Imaging of Osteoarthritis

Radiographic Findings of Inflammatory Arthritis and Mimics in the Hands

Clinical presentation could be challenging in patients with arthralgia, and imaging plays an important role in the evaluation of these patients to make the diagnosis or narrow the differential diagnosis. Radiography of the hands is a commonly available imaging modality that can provide crucial information with regard to the pattern and pathology of the involved joints. It is important that radiologists and rheumatologists are familiar with the imaging findings of different rheumatic diseases to make the diagnosis in the early stages of disease to initiate treatment.

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.

Construct validity of a clinically correlated knee osteoarthritis ultrasonographic scale: a cross-sectional observational study

OBJECTIVES

To assess the validity of a novel ultrasonographic scale for knee osteoarthritis (KOA) and its relation with the degree of pain and clinical features.

DESIGN

A cross-sectional observational study including 245 patients with knee pain who fulfilled the American College of Rheumatology criteria for KOA. All patients were subjected to clinical assessment Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC) scale, global visual analogue scale (VAS) and functional assessment through the use of Health Assessment Questionnaire-II (HAQ-II). Ultrasonographic assessment was conducted following ZAGAZIG scale comprising five domains: one for degenerative features (one-third of total score) and the other four for inflammatory features (two-thirds of score).

RESULTS

There were positive correlations between ZAGAZIG score and all WOMAC subscales (pain, stiffness and function) (r=0.71, p=0.00; r=0.62, p=0.00; r=0.70, p=0.00, respectively).Moreover, there was a strong positive correlation between ZAGAZIG scale and both VAS and HAQ-II (r=0.82, p=0.00 and r=0.67, p=0.00). At cut-off point of >5, total US score distinguishes between patients with KOA with no or mild pain and those with moderate pain (87.2 sensitivity and 87.2 specificity). At cut-off point of 7, total score of ZAGAZIG scale distinguishes between patients with KOA with moderate pain and those with severe pain (94.5 sensitivity and 42.5 specificity).

CONCLUSION

ZAGAZIG scale constitutes a validated tool for KOA assessment. ZAGAZIG scale correlated with WOMAC subscales (pain, stiffness and function), VAS and HAQ.

Postsurgical status of articular cartilage after arthroscopic posterior cruciate ligament reconstruction in patients with or without concomitant meniscal pathology

PURPOSE

Several factors present at the time of posterior cruciate ligament reconstruction (PCLR) may cause the subsequent progression of articular cartilage lesions. This study aimed to evaluate postsurgical articular cartilage lesions which can be seen on MRI in patients who underwent arthroscopic PCLR with or without concomitant meniscal pathology.

MATERIAL AND METHODS

A total of sixty-five patients (mean age 35.8 ± 12.3 years) who underwent arthroscopic PCLR were included in this retrospective study. Patients were divided into two groups: ten patients with concomitant meniscal injuries at the time of PCLR who underwent meniscal surgery and fifty-five patients with intact menisci. The cartilage status of all knees was evaluated by MRI and modified Noyes classification.

RESULTS

Cartilage lesions were observed in 18 patients (27.7%) on the last follow-up MRI. The cartilage lesions were more common in the medial (15.4%) and patellofemoral (12.3%) compartments than in the lateral compartment (7.7%). Progression of cartilage lesions was present in 11 patients (16.9%) during follow-up MRI. The majority of cartilage lesions with progression were located in the medial compartment. The meniscal pathology group showed a higher prevalence of articular cartilage lesions on the last follow-up MRI (21.8% versus 60%, p = 0.022). In multivariate Cox regression, concomitant meniscal pathology was significantly associated with progression of articular cartilage lesions (p = 0.044).

CONCLUSION

PCLR patients with associated meniscal pathology showed worse cartilage condition and more progression of cartilage lesions than isolated PCLR patients. Attention to this risk factor might provide more applicable treatment options for potential osteoarthritis prevention strategies.

Trabecular bone texture analysis of conventional radiographs in the assessment of knee osteoarthritis: review and viewpoint

BACKGROUND

Trabecular bone texture analysis (TBTA) has been identified as an imaging biomarker that provides information on trabecular bone changes due to knee osteoarthritis (KOA). Consequently, it is important to conduct a comprehensive review that would permit a better understanding of this unfamiliar image analysis technique in the area of KOA research. We examined how TBTA, conducted on knee radiographs, is associated to (i) KOA incidence and progression, (ii) total knee arthroplasty, and (iii) KOA treatment responses. The primary aims of this study are twofold: to provide (i) a narrative review of the studies conducted on radiographic KOA using TBTA, and (ii) a viewpoint on future research priorities.

METHOD

Literature searches were performed in the PubMed electronic database. Studies published between June 1991 and March 2020 and related to traditional and fractal image analysis of trabecular bone texture (TBT) on knee radiographs were identified.

RESULTS

The search resulted in 219 papers. After title and abstract scanning, 39 studies were found eligible and then classified in accordance to six criteria: cross-sectional evaluation of osteoarthritis and non-osteoarthritis knees, understanding of bone microarchitecture, prediction of KOA progression, KOA incidence, and total knee arthroplasty and association with treatment response. Numerous studies have reported the relevance of TBTA as a potential bioimaging marker in the prediction of KOA incidence and progression. However, only a few studies have focused on the association of TBTA with both OA treatment responses and the prediction of knee joint replacement.

CONCLUSION

Clear evidence of biological plausibility for TBTA in KOA is already established. The review confirms the consistent association between TBT and important KOA endpoints such as KOA radiographic incidence and progression. TBTA could provide markers for enrichment of clinical trials enhancing the screening of KOA progressors. Major advances were made towards a fully automated assessment of KOA.

Opioid users show worse baseline knee osteoarthritis and faster progression of degenerative changes: a retrospective case-control study based on data from the Osteoarthritis Initiative (OAI)

BACKGROUND

Opioids are frequently prescribed for pain control in knee osteoarthritis patients, despite recommendations by current guidelines. Previous studies have investigated the chondrotoxicity of different opioid subtypes. However, the impact opioids may have on progression of osteoarthritis in vivo remains unknown. The aim of this study was thus to describe the associations between opioid use and knee structural changes and clinical outcomes, over 4 years.

METHODS

Participants with baseline opioid use (n=181) and who continued use for ≥1 year between baseline and 4-year follow-up (n=79) were included from the Osteoarthritis Initiative cohort and frequency matched with non-users (controls) (1:2). Whole-Organ Magnetic Resonance Imaging Scores (WORMS) were obtained, including a total summation score (WORMS total, range 0-96) and subscores for cartilage (0-36), menisci (0-24), and bone marrow abnormalities and subchondral cyst-like lesions (0-18, respectively). Knee Injury Osteoarthritis Outcomes score (KOOS) symptoms, quality of life (QOL), and pain were also obtained at baseline and follow-up (range 0-100; lower scores indicate worse outcomes). Using linear regression models, associations between baseline and longitudinal findings were investigated. As pain may modify observations, a sensitivity analysis was performed for longitudinal findings. All analyses were adjusted for sex, BMI, age, race, and Kellgren-Lawrence grade.

RESULTS

Opioid users had greater structural degeneration at baseline (WORMS total: Coef. [95% CI], P; 7.1 [5.5, 8.8], <0.001) and a greater increase over 4 years (4.7 [2.9, 6.5], <0.001), compared to controls. Cartilage and meniscus scores increased greater in opioid users, compared to controls (P≤0.001), and findings withstood the adjustment for baseline pain (P≤0.002). All baseline KOOS scores were lower in opioid users compared to controls (P<0.001). QOL loss was greater, when adjusted for baseline KOOS pain (QOL -6.9 [-11.6, -2.1], 0.005).

CONCLUSIONS

Opioid users had worse baseline knee structural degeneration and faster progression. Opioid use was also associated with worse symptoms, pain, and QOL. Furthermore, QOL loss was greater in opioid users compared to controls, when adjusted for baseline KOOS pain, indicating that opioids may not be suited to prevent subjective disease progression in KOA patients.

Ultrasonographic Evaluation of Osteoarthritis-affected Knee Joints: Comparison with Kellgren-Lawrence Grading and Pain Scores

Background:

The objective was to compare ultrasonographic findings with clinical and radiographic findings in osteoarthritis (OA)-affected knee joints.

Methods:

This prospective study was conducted in Subharti Medical College, Meerut, after getting clearance from the ethical committee. Eighty-five symptomatic knees fulfilling American College of Rheumatology criteria for OA were included in the study. Patients with trauma, inflammatory, and infective conditions of the knee and with a history of intra-articular interventions and surgery were excluded. Demographic data, body mass index (BMI), visual analog scale (VAS), and Western Ontario and McMaster Universities Arthritis (WOMAC) questionnaire score were obtained. Kellgren–Lawrence (K-L) score was obtained on radiography. Ultrasonographic findings which were recorded include effusion, meniscal extrusion, femorotrochlear cartilage grading, maximum length of osteophytes at medial and lateral compartments, and presence or absence of Baker cyst.

Results:

A total of 85 consecutive symptomatic knees were examined. The male: female ratio was 22:63, with a mean age of 54.52 ± 9.44 years, mean duration of disease of 24.24 ± 19.14 months, mean BMI of 28.91 ± 3.69 kg/m², and mean score of VAS and WOMAC pain scale of 6.27 ± 1.45 and 62.45 ± 10.96, respectively. K-L grading of 1, 2, 3, and 4 was reported in 12.9%, 21.2%, 25.9%, and 40% of the knees, respectively. The mean VAS score and WOMAC score showed statistically significant correlation with KL grading (P < 0.05). Knees with the presence of osteophytes, medial meniscal extrusion, effusion, and medial femoral trochlear cartilage grading showed statistically significant correlation with VAS and WOMAC scores (P < 0.05). However, the correlation was not significant for lateral meniscus extrusion and lateral femoral trochlear cartilage grading.

Conclusion:

Our study found that K-L grading and few ultrasonographic criteria showed a significant positive correlation with pain scores, while few other ultrasonographic criteria did not. Both imaging modalities are complementary to each other, rather than one being superior to the other.

Imaging of knee osteoarthritis: A review of current evidence and clinical guidelines

BACKGROUND

Knee osteoarthritis (OA) is one of the most common and debilitating degenerative joint diseases worldwide. While radiography is the most commonly used imaging modality, it is associated with drawbacks which newer modalities such as magnetic resonance imaging (MRI) and ultrasound could overcome. Nevertheless, the role of imaging in clinical practice and research in knee OA has not been clearly defined. Furthermore, guidelines on imaging in knee OA from different authoritative bodies have not been compared in previous studies. Therefore, the present review aims to summarise existing evidence and compare guidelines on the use of different imaging modalities in evaluating knee OA.

METHODS

This is a narrative review based on a search of published clinical guidelines and the PubMed database for articles published between 1 January 1990 and 31 May 2020.

RESULTS

There is no broad consensus on the value of imaging in patients with typical OA presentation. If imaging is required, current evidence and clinical guidelines support the use of radiography and MRI as first- and second-line diagnostic modalities respectively. Since radiographic OA features have limited sensitivity and do not manifest in early stages, MRI is the preferred option for whole-joint evaluation in OA research. Discrepancies exist regarding the use of alternative imaging modalities including ultrasound, computed tomography and nuclear medicine.

CONCLUSION

Radiography and MRI are the imaging modalities of choice. Other modalities have their respective advantages, and more research is warranted for the standardisation of image acquisition and interpretation methodology, in order to evaluate their validity, reliability and responsiveness in OA research.

AFM-Based Method for Measurement of Normal and Osteoarthritic Human Articular Cartilage Surface Roughness

In osteoarthrosis, pathological features of articular cartilage are associated with degeneration and nanomechanical changes. The aim of this paper is to show that indentation-atomic force microscopy can monitor wear-related biomechanical changes in the hip joint of patients with osteoarthritis. Fifty patients (N = 50), aged 40 to 65, were included in the study. The mechanical properties and the submicron surface morphology of hyaline cartilage were investigated using atomic force microscopy. Measurements of the roughness parameters of cartilage surfaces were performed, including the arithmetic average of absolute values (Ra), the maximum peak height (Rp), and the mean spacing between local peaks (S). The arithmetic mean of the absolute values of the height of healthy cartilage was 86 nm, while wear began at Ra = 73 nm. The maximum changes of values of the roughness parameters differed from the healthy ones by 71%, 80%, and 51% for Ra, Rp, and S, respectively. Young's modulus for healthy cartilage surfaces ranged from 1.7 to 0.5 MPa. For the three stages of cartilage wear, Young's modulus increased, and then it approached the maximum value and decreased. AFM seems to be a powerful tool for surface analysis of biological samples as it enables indentation measurements in addition to imaging.

Inflammation and Hypervascularization in a Large Animal Model of Knee Osteoarthritis: Imaging with Pathohistologic Correlation

PURPOSE

To evaluate if synovial inflammation and hypervascularization are present in a dog model of knee osteoarthritis and can be detected on conventional magnetic resonance imaging (MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), contrast-enhanced magnetic resonance imaging (CE-MRI), and quantitative digital subtraction angiography (Q-DSA) imaging.

MATERIALS AND METHODS

Six dogs underwent MRI and angiography of both knees before and 12 weeks after right knee anterior cruciate ligament injury. Synovial vascularity was evaluated on CE-MRI, DCE-MRI, and Q-DSA by 2 independent observers. Synovial inflammation and vascularity were histologically scored independently. Cartilage lesions and osteophytes were analyzed macroscopically, and cartilage volumetry was analyzed by MRI. Vascularity and osteoarthritis markers on imaging were compared before and after osteoarthritis generation, and between the osteoarthritis model and the control knee, using linear mixed models accounting for within-dog correlation.

RESULTS

In all knees, baseline imaging showed no abnormalities. Control knees did not develop significant osteoarthritis changes, synovial inflammation, or hypervascularization. In osteoarthritis knees, mean synovial enhancement score on CE-MR imaging increased by 13.1 ± 0.59 (P < .0001); mean synovial inflammation variable increased from 47.33 ± 18.61 to 407.97 ± 18.61 on DCE-MR imaging (P < .0001); and area under the curve on Q-DSA increased by 1058.58 ± 199.08 (P = .0043). Synovial inflammation, hypervascularization, and osteophyte formations were present in all osteoarthritis knees. Histology scores showed strong correlation with CE-MR imaging findings (Spearman correlation coefficient [SCC] = 0.742; P = .0002) and Q-DSA findings (SCC = 0.763; P < .0001) and weak correlation with DCE-MR imaging (SCC = -0.345; P = .329). Moderate correlation was found between CE-MR imaging and DSA findings (SCC = 0.536; P = .0004).

CONCLUSIONS

In this early-stage knee osteoarthritis dog model, synovial inflammation and hypervascularization were found on imaging and confirmed by histology.

Performance of distinct knee osteoarthritis classification criteria in the ELSA-Brasil musculoskeletal study

OBJECTIVE

To compare the performance of different knee osteoarthritis (OA) classification criteria in a subsample of subjects of ELSA-Brasil Musculoskeletal cohort (ELSA-Brasil MSK) in comparison with the clinical-radiographic evaluation of an experienced rheumatologist.

METHOD

A cross-sectional study of the diagnostic accuracy of different knee OA classification criteria: radiographic OA, symptomatic OA, clinical and clinical-radiographic criteria of the American College of Rheumatology (ACR), and the definition proposed by the National Institute for Health and Care Excellence (NICE), UK. The study also evaluated some alternative definitions of OA including a combination of criteria. In total, 250 subjects participated. Only one knee per subject was included. When both or none of the knees were affected, one knee was randomly selected for analysis. OA prevalence, sensitivity, specificity, positive and negative predictive values, and accuracy were presented (CI 95%; α = 5%).

RESULTS

The mean age was 56.1 years (SD = 8.7), 48.8% female, and 39.2% presented knee OA according to the rheumatologist. The sensitivity and the specificity of radiographic OA were 51% and 96.7%, respectively, while the NICE definition showed 57.0% and 76.3%, respectively. The other OA criteria showed good levels of specificity, but the levels of sensitivity were below 30%. Considering NICE and/or X-ray result in combination, the sensitivity increased (73.4%), while the specificity reduced slightly (73.0%) in relation to the original NICE definition.

CONCLUSIONS

Radiographic OA showed the best performance, followed by NICE definition, especially in combination with X-ray results.

Quantitative measurement of cartilage volume is possible using two-dimensional magnetic resonance imaging data sets

PURPOSE

3D Magnetic resonance imaging (MRI) scans are generally used for quantitative cartilage measurements in knee osteoarthritis. However, a great deal of MRI data is from 2D scans, often thought to be unsuitable for quantitative cartilage assessment. The goal of our study was to demonstrate that mLACS, a modified version of the Local Area Cartilage Segmentation (LACS) method, could be used to measure cartilage volume on 2D MRI images.

METHODS

We studied 301 randomly selected subjects from the OA Biomarkers Consortium FNIH Study, a nested case-control study within the Osteoarthritis Initiative (OAI). The study comprised four subgroups based on radiographic and pain progression. We compared mLACS applied to 2D TSE scans to LACS on 3D DESS data. The Pearson's correlation coefficient was used to establish agreement between LACS and mLACS, standardized response means (SRMs) for responsiveness, and intra-class correlation coefficients (ICCs) to measure reader precision. Logistic regression in a case/control analysis was used to compare the clinical validity between the two methods.

RESULTS

We found R² = 0.76 for the correlation between LACS and mLACs. For LACS, the responsiveness was SRM = 0.49 compared to 0.39 for mLACS. The odds ratios (OR) for the primary case/control analyses were 1.62 for LACS and 1.78 for mLACS. The intra and inter reader reproducibility values for mLACS were ICC = 0.90 and 0.86, respectively.

CONCLUSION

This study has demonstrated that a reproducible, responsive, and clinically valid quantitative measurement of cartilage volume can be made using 2D TSE scans with a modest loss of responsiveness compared to 3D scans.

Comparative study of CTX-II, Zn2+, and Ca2+ from the urine for knee osteoarthritis patients and healthy individuals

The aim of the study was to explore the relationship between the concentration of C-telopeptide fragments of type II collagen (CTX-II), Zn, and Ca in urine and knee osteoarthritis (KOA).Eighty-two patients with KOA and 20 healthy volunteers were enrolled. Anteroposterior and lateral position x-rays of knee joints were collected. The images were classified according to Kellgren-Lawrence radiographic grading criterion. The patients were divided into group grade I, group grade II, group grade III, and grade IV. The concentration of CTX-II in the urine was detected by enzyme-linked immunosorbent assay. The concentration of Zn and Ca in urine was detected by inductively coupled plasma atomic emission spectrometry.Compared with the healthy individuals, the concentration of CTX-II was significantly higher in KOA patients. The concentration of CTX-II in KOA patients from high to low was as follows: group IV, group III, group II, and group I. There was no significant difference between group I and healthy individuals. The concentration of Zn and Ca in urine of KOA patients was higher than that in healthy individuals. There was no difference in each KOA group.The concentration of CTX-II is instrumental to diagnose the progress of KOA. The concentration of Zn and Ca in urine is helpful for early diagnosis of KOA.

Integration of accelerated MRI and post-processing software: a promising method for studies of knee osteoarthritis

OBJECTIVE

Magnetic resonance imaging (MRI) is a widely used imaging modality for studies of knee osteoarthritis (OA). Compared to radiography, MRI offers exceptional soft tissue imaging and true three-dimensional (3D) visualization. However, MRI is expensive both due to the cost of acquisition and evaluation of the images. The goal of our study is to develop a new method to address the cost of MRI by combining innovative acquisition methods and automated post-processing software.

METHODS

Ten healthy volunteers were scanned with three different MRI protocols: A standard 3D dual-echo steady state (DESS) pulse sequence, an accelerated DESS (DESS_Acc), acquired at approximately half the time compared to DESS, and a multi-echo time DESS (DESS_MTE), which is capable of producing measurements of T2 relaxation time. A software tool was used to measure cartilage volume. Accuracy was quantified by comparing DESS to DESS_Acc and DESS_MTE and precision was measured using repeat readings and acquisitions. T2 precision was determined using duplicate DESS_MTE acquisitions. Intra-class correlation coefficients (ICCs), root-mean square standard deviation (RMSSD), and the coefficient of variation (CoV) were used to quantify accuracy and precision.

RESULTS

The accuracies of DESS_Acc and DESS_MTE were CoV = 3.7% and CoV = 6.6% respectively, while precision was 3.8%, 3.0%, and 3.1% for DESS, DESS_Acc and DESS_MTE. T2 repositioning precision was 5.8%.

CONCLUSION

The results demonstrate that accurate and precise quantification of cartilage volume is possible using a combination of substantially faster MRI acquisition and post-processing software. Precise measurements of cartilage T2 and volume can be made using the same acquisition.

Degenerative Changes in the Knee 2 Years After Anterior Cruciate Ligament Rupture and Related Risk Factors: A Prospective Observational Follow-up Study

BACKGROUND

Anterior cruciate ligament (ACL) rupture is a well-known risk factor for development of knee osteoarthritis. Early identification of those patients at risk and early identification of the process of ACL rupture leading to osteoarthritis may aid in preventing the onset or progression of osteoarthritis.

PURPOSE

To identify early degenerative changes as assessed on magnetic resonance imaging (MRI) after 2-year follow-up in patients with a recent ACL rupture and to evaluate which determinants are related to these changes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Included in this study were 154 adults aged between 18 and 45 years with acute ACL rupture diagnosed by physical examination and MRI, without previous knee trauma or surgery, and without osteoarthritic changes on radiographs. A total of 143 patients completed the 2-year follow-up, and the results in this study apply to these 143 patients. All patients were treated according to the Dutch guideline on ACL injury. Of the 143 patients, 50 patients were treated nonoperatively during the 2-year follow-up period. Main outcome was early degenerative changes assessed on MRI defined as progression of cartilage defects and osteophytes in tibiofemoral and patellofemoral compartments. Patient characteristics, activity level, functional instability, treatment type, and trauma-related variables were evaluated as determinants.

RESULTS

The median time between MRI at baseline and MRI at 2-year follow-up was 25.9 months (interquartile range, 24.7-26.9 months). Progression of cartilage defects in the medial and lateral tibiofemoral compartments was present in 12% and 27% of patients, and progression of osteophytes in tibiofemoral and patellofemoral compartments was present in 10% and 8% of patients, respectively. The following determinants were positively significantly associated with early degenerative changes: male sex (odds ratio [OR], 4.43; 95% CI, 1.43-13.66; P = .010), cartilage defect in the medial tibiofemoral compartment at baseline (OR, 3.66; 95% CI, 1.04-12.95; P = .044), presence of bone marrow lesions in the medial tibiofemoral compartment 1 year after trauma (OR, 5.19; 95% CI, 1.56-17.25; P = .007), joint effusion 1 year after trauma (OR, 4.19; 95% CI, 1.05-16.72; P = .042), and presence of meniscal tears (OR, 6.37; 95% CI, 1.94-20.88; P = .002). When the patients were categorized into 3 treatment groups (nonoperative, reconstruction <6 months after ACL rupture, and reconstruction ≥6 months after ACL rupture), there was no significant relationship between the treatment options and the development of early degenerative changes.

CONCLUSION

Two years after ACL rupture, early degenerative changes were assessed on MRI. Concomitant medial cartilage defect and meniscal injury, male sex, persistent bone marrow lesions in the medial tibiofemoral compartment, and joint effusion are risk factors for degenerative changes.

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.

(99m)Tc-MDP bone scintigraphy of the hand: comparing the use of novel cadmium zinc telluride (CZT) and routine NaI(Tl) detectors

Background

Cadmium zinc telluride (CZT) solid-state detectors have been recently introduced in the field of nuclear medicine in cardiology and breast imaging. The aim of the current study was to evaluate the performance of the novel detectors (CZT) compared to that of the routine NaI(Tl) in bone scintigraphy. A dual-headed CZT-based camera dedicated originally to breast imaging has been used, and in view of the limited size of the detectors, the hands were chosen as the organ for assessment. This is a clinical study.

Methods

Fifty-eight consecutive patients (total 116 hands) referred for bone scan for suspected hand pathology gave their informed consent to have two acquisitions, using the routine camera and the CZT-based camera. The latter was divided into full-dose full-acquisition time (FD CZT) and reduced-dose short-acquisition time (RD CZT) on CZT technology, so three image sets were available for analysis. Data analysis included comparing the detection of hot lesions and identification of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints.

Results

A total of 69 hot lesions were detected on the CZT image sets; of these, 61 were identified as focal sites of uptake on NaI(Tl) data. On FD CZT data, 385 joints were identified compared to 168 on NaI(Tl) data (p < 0.001). There was no statistically significant difference in delineation of joints between FD and RD CZT data as the latter identified 383 joints.

Conclusions

Bone scintigraphy using a CZT-based gamma camera is associated with improved lesion detection and anatomic definition. The superior physical characteristics of this technique raised a potential reduction in administered dose and/or acquisition time without compromising image quality.

OARSI Clinical Trials Recommendations: Knee imaging in clinical trials in osteoarthritis

Significant advances have occurred in our understanding of the pathogenesis of knee osteoarthritis (OA) and some recent trials have demonstrated the potential for modification of the disease course. The purpose of this expert opinion, consensus driven exercise is to provide detail on how one might use and apply knee imaging in knee OA trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, sequences artifacts); quality assurance (QA)/control procedures; measurement methods; measurement performance (reliability, responsiveness, validity); recommendations for trials; and research recommendations.

Morphological MR imaging of the articular cartilage of the knee at 3 T-comparison of standard and novel 3D sequences

Objectives

This study sought to compare various 3D cartilage sequences and to evaluate the usefulness of ultrashort TE (UTE) imaging, a new technique to isolate signal from the osteochondral junction.

Methods

Twenty knees were examined at 3 T with 3D spoiled GRE (FLASH), double-echo steady-state (DESS), balanced SSFP, 3D turbo spin-echo (TSE), and a prototype UTE sequence. Two radiologists independently evaluated all images. Consensus readings of all sequences were the reference standard. Statistical analysis included Friedman and pairwise Wilcoxon tests. Retrospective analysis of UTE morphology of osteochondral tissue in normal and abnormal cartilage seen at conventional MR was also performed.

Results

Three-dimensional TSE was superior to other sequences for detecting cartilage lesions. FLASH and DESS performed best in the subjective quality analysis. On UTE images, normal cartilage exhibited a high-intensity linear signal near the osteochondral junction. Retrospective analysis revealed abnormal UTE morphology of the osteochondral junction in 50 % of cartilage lesions diagnosed at conventional MR.

Conclusions

Cartilage imaging of the knee at 3 T can be reliably performed using 3D TSE, showing high accuracy when compared to standard sequences. Although UTE depicts signal from the deep cartilage layer, further studies are needed to establish its role for assessment of cartilage.

Main Messages

• MRI is the best available imaging method for assessment of knee cartilage.

• Cartilage imaging can be reliably performed using 3D TSE.

• UTE cannot be used as a single sequence to assess cartilage.

Meniscus treatment and age associated with narrower radiographic joint space width 2-3 years after ACL reconstruction: data from the MOON onsite cohort

OBJECTIVE

To identify risk factors for radiographic signs of post-traumatic osteoarthritis (OA) 2-3 years after anterior cruciate ligament (ACL) reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort.

METHODS

A nested cohort within the Multicenter Orthopaedic Outcomes Network (MOON) cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors.

RESULTS

Unexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96-5.15 mm) vs 4.71 mm (95% CI 4.62-4.80 mm), P < 0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38-0.90 mm) (P < 0.001). Age (P < 0.001) and meniscus repair (P = 0.001) were also significantly associated with mJSW difference.

CONCLUSION

Semi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2-3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study.

Imaging of non-osteochondral tissues in osteoarthritis

OBJECTIVE

The aim of this review is to describe imaging techniques for evaluation of non-osteochondral structures such as the synovium, menisci in the knee, labrum in the hip, ligaments and muscles and to review the literature from recent clinical and epidemiological studies of OA.

METHODS

This is a non-systematic narrative review of published literature on imaging of non-osteochondral tissues in OA. PubMed and MEDLINE search for articles published up to 2014, using the keywords osteoarthritis, synovitis, meniscus, labrum, ligaments, plica, muscles, magnetic resonance imaging (MRI), ultrasound, computed tomography (CT), scintigraphy, and positron emission tomography (PET).

RESULTS

Published literature showed imaging of non-osteochondral tissues in OA relies primarily on MRI and ultrasound. The use of semiquantitative and quantitative imaging biomarkers of non-osteochondral tissues in clinical and epidemiological OA studies is reported. We highlight studies that have compared both imaging methodologies directly, and those that have established a relationship between imaging biomarkers and clinical outcomes. We provide recommendations as to which imaging protocols should be used to assess disease-specific changes regarding synovium, meniscus in the knee, labrum in the hip, and ligaments, and highlight potential pitfalls in their usage.

CONCLUSION

MRI and ultrasound are currently the most useful imaging modalities for evaluation of non-osteochondral tissues in OA. MRI evaluation of any tissue needs to be performed using appropriate MR pulse sequences. Ultrasound may be particularly useful for evaluation of small joints of the hand. Nuclear medicine and CT play a limited role in imaging of non-osteochondral tissues in OA.

2D and 3D MOCART scoring systems assessed by 9.4 T high-field MRI correlate with elementary and complex histological scoring systems in a translational model of osteochondral repair

OBJECTIVE

To compare the 2D and 3D MOCART system obtained with 9.4 T high-field magnetic resonance imaging (MRI) for the ex vivo analysis of osteochondral repair in a translational model and to correlate the data with semiquantitative histological analysis.

METHODS

Osteochondral samples representing all levels of repair (sheep medial femoral condyles; n = 38) were scanned in a 9.4 T high-field MRI. The 2D and adapted 3D MOCART systems were used for grading after point allocation to each category. Each score was correlated with corresponding reconstructions between both MOCART systems. Data were next correlated with corresponding categories of an elementary (Wakitani) and a complex (Sellers) histological scoring system as gold standards.

RESULTS

Correlations between most 2D and 3D MOCART score categories were high, while mean total point values of 3D MOCART scores tended to be 15.8-16.1 points higher compared to the 2D MOCART scores based on a Bland-Altman analysis. "Defect fill" and "total points" of both MOCART scores correlated with corresponding categories of Wakitani and Sellers scores (all P ≤ 0.05). "Subchondral bone plate" also correlated between 3D MOCART and Sellers scores (P < 0.001).

CONCLUSIONS

Most categories of the 2D and 3D MOCART systems correlate, while total scores were generally higher using the 3D MOCART system. Structural categories "total points" and "defect fill" can reliably be assessed by 9.4 T MRI evaluation using either system, "subchondral bone plate" using the 3D MOCART score. High-field MRI is valuable to objectively evaluate osteochondral repair in translational settings.

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

PURPOSE

The aim of this study was to prospectively determine the feasibility and compare the novel use of a positron emission mammography (PEM) scanner with standard PET/CT for evaluating hand osteoarthritis (OA) with (18)F-FDG.

METHODS

Institutional review board approval and written informed consent were obtained for this HIPAA-compliant prospective study in which 14 adults referred for oncological (18)F-FDG PET/CT underwent dedicated hand PET/CT followed by arthro-PET using the PEM device. Hand radiographs were obtained and scored for the presence and severity of OA. Summed qualitative and quantitative joint glycolytic scores for each modality were compared with the findings on plain radiography and clinical features.

RESULTS

Eight patients with clinical and/or radiographic evidence of OA comprised the OA group (mean age 73 ± 7.7 years). Six patients served as the control group (53.7 ± 9.3 years). Arthro-PET quantitative and qualitative joint glycolytic scores were highly correlated with PET/CT findings in the OA patients (r = 0.86. p = 0.007; r = 0.94, p = 0.001). Qualitative arthro-PET and PET/CT joint scores were significantly higher in the OA patients than in controls (38.7 ± 6.6 vs. 32.2 ± 0.4, p = 0.02; 37.5 ± 5.4 vs. 32.2 ± 0.4, p = 0.03, respectively). Quantitative arthro-PET and PET/CT maximum SUV-lean joint scores were higher in the OA patients, although they did not reach statistical significance (20.8 ± 4.2 vs. 18 ± 1.8, p = 0.13; 22.8 ± 5.38 vs. 20.1 ± 1.54, p = 0.21). By definition, OA patients had higher radiographic joint scores than controls (30.9 ± 31.3 vs. 0, p = 0.03).

CONCLUSION

Hand imaging using a small field of view PEM system (arthro-PET) with FDG is feasible, performing comparably to PET/CT in assessing metabolic joint activity. Arthro-PET and PET/CT showed higher joint FDG uptake in OA. Further exploration of arthro-PET in arthritis management is warranted.

Long-term T2 and Qualitative MRI Morphology After First-Generation Knee Autologous Chondrocyte Implantation: Cartilage Ultrastructure Is Not Correlated to Clinical or Qualitative MRI Outcome

BACKGROUND

There are several reports on long-term clinical outcomes after autologous chondrocyte implantation (ACI) for knee cartilage defect treatment. Few published articles have evaluated defect quality using quantitative magnetic resonance (MR) imaging techniques.

PURPOSE

To evaluate clinical outcomes and the quality of repair tissue (RT) after first-generation periosteum-covered ACI (ACI-P) using qualitative MR outcomes and T2-weighted relaxation times.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients (n = 86) who underwent knee joint ACI-P (from 1997 through 2001) with a postoperative follow-up of at least 10 years were invited for clinical and MR evaluation. Clinical outcomes analysis included pre- and postoperative Lysholm and numeric analog scale (NAS) for pain (10 = worst, 0 = best). Radiographic analysis included postoperative T2-weighted mapping of the RT, RT-associated regions, and healthy control cartilage; MOCART (magnetic resonance observation of cartilage repair tissue) score; a modified Knee Osteoarthritis Scoring System (mKOSS; 0 = best, 15 = worst) score; as well as numeric grading for subjective RT and whole knee joint evaluation (1 = best, 6 = worst).

RESULTS

A total of 70 patients (45 male, 25 female; mean age, 33.3 ± 10.2 years; 81% follow-up rate) with 82 defects were available for follow-up at an average 10.9 ± 1.1 years postoperatively, with MR analysis for 59 patients with 71 transplant sites (average defect size, 6.5 ± 4.0 cm(2)). Final Lysholm (71.0 ± 17.4) and NAS (7.2 ± 1.9) scores improved significantly when compared with preoperative scores (Lysholm: 42.0 ± 22.5; NAS: 2.1 ± 2.1; P < .01 for both). Average transplant T2 was 35.2 ± 11.3 ms and thereby significantly lower (P = .005) when compared to the intraknee healthy femur T2 (39.7 ± 6.8 ms). The MOCART was 44.9 ± 23.6 and mKOSS was 4.8 ± 3.2. RT subjective grading was 3.3 ± 1.4, while it was 2.3 ± 0.7 for whole joint evaluation. The RT T2 significantly correlated with postoperative NAS (P = .04; r = -0.28); it also correlated with the healthy femur T2 (P = .004; r = 0.4). The MOCART significantly correlated with the mKOSS (P < .001).

CONCLUSION

The MRI outcome is imperfect in this collective of patients. There is only weak correlation of quantitative imaging data and clinical function. Qualitative imaging data are much better correlated to functional outcomes.

Comparison of 1.5- and 3-T MR imaging for evaluating the articular cartilage of the knee

PURPOSE

The aim of this prospective study was to compare routine MRI scans of the knee at 1.5 and 3 T obtained in the same individuals in terms of their performance in the diagnosis of cartilage lesions.

METHODS

One hundred patients underwent MRI of the knee at 1.5 and 3 T and subsequent knee arthroscopy. All MR examinations consisted of multiplanar 2D turbo spin-echo sequences. Three radiologists independently graded all articular surfaces of the knee joint seen at MRI. With arthroscopy as the reference standard, the sensitivity, specificity, and accuracy of 1.5- and 3-T MRI for detecting cartilage lesions and the proportion of correctly graded cartilage lesions within the knee joint were determined and compared using resampling statistics.

RESULTS

For all readers and surfaces combined, the respective sensitivity, specificity, and accuracy for detecting all grades of cartilage lesions in the knee joint using MRI were 60, 96, and 87% at 1.5 T and 69, 96, and 90% at 3 T. There was a statistically significant improvement in sensitivity (p < 0.05), but not specificity or accuracy (n.s.) for the detection of cartilage lesions at 3 T. There was also a statistically significant (p < 0.05) improvement in the proportion of correctly graded cartilage lesions at 3 T as compared to 1.5 T.

CONCLUSION

A 3-T MR protocol significantly improves diagnostic performance for the purpose of detecting cartilage lesions within the knee joint, when compared with a similar protocol performed at 1.5 T.

LEVEL OF EVIDENCE

III.

Pre-radiographic osteoarthritic changes are highly prevalent in the medial patella and medial posterior femur in older persons: Framingham OA study

OBJECTIVE

To determine which subregions of the knee joint have a high prevalence of pre-radiographic osteoarthritic changes, i.e., cartilage damage and osteophytes that can only be detected by magnetic resonance imaging (MRI), in radiographically normal knees.

METHODS

Institutional Review Board approval and written informed consent from all participants was obtained. Data was collected from a community cohort in Framingham, MA, involving people aged 50-79. Participants underwent weight-bearing posteroanterior and lateral knee radiography with the fixed-flexion protocol, and 1.5 T MRI. Knees without radiographic osteoarthritis (Kellgren Lawrence grade 0 for the tibiofemoral joint and absence of any osteophytes or joint space narrowing in the patellofemoral joint) were included. The knee joint was divided into 14 subregions for cartilage and 16 subregions for osteophytes, and prevalence and severity of cartilage damage (grade 0-6) and osteophytes (grade 0-7) were semiquantitatively assessed using the Whole Organ Magnetic Resonance Imaging Score (WORMS).

RESULTS

The mean age of 696 participants was 62.3 ± 8.4 years, and the mean body mass index was 27.9 ± 5.1 kg/m2. Women comprised 55.2% of the study sample (384/696). Prevalence of cartilage damage (grade ≥2) was 47.7% (332/696) in the medial patellar and 29.9% (208/696) in patellar lateral (PL) subregions, and 24.0% (167/696) in femoral medial anterior (FMA) and 26.5% (184/696) in femoral medial central (FMC) subregions. Prevalence of osteophytes (grade ≥2) was highest at 60.8% (423/696) in the medial femoral posterior subregion, followed by 34.0% (237/696) in PL and 24.6% (171/696) in patellar medial (PM) subregions. For all other subregions, prevalence of these lesions was lower than the aforementioned percentages.

CONCLUSION

MRI-detected cartilage damage and osteophytes are highly prevalent in the medial patellofemoral and medial posterior tibiofemoral joints in radiographically normal knees in persons aged 50-79.

Structural correlates of pain in joints with osteoarthritis

OBJECTIVE

To describe the insights on the epidemiology of pain-structure association and the ramifications of these studies for clinical trials.

DESIGN

Narrative review summarizing the pertinent literature in this area, summarizing some of the methodologic challenges inherent and proposing some research initiatives to further understanding of this complex science.

RESULTS

The predominant symptom in most patients presenting with osteoarthritis (OA) is pain. Over recent years a number of imaging based studies have narrowed the discord between structural findings on imaging and symptoms. The interpretation of pain in OA is still enigmatic and difficult to deal with both for clinicians and scientists.

CONCLUSIONS

We would envisage that over the next few years many of the pressing questions pertaining to research into the structure pain relationship will continue to be addressed. With this, we can expect clinically appropriate therapeutic advance.

Hand, hip and knee osteoarthritis in a Norwegian population-based study--the MUST protocol

BACKGROUND

Knowledge about the prevalence and consequences of osteoarthritis (OA) in the Norwegian population is limited. This study has been designed to gain a greater understanding of musculoskeletal pain in the general population with a focus on clinically and radiologically confirmed OA, as well as risk factors, consequences, and management of OA.

METHODS/DESIGN

The Musculoskeletal pain in Ullensaker STudy (MUST) has been designed as an observational study comprising a population-based postal survey and a comprehensive clinical examination of a sub-sample with self-reported OA (MUST OA cohort). All inhabitants in Ullensaker municipality, Norway, aged 40 to 79 years receive the initial population-based postal survey questionnaire with questions about life style, general health, musculoskeletal pain, self-reported OA, comorbidities, health care utilisation, medication use, and functional ability. Participants who self-report OA in their hip, knee and/or hand joints are asked to attend a comprehensive clinical examination at Diakonhjemmet Hospital, Oslo, including a comprehensive medical examination, performance-based functional tests, different imaging modalities, cardiovascular assessment, blood and urine samples, and a number of patient-reported questionnaires including five OA disease specific instruments. Data will be merged with six national data registries. A subsample of those who receive the questionnaire has previously participated in postal surveys conducted in 1990, 1994, and 2004 with data on musculoskeletal pain and functional ability in addition to demographic characteristics and a number of health related factors. This subsample constitutes a population based cohort with 20 years follow-up.

DISCUSSION

This protocol describes the design of an observational population-based study that will involve the collection of data from a postal survey on musculoskeletal pain, and a comprehensive clinical examination on those with self-reported hand, hip and/or knee OA. These data, in addition to data from national registries, will provide unique insights into clinically and radiologically confirmed OA with respect to risk factors, consequences, and management.