Atlas-based knee osteophyte assessment with ultrasonography and radiography: relationship to arthroscopic degeneration of articular cartilage

The ultrasound assessment of osteoarthritis: the current status

Traditionally, osteoarthritis (OA) is diagnosed with the clinical examination supplemented by the conventional radiography (CR). In the research literature, the role of ultrasound (US) imaging in the diagnostics of OA has risen steadily during the last two decades. US imaging is cheap and globally widely available often already in primary healthcare. Here, we reviewed the most essential US literature focusing on OA diagnostics and progression prediction using the various search engines. Starting from the year 2000, our search provided 1 445 journal articles. After reviewing the abstracts, 89 articles were finally included. Most of the reviewed articles focused on the imaging of knee and hand OA, whereas only a minority dealt with the imaging of hip, ankle, midfoot, acromioclavicular, and temporomandibular joints. Overall, during the last 20 years, the use of US imaging for OA assessment has increased in the scientific literature. In knee and hand joints, US imaging has been reported to be a promising tool to evaluate OA changes. Furthermore, the reproducibility of US as well as its association to MRI findings are excellent. Importantly, US seems to even outperform CR in certain aspects, such as detection of osteophytes, joint inflammation, meniscus protrusion, and localized cartilage damage (especially at the medial femoral condyle and sulcus area). Based on the reviewed literature, US can be truly considered as a complementary tool to CR in the clinical setup for OA diagnostics. New technical developments may even enhance the diagnostic value of the US in the future.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Reliability and Convergent Construct Validity of Quantitative Ultrasound for Synovitis, Meniscal Extrusion, and Osteophyte in Knee Osteoarthritis With MRI

AIMS

To determine: 1) inter-rater reliability of quantitative measurements of ultrasound-detected synovitis, meniscal extrusion, and osteophytes; and 2) construct (convergent) validity via correlations and absolute agreements between ultrasound- and gold-standard magnetic resonance imaging (MRI)-outcomes in knee osteoarthritis.

METHODS

Dynamic ultrasound images for supra-patellar synovitis, meniscal extrusion, and osteophytes were acquired and quantified by a physician operator, musculoskeletal ultrasonographer, and medical student independently. On the same day, 3T MRI images were acquired. Effusion-synovitis, meniscal extrusion, and osteophytes were quantified on sagittal or coronal proton-density-weighted fat-suppressed noncontrast TSE sequences, respectively. Intra-class correlation coefficients (ICCs), Pearson's correlations (r), and Bland-Altman plots were used to analyze inter-rater reliability, and correlations, and agreements between the two imaging modalities.

RESULTS

Eighty-nine participants [48 females (53.9%)] with mean (standard deviation) age of 61.5 ± 6.9 years were included. The inter-rater reliability was excellent for osteophytes (ICC range = 0.90-0.96), meniscal extrusion (ICC range = 0.90-0.93), and synovitis (ICC range = 0.86-0.88). The correlations between ultrasound pathologies and their MRI counterparts were very strong (ICC range = 0.85-0.98) except for lateral meniscal extrusion [0.66 (95% CI, 0.52-0.76)]. Bland-Altman plots showed 0.01, 0.05, 0.10, 0.53, and 0.60 mm larger size in ultrasound medial tibial and medial femoral osteophytes, medial meniscal extrusions, synovitis, and lateral meniscal extrusions with 95% limits of agreements [±0.39, ±0.44, ±0.85, ±0.70, and ±0.90 (SDs)] than MRI measures, respectively. The lines of equality were within 95% CI of the mean differences (bias) only for medial osteophytes and medial meniscal extrusion.

CONCLUSION

The quantitative assessment of synovitis, meniscal extrusion, and osteophytes generally showed excellent inter-rater reliability and strong correlations with MRI-based measurements. Absolute agreement was strong for medial tibiofemoral pathologies.

Diagnostic Performance of Ultrasonography for Evaluation of Osteoarthritis of Ankle Joint: Comparison With Radiography, Cone-Beam CT, and Symptoms

OBJECTIVES

To determine the diagnostic performance of ultrasonography (US) for evaluation of the ankle joint osteoarthritic (OA) changes. Cone-beam computed tomography (CT) was used as the gold standard and US performance was compared with conventional radiography (CR). As a secondary aim, associations between the imaging findings and ankle symptoms were assessed.

METHODS

US was performed to 51 patients with ankle OA. Every patient had prior ankle CR and underwent cone-beam CT during the same day as US examination. On US, effusion/synovitis, osteophytes, talar cartilage damage, and tenosynovitis were evaluated. Comparison to respective imaging findings on CR and cone-beam CT was then performed. Single radiologist blinded to other modalities assessed all the imaging studies. Symptoms questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), was available for 48 patients.

RESULTS

US detected effusion/synovitis of the talocrural joint with 45% sensitivity and 90% specificity. For the detection of anterior talocrural osteophytes, US sensitivity was 78% and specificity 79%. For the medial talocrural osteophytes, they were 39 and 83%, and for the lateral talocrural osteophytes 54 and 100%, respectively. Considering cartilage damage of the talus, US yielded a low sensitivity of 18% and high specificity of 97%. Overall, the performance of US was only moderate and comparable to CR. The imaging findings showed only weak associations with ankle symptoms.

CONCLUSIONS

The ability of US to detect ankle OA is only moderate. Interestingly, performance of CR also remained moderate. The associations between imaging findings and WOMAC score seem to be weak in ankle OA.

Role of global femoral cartilage in assessing severity of primary knee osteoarthritis

Background/objective

Osteoarthritis is a degenerative joint disease marked by structural changes in the joint. Radiological evaluation can be used to assess structural changes. Pain, inflammation, and stiffness are common clinical symptoms, leading to limitations in daily activities. Ultrasound, unlike traditional radiography, allows for a direct examination of changes in soft tissues. In addition, it is sensitive in detecting osteophytes as well as identifying early OA changes in femoral cartilage associated with clinical manifestations and function.

Results

A cross- sectional study of 40 patients with primary KOA diagnosed according to the American College of Rheumatology (ACR) criteria. After radiographic evaluation using Kellgren-Lawrence (K-L) scale and US examination assessing global femoral hyaline cartilage (GFC), osteophytes, meniscal extrusion, effusion, and Baker’s cyst of the most symptomatic knee, there was significant correlation between (K-L) grading and (GFC) ultrasonographic grading (p = < 0.001). After assessment of pain and functional disability using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale, there was significant correlation between KL and GFC grading with age (p = < 0.001 for both), disease duration (p = < 0.001 for both) as well as WOMAC total scores (p = < 0.001 for both). GFC grading was the only independent predictor relative to other ultrasonographic variables for WOMAC total score (p = < 0.001).

Conclusions

US is a valid tool to evaluate knee joint space and is well correlated with radiographic images. KOA severity assessed by KL grading and GFC ultrasonographic grading showed good correlation with age, duration of the disease, pain intensity, and functional disability.

Ultrasonographic Changes of the Knee Joint Reflect Symptoms of Early Knee Osteoarthritis in General Population; The Nagahama Study

OBJECTIVE

Radiographic changes in knee osteoarthritis (OA) are not always associated with symptoms, especially in its early stages. Ultrasonography (US) can detect early changes in the knee joint, but the changes that reflect symptoms have not been fully elucidated. This study aimed to identify US-detectable changes in the knee that are often associated with knee symptoms and demonstrate the feasibility of early diagnosis in symptomatic knee OA using US.

DESIGN

In this cross-sectional community-based study, 1,667 participants aged ≥60 years (1,103 women [66%]) were included. All participants concurrently underwent US and radiography of the knee and completed the Knee Society Knee Scoring System (KSS) questionnaire. Simple and multiple regression analyses were used to examine the associations between US findings and KSS symptom subscales.

RESULTS

Among all participants, medial meniscus protrusion and medial osteophytes, age, and body mass index showed significant associations with KSS symptom scores. Among 894 participants with Kellgren-Lawrence (KL) grade ≤1, medial osteophytes and age were significantly associated with KSS symptom score. US measures were more related to KSS symptoms than KL grades.

CONCLUSIONS

Among the knee US-detectable changes, medial osteophytes were strongly associated with knee symptoms. Osteophytes are reliable predictors of symptomatic early knee OA, even in participants with few radiographic OA changes.

Ultrasound-Based Quantification of Cartilage Damage After In Vivo Articulation With Metal Implants

OBJECTIVE

This study aims to evaluate the applicability of the ultrasound roughness index (URI) for quantitative assessment of cartilage quality ex vivo (post-mortem), after 6 months of in vivo articulation with a Focal Knee Resurfacing Implant (FKRI).

DESIGN

Goats received a metal FKRI (n = 8) or sham surgery (n = 8) in the medial femoral condyles. After 6 months animals were sacrificed, tibial plateaus were stained with Indian ink, and macroscopic scoring of the plateaus was performed based on the ink staining. The URI was calculated from high-frequency ultrasound images at several sections, covering both areas that articulated with the implant and non-articulating areas. Cartilage quality at the most damaged medial location was evaluated with a Modified Mankin Score (MMS).

RESULTS

The URI was significantly higher in the FKRI-articulating than in the sham plateaus at medial articulating sections, but not at sections that were not in direct contact with the implant, for example, under the meniscus. The mean macroscopic score and MMS were significantly higher in the FKRI-articulating group than in the sham group (P=0.035, P<0.001, respectively). Correlation coefficients between URI and macroscopic score were significant in medial areas that articulated with the implant. A significant correlation between URI and MMS was found at the most damaged medial location (ρ=0.72,P=0.0024).

CONCLUSIONS

This study demonstrates the potential of URI to evaluate cartilage roughness and altered surface morphology after in vivo articulation with a metal FKRI, rendering it a promising future tool for quantitative follow-up assessment of cartilage quality.

Tenderness of the knee is associated with thinning of the articular cartilage evaluated with ultrasonography in a community-based cohort: The Nagahama study

OBJECTIVES

This study aimed to elucidate the association between joint line tenderness (JLT) of the knee and knee joint structural changes evaluated with ultrasonography (US) for the early diagnosis of knee osteoarthritis (KOA).

METHODS

This cross-sectional study included 121 participants (age 71.7 ± 5.8 years, 75 women) from a community-based population. Bilateral structural changes in the knee joint were evaluated with US, and the presence or absence of JLT was evaluated using a pressure algometer. Logistic regression analysis was performed to evaluate the odds ratios (ORs) of US findings for the presence of JLT. Moreover, when the analysis was limited to knees with pre-/early radiographic KOA, the ORs were also calculated using logistic regression analysis.

RESULTS

Among the 242 knees, 38 had medial JLT, which was significantly associated with female sex (OR 11.87) and loss of cartilage thickness of the distal medial femoral condyle (CTh-MFC) (OR 0.12). Among 96 knees with Kellgren-Lawrence grade ≤ 2, 18 knees had medial JLT, which was also significantly associated with loss of CTh-MFC (OR 0.07) and medial osteophytes (OR 2.01).

CONCLUSIONS

JLT is significantly associated with thinning of the femoral cartilage and larger osteophytes in elderly patients, even in those with pre-/early radiographic KOA.

Study protocol for the follow-up examination of the Nor-Hand study: A hospital-based observational cohort study exploring pain and biomarkers in people with hand osteoarthritis

Objective

This study aims to increase the understanding of pain mechanisms in hand OA and explore potential risk factors for pain development or worsening in a biopsychosocial framework. Another important aim is to validate potential soluble and imaging OA biomarkers.

Design

The follow-up examination of the Nor-Hand hospital-based observational cohort study started in October 2019 and was completed in May 2021. In total, 212 of the 300 participants with hand OA who were examined at baseline attended the follow-up study. The participants underwent clinical joint examinations, medical and functional assessments, quantitative sensory testing, fluorescence optical imaging, ultrasound of the hands, acromioclavicular joints, feet, knees and hips, conventional radiographs of the hands and feet and magnetic resonance imaging of the dominant hand. Blood and urine samples were collected, and all participants answered questions about demographic factors and OA-related questionnaires. Associations between disease variables and symptoms will be examined in cross-sectional and longitudinal analyses. Longitudinal analyses will be performed to assess the predictive value of baseline variables on hand OA outcomes.

Conclusion

Current knowledge about predictors for disease progression in hand OA is limited, but with longitudinal data we will be able to explore the predictive value of baseline variables on hand OA outcomes, such as changes in patient-reported outcomes or changes in soluble and imaging biomarkers. This provides a unique opportunity to gain more knowledge about the natural disease course of hand OA.

Ultrasonographic Assessment of the Normal Femoral Articular Cartilage of the Knee Joint: Comparison with 3D MRI

Objective

Ultrasonography (US) has a promising role in evaluating the knee joint, but capability to visualize the femoral articular cartilage needs systematic evaluation. We measured the extent of this acoustic window by comparing standardized US images with the corresponding MRI views of the femoral cartilage.

Design

Ten healthy volunteers without knee pathology underwent systematic US and MRI evaluation of both knees. The femoral cartilage was assessed on the oblique transverse axial plane with US and with 3D MRI. The acoustic window on US was compared to the corresponding views of the femoral sulcus and both condyles on MRI. The mean imaging coverage of the femoral cartilage and the cartilage thickness measurements on US and MRI were compared.

Results

Mean imaging coverage of the cartilage of the medial femoral condyle was 66% (range 54%-80%) and on the lateral femoral condyle 37% (range 25%-51%) compared with MRI. Mean cartilage thickness measurement in the femoral sulcus was 3.17 mm with US and 3.61 mm with MRI (14.0% difference). The corresponding measurements in the medial femoral condyle were 1.95 mm with US and 2.35 mm with MRI (21.0% difference), and in the lateral femoral condyle, they were 2.17 mm and 2.73 mm (25.6% difference), respectively.

Conclusion

Two-thirds of the articular cartilage of the medial femoral condyle, and one-third in the lateral femoral condyle, can be assessed with US. The cartilage thickness measurements seem to be underestimated by US. These results show promise for the evaluation of the weight-bearing cartilage of the medial femoral condyle with US.

Three-dimensional ultrasound for knee osteophyte depiction: a comparative study to computed tomography

Purpose

Osteophytes are common radiographic markers of osteoarthritis. However, they are not accurately depicted using conventional imaging, thus hampering surgical interventions that rely on pre-operative images. Studies have shown that ultrasound (US) is promising at detecting osteophytes and monitoring the progression of osteoarthritis. Furthermore, three-dimensional (3D) ultrasound reconstructions may offer a means to quantify osteophytes. The purpose of this study was to compare the accuracy of osteophyte depiction in the knee joint between 3D US and conventional computed tomography (CT).

Methods

Eleven human cadaveric knees were pre-screened for the presence of osteophytes. Three osteoarthritic knees were selected, and then, 3D US and CT images were obtained, segmented, and digitally reconstructed in 3D. After dissection, high-resolution structured light scanner (SLS) images of the joint surfaces were obtained. Surface matching and root mean square (RMS) error analyses of surface distances were performed to assess the accuracy of each modality in capturing osteophytes. The RMS errors were compared between 3D US, CT and SLS models.

Results

Average RMS error comparisons for 3D US versus SLS and CT versus SLS models were 0.87 mm ± 0.33 mm (average ± standard deviation) and 0.95 mm ± 0.32 mm, respectively. No statistical difference was found between 3D US and CT. Comparative observations of imaging modalities suggested that 3D US better depicted osteophytes with cartilage and fibrocartilage tissue characteristics compared to CT.

Conclusion

Using 3D US can improve the depiction of osteophytes with a cartilaginous portion compared to CT. It can also provide useful information about the presence and extent of osteophytes. Whilst algorithm improvements for automatic segmentation and registration of US are needed to provide a more robust investigation of osteophyte depiction accuracy, this investigation puts forward the potential application for 3D US in routine diagnostic evaluations and pre-operative planning of osteoarthritis.

Using intra-articular allogenic lyophilized growth factors in primary knee osteoarthritis: a randomized pilot study

Objective: Investigating the safety in addition to clinical and structural efficacy of allogenic lyophilized growth factors (L-GFs) in patients with symptomatic primary knee osteoarthritis. Design: A prospective, open-label pilot study. A total of 31-patients randomized into non-intervention and intervention groups. Materials & methods: The intervention group received two intra-articular doses at baseline and after 2-months. Post-injection complications were documented, and the efficacy was assessed by Western Ontario and McMaster Universities Osteoarthritis Index scores and ultrasonography. Results: One dropout from the intervention group. The percentage of improvement of mean Western Ontario and McMaster Universities Osteoarthritis Index-scores and ultrasonography-detected effusion were statistically significant in the intervention group compared with the non-intervention. A brief, mild, post-injection pain was reported by all intervention group. Conclusion: This study provides the safety of intra-articular injection of allogenic L-GFs in knee osteoarthritis. The conclusion of efficacy was limited by small sample size and lack of control injection. Clinical trial registration: NCT04331327 (ClinicalTrials.gov, retrospectively registered).

Comparison of ultrasonographic, radiographic and intra-operative findings in severe hip osteoarthritis

Aim of this study was to assess the US findings of patients with late-stage hip OA undergoing total hip arthroplasty (THA), and to associate the US findings with conventional radiography (CR) and intraoperative findings. Moreover, the inter-rater reliability of hip US, and association between the US and Oxford Hip Score (OHS) were evaluated. Sixty-eight hips were included, and intraoperative findings were available on 48 hips. Mean patient age was 67.6 years and 38% were males. OA findings-osteophytes at femoral collum and anterosuperior acetabulum, femoral head deformity and effusion-were assessed on US, CR and THA. The diagnostic performance of US and CR was compared by applying the THA findings as the gold standard. Osteoarthritic US findings were very common, but no association between the US findings and OHS was observed. The pooled inter-rater reliability (n = 65) varied from moderate to excellent (k = 0.538-0.815). When THA findings were used as the gold standard, US detected femoral collum osteophytes with 95% sensitivity, 0% specificity, 81% accuracy, and 85% positive predictive value. Concerning acetabular osteophytes, the respective values were 96%, 0%, 88% and 91%. For the femoral head deformity, they were 92%, 36%, 38% and 83%, and for the effusion 49%, 85%, 58% and 90%, respectively. US provides similar detection of osteophytes as does CR. On femoral head deformity, performance of the US is superior to CR. The inter-rater reliability of the US evaluation varies from moderate to excellent, and no association between US and OHS was observed in this patient cohort.

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.

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

Objective

This study sought to develop and employ a comprehensive and standardized ultrasound (US) protocol and scoring atlas for the evaluation of features relevant to knee osteoarthritis (KOA) in a community‐based cohort in the United States, with the goals of demonstrating feasibility, reliability, and validity.

Methods

We utilized data from the fourth follow‐up (2016‐2018) of the Johnston County OA Project, which includes individuals with (~50%) and without radiographic KOA. All participants underwent standardized knee radiography and completed standard questionnaires including the Knee Injury and Osteoarthritis Outcome Score (KOOS). Bilateral knee US images were obtained by a trained sonographer using a standardized protocol and scored by trained rheumatologists using an atlas developed for this study. A total of 396 knees were each scored by two readers according to the atlas. Associations between US features, radiographic findings (graded by an expert radiologist), and KOOS scores were assessed.

Results

Overall interreader reliability for US scoring was fair to moderate. The strongest correlations between US and radiographic features were seen for osteophytes, and similarly strong correlations were seen between US osteophytes and overall radiographic Kellgren‐Lawrence Grade, demonstrating criterion validity. Features of effusion/synovitis and osteophytes were most associated with KOOS pain and impaired function.

Conclusion

US is a feasible, reliable, and valid method to assess features relevant to KOA in clinical and research settings. The protocol and atlas developed in this study can be utilized to evaluate KOA in a standardized fashion in future clinical studies, enabling greater utilization of this valuable modality in osteoarthritis.

Association between grayscale sonographic and clinical findings in severe knee osteoarthritis

PURPOSE

To assess whether ultrasonographic (US) findings associate with clinical findings in severe knee osteoarthritis (OA). Association of US findings with side-of-knee pain and inter-reader agreement of knee US were also evaluated.

METHODS

One-hundred-two patients (in total 123 knees) with severe knee OA were recruited for this cross-sectional study. US was performed by a single observer, and on 53 knees by two independent observers to assess inter-reader reliability. Preoperative clinical data was available for 69 knees. Cutoff values were applied to dichotomize US and clinical findings. The Chi-square test, Mann-Whitney test, and prevalence- and bias-adjusted kappa (PABAK) were applied for statistical analyses.

RESULTS

Seven of 99 associations tested were statistically significant. Associations were observed between range of flexion and lateral femoral (P = .009) and tibial (P = .001) osteophytes, mediolateral instability and damage to the lateral femoral cartilage (P = .014) and damage to the lateral meniscus (P = .031), and alignment and damage to the lateral femoral cartilage (P < .001), lateral tibial osteophytes (P = .037), and damage to the lateral meniscus (P < .001). A strong association was observed between medial-sided pain and same-sided cartilage damage and osteophytes (P < .001). That inter-reader agreement was excellent on the medial side of the knee joint (PABAK = 0.811-0.887).

CONCLUSIONS

US findings show a rather poor association with clinical OA findings. Inter-reader agreement of knee US is excellent on the medial side.

Correlation Between Medial Meniscal Extrusion Determined by Dynamic Ultrasound and Magnetic Resonance Imaging Findings of Medial-Type Knee Osteoarthritis in Patients With Knee Pain

OBJECTIVES

The aim of our study was to investigate the relationship between medial meniscal extrusion (MME) determined by dynamic ultrasound (US) and magnetic resonance imaging findings of medial-type knee osteoarthritis (OA).

METHODS

Single knees of 102 patients with knee pain were assessed by radiography, dynamic US, and magnetic resonance imaging. All knee radiographs were interpreted and grouped according to the Kellgren-Lawrence (KL) scale. Medial meniscal extrusion in non-weight-bearing and weight-bearing positions and the difference of these values (ΔMME) were measured by dynamic US. The medial tibiofemoral compartments of all knees were evaluated and grouped according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Mean values of non-weight-bearing MME, weight-bearing MME, and ΔMME ± standard deviations for groups formed according to the KL scale and WORMS system were compared.

RESULTS

We demonstrated that different from non-weight-bearing MME, weight-bearing MME was significantly correlated with not only high grades but also lower grades of cartilage damage and subchondral bone marrow lesions in medial-type knee OA. Although the difference in non-weight-bearing MME between cartilage status groups 1 and 2 was not significant (P = .071), there were significant differences in of weight-bearing MME between groups 1 and 2, between groups 2 and 3, and between groups 3 and group 4 (P = .003, .002, and .032, respectively).

CONCLUSIONS

We found statistically significant associations between MME values and the severity of the OA findings according to both the KL scale and WORMS system. We offer dynamic US as an initial tool for the diagnosis and a screening method to estimate the severity of knee OA.

Stratifying Minimal Versus Severe Pain in Knee Osteoarthritis Using a Musculoskeletal Ultrasound Protocol

OBJECTIVE

The aim of this cross-sectional correlational study was to determine the association of pain with morphologic and inflammatory sonographic findings in patients with knee osteoarthritis.

METHODS

A total of 113 participants with knee osteoarthritis were assessed using visual analog scale pain score and sonography. Ultrasound evaluation included morphologic changes (ie, articular cartilage degeneration, medial and lateral meniscal protrusion, and presence of osteophytes on the joint margins) and inflammatory changes (ie suprapatellar effusion and/or synovitis, Baker cyst, superficial and deep infrapatellar effusion, pes anserine tendinopathy, and Hoffa panniculitis).

RESULTS

Cluster analysis via Ward's method grouped patients with minimal pain (visual analog scale score, 0-4) and with substantial pain (visual analog scale score, 5-10). Stepwise logistic regression yielded 5 variables that significantly explained the variation in the probability of perceived substantial pain at 10% level of significance: lateral cartilage clarity (LCC; P = .025), medial cartilage clarity (MCC; P = .20), medial cartilage thickness (MCT; P = .041), medial meniscus protrusion (MMP) (P = .029), and osteophytes at medial femoral margin (P = .082), with 63% overall prediction accuracy. When age and sex were added, 4 variables remained significant at a 10% level of significance: LCC, MCC, MCT, and MMP, with 65% overall prediction accuracy. The receiver operating characteristic curve of this model was 0.667.

CONCLUSION

The study was able to demonstrate that morphologic abnormalities in the ultrasound parameters for LCC, MCC, MCT, and MMP were able to predict significant joint pain in knee osteoarthritis. There were no inflammatory changes that contributed to significant joint pain in this study.

Ultrasound imaging and guidance in the management of knee osteoarthritis in regenerative medicine field

Ultrasound (US) is an excellent imaging tool to evaluate most of the structures in the knee joint. US is useful in various applications of regenerative medicine, starting from the biomaterial harvesting stage of the procedures, it can thus/conveniently be used for the diagnosis and treatment of various forms of knee osteoarthritis (OA) where the interventions need to be carried out under US guidance. In this paper, we have reviewed US guided bioharvesting of venous blood, bone marrow and adipose tissue, the US evaluation of the knee joint and the relevant findings in knee OA along with US guided regenerative interventions for the knee joint.

Ultrasonography of the late-stage knee osteoarthritis prior to total knee arthroplasty: comparison of the ultrasonographic, radiographic and intra-operative findings

The purpose of this study was to assess the effectiveness of the ultrasonography (US) on detecting osteoarthritis of the knee, and compare US and radiographic findings to intraoperative total knee arthroplasty (TKA) findings. Fifty-seven late-stage osteoarthritic knees undergoing TKA were evaluated with US and radiography. Standard knee US assessing femoral cartilage damage, osteophytes, effusion, synovitis, and meniscal extrusion was performed. On radiographs, osteophytes, joint space narrowing, and Kellgren-Lawrence grade were evaluated. Corresponding intra-operative findings were assessed during TKA as the gold standard. On the damage of the medial femoral condyle cartilage, the sensitivity of US was high (92%), whereas on the lateral condyle and sulcus area, sensitivities were 58% and 46%, respectively. On osteophytes, the detection rate of the US was remarkable especially on the medial side yielding sensitivities of 90–95%. The sensitivities for detecting effusion and synovitis were also excellent (97%). US detection rate of femoral cartilage damage was in concordance with the radiographic joint space narrowing. For the detection of osteophytes, US provided superior results to radiography particularly on the medial side. In conclusion, US can reliably assess the late-stage OA changes of the knee especially on the medial side of the knee joint.

Clinimetrics of ultrasound pathologies in osteoarthritis: systematic literature review and meta-analysis

OBJECTIVE

The aims of this study were to systematically review clinimetrics of commonly assessed ultrasound pathologies in knee, hip and hand osteoarthritis (OA), and to conduct a meta-analysis for each clinimetric.

METHODS

Medline, Embase, and Cochrane Library databases were searched from their inceptions to September 2016. According to the Outcome Measures in Rheumatology (OMERACT) Instrument Selection Algorithm, data extraction focused on ultrasound technical features and performance metrics. Methodological quality was assessed with modified 19-item Downs and Black score and 11-item Quality Appraisal of Diagnostic Reliability (QAREL) score. Separate meta-analyses were performed for clinimetrics: (1) inter-rater/intra-rater reliability; (2) construct validity; (3) criteria validity; and (4) internal/external responsiveness. Statistical Package for the Social Sciences (SPSS), Excel and Comprehensive Meta-analysis were used.

RESULT

Our search identified 1126 records; of these, 100 were eligible, including a total of 8542 patients and 32,373 joints. The average Downs and Black score was 13.01, and average QAREL was 5.93. The stratified meta-analysis was performed only for knee OA, which demonstrated moderate to substantial reliability [minimum kappa > 0.44(0.15,0.74), minimum intraclass correlation coefficient (ICC) > 0.82(0.73-0.89)], weak construct validity against pain (r = 0.12 to 0.27), function (r = 0.15 to 0.23), and blood biomarkers (r = 0.01 to 0.21), but weak to strong correlation with plain radiography (r = 0.13 to 0.60), strong association with Magnetic Resonance Imaging (MRI) [minimum r = 0.60(0.52,0.67)] and strong discrimination against symptomatic patients (OR = 3.08 to 7.46). There was strong criterion validity against cartilage histology [r = 0.66(-0.05,0.93)], and small to moderate internal [standardized mean difference(SMD) = 0.20 to 0.58] and external (r = 0.35 to 0.43) responsiveness to interventions.

CONCLUSION

Ultrasound demonstrated strong criterion validity with cartilage histology, poor to strong correlation with patient findings and MRI, moderate reliability, and low responsiveness to interventions.

PROSPERO REGISTRATION NO

CRD42016039954.

Imaging of osteoarthritis-recent research developments and future perspective

In osteoarthritis research, imaging plays an important role in clinical trials and epidemiological observational studies. In this narrative review article, we will describe recent developments in imaging of osteoarthritis in the research arena, mainly focusing on literature evidence published within the past 3 years (2014-2017). We will primarily focus on MRI including advanced imaging techniques that are not currently commonly used in routine clinical practice, although radiography, ultrasound and nuclear medicine (radiotracer) imaging will also be discussed. Research efforts to uncover the disease process of OA as well as to discover a disease modifying OA drug continue. MRI continues to play a large role in these endeavors, while compositional MRI techniques will increasingly become important due to their ability to assess "premorphologic" biochemical changes of articular cartilage and other tissues in and around joints. Radiography remain the primary imaging modality for defining inclusion/exclusion criteria as well as an outcome measure in OA clinical trials, despite known limitations for visualization of OA features. Compositional MRI techniques show promise for predicting structural and clinical outcomes in OA research. Ultrasound can be a useful adjunct to radiography and MRI particularly for evaluation of hand OA. Newer imaging techniques such as hybrid PET/MRI may have a potential but require further research and validation.

A hospital-based observational cohort study exploring pain and biomarkers in patients with hand osteoarthritis in Norway: The Nor-Hand protocol

INTRODUCTION

We have limited knowledge about the underlying disease mechanisms and causes of pain in hand osteoarthritis (OA). Consequently, no disease-modifying drug exists, and more knowledge about the pathogenesis of hand OA is needed, as well as a validation of different outcome measures. Our first aim of this study is to explore the validity of various imaging modalities for the assessment of hand OA. Second, we want to gain a better understanding of the disease processes, with a special focus on pain mechanisms.

METHODS AND ANALYSIS

The Nor-Hand study is a hospital-based observational study including 300 patients with evidence of hand OA by ultrasound and/or clinical examination. The baseline examination consists of functional tests and joint assessment of the hands, medical assessment, pain sensitisation tests, ultrasound (hands, acromioclavicular joint, hips, knees and feet), CT and MRI of the dominant hand, conventional radiographs of the hands and feet, fluorescence optical imaging of the hands, collection of blood and urine samples as well as self-reported demographic factors and OA-related questionnaires. Two follow-up examinations are planned. Cross-sectional analyses will be used to investigate agreements and associations between different relevant measures at the baseline examination, whereas the longitudinal data will be used for evaluation of predictors for clinical outcomes.

ETHICS AND DISSEMINATION

The protocol is approved by the Norwegian Regional Committee for Medical and Health Research Ethics (Ref. no: 2014/2057). The participants receive oral and written information about the project and sign a consent form before participation. They can, whenever they want, withdraw from the study, and all de-identified data will be safely stored on the research server at Diakonhjemmet Hospital. Results will be presented at international and national congresses and in peer-reviewed rheumatology journals.

TRIAL REGISTRATION NUMBER

NCT03083548; Pre-results.

Association of medial meniscal extrusion with medial tibial osteophyte distance detected by T2 mapping MRI in patients with early-stage knee osteoarthritis

Background

Medial meniscal extrusion (MME) is associated with progression of medial knee osteoarthritis (OA), but no or little information is available for relationships between MME and osteophytes, which are found in cartilage and bone parts. Because of the limitation in detectability of the cartilage part of osteophytes by radiography or conventional magnetic resonance imaging (MRI), the rate of development and size of osteophytes appear to have been underestimated. Because T2 mapping MRI may enable us to evaluate the cartilage part of osteophytes, we aimed to examine the association between MME and OA-related changes, including osteophytes, by using conventional and T2 mapping MRI.

Methods

Patients with early-stage knee OA (n = 50) were examined. MRI-detected OA-related changes, in addition to MME, were evaluated according to the Whole-Organ Magnetic Resonance Imaging Score. T2 values of the medial meniscus and osteophytes were measured on T2 mapping images. Osteophytes surgically removed from patients with end-stage knee OA were histologically analyzed and compared with findings derived by radiography and MRI.

Results

Medial side osteophytes were detected by T2 mapping MRI in 98% of patients with early-stage knee OA, although the detection rate was 48% by conventional MRI and 40% by radiography. Among the OA-related changes, medial tibial osteophyte distance was most closely associated with MME, as determined by multiple logistic regression analysis, in the patients with early-stage knee OA (β = 0.711, p < 0.001). T2 values of the medial meniscus were directly correlated with MME in patients with early-stage knee OA, who showed ≥ 3 mm of MME (r = 0.58, p = 0.003). The accuracy of osteophyte evaluation by T2 mapping MRI was confirmed by histological analysis of the osteophytes removed from patients with end-stage knee OA.

Conclusions

Our study demonstrates that medial tibial osteophyte evaluated by T2 mapping MRI is frequently observed in the patients with early-stage knee OA, showing close association with MME, and that MME is positively correlated with the meniscal degeneration.

Ultrasound-detected osteophytes predict the development of radiographic and clinical features of hand osteoarthritis in the same finger joints 5 years later

Background

Structural pathology may be present in joints without radiographic evidence of osteoarthritis (OA). Ultrasound is a sensitive tool for early detection of osteophytes. Our aim was to explore whether ultrasound-detected osteophytes (in radiographically and clinically normal finger joints) predicted the development of radiographic and clinical hand OA 5 years later.

Methods

We included finger joints without radiographic OA (Kellgren-Lawrence grade (KLG)=0; n=301) or no clinical bony enlargements (n=717) at baseline and examined whether ultrasound-detected osteophytes predicted incident radiographic OA (KLG ≥1, osteophytes or joint space narrowing (JSN)) or incident clinical bony enlargement (dependent variables) in the same joints 5 years later. We applied logistic regression with generalised estimating equations adjusted for age, sex, body mass index and follow-up time.

Results

Ultrasound demonstrated osteophytes in 86/301 (28.6%) joints without radiographic OA and 392/717 (54.7%) joints without clinical bony enlargement. These osteophytes were confirmed in the majority of joints where MRI assessment was available. Significant associations were found between ultrasound-detected osteophytes and development of both radiographic OA (OR=4.1, 95% CI 2.0 to 8.1) and clinical bony enlargement (OR=3.5, 95% CI 2.4 to 5.1) and also incident radiographic osteophytes (OR=4.2, 95% CI 2.1 to 8.5) and JSN (OR=5.3, 95% CI 2.1 to 13.4).

Conclusion

Ultrasound-detected osteophytes predicted incident radiographic and clinical hand OA 5 years later. These results support the use of ultrasound for early detection of OA.

Coexisting lateral tibiofemoral osteoarthritis is associated with worse knee pain in patients with mild medial osteoarthritis

OBJECTIVE

To examine the clinical impact of coexisting lateral osteoarthritis (OA) in knees with mild medial OA.

DESIGN

In patients with Kellgren/Lawrence (K/L) grade 2 OA in the medial compartment (n = 100; age: 56-89 years; 80.0% female), anteroposterior knee radiography was used to assess the presence of lateral OA, using grading systems from the Osteoarthritis Research Society International (OARSI) atlas and the K/L classification. The Japanese Knee Osteoarthritis Measure (JKOM), knee range of motion (ROM), and performance-based functional measures (10 m walk, timed up and go and five repetition chair stand maneuvers) were evaluated. The outcomes were compared between patients with and without lateral OA using an analysis of covariance (ANCOVA) or nonparametric rank ANCOVA. Furthermore, ordinal logistic regression analysis was performed, with responses on individual JKOM pain questionnaires as the outcomes and lateral OA as the predictor.

RESULTS

Knees with coexisting lateral OA had a significantly worse score of JKOM pain question compared with those without, after adjusting for covariates. The presence of lateral OA was significantly associated with knee pain while ascending/descending stairs and standing. These results were consistent between different definitions of the K/L and OARSI grading systems. The knee ROM and performance-based functional measures were not significantly different between patients with and without lateral OA.

CONCLUSION

Knees with concomitant lateral and mild medial OA may be more symptomatic compared to those without lateral OA. These findings might help to define a clinically distinct subgroup based on a simple radiographic finding in mild knee OA.

Role of Ultrasonography in Knee Osteoarthritis

Ultrasound has become popular among rheumatologists as the first-choice imaging investigation for the evaluation and monitoring of osteoarthritis (OA). Because of recent improvement in technology, ultrasound has the ability to demonstrate and assess the minimal structural abnormalities, which involve the pathophysiology and progression of OA, such as articular cartilage, synovial tissue, bony cortex, and other soft tissue. Nowadays, ultrasonography is a promising technique for assessing soft tissue abnormalities such as joint effusion, synovial hypertrophy, Baker cyst, and other structural changes including the decrease in cartilage thickness, meniscus bulging, and formation of osteophyte. Ultrasonography not only possesses diagnostic potential in knee OA but also reveals long-term predictability for disease progress as imaging biomarker. Ultrasonography has also been proven as a useful tool in guiding therapeutic interventions and monitoring treatment effectiveness. This review addresses the utility, reliability, and potential utilization of ultrasonography as an imaging technique in knee OA.

Structure-symptom relationship with wide-area ultrasound scanning of knee osteoarthritis

The aetiology of knee pain in osteoarthritis (OA) is heterogeneous and its relationship with structural changes and function is unclear. Our goal was to determine the prevalence of wide-area scanned ultrasound-defined knee OA structural features and their association with pain and functional impairment in 79 symptomatic and 63 asymptomatic subjects. All subjects underwent ultrasound knee wide-area scanning and the severity of articular cartilage degeneration, the presence and size of osteophytes, and meniscal extrusion were evaluated. Subjects filled in a self-administrated questionnaire on present knee pain, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) on clinical symptoms and function over the past week. Cartilage changes were the most prevalent followed by lateral meniscal extrusion, osteophytes and medial meniscal extrusion. The global femoral cartilage grade associated strongly with pain and the WOMAC index. Site-specifically, early medial cartilage changes and thinning in sulcus and lateral site were associated with symptoms. The presence of femoral lateral osteophytes was also associated with both outcomes. Using the novel wide-area ultrasound scanning technique, we were able to confirm the negative impact of femoral cartilage OA changes on clinical symptoms. Presence, not necessarily size, of lateral femoral osteophytes was also associated with increased pain and disability.

Imaging of osteoarthritis (OA): What is new?

In daily clinical practice, conventional radiography is still the most applied imaging technique to supplement clinical examination of patients with suspected osteoarthritis (OA); it may not always be needed for diagnosis. Modern imaging modalities can visualize multiple aspects of the joint, and depending on the diagnostic need, radiography may no longer be the modality of choice. Magnetic resonance imaging (MRI) provides a complete assessment of the joint and has a pivotal role in OA research. Computed tomography (CT) and nuclear medicine offer alternatives in research scenarios, while ultrasound can visualize bony and soft-tissue pathologies and is highly feasible in the clinic. In this chapter, we overview the recent literature on established and newer imaging modalities, summarizing their ability to detect and quantify the range of OA pathologies and determining how they may contribute to early OA diagnosis. This accurate imaging-based detection of pathologies will underpin true understanding of much needed structure-modifying therapies.

Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

Elbow clinical, ultrasonographic and radiographic study in patients with inflammatory joint diseases

The main objective of this cross-sectional observational study was to investigate the relationship between clinical, ultrasonographic (US) and radiographic elbow features in patients with inflammatory joint diseases (IJD). The secondary objective was to evaluate the association between regional clinical elbow diagnoses and imaging findings. Consecutive patients with IJD attending follow-up visits were assessed for elbow pain and standardized elbow examination. Seven regional clinical diagnoses were defined. Digital elbow radiographs were read for 9 abnormalities. A standardized elbow grayscale (GS) and power Doppler (PD) scan recorded 13 defined abnormalities. Analysis encompassed 361 clinical, 361 US and 340 radiographic elbow assessments from 181 patients. US and clinical assessments showed an overall higher agreement than radiographic and clinical assessments (68.8 vs 59.1%, p = 0.001). When structural US abnormalities were compared with radiographic findings, agreement was slightly higher than when comparing all US abnormalities with radiographic findings (77.3%, k 0.533 and 73.5%, k 0.492). Enthesophytes, the most common abnormalities, were not associated with clinical findings. Subclinical US-synovitis and US-enthesopathy were found, respectively, in 17.3 and 14.1% of the clinically normal elbows. Clinical elbow arthritis prevalence and bias-adjusted kappa (PABAK) agreement was good for radiographic fat pad sign, PD-synovitis and GS-synovitis. Clinical elbow enthesopathy PABAK agreement was moderate for GS-enthesopathy and radiographic calcifications. US showed acceptable agreement with clinical and radiographic assessments for detecting elbow inflammatory and structural abnormalities in patients with IJD. Because US detected more abnormalities than radiography and has the capability to detect more subclinical abnormalities, US may be potentially used as a first-line elbow diagnostic tool in this clinical setting.