Andrew J. Grainger

The reliability of a new scoring system for knee osteoarthritis MRI and the validity of bone marrow lesion assessment: BLOKS (Boston–Leeds Osteoarthritis Knee Score)

Aim: MRI provides unparalleled visualisation of all the anatomical structures involved in the osteoarthritis (OA) process. There is a need for reliable methods of quantifying abnormalities of these structures. The aim of this work was to assess the reliability of a novel MRI scoring system for evaluating OA of the knee and explore the validity of the bone marrow lesion (BML) scoring component of this new tool. Methods: After review of the relevant literature, a collaborative group of rheumatologists and radiologists from centres in the UK and USA established preliminary anatomical divisions, items (necessarily broadly inclusive) and scaling for a novel semi-quantitative knee score. A series of iterative reliability exercises were performed to reduce the initial items, and the reliability of the resultant Boston–Leeds Osteoarthritis Knee Score (BLOKS) was examined. A further sample had both the BLOKS and WORMS (Whole Organ MRI Score) bone marrow lesion (BML) score performed to assess the construct validity (relation to knee pain) and longitudinal validity (prediction of cartilage loss) of each scoring method. Results: The BLOKS scoring method assesses nine intra-articular regions and contains eight items, including features of bone marrow lesions, cartilage, osteophytes, synovitis, effusions and ligaments. The scaling for each feature ranges from 0–3. The inter-reader reliability for the final BLOKS items ranged from 0.51 for meniscal extrusion up to 0.79 for meniscal tear. The reliability for other key features was 0.72 for BML grade, 0.72 for cartilage morphology, and 0.62 for synovitis. Maximal BML size on the BLOKS scale had a positive linear relation with visual analogue scale (VAS) pain, however the WORMS scale did not. Baseline BML was associated with cartilage loss on both BLOKS and WORMS scale. This association was stronger for BLOKS than WORMS. Conclusion: We have designed a novel scoring system for MRI OA knee, BLOKS, that demonstrates good reliability. Preliminary inspection of the validity of one of the components of this new tool supports the validity of the BLOKS BML scoring method over an existing instrument. Further iterative development will include validation for use in both clinical trials and epidemiological studies.

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

Objective: To examine the relationship between longitudinal fluctuations in synovitis with change in pain and cartilage in knee osteoarthritis. Methods: Study subjects were patients 45 years of age and older with symptomatic knee osteoarthritis from the Boston Osteoarthritis of the Knee Study. Baseline and follow-up assessments at 15 and 30 months included knee magnetic resonance imaging (MRI), BMI and pain assessment (VAS) over the last week. Synovitis was scored at 3 locations (infrapatellar fat pad, suprapatellar and intercondylar regions) using a semiquantitative scale (0–3) at all 3 time points on MRI. Scores at each site were added to give a summary synovitis score (0–9). Results: We assessed 270 subjects whose mean (SD) age was 66.7 (9.2) years, BMI 31.5 (5.7) kg/m2; 42% were female. There was no correlation of baseline synovitis with baseline pain score (r = 0.09, p = 0.17). The change in summary synovitis score was correlated with the change in pain (r = 0.21, p = 0.0003). An increase of one unit in summary synovitis score resulted in a 3.15-mm increase in VAS pain score (0–100 scale). Effusion change was not associated with pain change. Of the 3 locations for synovitis, changes in the infrapatellar fat pad were most strongly related to pain change. Despite cartilage loss occurring in over 50% of knees, synovitis was not associated with cartilage loss in either tibiofemoral or patellofemoral compartment. Conclusions: Change in synovitis was correlated with change in knee pain, but not loss of cartilage. Treatment of pain in knee osteoarthritis (OA) needs to consider treatment of synovitis.

Can ultrasonography improve on radiographic assessment in osteoarthritis of the hands? A comparison between radiographic and ultrasonographic detected pathology

Objectives: Ultrasonography (US) is used in rheumatology to assess small joints in inflammatory arthritis. Recently there has been some investigation into the utility of US in osteoarthritis (OA), however there has been little comparison of US to other imaging modalities in OA. This study aimed to compare the detection of osteophytosis and joint space narrowing (JSN) by US and conventional radiography (CR) in OA of the hand. Methods: Subjects with OA of the hand underwent US and CR examination of the small joints of both hands to identify osteophytosis and joint space narrowing. Results: 1106 joints of 37 patients were imaged with US and CR. US detected osteophytosis in 448 joints, compared to CR that detected osteophytosis in 228 joints (approximately 30% fewer joints). Where osteophytosis was detected by US but not CR, this was usually proximal to the joint line. Joint space narrowing was detected in 450 joints by US, but only 261 joints by CR. The distribution of US and CR detected osteoarthritis changes in this cohort was consistent with population studies of radiographic hand OA, although metacarpophalangeal (MCP) involvement was higher than might be expected Conclusions: US detected more osteophytosis and joint space narrowing than CR in OA of the hand. Involvement of MCP joints was more common than would be expected from population radiographic studies. The increased detection of OA structural pathology by US may make this a useful tool for hand OA research.

Clinical indications for musculoskeletal ultrasound: A Delphi-based consensus paper of the European society of musculoskeletal radiology

AbstractObjectiveTo develop clinical guidelines for musculoskeletal ultrasound (MSKUS) referral in Europe.MethodsSixteen musculoskeletal radiologists from seven European countries participated in a consensus-based interactive process (Delphi method) using consecutive questionnaires and consensus procedure meetings at several European radiology meetings. The evaluation of musculoskeletal diseases was established by literature reviews, followed by consensus on clinical utility in three consensus meetings. This involved a thorough, transparent, iterative approach which including interview, questionnaire, Delphi and standard setting methodologies. European MSK radiologists with a special interest in MSKUS formed two different expert groups who worked on reaching a consensus in the first two meetings. The third meeting resolved questions that did not achieve a consensus level of 67% using the first two questionnaires.ResultsOn expert consensus, the use of MSKUS is indicated to detect joint synovitis, fluid and septic effusion for potential aspiration, and poorly indicated to detect loose bodies. Recommendations for most appropriate use of musculoskeletal ultrasound are reported in six areas relevant to musculoskeletal ultrasound: hand/wrist, elbow, shoulder, hip, knee and ankle/foot.ConclusionA comprehensive evidence-based, expert consensus-defined educational framework on clinical ultrsound is presented. This should facilitate referrals for this important imaging technique throughout Europe.Key Points• Musculoskeletal ultrasound is indicated for detecting joint synovitis, effusions and fluid collections. • Musculoskeletal ultrasound is poor at detecting loose bodies. • Musculoskeletal ultrasound is relevant for most joints.

Combined high-resolution magnetic resonance imaging and histological examination to explore the role of ligaments and tendons in the phenotypic expression of early hand osteoarthritis.

Background: The pathogenesis of the early stages of hand osteoarthritis is poorly understood, but recent high-resolution magnetic resonance imaging (hrMRI) studies suggest that the joint ligaments have a major role in the phenotypic expression of the disease. Objective: To combine hrMRI and cadaveric histological studies to better understand the mechanisms of damage, and especially the role of joint ligaments and tendons in disease expression. Methods: hrMRI was carried out in the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints in 20 patients with osteoarthritis,with a disease duration ⩽12 months. Histological sections of the DIP and PIP joints were obtained from three dissecting-room specimens for comparative analysis. Results: The collateral ligaments influenced the location of both hrMRI-determined bone oedema and bone erosion in early osteoarthritis. These changes were best understood in relation to the enthesis organ concept, whereby the interaction between ligament fibrocartilages leads to bone disease. Normal ligaments were commonly associated with microdamage at insertions corresponding to ligament thickening noted in early osteoarthritis. The ligaments also influenced the location of node formation in early osteoarthritis. The DIP extensor tendon insertions were associated with the development of a neoarticular surface. Conclusions: Small-joint collateral ligaments and tendons have a central role in the early stages of hand osteoarthritis, and determine the early expression of both the soft tissue and bony changes in disease.

Cadaveric and MRI Study of the Musculotendinous Contributions to the Capsule of the Symphysis Pubis

OBJECTIVE The purpose of this article is to define the relations of the symphysis pubis and capsular tissues to the adductor and rectus abdominis soft-tissue attachments on cadaver dissection and correlate with MRI of the anterior pelvis. SUBJECTS AND METHODS Seventeen cadavers (8 males and 9 females; mean age, 80 years) were dissected bilaterally. Rectus abdominis and adductor muscles were traced to the pubis and further attachments to the pubic symphysis were defined. Ten asymptomatic (mean age, 17; age range, 16.5-29 years) male athletes underwent 1.5-T MRI of the anterior pelvis with two surface microcoils (each 42 mm in diameter). An axial T2-weighted turbo spin-echo (TSE) sequence (TR/TE, 2,609/106; voxel size, 0.4 mm) was obtained. Axial and sagittal 3D T1-weighted fast-field echo (FFE) sequences (25/4.9; voxel size, 0.3 mm) were obtained. Sequences were repeated incorporating fat suppression and i.v. gadolinium. The relation of the symphysis pubis, disk, and capsular tissues to the insertions of the rectus abdominis, adductor muscles, and gracilis were independently evaluated by two experienced radiologists blinded to all clinical details. RESULTS In all 17 cadaver specimens, the adductor longus and rectus abdominis attached to the capsule and disk of the symphysis pubis, whereas the adductor brevis had an attachment to the capsule in seven specimens and the gracilis in one. All adductor tendons attached to the pubis. In all 10 athletes, the adductor longus and rectus abdominis bilaterally contributed to the capsular tissues and disk. This was only the case for the adductor brevis in four athletes. No other tendons involved the capsular tissues. CONCLUSION Cadaver and MRI findings show an intimate relationship between the adductor longus; rectus abdominis; and symphyseal cartilage, disk, and capsular tissues.

Association of plasma n-6 and n-3 polyunsaturated fatty acids with synovitis in the knee: the MOST study.

In osteoarthritis (OA) the synovium is often inflamed and inflammatory cytokines contribute to cartilage damage. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have anti-inflammatory effects whereas omega-6 polyunsaturated fatty acids (n-6 PUFAs) have, on balance, proinflammatory effects. The goal of our study was to assess the association of fasting plasma phospholipid n-6 and n-3 PUFAs with synovitis as measured by synovial thickening on contrast enhanced (CE) knee MRI and cartilage damage among subjects in the Multicenter Osteoarthritis Study (MOST). MOST is a cohort study of individuals who have or are at high risk of knee OA. An unselected subset of participants who volunteered obtained CE 1.5T MRI of one knee. Synovitis was scored in six compartments and a summary score was created. This subset also had fasting plasma, analyzed by gas chromatography for phospholipid fatty acid content, and non-CE MRI, read for cartilage morphology according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) method. The association between synovitis and cartilage morphology and plasma PUFAs was assessed using logistic regression after controlling for the effects of age, sex, and BMI. 472 out of 535 subjects with CE MRI had complete data on synovitis, cartilage morphology and plasma phospholipids. Mean age was 60 years, mean BMI 30, and 50% were women. We found an inverse relation between total n-3 PUFAs and the specific n-3, docosahexaenoic acid with patellofemoral cartilage loss, but not tibiofemoral cartilage loss or synovitis. A positive association was observed between the n-6 PUFA, arachidonic acid, and synovitis. In conclusion, systemic levels of n-3 and n-6 PUFAs which are influenced by diet, may be related to selected structural findings in knees with or at risk of OA. Future studies manipulating the systemic levels of these fatty acids may be warranted to determine the effects on structural damage in knee OA.

Ultrasound assessment of tendons in asymptomatic volunteers: a study of reproducibility.

The purpose was to evaluate the inter-visit, inter-observer and intra-observer variation of quantitative and qualitative tendon examinations in vivo for a cohort of asymptomatic volunteers. Eleven healthy male subjects were recruited. The following tendons were assessed by ultrasonography: Achilles tendon, patellar tendon, triceps tendon, extensor pollicis longus, flexor carpi radialis and supraspinatus. For each tendon a quantitative measurement of tendon size was made at a predefined anatomical location. Two experienced sonologists, blind to one another’s findings, evaluated each of the tendons independently. Each tendon was evaluated on two occasions 1 week apart. No difference was found to be attributed to variation in tendon size between visits. Inter-observer variation was a source of error with intra-subject, inter-visit measurements proving more reproducible. There was some significant variation between observers. This variation was more marked with some tendon measures than others. Inter-observer variation for triceps, flexor carpi radialis and supraspinatus was most marked. Minimum detectable change in tendons varied from 13 to 57% depending on the plane of scanning and the tendon being examined. Good reproducibility of quantitative tendon measurements can be achieved within a study using two observers by following a defined scanning protocol. However, it is recommended that the same observer perform serial assessments. The data allow minimal detectable changes in tendon size to be calculated.

Subacute posteromedial impingement of the ankle in athletes: MR imaging evaluation and ultrasound guided therapy.

ObjectiveTo describe the use of MR imaging and efficacy of ultrasound-guided steroid injection in the diagnosis and management of athletes with clinical posteromedial impingement of the ankle.Design and patientsA retrospective analysis of imaging findings on MR was undertaken in nine elite athletes with clinical posteromedial ankle impingement. MR studies from six professional athletes with posterolateral pain were also reviewed as an imaging control group. The two reviewing radiologists were blinded to the clinical details and the proportion of control and study subjects. The nine study athletes also underwent diagnostic ultrasound and ultrasound-guided injection of steroid and anaesthetic into the posteromedial capsular abnormality. Follow-up was by telephone interview.ResultsPosteromedial capsular thickening was seen only in athletes with posteromedial impingement (7/9). Posteromedial synovitis was present in all athletes with posteromedial impingement; however, posterior and posterolateral synovitis was also seen in these athletes. Mild posteromedial synovitis was present in two control athletes. Ultrasound identified abnormal posteromedial soft tissue thickening deep to tibialis posterior between the medial malleolus and talus in all nine athletes. After injection all athletes returned to their previous level of sport, with eight of the nine not experiencing any residual or recurrent symptoms.ConclusionIf MR imaging excludes significant coexistent abnormality, ultrasound can localise posteromedial soft tissue abnormality and guide injection therapy, allowing return to athletic activity without surgical intervention.

Dynamic contrast enhanced MRI of bone marrow oedema in rheumatoid arthritis.

Aims: The aim of this work was to assess the feasibility of using dynamic contrast enhanced (DCE) MRI of bone marrow oedema, to compare it with conventional marrow oedema scoring systems, and to determine the effects of anti-tumour necrosis factor (TNF)α therapy. Methods: The wrist and metacarpophalangeal (MCP) joints of 25 patients with rheumatoid arthritis were studied. A total of 14 were imaged before and 1–2 weeks after anti-TNFα therapy. T2-weighted fat-suppressed images were collected. A dynamic series of 24 3D spoiled gradient-echo images were acquired before, during and after the intravenous administration of gadolinium-based contrast medium. Oedema was scored using the conventional Rheumatoid Arthritis MRI Scoring (RAMRIS) system from T2-weighted images. The relative enhancement rate (RER) was calculated using the dynamic series from oedematous bone, bone adjacent to oedema and from an uninvolved bone. Results: A total of 56% of patients showed bone marrow oedema. The RER was significantly increased in and adjacent to areas of marrow oedema. There was a significant reduction in the RER after treatment, but not in the RAMRIS score. Conclusions: Dynamic contrast enhanced MRI of bone marrow oedema yields additional information to RAMRIS scoring and may be a more sensitive marker of inflammatory activity and response to treatment.