Trine Torfing

MRI bone oedema is the strongest predictor of subsequent radiographic progression in early rheumatoid arthritis. Results from a 2-year randomised controlled trial (CIMESTRA)

Objective: To identify predictors of radiographic progression in a 2-year randomised, double-blind, clinical study (CIMESTRA) of patients with early rheumatoid arthritis (RA). Methods: Patients with early RA (n = 130) were treated with methotrexate, intra-articular betamethasone and ciclosporin/placebo-ciclosporin. Baseline magnetic resonance imaging (MRI) of the wrist (wrist-only group, n = 130) or MRI of wrist and metacarpophalangeal (MCP) joints (wrist+MCP group, n = 89) (OMERACT RAMRIS), x-ray examination of hands, wrists and forefeet (Sharp/van der Heijde Score (TSS)), Disease Activity Score (DAS28), anti-cyclic citrullinated peptide antibodies (anti-CCP), HLA-DRB1-shared epitope (SE) and smoking status were assessed. Multiple regression analysis was performed with delta-TSS (0–2 years) as dependent variable and baseline DAS28, TSS, MRI bone oedema score, MRI synovitis score, MRI erosion score, anti-CCP, smoking, SE, age and gender as explanatory variables. Results: Baseline values: median DAS28 5.6 (range 2.4–8.0); anti-CCP positive 61%; radiographic erosions 56%. At 2 years: DAS28 2.0 (0.5–5.7), in DAS remission: 56%, radiographic progression 26% (wrist+MCP group, similar for wrist-only group). MRI bone oedema score was the only independent predictor of delta-TSS (wrist+MCP group: coefficient = 0.75 (95% CI 0.55 to 0.94), p<0.001; wrist-only group: coefficient = 0.59 (95% CI 0.40 to 0.77), p<0.001). Bone oedema score explained 41% of the variation in the progression of TSS (wrist+MCP group), 25% in wrist-only group (Pearson’s r = 0.64 and r = 0.50, respectively). Results were confirmed by sensitivity analyses. Conclusion: In a randomised controlled trial aiming at remission in patients with early RA, baseline RAMRIS MRI bone oedema score of MCP and wrist joints (and of wrist only) was the strongest independent predictor of radiographic progression in hands, wrists and forefeet after 2 years. MRI synovitis score, MRI erosion score, DAS28, anti-CCP, SE, smoking, age and gender were not independent risk factors. Trial registration number: NCT00209859.

The role of fat pad sign in diagnosing occult elbow fractures in the pediatric patient: a prospective magnetic resonance imaging study

In 1954, Norell described the ‘fat pad sign’ for the first time. This refers to the radiological visualization of the elbow fatty tissue. This is a prospective study with the aim of clarifying the relation between the presence of a positive fat pad sign on the lateral radiograph and the type of injury verified on MRI. From January to December 2010, 31 children were diagnosed primarily with a positive fat pad sign. An above-the-elbow cast was applied and all patients were referred for an MRI within a few days. All patients were recommended a clinical follow-up and informed about the MRI results. After revision, five patients were found to have a negative fat pad sign and were excluded. This resulted in a total of 26 patients, 10 men and 16 women, mean age 10±2.62 years. The time between the injury and the initial radiological examination was 0.8±0.27 days and the MRI was obtained on an average of 6.6±3.84 days. A total of 12 patients had an injury of the left side and 14 of the right side. The MRI showed a posterior positive sign in all except five cases and six occult fractures, which accounts for 23%. Nineteen patients (73%) had a bone bruise. All patients except one had a normal range of movement with no pain on the last clinical examination after 2–3 weeks. The presence of a positive fad pad sign is not synonymous with occult fractures. Finding occult fractures on MRI does not alter the final treatment of these patients. On the basis of this study and review of other similar studies, pediatric patients who presented with elbow effusion verified on conventional radiographs could be treated with a cast for 2–3 weeks and extra clinical or radiological controls did not seem to be indicated. Level of evidence: Level III, development of diagnostic criteria on the basis of consecutive patients.

The diagnostic value of digital subtraction arthrography and radionuclide bone scan in revision hip arthroplasty

A prospective analysis of plain serial radigraphs (PSR), digital subtraction arthrography (DSA), and radionuclide bone scans (RBS) was performed in 56 cemented total hip arthroplasties to evaluate the efficacy and usefulness of each study in the diagnosis of loosening. To avoid selection bias in the evaluation of DSA and RBS, the decision to perform repeat surgery was based exclusively on the clinical history and PSR. Results of each study were compared with intraoperative assessment of the status of components and expressed in terms of sensitivity, specificity, and accuracy. Overall accuracy for the acetabular component by PSR was 66%; by DSA, 93%; by RBS, 46%. Overall accuracy for the femoral component by PSR was 79%; by DSA, 93%; RBS, 50%. Our results indicate that DSA can be recommended as a further analysis in cases with a painful hip prosthesis and no or inconclusive findings on PSR. RBS did not give any useful information and cannot be recommended routinely.

Evaluation of Periprosthetic Bone Cysts in Patients With a Scandinavian Total Ankle Replacement: Weight-Bearing Conventional Digital Radiographs Versus Weight-Bearing Multiplanar Reconstructed Fluoroscopic Imaging

OBJECTIVE Periprosthetic bone cysts are a known finding after total ankle replacement (TAR). The significance of cysts is uncertain, but they may threaten the long-term survival of the implant. The aim of this prospective study was to evaluate the diagnostic accuracy of weight-bearing digital radiography compared with 3D weight-bearing multiplanar reconstructed (MPR) fluoroscopic imaging when diagnosing periprosthetic bone cysts in patients who have undergone TAR. SUBJECTS AND METHODS Forty-two consecutive patients with a Scandinavian Total Ankle Replacement (STAR) were consecutively enrolled and underwent digital radiography and 3D MPR imaging in the same session. All 3D MPR images were interpreted in a blinded fashion, specifically with regard to the presence and extent of periprosthetic bone cysts. Cysts were measured in three planes whenever possible. Interrater and intrarater reliability was assessed by using Cohen kappa test, and comparisons between the two modalities were performed with the Wilcoxon signed-rank and McNemar tests. RESULTS Significantly more cysts were detected on 3D MPR (74 vs 55) (p = 0.03), with the mean size of cysts detected by 3D MPR significantly larger than that of cysts diagnosed on digital radiography (1545 mm(3) vs 253 mm(3)) (p < 0.0001). Statistical analysis based on the presence or absence of cysts in individual patients did not show a significant difference between 3D MPR and digital radiography (p = 0.23). CONCLUSION The data imply that cysts are better detected and more accurately measured with 3D fluoroscopic MPR imaging compared with digital radiography, which underestimates not only the presence but also the extent of periprosthetic cysts.

The proportion of distal fibula Salter-Harris type I epiphyseal fracture in the paediatric population with acute ankle injury: a prospective MRI study.

Ankle injuries are common among the paediatric population. There are few prospective studies utilizing MRI to diagnose a clinically suspected Salter–Harris type I of the distal fibula (SH1FDF). The aim of this study was to examine the proportion of clinically suspected SH1FDF in children. All paediatric patients with ankle injury, seen at the emergency room from September 2012 to May 2013 at a single institution, underwent a standardized clinical examination, and their radiographs were obtained if found necessary. All images and data were recorded prospectively and patients suspected of having SH1FDF were referred for MRI of the ankle joint. Out of 391 paediatric patients seen at the emergency room with ankle injury, 38 patients had a clinical suspicion of SH1FDF. A total of 31 patients, 18 male and 13 female, with a mean age of 10±2.86 years, were included in the study. Only seven patients were excluded from the study. MRI was obtained on an average of 6.9±2.87 days. None of the included patients had evidence of SH1FDF on MRI. Our study and review of the literature verifies the high false-positive rate of clinically suspected SH1FDF. Most children had ligamentous lesions, bone contusion or joint effusion, rather than SH1FDF.

Agreement and precision of periprosthetic bone density measurements in micro-CT, single and dual energy CT.

The objective of this study was to test the precision and agreement between bone mineral density measurements performed in micro CT, single and dual energy computed tomography, to determine how the keV level influences density measurements and to assess the usefulness of quantitative dual energy computed tomography as a research tool for longitudinal studies aiming to measure bone loss adjacent to total hip replacements. Samples from 10 fresh‐frozen porcine femoral heads were placed in a Perspex phantom and computed tomography was performed with two acquisition modes. Bone mineral density was calculated and compared with measurements derived from micro CT. Repeated scans and dual measurements were performed in order to measure between‐ and within‐scan precision. Mean density difference between micro CT and single energy computed tomography was 72 mg HA/cm3. For dual energy CT, the mean difference at 100 keV was 128 mg HA/cm3 while the mean difference at 110–140 keV ranged from −84 to −67 mg HA/cm3 compared with micro CT. Rescanning the samples resulted in a non‐significant overall between‐scan difference of 13 mg HA/cm3. Bland–Altman limits of agreement were wide and intraclass correlation coefficients ranged from 0.29 to 0.72, while 95% confidence intervals covered almost the full possible range. Repeating the density measurements for within‐scan precision resulted in ICCs >0.99 and narrow limits of agreement. Single and dual energy quantitative CT showed excellent within‐scan precision, but poor between‐scan precision. No significant density differences were found in dual energy quantitative CT at keV‐levels above 110 keV.

Magnetic resonance imaging assessed inflammation in the wrist is associated with patient-reported physical impairment, global assessment of disease activity and pain in early rheumatoid arthritis: longitudinal results from two randomised controlled trials

Objectives To examine whether MRI assessed inflammation and damage in the wrist of patients with early rheumatoid arthritis (RA) are associated with patient-reported outcomes (PROs). Methods Wrist and hand MRIs of 210 patients with early RA from two investigator-initiated, randomised controlled studies (CIMESTRA/OPERA) were assessed according to the Outcome Measures in Rheumatology RA MRI score (RAMRIS) for synovitis, tenosynovitis, osteitis, bone erosions and joint space narrowing (JSN) at baseline, 1 and 5 years follow-up. These features, and changes therein, were assessed for associations with health assessment questionnaires (HAQ), patient global visual analogue scales (VAS-PtGlobal) and VAS-pain using Spearman’s correlations, generalised estimating equations and univariate/multivariable linear regression analyses. MRI features were further tested for trends against specific hand-related HAQ items using Jonckheere trend tests. Results MRI inflammation, but not damage, showed statistically significant associations with HAQ, VAS-PtGlobal and VAS-pain for status and change scores, independently of C reactive protein and swollen joint count. MRI-assessed synovitis was most consistently associated with PROs, particularly VAS-PtGlobal and VAS-pain. MRI-assessed synovitis and tenosynovitis mean scores were positively associated with patient-reported difficulty to cut meat and open a milk carton (p<0.01), and similar patterns were seen for other hand-related HAQ items. Incorporating metacarpophalangeal joints in the analyses did not strengthen the associations between MRI pathology and PROs. Conclusions MRI-assessed inflammation, but not damage, in early RA wrists is associated with patient-reported physical impairment, global assessment of disease activity and pain and influences the physical function in the hand. Trial registration number NCT00660647.

Intra- and inter-observer agreement and reliability of bone mineral density measurements around acetabular cup: a porcine ex-vivo study using single- and dual-energy computed tomography

Background Periprosthetic bone loss is considered to be a potentially contributing factor in aseptic loosening of acetabular hip components, but no studies have shown this association. The lack of association might be caused by insufficient image quality because of metal artifacts and challenges in measuring bone density (BMD) in complex anatomic structures which might be overcome using dual-energy computed tomography (DECT). Purpose To test inter- and intra-observer agreement and reliability of in-house segmentation software measuring BMD adjacent to acetabular cup and to compare measurements performed with single-energy CT (SECT) and DECT in cemented and cementless cups. Material and Methods Twenty-four acetabular cups inserted in porcine hip specimens were scanned with SECT and DECT. Bone density was measured in a three-dimensional volume adjacent to the cup. Double measurements were performed. Results BMD derived from SECT was approximately four times higher than that of DECT. In both scan modes, intraclass correlation coefficient (ICC) was >0.90 with no differences between repeated measurements, except for uncemented cups where a statistically significant difference of 11 mg/cm3 was found with DECT. DECT showed narrower limits of agreement than SECT. Inter-observer analysis showed small differences. Conclusion BMD can be estimated with high intra- and inter-observer reliability with SECT and DECT around acetabular cups using custom software. The intra- and inter-observer agreement of DECT is superior to that of SECT and better in the cementless concept. Good intra- and inter-observer reliability can be obtained in both cemented and cementless cups using the segmentation software. SECT and DECT cannot be used interchangeably.

Effect of a treat-to-target strategy based on methotrexate and intra-articular betamethasone with or without additional cyclosporin on MRI-assessed synovitis, osteitis, tenosynovitis, bone erosion, and joint space narrowing in early rheumatoid arthritis: results from a 2-year randomized double-blind placebo-controlled trial (CIMESTRA)

Objectives: To investigate whether a treat-to-target strategy based on methotrexate (MTX) and intra-articular (IA) betamethasone suppresses magnetic resonance imaging (MRI)-determined measures of disease activity and reduces joint destruction in early rheumatoid arthritis (eRA) patients, and to investigate whether concomitant cyclosporin A (CyA) provides an additional effect. Method: In the 2-year randomized, double-blind, treat-to-target trial CIMESTRA, 160 patients with eRA (< 6 months) were randomized to MTX, intra-articular betamethasone and CyA, or placebo CyA. A total of 129 patients participated in the MRI substudy, and had contrast-enhanced MR images of the non-dominant hand at months 0, 6, 12, and 24. MR images were evaluated for osteitis, synovitis, tenosynovitis, bone erosion, and joint space narrowing (JSN), using validated scoring methods. Results: Significant reductions were seen at 6 months in all inflammatory parameters [synovitis, mean change –1.6 (p < 0.001, Wilcoxon), tenosynovitis, –3.5 (p < 0.001), and osteitis, –1.3 (p < 0.05)] and at 12/24 months in synovitis and tenosynovitis [–1.6/–2.2 and –3.6/–3.8, respectively; all p < 0.001]. MRI signs of inflammation were not fully eliminated, and increases in erosion and JSN scores were observed at 6 months [0.4 (p < 0.01)/0.1 (p < 0.05)], 12 months [0.8 (p < 0.001)/0.3 (p < 0.01)], and 24 months [1.0 (p < 0.001)/0.4 (p < 0.001)]. Clinical measures decreased significantly (p < 0.001) at all time points. There were no consistent statistically significant differences between treatment groups. Conclusions: In this eRA treat-to-target trial, MTX and intra-articular glucocorticoids markedly reduced, but did not eliminate, MRI osteitis, synovitis, and tenosynovitis. Accordingly, minimal but statistically significant increases in bone erosion and JSN were observed. No additional effect of CyA was demonstrated.

Glenoid morphology in obstetrical brachial plexus lesion: a three-dimensional computed tomography study

BACKGROUND Obstetric brachial plexus lesion (OBPL) frequently leads to glenohumeral dysplasia, and excessive retroversion of the glenoid is among the best known developmental disturbances. Most analyses of the glenoid are based on 2-dimensional (D) imaging and do not address glenoid inclination or provide information on the glenoid in the sagittal plane. We aim to describe the 3-D deformity of the glenoid in children with OBPL. METHODS Preoperative computed tomography (CT) scans of the nonaffected and the affected scapula of 24 children (aged 5 to 12 years) with developmental disturbances after OBPL years were analyzed. The dimensions of the scapula and the deformation of the glenoid were visualized in 3-D. RESULTS The retroversion of the glenoid fossa was greater in all affected shoulders, and 2-D measurements significantly overestimated retroversion compared with angles measured in 3-D. The inclination of the glenoid fossa was altered, and a distal bony edge loss was observed on 3-D reformations in the sagittal plane. The reliability of the measured angles was excellent, and the κ agreement for the description of the glenoid form was substantial. Furthermore, the dimensions of the scapula were significantly smaller on the affected shoulders. CONCLUSION OBPL is indeed a 3-D disorder. Our measurements revealed excessive retroversion of the glenoid fossa, and the reliability of the 3-D CT measurements was superior to their 2-D counterparts. 3-D CT reformations of the glenoid in the coronal and the sagittal plane added further to 3-D understanding of glenoid morphology in OBPL. These new findings legitimatize a 3-D CT-based description of the glenoid deformities connected with OPBL.