2.34 ± 2.65 mm, P = 0.008). No significant changes were detected in medial and patellofemoral joint space width.

CONCLUSION

Wearing 8-cm high-heel shoes significantly reduces the lateral joint space width of the knee in healthy young females during standing, suggesting increased lateral knee joint stress. The current study underscores the importance of including standing as a test component when measuring joint space changes in future studies and clinical practice to comprehensively evaluate the effects of high-heel usage on knee joint biomechanics.

Associations and Diagnostic Accuracy of Ultrasound Features in Knee Osteoarthritis: Cross-Sectional Results From a Large Community-Based Cohort

OBJECTIVE

Our study objectives were (1) to determine associations among ultrasound (US) features of knee osteoarthritis (KOA), radiographic KOA (rKOA), and patient-reported symptoms and (2) to determine diagnostic accuracy of US definitions for rKOA, in a community-based cohort.

METHODS

Participants enrolled in the Johnston County Health Study (JoCoHS; 2019-2024, n = 902) provided demographics, comorbidities, clinical features, and symptoms, along with imaging with standardized acquisition and scoring protocols. Logistic regression models provided odds ratios adjusted for age, sex, race, ethnicity, body mass index (BMI), education level, comorbidities, and knee injury for associations among US features and KOA outcomes. Diagnostic accuracy was assessed using standard metrics with rKOA as the gold standard.

RESULTS

Complete imaging data were available for 861 participants (1,711 knees): 34% men, 25% Black, 10% Hispanic, mean age 55 years, and mean BMI 33. Half of knees were symptomatic, one-third had rKOA, and one in five had symptomatic rKOA. US-identified osteophytes, effusion, meniscal extrusion, cartilage damage, calcium crystals, and popliteal cysts were associated with KOA outcomes. A US definition including both mild osteophytes and mild cartilage damage gave an area under the receiver operating characteristic curve of 0.76 for diagnosing rKOA (validated in an external cohort).

CONCLUSION

We identified common US features in participants with and without KOA, along with significant associations between US features and rKOA, symptomatic rKOA, and symptoms. US-based diagnosis of rKOA shows promise for general use. US is a valuable and accessible modality for assessment of knee OA features in clinical and research settings, including those with limited resources.

Osteoarthritis early-, mid- and late-stage progression in the rat medial meniscus transection model

Osteoarthritis is a degenerative disease of synovial joints affecting all tissues, including articular cartilage and subchondral bone. Osteoarthritis animal models can recapitulate aspects of human disease progression and are used to test efficacy of drugs, biomaterials, and cell therapies. The rat medial meniscus transection (MMT) model is a surgically induced posttraumatic osteoarthritis model commonly used for preclinical therapeutic screening. We describe herein, the qualitative and quantitative changes to articular cartilage, subchondral bone, and formation of osteophytes at early-, mid-, and late-stages of osteoarthritis progression. Tibia of MMT-operated animals showed proteoglycan loss and fibrillation along articular cartilage surfaces as early as 3-weeks post-surgery. With contrast-enhanced micro-CT technique, quantitative, 3-dimensional analysis of the tibia showed that the articular cartilage thickened at 3- and 6-weeks post-surgery and decreased at 12-weeks post-surgery. This decreased cartilage thickness corresponded with increased lesions in the articular cartilage that led to its full degradation and exposing the subchondral bone layer. Further, subchondral bone thickening was significant at 6-weeks post-surgery and followed cartilage damage. Osteophytes were found as early as 3-weeks post-surgery and coincided with articular cartilage degradation. Cartilaginous osteophytes preceded mineralization, suggesting endochondral ossification. The rat MMT model has predominantly been used out to 3-weeks, and most studies determined the effect of therapies to delay or prevent the onset of osteoarthritis. We provide evidence that an extension of the rat MMT model out to 6- and 12-weeks more resembled severe phenotypes of human osteoarthritis. Thus, evaluating novel therapeutics at late-stage will be important for eventual clinical translation.

Assessment of validity, reliability, and feasibility of OMERACT ultrasound knee osteoarthritis scores in Egyptian patients with primary knee osteoarthritis

BACKGROUND

Ultrasound (US) can evaluate all joint components affected by knee osteoarthritis (KOA); however, standardized scoring of US-detected pathology is needed to improve its diagnostic and monitoring capabilities.

OBJECTIVES

To examine the validity, reliability, and feasibility of the Outcome Measures in Rheumatology (OMERACT) ultrasound scoring for KOA, comparing with clinical and radiography measures, using predefined cutoff values.

METHODS

This cross-sectional study included 75 Egyptian patients with primary KOA. All patients had Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, bilateral knee radiography, and ultrasonography. Inter-observer reliability of ultrasound was evaluated in 30 knees by another newly trained operator.

RESULTS

Most of the OMERACT-US KOA scores showed significant associations with WOMAC clinical scores, except for femoral cartilage damage and effusion. The synovitis score was significantly associated with WOMAC-pain score (p-value 0.046), while medial meniscus extrusion (MME) and medial osteophytes were significantly associated with WOMAC-stiffness score (p-value 0.009 and 0.023, respectively). MME and synovitis were significantly associated with WOMAC-physical score (p-value 0.035 and 0.020, respectively). The ultrasound scores also showed a strong correlation with radiographic scoring. Inter-observer reliability ranged from moderate to excellent agreement (k = 0.58 to k = 0.83); it was highest for lateral osteophytes (k = 0.83), good agreement for synovitis (k = 0.72), any osteophytes (k = 0.71), damage of femoral cartilage (k = 0.70), and moderate agreement for medial osteophytes (k = 0.58) and MME (k = 0.59).

CONCLUSION

OMERACT-US scoring system for KOA demonstrated validity, reliability, and feasibility for evaluating both structural and inflammatory components. Using cutoff values improved the scoring reliability for osteophytes and MME. Key Points • OMERACT-US scores provide a valid assessment of inflammatory and structural components of knee osteoarthritis. • The following changes may improve the performance of the OMERACT-US scores. a. The binary score for effusion and synovial hypertrophy can be omitted, as they have no added value. b. A semi-quantitative grading for effusion may capture the impact of effusion on clinical outcomes. c. Added cutoff values to score medial meniscal extrusion, osteophytes, and pathological effusion improved the respective scores' reliability. d. Applying the updated OMERACT definition of synovitis. • OMERACT-US scores are reliable to be used with a newly trained operator, particularly when cutoff values are included, and proper training time is provided. • The OMERACT-US score is feasible to be used in clinical practice, as the time taken to perform was short, even for a newly trained operator.

Do standardization of the procedure reduce measurement variability of the sonographic anterior drawer test of the ankle?

BACKGROUND

In quantitative ankle stress sonography, different examiners use different techniques, which may cause measurement variability. This study aimed to clarify whether standardizing stress sonography techniques reduces variability in the quantitative measurement of anterior talofibular ligament length change.

METHODS

Fourteen examiners with a mean ultrasound experience of 8.7 years participated in this study. Each examiner performed stress ultrasonography of the ankle using their preferred method on one patient with an intact anterior talofibular ligament (Patient 1) and on two patients with chronic ankle instability (Patient 2 and 3). Changes in the ligament length between the resting and stressed positions were determined. A consensus meeting was then conducted to standardize the sonographic technique, which was used by the examiners during a repeat stress sonography on the same patients. The variance and measured values were compared between the preferred and standardized techniques using F-tests and paired t-tests, respectively.

RESULTS

At a consensus meeting, a sonographic technique in which the examiner pushed the lower leg posteriorly against the fixed foot was adopted as the standardized technique. In Patient 1, the change in the anterior talofibular ligament length was 0.4 (range, -2.3-1.3) mm and 0.6 (-0.6-1.7) mm using the preferred and standardized techniques, respectively, with no significant difference in the variance (P = 0.51) or the measured value (P = 0.52). The length changes in Patient 2 were 2.0 (0.3-4.4) mm and 1.7 (-0.9-3.8) mm using the preferred and standardized techniques, respectively. In Patient 3, the length changes were 1.4 (-2.7-7.1) mm and 0.7 (-2.0-2.3) mm. There were no significant differences between the techniques in either patient group.

CONCLUSION

Variability in the quantitative measurement of ankle stress sonography was not reduced despite the standardization of the technique among examiners. Hence, comparing the measured values between different examiners should be avoided.

Association between synovial tissue damage and pain in late-stage knee osteoarthritis: A cross-sectional study

OBJECTIVE

To identify the presence and distribution of histopathological features of synovial inflammation and tissue damage, and to test their associations with ultrasound (US) imaging measures of synovitis and patient-reported measures of pain in knee osteoarthritis (OA).

DESIGN

In the cross-sectional study of 122 patients undergoing surgery for painful late-stage (Kellgren-Lawrence Grade 3 or 4) knee OA, we compared US measures of synovitis (n = 118) and pain (Knee Injury and Osteoarthritis Outcome Score) to histopathological measures of inflammation vs. synovial tissue damage in synovial tissue biopsies. Associations of histopathological features with US measures of inflammation or pain were assessed using linear or logistic regression while controlling for covariates.

RESULTS

Histopathological features of inflammation were associated with higher odds of moderate/severe US synovitis (odds ratio [OR] = 1.34 [95%CI 1.04, 1.74), whereas features of synovial tissue damage were associated with lower odds of moderate/severe US synovitis (OR = 0.77 [95%CI 0.57, 1.03]). Worse histopathological scores for synovial tissue damage were associated with more pain (-1.47 [95%CI -2.88, -0.05]), even while adjusting for synovial inflammation (-1.61 [95%CI -3.12, -0.10]).

CONCLUSIONS

Synovial tissue damage is associated with pain in late-stage knee OA, independent from inflammation and radiographic damage. These novel findings suggest that preventing synovial tissue damage may be an important goal of disease-modifying OA therapy.

Cross-sectional reliability and concurrent validity of a quantitative 2-dimensional ultrasound image analysis of effusion and synovial hypertrophy in knee osteoarthritis

Objective

Effusion-synovitis is related to pain and progression in knee osteoarthritis (OA), but current gold standard ultrasound (US) measures are limited to semi-quantitative grading of joint distension or 1-dimensional thickness measures. A novel quantitative 2-dimensional image analysis methodology is applied to US images of effusion-synovitis; reliability and concurrent validity was assessed in patients with knee OA.

Methods

Cross sectional analysis of US images collected from 51 patients with symptomatic knee OA were processed in ImageJ and segmented in 3DSlicer to produce a binary mask of the supra-patellar synovitis region of interest (ROI). Area measures (mm²) of total synovitis, effusion and hypertrophy components were exported. Intra-rater reliability and test-retest reliability (1-14 days washout) were estimated with intra-class correlation coefficients (ICCs). Concurrent validity was measured by Spearman correlations between quantitative measures and gold standard OMERACT and caliper measurements of synovitis.

Results

Intra-rater reliability for hypertrophy area was estimated at 0.98, 0.99 for effusion area, and 0.99 for total synovitis area. The test-retest reliability for total synovitis area was 0.63 (SEM 87.8 ​mm²), 0.59 for hypertrophy area (SEM 21.0 ​mm²), and 0.64 for effusion area (SEM 73.8 ​mm²). Correlation between total synovitis area and OMERACT grade was 0.84, 0.81 between total synovitis area and effusion-synovitis calipers, and 0.81 between total effusion area and effusion calipers.

Conclusion

This new research tool for image analysis demonstrated excellent intra-rater reliability, good concurrent validity, and moderate test-retest reliability. Quantitative 2D US measures of effusion-synovitis and its individual components may enhance the study and management of knee OA.

Preliminary Study on Grading Diagnosis of Early Knee Osteoarthritis by Shear Wave Elastography

Knee osteoarthritis (KOA) is the most common chronic bone joint disease. The WHO points out that KOA has become the fourth most disabling disease in the world, and the main clinical treatment is prevention. At present, the clinical diagnosis of knee osteoarthritis with deformation is mainly made by X-ray and two-dimensional ultrasound, and the preventive treatment effect is not good. Shear wave elastography (SWE) has been widely used in clinical practice for its advantages of noninvasive, simple, rapid, and high accuracy in soft tissue hardness. This study investigates the feasibility of using SWE in the grading diagnosis of KOA and the detection of early skeletal muscle injury. 60 patients were enrolled with unilateral KOA who met the inclusion criteria. Routine scanning and SWE exploration were carried out and compared between the affected and healthy knee joints. The measurements included morphology, damage degree of cartilage, joint effusion, joint synovial thickness, the degree of meniscus convexity, and shear wave speed (SWS) in the tendon attachment area of the quadriceps femoris superior patella, and tendon thickness and SWS between and within groups. The affected was scored according to the ultrasonic characteristics. The correlation between them was analyzed to evaluate the feasibility of SWE in grading the diagnosis of KOA. 57 cases had knee cavity effusion (57/60, 95.0%), 58 cases had knee cartilage injury (58/60, 96.6%), and 35 cases had a lateral process of the medial meniscus (35/60, 53.3%); 30 cases had synovial hyperplasia (30/60, 50%), 21 cases had osteophyte formation (21/60, 35%), and no one had a popliteal cyst. There was no significant difference in tendon thickness between and within groups (p > 0.05), but a significant difference in SWS (p < 0.01); the SWS of the quadriceps femoris tendon is negatively correlated with ultrasound score (r = 0.955, p < 0.01). There is a strong negative correlation between SWS and the degree of KOA. It can be used in the grading diagnosis of KOA to help find more early strain points.

Test-Retest Reliability and Sensitivity to Change of Ultrasound-Based Methods of Measuring Synovial Inflammation in Knee Osteoarthritis

OBJECTIVES

To assess test-retest reliability of musculoskeletal ultrasound (US) measures of inflammation in patients with knee osteoarthritis (OA) and to assess the sensitivity to change of US measures of inflammation in patients with knee OA.

METHODS

To mimic a common clinical scenario, 36 patients (n = 70 knees) with symptomatic knee OA who were in stable condition underwent 2 assessments within 14 days by different operators and different US machines, graded by a single rater. Test-retest reliability was measured using Cohen's kappa coefficient, intraclass correlation coefficient (ICC), and absolute agreement parameters. A total of 51 patients (n = 72 knees) were tested immediately before and 21-28 days after intraarticular glucocorticoid injection to investigate sensitivity to change and longitudinal construct validity. Paired t-tests and standardized response mean (SRM) were used to assess sensitivity to change. Multivariate linear regression was used to investigate longitudinal construct validity of US with Knee Injury and Osteoarthritis Outcome Score (KOOS) pain scores, while adjusting for covariates.

RESULTS

US measures of inflammation demonstrated moderate (κ = 0.41, 0.60) to substantial (κ = 0.61, 0.80) agreement. Quantitative measures of synovitis and effusion demonstrated good test-retest reliability (ICC_2,1 0.71, 0.92). US measures of synovitis and effusion demonstrated low-to-moderate sensitivity to change (SRM -0.29, -0.50). The associations between changes in US measures and KOOS pain scores over time were low, and 95% confidence intervals included zero.

CONCLUSION

In a clinical setting, US measures of inflammatory features of knee OA have substantial reliability and low-to-moderate sensitivity to change, whereas measures of structural OA features are less reliable. Longitudinal construct validity of US measures of synovitis and effusion to KOOS pain scores is not strongly supported.

Synovitis is associated with constant pain in knee osteoarthritis: a cross-sectional study of OMERACT knee ultrasound scores

OBJECTIVE

To examine the association between ultrasound (US)-detected knee inflammation and intermittent and constant pain experiences in patients with knee osteoarthritis (OA).

METHODS

Participants with radiographically early- (KL ≤ 2) and late-stage (KL ≥ 3) disease and frequent symptoms underwent musculoskeletal US measures of inflammation using the OMERACT knee US scoring system. Pain experiences were captured using the Intermittent and Constant OA Pain (ICOAP) tool. We assessed the association between US-synovitis and ICOAP pain experiences using a series of linear, logistic, or multinomial logistic regression models (as appropriate for each variable), while adjusting for age, sex, body mass index (BMI), and radiographic stage. Secondary analyses were performed similarly by radiographic stage.

RESULTS

Pain and synovitis measures from 248 patients (453 knees) were included. Worse synovitis was associated with higher ICOAP constant pain scores (β 8.05 [95%CI 0.67, 15.43]), but not intermittent pain scores. Moderate-to-severe synovitis was associated with a 4.73-fold increased relative risk [95%CI 1.06, 8.80] of a constant pain pattern. In secondary analyses, moderate-to-severe synovitis in early radiographic OA was associated with 2.70-higher odds [95%CI 1.04, 7.02] of any constant pain, 3.28-higher odds [95%CI 1.43, 7.52] of any intermittent pain, and with higher intermittent (β 10.47 [95%CI 1.03, 19.91]) and constant (β 12.62 [95%CI 3.02, 22.23]) pain scores. No associations identified for synovitis in those with late radiographic OA.

CONCLUSION

In patients with knee OA, moderate-to-severe synovitis is most strongly associated with constant pain. Inflammation may play context-specific roles across pain experiences, especially in earlier radiographic stages of knee OA.

Prevalence of ultrasound-detected knee synovial abnormalities in a middle-aged and older general population-the Xiangya Osteoarthritis Study

Background

There is paucity of data on the prevalence of ultrasound-detected synovial abnormalities in the general population, and the relationship between synovial changes and knee pain remains unclear. We examined the prevalence of synovial abnormalities on ultrasound and the relationship of these features with knee pain and radiographic osteoarthritis (ROA) in a community sample.

Methods

Participants aged 50 years or over were from the Xiangya Osteoarthritis Study, a community-based cohort study. Participants were questioned about chronic knee pain and underwent (1) ultrasonography of both knees to determine presence of synovial hypertrophy (≥ 4 mm), effusion (≥ 4 mm), and Power Doppler signal [PDS; yes/no]; and (2) standard radiographs of both knees (tibiofemoral and patellofemoral views) to determine ROA.

Results

There were 3755 participants (mean age 64.4 years; women 57.4%). The prevalence of synovial hypertrophy, effusion, and PDS were 18.1% (men 20.2%; women 16.5%), 46.6% (men 49.9%; women 44.2%), and 4.9% (men 4.9%; women 5.0%), respectively, and increased with age (P for trend < 0.05). Synovial abnormalities were associated with knee pain, with adjusted odds ratios (aORs) of 2.39 (95% confidence interval [CI] 2.00–2.86) for synovial hypertrophy, 1.58 (95%CI 1.39–1.80) for effusion, and 4.36 (95%CI 3.09–6.17) for PDS. Similar associations with ROA were observed, the corresponding aORs being 4.03 (95%CI 3.38–4.82), 2.01 (95%CI 1.76–2.29), and 6.49 (95%CI 4.51–9.35), respectively. The associations between synovial hypertrophy and effusion with knee pain were more pronounced among knees with ROA than those without ROA, and the corresponding P for interaction were 0.004 and 0.067, respectively.

Conclusions

Knee synovial hypertrophy and effusion are more common and increase with age, affecting men more than women. All three ultrasound-detected synovial abnormalities associate both with knee pain and ROA, and knee synovial hypertrophy or effusion and ROA may interact to increase the risk of knee pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02539-2.

Turning the Page in Osteoarthritis Assessment with the Use of Ultrasound

PURPOSE OF REVIEW

This narrative review summarizes the last 5 years of published, peer-reviewed research on the use of musculoskeletal ultrasound (US) in osteoarthritis (OA).

RECENT FINDINGS

Multiple features relevant to OA can be visualized on US, including synovitis, erosion, enthesitis, osteophytes, cartilage damage, meniscal extrusion, and popliteal cysts. US can be used to confirm a diagnosis of OA or make an alternate diagnosis in the clinical setting. When a standardized protocol is used, US is a reliable modality for assessment of the features of OA. Findings on US can predict progression and response to therapy in OA of the hand and knee and can allow characterization of risk factors in a cost-effective, non-invasive, repeatable manner. US is becoming more widely used in OA imaging and has clear value in addition to radiography and clinical assessment. US will likely prove useful in defining phenotypes and providing treatment guidance in OA.