Primary arthrodesis versus open reduction and internal fixation following intra-articular calcaneal fractures: a weight-bearing CT analysis

PURPOSE

To compare primary arthrodesis (PA) versus open reduction and internal fixation (ORIF) in displaced intra-articular calcaneal fractures (DIACFs), based on clinical outcome and 2D and 3D geometrical analyses obtained from weight-bearing (WB) cone-beam CT images.

MATERIALS AND METHODS

In this prospective study, 40 patients with surgically treated calcaneal fractures were included, consisting of 20 PA and 20 ORIF patients. Weight-bearing cone-beam CT-images of the left and right hindfoot and forefoot were acquired on a Planmed Verity cone-beam CT-scanner after a minimum of 1-year follow-up. Automated 2D and 3D geometric analyses, i.e., (minimal and average) talo-navicular joint space, calcaneal pitch (CP), and Meary's angle (MA), were obtained for injured and healthy feet. Clinical outcomes were measured using the EQ5D and FFI questionnaires.

RESULTS

Overall, there were no differences in baseline patient characteristics apart from age (p < 0.005). The calcaneal pitch in 2D after treatment by ORIF (13.8° ± 5.6) was closer to the uninjured side (18.1° ± 5.5) compared to PA (10.9° ± 4.5) (p < 0.001). Meary's angle in 2D was closer to the uninjured side (8.7° ± 6.3) after surgery in the PA cohort (7.0° ± 5.8) compared to the ORIF cohort (15.5° ± 5.9) (p = 0.046). In 3D measurements, CP was significantly decreased for both cohorts after surgery (- 4.09° ± 6.2) (p = 0.001). MA was not significantly affected overall or between cohorts in 3D. Clinical outcomes were not significantly different between the ORIF and PA cohorts. None of the radiographic measurements in 2D or 3D correlated with any of the clinical outcomes studied.

CONCLUSION

Three-dimensional WB CT imaging enables functional 2D and 3D analyses under natural load in patients with complex calcaneal fractures. Based on clinical outcome, both PA and ORIF appear viable treatment options. Clinical correlation with geometrical outcomes remains to be established.

Load-induced deformation of the tibia and its effect on implant loosening detection

CT imaging under external valgus and varus loading conditions and consecutive image analysis can be used to detect tibial implant loosening after total knee arthroplasty. However, the applied load causes the tibia to deform, which could result in an overestimation of implant displacement. This research evaluates the extent of tibia deformation and its effect on measuring implant displacement. Ten cadaver specimen with TKA were CT-scanned under valgus/varus loading (20 Nm), first implanted without bone cement fixation (mimicking a loose implant) and subsequently with bone cement fixation (mimicking a fixed implant). By means of image analysis, three relative displacements were assessed: (1) between the proximal and distal tibia (measure of deformation), (2) between the implant and the whole tibia (including potential deformation effect) and (3) between the implant and the proximal tibia (reduced deformation effect). Relative displacements were quantified in terms of translations along, and rotations about the axes of a local coordinate system. As a measure of deformation, the proximal tibia moved relative to the distal tibia by, on average 1.27 mm (± 0.50 mm) and 0.64° (± 0.25°). Deformation caused an overestimation of implant displacement in the cemented implant. The implant displaced with respect to the whole tibia by 0.45 mm (± 0.22 mm) and 0.79° (± 0.38°). Relative to the proximal tibia, the implant moved by 0.23 mm (± 0.10 mm) and 0.62° (± 0.34°). The differentiation between loose and fixed implants improved when tibia deformation was compensated for by using the proximal tibia rather than the whole tibia.

Sub-calcaneal plantar fat pad assessment using dual-energy computed tomography: First experience in the diabetic foot

BACKGROUND

This study assessed the use of dual-energy computed tomography (CT) to evaluate sub-calcaneal plantar fat pad changes in people with diabetic neuropathy.

METHODS

Dual-energy CT scans of people with diabetic neuropathy and non-diabetic controls were retrospectively included. Average CT values (in Hounsfield Units) and thickness (in centimeters) of the sub-calcaneal plantar fat pad were measured in mono-energetic images at two energy levels (40 keV and 70 keV). The CT values measured in patients with diabetic neuropathy were correlated to barefoot plantar pressure measurements performed during walking in a clinical setting.

FINDINGS

Forty-five dual-energy CT scans of people with diabetic neuropathy and eleven DECT scans of non-diabetic controls were included. Mean sub-calcaneal plantar fat pad thickness did not significantly differ between groups (diabetes group 1.20 ± 0.34 cm vs. control group 1.21 ± 0.28 cm, P = 0.585). CT values at both 40 keV (-34.7 ± 48.7 HU vs. -76.0 ± 42.8 HU, P = 0.013) and 70 keV (-11.2 ± 30.8 HU vs. -36.3 ± 27.2 HU, P = 0.017) were significantly higher in the diabetes group compared to controls, thus contained less fatty tissue. This elevation was most apparent in patients with Type 1 diabetes. CT values positively correlated with the mean peak plantar pressure.

INTERPRETATION

Dual-energy CT was able to detect changes in the plantar fat pad of people with diabetic neuropathy.

The association between echogenicity and progression of Dupuytren's disease (DD): Birth of an imaging biomarker?

BACKGROUND

The shift of focus towards disease-controlling treatments to prevent DD progression at an early stage underlines the need for objective and reliable measurements that can monitor and predict the course of disease. Ultrasound has been studied as a potential tool for this purpose. This study examined to what extent echogenicity of early DD nodules predicts clinical progression.

METHODS

Sonographic assessments of Dupuytren's nodules were performed by the same observer on 151 participants as part of an ongoing prospective cohort study on the course of DD. Echogenicity was assessed by determining the greyness of a nodule relative to the surrounding tissue, using ImageJ software. Progression of disease was defined as 1) an increase in total passive extension deficit (TPED) of ≥15 degrees and 2) surgical intervention of the examined ray, both occurring after the sonographic assessment. The associations between echogenicity and time to progression were estimated using Cox-regression models.

RESULTS

The association between echogenicity and time to TPED progression showed that for every additional decrease of 1% in relative greyness (darker image) of a nodule, the risk of TPED progression during follow-up increases by 3.4% (hazard ratio [HR] = 0.966, 95% confidence interval [CI]: 0.935-0.966). Similarly, echogenicity was also associated with time to surgical intervention (HR = 0.967, 95% CI: 0.938-0.997), which indicates a higher risk for surgery during follow-up for darker nodules.

CONCLUSIONS

These results suggest that echogenicity is predictive of the prognosis of the early stages of DD and might potentially be used as a prognostic imaging biomarker in the future.

Metatarsophalangeal and interphalangeal joint angle measurements on weight-bearing CT images

BACKGROUND

The aim of this study was to present and evaluate methods of measuring toe joint angels using joint-surface based and inertial axes approaches.

METHODS

Nine scans of one frozen human cadaveric foot were obtained using weight-bearing CT. Two observers independently segmented bones in the forefoot and measured metatarsalphalangeal joint (MTPJ) angles, proximal and distal interphalangeal joint (PIPJ and DIPJ) angles and interphalangeal angles of the hallux (IPJ) using 1) inertial axes, representing the long anatomical axes, of the bones and 2) axes determined using centroids of articular joint surfaces.

RESULTS

The standard deviations (SD) of the IPJ/PIPJ and DIPJ angles were lower using joint-surface based axes (between 1.5˚ and 4.1˚) than when the inertial axes method was used (between 3.3˚ and 16.4˚), for MTPJ the SD's were similar for both methods (between 0.5˚ and 2.6˚). For the IPJ/PIPJ and DIPJ angles, the width of the 95% CI and the range were also lower using the joint-surface axes method (95% CI: 2.0˚-4.1˚ vs 3.2˚-16.3˚; range: 3.1˚-7.4˚ vs 3.8˚-35.8˚). Intra-class correlation coefficients (ICC) representing inter- and intra-rater reliability were good to excellent regarding the MTPJ and IPJ/PIPJ angles in both techniques (between 0.85 and 0.99). For DIPJ angles, ICC's were good for the inertial axes method (0.78 and 0.79) and moderate for the joint-surface axes method (0.60 and 0.70).

CONCLUSION

The joint-surface axes method enables reliable and reproducible measurements of MTPJ, IPJ/PIPJ and DIPJ angles. For PIPJ and DIPJ angles this method is preferable over the use of inertial axes.

Preliminary evaluation of dual-energy CT to quantitatively assess bone marrow edema in patients with diabetic foot ulcers and suspected osteomyelitis

OBJECTIVES

The purpose of this study is to evaluate the value of dual-energy CT (DECT) with virtual non-calcium (VNCa) in quantitatively assessing the presence of bone marrow edema (BME) in patients with diabetic foot ulcers and suspected osteomyelitis.

METHODS

Patients with a diabetic foot ulcer and suspected osteomyelitis that underwent DECT (80 kVp/Sn150 kVp) with VNCa were retrospectively included. Two observers independently measured CT values of the bone adjacent to the ulcer and a reference bone not related to the ulcer. The patients were divided into two clinical groups, osteomyelitis or no-osteomyelitis, based on the final diagnosis by the treating physicians.

RESULTS

A total of 56 foot ulcers were identified of which 23 were included in the osteomyelitis group. The mean CT value at the ulcer location was significantly higher in the osteomyelitis group (- 17.23 ± 34.96 HU) compared to the no-osteomyelitis group (- 69.34 ± 49.40 HU; p < 0.001). Within the osteomyelitis group, the difference between affected bone and reference bone was statistically significant (p < 0.001), which was not the case in the group without osteomyelitis (p = 0.052). The observer agreement was good for affected bone measurements (ICC = 0.858) and moderate for reference bone measurements (ICC = 0.675). With a cut-off value of - 40.1 HU, sensitivity was 87.0%, specificity was 72.7%, PPV was 69.0%, and NPV was 88.9%.

CONCLUSION

DECT with VNCa has a potential value for quantitatively assessing the presence of BME in patients with diabetic foot ulcers and suspected osteomyelitis.

KEY POINTS

• Dual-energy CT (DECT) with virtual non-calcium (VNCa) is promising for detecting bone marrow edema in the case of diabetic foot ulcers with suspected osteomyelitis. • DECT with VNCa has the potential to become a more practical alternative to MRI in assessing the presence of bone marrow edema in suspected osteomyelitis when radiographs are not sufficient to form a diagnosis.

The efficacy of flexor tenotomy to prevent recurrent diabetic foot ulcers (DIAFLEX trial): Study protocol for a randomized controlled trial

Foot ulcers are a frequent and costly problem in people with diabetes mellitus and can lead to amputations. Prevention of these ulcers is therefore of paramount importance. Claw/hammer toe deformities are commonly seen in people with diabetes. These deformities increase the risk of ulcer development specifically at the (tip of) the toe. Percutaneous needle tenotomy of the tendon of the m. flexor digitorum longus (tendon tenotomy) can be used to reduce the severity of claw/hammer toe deformity with the goal to prevent ulcer recurrence. The main objective of this randomized controlled trial is to assess the efficacy of flexor tenotomy to prevent recurrence of toe ulcers in people with diabetes and a history of toe (pre-)ulcers. Additionally, we aim to assess interphalangeal joints (IPJ) and metatarsophalangeal joint (MTPJ) angles in a weight-bearing and non-weight-bearing position, barefoot plantar pressure during walking, cost-effectiveness and quality of life before and after the intervention and compare intervention and control study groups. Sixty-six subjects with diabetes and claw/hammer toe deformity and a recent history of (pre-)ulceration on the tip of the toe will be included and randomized between flexor tenotomy of claw/hammer toes (intervention) versus standard of care including orthosis and shoe offloading (controls) in a mono-center randomized controlled trial.

Clinicaltrialsgov registration

NCT05228340.

Osteoarthritic changes in the knees of recently retired male professional footballers: a pilot study

Background

Knee osteoarthritis (OA) is common amongst retired male professional footballers. There is limited understanding with respect to the interplay between imaging findings, clinical presentation and patient-reported outcome measures (PROMs) in retired professional footballers with knee OA.

Objectives

This pilot study aimed to evaluate the extent of radiological and clinical knee OA in a cohort of retired male professional footballers, and to explore the relationship between these findings and knee-related PROMs.

Methods

Fifteen retired male professional footballers underwent knee radiographs and were surveyed on their history of clinical OA, severe knee injury and previous knee surgery. The Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS) and the Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) were used to assess health outcomes, such as level of function and pain.

Results

Radiological knee OA was diagnosed in six out of 15 participants. Seven of the participants had a clinical diagnosis of knee OA. Evidence of clinical and radiological OA was present amongst four participants. Radiological knee OA and clinical OA was significantly associated with a history of severe knee injury and previous knee surgery. Low correlations (ρ<-0.40) were found between knee OA severity and knee-related PROMs. Moderate correlation (ρ=-0.65) was found between clinical knee OA and KOOS-SP.

Conclusion

Clinical knee OA correlates with PROMs amongst retired professional footballers but radiological OA does not. Further studies are required to understand the relationship between imaging findings, clinical presentation and PROMs amongst retired professional footballers with knee OA.

Assessment of foot deformities in individuals with cerebral palsy using weight-bearing CT

OBJECTIVE

The aims of this study were to visualize and quantify relative bone positions in the feet of individuals with cerebral palsy (CP) with a foot deformity and compare bone positions with those of typically developed (TD) controls.

MATERIALS AND METHODS

Weight-bearing CT images of 14 individuals with CP scheduled for tendon transfer and/or bony surgery and of 20 TD controls were acquired on a Planmed Verity WBCT scanner. Centroids of the navicular and calcaneus with respect to the talus were used to quantify foot deformities. All taluses were aligned and the size and dimensions of the individuals' talus were scaled to correct for differences in bone sizes. In order to visualize and quantify variations in relative bone positions, 95% CI ellipsoids and standard deviations in its principle X-, Y-, and Z-directions were determined.

RESULTS

In individuals with CP (age 11-17), a large variation in centroid positions was observed compared to data of TD controls. Radiuses of the ellipsoids, representing the standard deviations of the 95% CI in the principle X-, Y-, and Z-directions, were larger in individuals with CP compared to TD controls for both the calcaneus (3.16 vs 1.86 mm, 4.26 vs 2.60 mm, 9.19 vs 3.60 mm) and navicular (4.63 vs 1.55 mm, 5.18 vs 2.10 mm, 16.07 vs 4.16 mm).

CONCLUSION

By determining centroids of the calcaneus and navicular with respect to the talus on WBCT images, normal and abnormal relative bone positions can be visualized and quantified in individuals with CP with various foot deformities.

AB0109 INCREASED NEUTROPHIL FREQUENCY IN LYMPH NODES OF PATIENTS WITH PSORIATIC ARTHRITIS

Background

Increased presence of neutrophils in the skin1, synovium2,3, and entheses4 of patients with Psoriatic Arthritis (PsA) and their downregulation upon successful treatment2,5,6, suggests a role for neutrophils in PsA pathogenesis. As neutrophils have been implicated in Th17 differentiation, gaining insight in the presence and function of neutrophils within lymph nodes, which are the epicentre of T cell activation and differentiation, could be important in unravelling disease pathogenesis.

Objectives

We hypothesize that activated neutrophils migrate from inflamed peripheral tissues to lymph nodes, where they steer inflammation by interaction with tissue resident cells and immune cells, ultimately resulting in activation of IL-17 producing T cells. To investigate this, we studied the presence of neutrophils in lymph node biopsies of patients with inflammatory arthritis, including PsA, and compared their frequencies to controls.

Methods

Ten PsA patients, 34 seropositive individuals at risk of developing rheumatoid arthritis (RA-risk), 26 ACPA- RA patients and 10 healthy controls (HC) underwent ultrasound-guided inguinal lymph node biopsy. These biobanked biopsies were analysed using qPCR and immunohistochemistry. Flow cytometry on fresh biopsies was used to determine cell frequencies in six active PsA patients (defined as arthritis in ≥1 joint) and two RA-risk individuals.

Results

qPCR analyses showed significantly increased mRNA levels of Cathepsin G (CTSG), which is highly expressed by neutrophils, in PsA patients compared to HC (p = 0.020). Immunohistochemistry showed that the neutrophil marker CD15 is significantly increased in PsA patients compared to HC (p = 0.008). Preliminary flow cytometry analyses indicates a clear population of CD45+CD16+CD66b+ neutrophils in lymph node biopsies of PsA patients while this was not observed in RA-risk individuals.

Conclusion

Overall, we show for the first time an increased presence of neutrophils in lymph nodes of PsA patients when compared to controls. Future studies are needed to investigate their functional role in immunoregulation within lymph node organs.

References

[1]Biasi D, Carletto A, Caramaschi P, et al. Neutrophil functions and IL-8 in psoriatic arthritis and in cutaneous psoriasis. Inflammation. 1998;22(5):533-543.

[2]van Mens LJJ, van de Sande MGH, Menegatti S, et al. Brief Report: Interleukin-17 Blockade With Secukinumab in Peripheral Spondyloarthritis Impacts Synovial Immunopathology Without Compromising Systemic Immune Responses. Arthritis Rheumatol. 2018;70(12):1994-2002.

[3]Kruithof E, Baeten D, De Rycke L, et al. Synovial histopathology of psoriatic arthritis, both oligo- and polyarticular, resembles spondyloarthropathy more than it does rheumatoid arthritis. Arthritis Res Ther. 2005;7(3).

[4]Stavre Z, Bridgewood C, Zhou Q, Maeda Y, Karman J, McGonagle D GE. The Role for Neutrophils in the Early Phases of Enthesitis in Spondyloarthritis [abstract]. Arthritis Rheumatol. 2020;72(July):supple10.

[5]Baeten D, Kruithof E, Van Bosch F Den, et al. Immunomodulatory effects of anti-tumor necrosis factor α therapy on synovium in spondylarthropathy: Histologic findings in eight patients from an open-label pilot study. Arthritis Rheum. 2001;44(1):186-195.

[6]Van Kuijk AWR, Gerlag DM, Vos K, et al. A prospective, randomised, placebo-controlled study to identify biomarkers associated with active treatment in psoriatic arthritis: Effects of adalimumab treatment on synovial tissue. Ann Rheum Dis. 2009;68(8):1303-1309.

[7]Mantovani A, Cassatella MA, Costantini C, Jaillon S. Neutrophils in the activation and regulation of innate and adaptive immunity. Nat Rev Immunol. 2011;11(8):519-531.

Acknowledgements

We would like to thank all participating patients and Tom de Groot for his expertise in evaluating neutrophils by flow cytometry.

Disclosure of Interests

Aoife M O’Byrne: None declared, J.W. Bolt: None declared, Chaja van Ansenwoude: None declared, J.F. Semmelink: None declared, Mario Maas: None declared, Marleen G.H. van de Sande Speakers bureau: UCB, Consultant of: Advisory board: Abbvie, Eli Lily, Novartis, UCB, Grant/research support from: Novartis, Janssen, UCB, Eli Lilly, Lisa van Baarsen: None declared

OP0099 INCREASED FREQUENCY OF CD4+ AND CD8+ FOLLICULAR HELPER T CELLS IN HUMAN LYMPH NODE BIOPSIES DURING THE EARLIEST STAGES OF RHEUMATOID ARTHRITIS

Background

Follicular T helper (Tfh) cells provide key help for B cell differentiation into plasma and memory B cells and are essential in germinal center formation and (auto) antibody generation (1).

Objectives

To gain more insights into the role of Tfh cells in RA development, we assessed whether Tfh cells have an altered frequency, phenotype and cytokine profile in peripheral blood, lymphoid and synovial tissues during the earliest stages of RA development.

Methods

Using flow cytometry, we analyzed the phenotpe, frequencies and cytokine profile of Tfh cells and B cells in peripheral blood and lymph node biopsies of healthy controls (HCs), autoantibody positive individuals at risk for developing RA (RA-risk individuals), and early RA patients. Using immunofluorescene we confirmed the presence of Tfh in B cell follicles of lymph nodes and synovial tissue biopsies of RA patients.

Results

In blood, the frequency of Tfh cells did not differ between study groups. In lymphoid and synovial tissue, Tfh cells were localized in B-cell areas, and their frequencies correlated strongly with the frequency of CD19+ B cells. Compared to lymphoid tissue of healthy controls, that of RA patients and RA-risk individuals, showed more CD19+ B cells and more CD4+CXCR5+ and CD8+CXCR5+ follicular T cells. Of note, compared to healthy controls, specifically lymph node Tfh cells of RA-risk and early RA patients produced less IL-21 upon ex-vivo stimulation.

Conclusion

Tfh cells are localised in B-cell rich areas in lymphoid and synovial tissues of early RA patients. The analysis of lymph node tissue in early RA patients showed increased frequencies of Tfh cells, where they clearly associate with B cells. Interestingly, IL-21 production is already aberrant in the very early at risk phase of the disease. Our data suggest that Tfh cells may present a novel rationale for therapeutic targeting during the preclinical stage of RA to prevent further disease progression.

References

[1]Ise W, Fujii K, Shiroguchi K, Ito A, Kometani K, Takeda K, et al. T Follicular Helper Cell-Germinal Center B Cell Interaction Strength Regulates Entry into Plasma Cell or Recycling Germinal Center Cell Fate. Immunity. 2018;48(4):702-15.e4.

Acknowledgements

We thank the participants in the study, the radiology department at the Academic Medical Center (AMC) for lymph node sampling; the flow cytometry facility at the Hematology department at AMC, especially J.A. Dobber; and the core facility Cellular Imaging of the Amsterdam UMC, location AMC.

Disclosure of Interests

Dornatien Anang: None declared, Tamara H.Ramwadhdoebe: None declared, Janine Hahnlein: None declared, Bo van Kuijk: None declared, Smits Noortje: None declared, Krijn P. van Lienden: None declared, Mario Maas: None declared, Danielle Gerlag Employee of: Employee of UCB Pharma. UCB pharma was not involved in this study, Paul-Peter Tak Employee of: Employee of Candel therapeutics. Candel therapeutics was not involved in the study, Niek de Vries: None declared, Lisa van Baarsen: None declared.

The Triangular Fibrocartilage Complex In The Human Wrist: A Scoping Review Towards Uniform And Clinically Relevant Terminology

The aim of this scoping review was to assess the composition, terminology, and anatomy of the triangular fibrocartilage complex (TFCC) of the wrist and propose unambiguous terminology regarding the individual components. The review was conducted according to the methodological framework by Arksey and O'Malley (International Journal of Social Research Methodology, 2005, 8, 19–32). Electronic databases were searched from inception until September 1, 2021 for original anatomical studies, using MeSH terms and keywords on terminology and anatomy of TFCC components. Studies using gross dissections or macro‐ or microscopic histology were included. Animal studies, fetal studies and studies with unknown disease status, were excluded. A total of 24 studies were included. The articular disc, the radioulnar ligaments, the meniscus homologue and the extensor carpi ulnaris tendon (sub)sheath were unanimously classified as TFCC components. One study did not include the ulnolunate and ulnotriquetral ligaments and only one study did include the ligamentum subcruentum. The largest disagreement existed regarding the inclusion of the ulnar collateral ligament. Terminological ambiguity was seen in “triangular fibrocartilage,” “triangular ligament,” “igamentum subcruentum,” and the “proximal and distal lamina.” Anatomical ambiguity existed especially regarding the radioulnar ligaments, the ulnar attachments of the TFCC and the ulnar collateral ligament. Definitions of the individual TFCC components are redundant, ambiguous, and ill‐defined and therefore subject to different interpretations. In order to preclude confusion, consensus regarding terminology is recommended. We proposed a concise definition of the healthy TFCC that can be used as a starting point for future studies and current clinical practice.

Defining disease status in gastroenteropancreatic neuroendocrine tumors: Choi-criteria or RECIST?

PURPOSE

Adequate monitoring of changes in tumor load is fundamental for the assessment of the course of disease and response to treatment. There is an ongoing debate on the utility of RECIST v1.1 in gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

In this retrospective real-life cohort study, Choi-criteria were compared with RECIST v1.1. The agreement between both criteria and the association with survival endpoints were evaluated.

RESULTS

Seventy-five patients were included with a median follow-up of 35 months (range 8-53). Median progression-free survival (mPFS) according to RECIST v1.1 was 15 months (range 2-50) compared to 14 months (range 2-50) in Choi. According to RECIST, 33 (44%) patients were classified as having stable disease (SD), 40 (53%) as progressive disease (PD) and two (3%) patients as partial response (PR), compared to 9 (12%) patients classified as SD, 50 (67%) as PD and 16 (21%) as PR according to Choi-criteria. Overall concordance between the criteria was moderate (Cohen's Kappa = 0.408, p < 0.001) and agreement varied between 57 and 69% at each consecutive scan (p < 0.001). Survival analysis showed significant differences in overall survival (OS) for RECIST v1.1 categories PD and non-PD (log-rank p = 0.02), however, in Choi no significant differences in OS were found (p = 0.27).

CONCLUSION

RECIST v1.1 had a better clinical utility and prognostic value compared to Choi-criteria. Still, RECIST were also not sufficient to adequately predict OS. This outlines the need for new tools that provides accurate information on the disease course and treatment response to support precise prognostication in patients with GEP-NETs.

Percutaneous cryoablation: a novel treatment option in non-visceral metastases of the abdominal cavity after prior surgery

PURPOSE

To assess the primary safety and oncological outcome of percutaneous cryoablation in patients with non-visceral metastases of the abdominal cavity after prior surgery.

METHODS

All patients with non-visceral metastases after prior abdominal surgery, treated with percutaneous cryoablation, and at least one year of follow-up were retrospectively identified. Technical success was achieved if the ice-ball had a minimum margin of 10 mm in three dimensions on the per-procedural CT images. Complications were recorded using the Society of Interventional Radiology (SIR) classification system. Time until disease progression was monitored with follow-up CT and/or MRI. Local control was defined as absence of recurrence at the site of ablation.

RESULTS

Eleven patients underwent cryoablation for 14 non-visceral metastases (mean diameter 20 ± 9 mm). Primary tumor origin was renal cell (n = 4), colorectal (n = 3), granulosa cell (n = 2), endometrium (n = 1) and appendix (n = 1) carcinoma. Treated metastases were localized retroperitoneal (n = 8), intraperitoneal (n = 2), or in the abdominal wall (n = 4). Technical success was achieved in all procedures. After a median follow-up of 27 months (12-38 months), all patients were alive. Local control was observed in 10/14 non-visceral metastases, and the earliest local progression was detected after ten months. No major adverse events occurred. One patient suffered a minor asymptomatic adverse event.

CONCLUSION

This proof-of-concept study suggests that cryoablation can be a minimal invasive treatment option in a selected group of patients with non-visceral metastases in the abdominal cavity after prior surgery.

Clinical added value of MRI to CT in patients scheduled for local therapy of colorectal liver metastases (CAMINO): study protocol for an international multicentre prospective diagnostic accuracy study

BACKGROUND

Abdominal computed tomography (CT) is the standard imaging method for patients with suspected colorectal liver metastases (CRLM) in the diagnostic workup for surgery or thermal ablation. Diffusion-weighted and gadoxetic-acid-enhanced magnetic resonance imaging (MRI) of the liver is increasingly used to improve the detection rate and characterization of liver lesions. MRI is superior in detection and characterization of CRLM as compared to CT. However, it is unknown how MRI actually impacts patient management. The primary aim of the CAMINO study is to evaluate whether MRI has sufficient clinical added value to be routinely added to CT in the staging of CRLM. The secondary objective is to identify subgroups who benefit the most from additional MRI.

METHODS

In this international multicentre prospective incremental diagnostic accuracy study, 298 patients with primary or recurrent CRLM scheduled for curative liver resection or thermal ablation based on CT staging will be enrolled from 17 centres across the Netherlands, Belgium, Norway, and Italy. All study participants will undergo CT and diffusion-weighted and gadoxetic-acid enhanced MRI prior to local therapy. The local multidisciplinary team will provide two local therapy plans: first, based on CT-staging and second, based on both CT and MRI. The primary outcome measure is the proportion of clinically significant CRLM (CS-CRLM) detected by MRI not visible on CT. CS-CRLM are defined as liver lesions leading to a change in local therapeutical management. If MRI detects new CRLM in segments which would have been resected in the original operative plan, these are not considered CS-CRLM. It is hypothesized that MRI will lead to the detection of CS-CRLM in ≥10% of patients which is considered the minimal clinically important difference. Furthermore, a prediction model will be developed using multivariable logistic regression modelling to evaluate the predictive value of patient, tumor and procedural variables on finding CS-CRLM on MRI.

DISCUSSION

The CAMINO study will clarify the clinical added value of MRI to CT in patients with CRLM scheduled for local therapy. This study will provide the evidence required for the implementation of additional MRI in the routine work-up of patients with primary and recurrent CRLM for local therapy.

TRIAL REGISTRATION

The CAMINO study was registered in the Netherlands National Trial Register under number NL8039 on September 20th 2019.

Prevalence of nodal involvement in rectal cancer after chemoradiotherapy

BACKGROUND

The purpose of this study was to investigate the prevalence of ypN+ status according to ypT category in patients with locally advanced rectal cancer treated with chemoradiotherapy and total mesorectal excision, and to assess the impact of ypN+ on disease recurrence and survival by pooled analysis of individual-patient data.

METHODS

Individual-patient data from 10 studies of chemoradiotherapy for rectal cancer were included. Pooled rates of ypN+ disease were calculated with 95 per cent confidence interval for each ypT category. Kaplan-Meier and Cox regression analyses were undertaken to assess influence of ypN status on 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

Data on 1898 patients were included in the study. Median follow-up was 50 (range 0-219) months. The pooled rate of ypN+ disease was 7 per cent for ypT0, 12 per cent for ypT1, 17 per cent for ypT2, 40 per cent for ypT3, and 46 per cent for ypT4 tumours. Patients with ypN+ disease had lower 5-year DFS and OS (46.2 and 63.4 per cent respectively) than patients with ypN0 tumours (74.5 and 83.2 per cent) (P < 0.001). Cox regression analyses showed ypN+ status to be an independent predictor of recurrence and death.

CONCLUSION

Risk of nodal metastases (ypN+) after chemoradiotherapy increases with advancing ypT category and needs to be considered if an organ-preserving strategy is contemplated.

AB0850 DUTCH RHEUMATOLOGISTS’ PERSPECTIVE ON MRI EDUCATION: DO WE NEED TO CHANGE?

Background:

Studies have shown the value of magnetic resonance imaging (MRI) as an objective tool for diagnosis, follow up and detection of complications for a broad spectrum of rheumatology associated diseases [1]. With increasing (potential) clinical applications of MRI, rheumatologists need basic knowledge about the technique and interpretation of the images to get most out of MRI use in clinical practice. Although radiologists will remain the experts of MRI protocols and readings, lack of sufficient rheumatologists training will not yield in optimal interaction between the specialists and will negatively influence the benefit of the MRI contribution to patient care. Despite offered MRI courses within EULAR, in the Netherlands there is currently no structural MRI education for rheumatologists (in training). This while rheumatologists are intrinsically motivated to improve their MRI skills [2,3].

Objectives:

By use of a developed questionnaire:

[1]To create an overview of the current communication methods between rheumatologists and radiologists regarding MRI and rheumatologists’ perspectives on the efficiency and effectiveness of the imaging requests and radiologists reports.

[2]To make an inventory of current knowledge and interpretation skills of rheumatologists concerning MRI.

[3]To assess the needs of rheumatologists for education to work with MRI requests, reading and reports in routine clinical care by development of a questionnaire to determine the current clinical situation.

Methods:

A questionnaire was created.

Results:

A total of 109 respondents (28% respons) have filled in the form with a 100% completion rate.

1. Communication:

Communication regarding MRI in rheumatology is done largely per request of the rheumatologist with a high level of satisfaction concerning the quality of the discussion. Most medical centers have no multidisciplinary team meeting with the radiology department, discussions are mostly performed on demand.

2. Interpretation:

Rheumatologist predominantly rely on the conclusion of the radiology report with little understanding of the technical and anatomical characteristics of the images. Only a small percentage (6%) of rheumatologists is able to interpret the images. Half of the responders do not feel competent to teach fellow colleagues about imaging.

3. Educational wishes:

When asked to prioritize the subject of imaging education, most people prefer interpretation skills, followed by instructions on how to provide most optimal clinical information and question(s) on the request form as well as knowledge on anatomy. Least preferred is education concerning the MRI technique itself.

The preferred method of advanced imaging education is a combination of classroom teaching and e-learning.

Conclusion:

Dutch rheumatologists express a satisfactory communication with their radiologists, which is mostly not performed structurally. Rheumatologists indicated that education, in particular in MRI imaging reading,will provide a better understanding in the MRI technique and applicability as well as confidence in self-interpretation of the images.

The preferred method of MRI imaging education is blended (e.g., a combination of classroom teaching and e-learning).

The results therefore show that MRI education of rheumatologists is still a need in clinical practice in the Netherlands. MRI education of rheumatologists can contribute to more efficient application of MRI in rheumatology patient care, including a more optimal interaction between radiologists and rheumatologists.

References:

[1]Sudol-Szopinska I et al: Recommendations of the ESSR Arthritis Subcommittee for the Use of Magnetic Resonance Imaging in Musculoskeletal Rheumatic Diseases. Seminars in musculoskeletal radiology 2015

[2]Bandinelli F et al: Rheumatology education in Europe: results of a survey of young rheumatologists. Clinical and experimental rheumatology 2011

[3]Maksymowych WP et al: Diagnosis of Axial Spondyloarthritis: A Primary Unmet Educational Need for Rheumatologists Is Interpretation of MRI [abstract]. Arthritis Rheumatol. 2020

Disclosure of Interests:

None declared

Statistical analysis of thermal conductivity experimentally measured in water-based nanofluids

Nanofluids are suspensions of nanoparticles in a base heat-transfer liquid. They have been widely investigated to boost heat transfer since they were proposed in the 1990s. We present a statistical correlation analysis of experimentally measured thermal conductivity of water-based nanofluids available in the literature. The influences of particle concentration, particle size, temperature and surfactants are investigated. For specific particle materials (alumina, titania, copper oxide, copper, silica and silicon carbide), separate analyses are performed. The conductivity increases with the concentration in qualitative agreement with Maxwell’s theory of homogeneous media. The conductivity also increases with the temperature (in addition to the improvement due to the increased conductivity of water). Surprisingly, only silica nanofluids exhibit a statistically significant effect of the particle size, whereby smaller particles lead to faster heat transfer. Overall, the large scatter in the experimental data prevents a compelling, unambiguous assessment of these effects. Taken together, the results of our analysis suggest that more comprehensive experimental characterizations of nanofluids are necessary to estimate their practical potential.

Predicting local tumour progression after ablation for colorectal liver metastases: CT-based radiomics of the ablation zone

PURPOSE

To assess whether CT-based radiomics of the ablation zone (AZ) can predict local tumour progression (LTP) after thermal ablation for colorectal liver metastases (CRLM).

MATERIALS AND METHODS

Eighty-two patients with 127 CRLM were included. Radiomics features (with different filters) were extracted from the AZ and a 10 mm periablational rim (PAR)on portal-venous-phase CT up to 8 weeks after ablation. Multivariable stepwise Cox regression analyses were used to predict LTP based on clinical and radiomics features. Performance (concordance [c]-statistics) of the different models was compared and performance in an 'independent' dataset was approximated with bootstrapped leave-one-out-cross-validation (LOOCV).

RESULTS

Thirty-three lesions (26 %) developed LTP. Median follow-up was 21 months (range 6-115). The combined model, a combination of clinical and radiomics features, included chemotherapy (HR 0.50, p = 0.024), cT-stage (HR 10.13, p = 0.016), lesion size (HR 1.11, p = <0.001), AZ_Skewness (HR 1.58, p = 0.016), AZ_Uniformity (HR 0.45, p = 0.002), PAR_Mean (HR 0.52, p = 0.008), PAR_Skewness (HR 1.67, p = 0.019) and PAR_Uniformity (HR 3.35, p < 0.001) as relevant predictors for LTP. The predictive performance of the combined model (after LOOCV) yielded a c-statistic of 0.78 (95 %CI 0.65-0.87), compared to the clinical or radiomics models only (c-statistic 0.74 (95 %CI 0.58-0.84) and 0.65 (95 %CI 0.52-0.83), respectively).

CONCLUSION

Combining radiomics features with clinical features yielded a better performing prediction of LTP than radiomics only. CT-based radiomics of the AZ and PAR may have potential to aid in the prediction of LTP during follow-up in patients with CRLM.

Geometric 3D analyses of the foot and ankle using weight-bearing and non weight-bearing cone-beam CT images: The new standard?

OBJECTIVES

We hypothesize that three-dimensional (3D) geometric analyses in weight bearing CT-images of the foot and ankle are more reproducible compared to two-dimensional (2D) analyses. Therefore, we compared 2D and 3D analyses on bones of weight-bearing and non weight-bearing cone-beam CT images of healthy volunteers.

METHODS

Twenty healthy volunteers (10 male, 10 female, mean age 37.5 years) underwent weight-bearing and non weight-bearing cone-beam CT imaging of both feet. Clinically relevant height and angle measurements were performed in 2D and 3D (for example: cuboid height, calcaneal pitch, talo-calcaneal angle, Meary's angle, intermetatarsal angle). Three-dimensional measurements were obtained using automated software. Intra-observer and inter-observer agreement were evaluated for all 2D measurements.

RESULTS

Overall intraclass correlation coefficients (ICC's) were higher than 0.750 for most 2D measurements, ranging from 0.352 to 0.995. Calcaneal pitch, angle between the first metatarsal (MT1) and proximal phalange 1, between the fifth metatarsal (MT5) and the calcaneus and heights of the sesamoid bones, navicular, cuboid and talus decreased during weight-bearing in both 2D and 3D results (p < 0.01). Meary's angle was not statistically different in 2D (p = 0.627) and 3D (p = 0.765). Higher coefficients of variation in 2D geometric analysis parameters (0.27 versus 0.16) indicate that 3D analyses are more precise compared to 2D (p < 0.01). Results of left and right feet are comparable for 2D and 3D analyses.

CONCLUSION

Although 2D and 3D geometrical analyses are fundamentally different, automated 3D analyses are more reproducible and precise compared to 2D analyses. In addition, 3D evaluation better demonstrates differences in bone configurations between weight-bearing and non weight-bearing conditions, which may be of value to demonstrate pathology.

The value of MRI STIR signal intensity on return to play prognosis and reinjury risk estimation in athletes with acute hamstring injuries

OBJECTIVES

Previous studies have shown low to moderate evidence for a variety of magnetic resonance imaging (MRI) features as prognostic factors in athletes with hamstring injuries. Short-tau inversion recovery (STIR) signal intensity has not yet been investigated for assessing the prognosis of acute muscle injuries. Our aim was to explore the relationship between MRI STIR signal intensity and time to return to play (RTP) and to investigate the association between MRI STIR and reinjury risk in athletes with acute hamstring injuries.

STUDY DESIGN

Case-control study.

METHODS

We used MRI STIR to measure intramuscular signal intensity in patients with clinically diagnosed hamstring injuries at two time points: at injury and RTP. At injury, we calculated the association of MRI STIR signal intensity with the time to RTP and reinjury risk. At RTP, the association of MRI STIR signal intensity and reinjury risk and the change in MRI STIR signal intensity over time on reinjury risk was evaluated.

RESULTS

51 patients were included. We found increased MRI STIR signal intensity: (1) at time of injury not to be associated with time to RTP, (2) at time of injury to be associated with a slightly lower risk for reinjury: odds 0.986 (0.975-0.998, p=0.02) and (3) at RTP not to be associated with reinjury risk. (4) We found no association between the change in MRI STIR signal intensity over time and reinjury risk.

CONCLUSION

Increased MRI STIR signal intensity at injury has no value in time to RTP prognosis, but is associated with a reduced reinjury risk.

Real-Time Ultrasound Image Fusion with FDG-PET/CT to Perform Fused Image-Guided Fine-Needle Aspiration in Neck Nodes: Feasibility and Diagnostic Value

BACKGROUND AND PURPOSE

New imaging techniques such as hybrid imaging of ultrasound and FDG-PET/CT are available but not yet investigated for node staging. The aim of the study was to evaluate the feasibility and added diagnostic value of real-time image-fused ultrasound-guided fine-needle aspiration with FDG-PET/CT data for node staging.

MATERIALS AND METHODS

Ninety-six patients who were referred for cervical lymph node staging with FDG-PET/CT before ultrasound were prospectively included. After routine ultrasound-guided fine-needle aspiration, all FDG-PET-positive nodes were marked on FDG-PET/CT, and real-time image fusing of ultrasound and FDG-PET/CT was performed using the electromagnetic navigation system PercuNav. Already-punctured nodes were confirmed to be PET-positive, and additional fused-ultrasound-guided fine-needle aspiration was performed in previously missed PET-positive nodes.

RESULTS

Of 96 patients, 87 (91%) patients had suspicious nodes requiring fine-needle aspiration cytology. Ultrasound-guided fine-needle aspiration was performed in 175 nodes. Cytology was inconclusive in 9/175 (5%) nodes, and 85/166 (51%) nodes were malignant. Target planning was performed in 201 PET-positive nodes; 195/201 (97%) of those nodes were fused successfully. Twenty of 175 ultrasound-guided fine-needle aspiration nodes turned out to be FDG-PET-negative, and 149/175 (85%) of the fused ultrasound-guided fine-needle aspiration nodes were confirmed to be FDG-PET-positive. Of 201 PET-positive nodes, 46 (23%) were additionally identified, and fused ultrasound-guided fine-needle aspiration was performed. Cytology was inconclusive in 4/46 nodes (9%), and 13/42 (31%) nodes were malignant.

CONCLUSIONS

Real-time ultrasound image fusion with FDG-PET-positive nodes is feasible in cervical lymph nodes, and fused ultrasound-guided fine-needle aspiration increases the number of malignant nodes detected.

Improved diagnostic confidence in evaluating bone non-union using virtual monochromatic dual-energy CT

PURPOSE

The aim of this study was to determine whether virtual monochromatic dual-energy CT imaging improves the evaluation of suspected non-union of the appendicular skeleton treated with titanium or stainless steel intramedullary nails and plates.

METHOD

Forty-one patients with a clinical suspected non-union with hardware in place were included and scanned on a dual-source CT-scanner using 100/Sn150kVp. Images including titanium hardware were extracted at 130 keV. Images including stainless steel hardware were extracted at 150 keV. Monochromatic 70 keV images served as reference. Non-union confirmed during revision surgery was used as gold standard. A musculoskeletal radiologist and orthopedic trauma surgeon evaluated images on image quality, degree and location of consolidation, non-union type and diagnostic confidence.

RESULTS

Likert scores with respect to image quality improved from 0.88 to 1.83 (p < 0.001) in high (130 and 150) keV images. High keV images reduced the number of false negative non-unions based on consolidation grade with 5% (p = 0.283). Agreement between observers regarding location of consolidation and non-union type did not improve in 130 and 150 keV images. Diagnostic confidence improved from 1.43 to 2.37 in high keV images compared to 70 keV images (p < 0.001). Overall diagnostic confidence was higher in intramedullary nails than plates (p < 0.05).

CONCLUSIONS

Use of virtual monochromatic 130 and 150 keV dual-energy CT compared to 70 keV images improves the evaluation of suspected non-union of the appendicular skeleton treated with titanium or stainless steel intramedullary nails and plates.

Urethral complications after gender reassignment surgery: a systematic review

The aim of the present systematic review is to evaluate the impact of gender reassignment surgery on the development of urethral complication. A systematic search in accordance the Preferred Reporting Items for Systematic Review and Meta-Analyses statement for original articles published up until June 2019 was performed using the Pubmed, Scopus, Embase, and Web of Science databases. Pooled analyses were done when appropriate. The bibliographic search with the included terms (("Transsexualism"[Mesh])) AND ("Sex Reassignment Surgery"[Mesh]) produced a literature of 879 articles altogether. After removing papers of not interest or articles in which the outcomes could not be deduced, 32 studies were examined for a total of 3463 patients screened. Thirty-two studies met our inclusion criteria and were evaluated, and references were manually reviewed in order to include additional relevant studies in this review. Female-to-male (FtM) surgery and male-to-female (MtF) surgery was discussed in 23 and 10 studies, respectively. One study discussed both. Varying patterns of complications were observed in FtM and MtF surgeries, with increased complications in the former because of the larger size of the neourethra. Meatal stenosis is a particular concern in MtF surgery, with complication rates ranging from 4 to 40%, and usually require meatotomy for repair. Stricture and fistulization are frequently reported complications following FtM surgery. In studies reporting on fistulae involving the urethra, 19-54% of fistulae resolved spontaneously without further surgical intervention. High rates of complications are reported in the current literature, which should be understood by patients and practitioners alike. Shared decision making with patients regarding incidence and management of urethral complications including stricture disease and fistulae, particularly after FtM surgery, is critical for setting expectations and managing postoperative outcomes.

The Value of Intraoperative 3-Dimensional Fluoroscopy in the Treatment of Distal Radius Fractures: A Randomized Clinical Trial

PURPOSE

This study attempted to determine the clinical effectiveness of the intraoperative use of 3-dimensional fluoroscopy compared with conventional 2-dimensional fluoroscopy in patients with distal radius fractures.

METHODS

We performed a multicenter randomized clinical trial in which 206 patients were randomized between the use of 3-dimensional fluoroscopy or not during operative treatment of the distal radius fracture. The primary outcome was the quality of fracture reduction and fixation assessed on a postoperative computed tomography scan with a dichotomous outcome: indication for revision, yes or no.

RESULTS

There was no significant difference in whether the fracture required revision surgery: 31% (2-dimensional group) versus 24% (3-dimensional group). In 11% of distal radius fractures allocated to the 3-dimensional group, additional intraoperative corrections (screw replacements) were performed.

CONCLUSIONS

Compared with 2-dimensional fluoroscopy, the use of intraoperative 3-dimensional fluoroscopy does not appear to improve the quality of reduction and fixation in the management of patients with a distal radius fracture. However, the use of 3-dimensional fluoroscopy appears to have advantages such as more intraoperative revisions and less revision surgeries that this study could not clearly demonstrate.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Interdisciplinary consensus of virtual monochromatic dual-energy CT images: is there discrepancy in preferred photon energy between surgeons and radiologists for the assessment of non-unions?

AIM

To investigate possible differences between surgeons and radiologists in selecting optimal photon energy settings from a set of virtual monochromatic dual-energy computed tomography (CT) images for the assessment of bone union in patients with a suspected non-union of the appendicular skeleton.

MATERIALS AND METHODS

Fifty patients suspected of having bone non-union after operative fracture treatment with a variety of fixation implants were included. Patients were scanned on a dual-source CT machine using 150/100-kVp. Monochromatic images were extracted at 70, 90, 110, 130, 150, and 190 keV. Images were reviewed by 159 orthopaedic trauma surgeons and 12 musculoskeletal radiologists in order to select the best and worst energy setting to assess bone union. Furthermore, a confidence score (1-4) was given in selecting the best and worst setting to assess bone union.

RESULTS

Monochromatic 190 keV images were selected most frequently as the optimal energy in titanium (34.8%), stainless steel (40%), and combined implants of stainless steel and titanium (40.5%). Confidence scores and average optimal energies were higher and average worst energies were lower for radiologists compared to surgeons in all hardware (p<0.05). Differences in optimal energy were not statistically significant for different alloys or type of fixation implant in both groups.

CONCLUSIONS

In both observer groups, 190 keV images were selected most frequently as the optimal energy to assess bone union in patients with a suspected non-union of the appendicular skeleton with hardware in situ. On average, musculoskeletal radiologists selected higher optimal and lower worst energy settings and were more confident in selecting both energy settings than orthopaedic trauma surgeons.

The distal radial physis: Exploring normal anatomy on MRI enables interpretation of stress related changes in young gymnasts

Rationale: Explore the MRI-appearance of the healthy distal radial physis and the distribution of stress-related changes in physeal thickness in young gymnasts to aid in the understanding of the pathophysiological process of stress-related physeal injury. Methods: Symptomatic gymnasts with clinically suspected overuse injury of the distal radial physis and age and gender-matched asymptomatic gymnasts and healthy non-gymnasts underwent an MRI-scan of the wrist. A cartilage-specific sequence was used to obtain three-dimensional reconstructions of the distal radial physis. Heat maps and line charts of these reconstructions visualised distribution of physeal thickness per study group and were used to explore differences between study groups. Symptomatic gymnasts displaying the most profound physeal widening (n = 10) were analysed separately. Results: Twenty-seven symptomatic - (skeletal age 12.9 ± 1.5 years), 16 asymptomatic - (skeletal age 12.8 ± 1.9 years) and 23 non-gymnasts (skeletal age 13.6 ± 1.9 years) were included for analysis. Physes of healthy non-gymnasts had a thin centre and increased in thickness towards the borders. Gymnasts demonstrated an increase in thickness of the entire physeal surface. In symptomatic gymnasts increase in physeal thickness was most prominent at the volar side when compared to asymptomatic gymnasts and non-gymnasts. Conclusion: The healthy distal radial physis is characterised by a thin centre surrounded by thicker borders. Stress applied to the wrist during gymnastics causes an overall increase in physeal thickness. Profound thickness increase is present at the volar side of the physis mainly in symptomatic gymnasts. These results can help unravel the pathophysiological mechanism of stress-related physeal injury in gymnasts and aid early injury identification.

It's a thin line: development and validation of Dixon MRI-based semi-quantitative assessment of stress-related bone marrow edema in the wrists of young gymnasts and non-gymnasts

Purpose

To assess reliability and clinical utility of evaluating stress-related metaphyseal water distribution using a semi-quantitative Dixon MRI-based method for early diagnosis of physeal stress injuries in adolescent gymnasts.

Methods

Twenty-four gymnasts with clinically suspected overuse injury of the distal radial physis, 18 asymptomatic gymnasts, and 24 non-gymnast controls aged 12 ± 1.5 years prospectively underwent hand radiographs and 3T MRI of the wrist including coronal T1-weighted and T2-weighted Dixon sequences. Two raters measured metaphyseal water signal fraction in 13 radial and ulnar regions of interest (ROI). Inter- and intrarater reliability, interslice (between 3 middle radial slices), and inter-ROI (between 3 ROIs on same level) reliability were assessed using intraclass correlation coefficients (ICC). Water signal fractions and their within-person ratios in distal versus most proximal ROIs were compared between groups using one-way analysis of variance.

Results

Inter- and intrarater ICCs were 0.79–0.99 and 0.94–1.0 for T1-weighted, and 0.88–1.0 and 0.88–1.0 for T2-weighted Dixon. Interslice and inter-ROI ICCs were 0.55–0.94 and 0.95–0.97 for T1-weighted, and 0.70–0.96 and 0.96–0.97 for T2-weighted Dixon. Metaphyseal water signal fraction in symptomatic gymnasts was higher in six distal ROIs compared with asymptomatic gymnasts and in nine ROIs compared with non-gymnasts (p < 0.05). Metaphyseal water score (ratio of distal versus most proximal ROIs) was 1.61 in symptomatic gymnasts and 1.35 in asymptomatic gymnasts on T2-weighted Dixon (p < 0.05).

Conclusion

Semi-quantitative Dixon MRI-based water signal fraction assessment has good to excellent reproducibility and shows increased metaphyseal water scores in symptomatic gymnasts compared with asymptomatic gymnastic peers.

Key Points

• The proposed Dixon MRI-based semi-quantitative method for assessment of metaphyseal bone marrow water content is reliable, with off-the-shelf availability and short scan times.

• The metaphyseal water score allows comparisons between gymnasts using a within-person reference area for unaffected metaphyseal bone.

• As metaphyseal water score was increased in symptomatic gymnasts compared with asymptomatic gymnasts, this semi-quantitative method can potentially be used as an indicator of bone marrow edema in the early diagnosis of gymnastic physeal stress injury.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06446-8) contains supplementary material, which is available to authorized users.

Guidelines for MR imaging in rectal cancer: Europe versus United States

The aim of this study was to compare and contrast recently published guidelines for staging and reporting of MR imaging in rectal cancer from the European Society of Gastrointestinal and Abdominal Radiology and the North American Society of Abdominal Radiology. These guidelines were assessed on the presence of consensus and disagreement. Items were compared by two reviewers, and items with agreement and disagreement between the guidelines were identified and are presented in the current paper. Differences between guidelines are discussed to offer insights in practice variations between both continents and among expert centers, which to some extent may explain the differences between guidelines.

Platelet-Rich plasma Injection Management for Ankle osteoarthritis study (PRIMA): protocol of a Dutch multicentre, stratified, block-randomised, double-blind, placebo-controlled trial

INTRODUCTION

Platelet-rich plasma (PRP) is a potentially efficacious treatment for ankle osteoarthritis (OA), but its use has not been examined in high-quality studies. Systematic reviews show that PRP injections significantly decrease pain and improve function in patients with knee OA. Ankle OA is more common than hip or knee OA in the young active population; with a prevalence of 3.4%.PRP injections in ankle OA are shown to be safe and improve quality of life over time, but no randomised controlled trial has been conducted. Our randomised controlled trial will evaluate the efficacy of PRP injections for symptom reduction and functional improvement, compared with placebo, in the treatment of ankle (talocrural) OA.

METHODS AND ANALYSIS

We will conduct the Platelet-Rich plasma Injection Management for Ankle OA study: a multicentre, randomised, placebo-controlled trial. One hundred patients suffering from ankle OA will be randomised into two treatment groups: PRP injection or placebo (saline) injection. Both groups will receive two injections of PRP or placebo at an interval of 6 weeks. Primary outcome is the American Orthopaedic Foot and Ankle Society score at 26 weeks. Secondary outcomes determined at several follow-up moments up to 5 years, include Ankle Osteoarthritis Score, Foot and Ankle Outcome Score, pain subscale of (0-40), Visual Analogue Scale score (0-100), Ankle Activity Score (0-10), subjective patient satisfaction Short Form Health Survey-36, Global Attainment Scaling and the EuroQol-5 dimensions-3 levels utility score. A cost-effectiveness analysis will be performed at 1 year.

ETHICS AND DISSEMINATION

The study is approved by the Medical Ethics Review Committee Amsterdam Medical Center, the Netherlands (ABR 2018-042, approved 23 July 2018) and registered in the Netherlands trial register (NTR7261). Results and new knowledge will be disseminated through the Dutch Arthritis Association (ReumaNederland), Dutch patient federation, conferences and published in a scientific peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NTR7261.

Content validity of the SOS-WRIST questionnaire for timely identification of wrist overuse in young athletes

Objectives: Young athletes do not always seek medical help for overuse wrist injuries, risking invalidating long-term consequences resulting from late diagnosis. This study aimed to develop a questionnaire to identify overuse wrist injuries in young athletes. Methods: According to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) criteria, items were collected from literature and 6 focus groups of sports physicians and of young athletes with (previous) overuse wrist injuries. An expert panel and 40 Delphi study participants performed item reduction. Young athletes evaluated comprehensiveness during interviews and English translation was performed according to linguistic validation guidelines. Results: In total 323 items were generated and 110 were marked important by focus group participants. The resulting questionnaire consists of 18 multiple-choice questions about wrist pain during sports (e.g. pain during training, skipping training sessions/elements) and daily life activities (e.g. writing, turning a key), and other symptoms (e.g. reduced strength, swelling). Conclusion: The SOS-WRIST questionnaire for identification of overuse wrist injuries in young athletes has good content validity. It can be used to promote awareness and timely treatment of overuse wrist injuries in young athletes.

Carpal Alignment: A New Method for Assessment

Background  Carpal alignment may be used as a tool to evaluate fracture reduction in patients with distal radius fractures. However, there is little consensus on how to measure and quantify carpal alignment. Purpose  The aim of this study was to compare the inter- and intraobserver variability of a new perpendicular method with the existing method in fractured and unfractured wrists. Additionally, the normal distribution of carpal alignment in unfractured wrists was investigated. Patients and Methods  Carpal alignment was assessed on lateral plain radiographs using two different methods, one described by Ng and McQueen and another newly proposed method, the perpendicular method. Using the perpendicular method, the observer draws one line along the inner rim of the volar cortex of the radius and one perpendicular line to the center of the capitate. The carpus is aligned when the line along the inner rim transects the center of the capitate. Three examiners measured the carpal alignment in 50 patients with nonfractured and 50 patients with fractured distal radius. Intra- and interobserver variability for both methods were determined. Results  The interobserver coefficient for the perpendicular method was 0.98 and that for the Ng method was 0.86. The intraobserver coefficients for three examiners were 0.89, 0.62, and 0.63, respectively, for the Ng method. For the perpendicular method, the intraobserver variability was 0.96, 0.89, and 0.72, respectively. In patients with unfractured wrists, the mean perpendicular to the center of the capitate was 0.25 mm dorsally. Conclusion  The new proposed method is a reproducible method for measuring carpal alignment with a high inter- and intraclass coefficient. Clinical Relevance  This method of measurement allows for a reproducible technique for measuring carpal alignment.

Risk of chronic ankle instability: A reliability study on radiographic assessment of the ankle joint geometry

BACKGROUND

Chronic ankle instability (CAI) is a multifactorial disabling condition. Ideally all factors contributing to CAI are identified and implemented in a risk assessment model. However, they need to meet strict reliability requirements. To assess usability of radiographic factors for this risk assessment model and future clinical practice, the objective of the current study was to assess the intra and inter observer reliability of three radiographic measurements.

METHODS AND METHODS

The radiographs of 39 consecutive patients, at least 16years, who visited the Emergency Department after sustaining a lateral ankle sprain (LAS), were assessed by four observers. The radiographic measurements included absolute and relative ankle alignment, sagittal fibular position and ankle joint congruency (talar radius and height, and tibiotalar sector), performed twice by all observers independently. Reliability was assessed by calculating the Intraclass Correlation Coefficient (ICC) which was considered good when ICC>0.70.

RESULTS

The intra observer reliability of the absolute and relative fibular position, and talar height were good to excellent, (ICC 0.84-0.98, 0.85-0.98, and 0.79-0.93, respectively). The talar radius (ICC 0.69-0.89) was moderate to good. The overall inter observer reliability was good for the absolute and relative fibular position, and talar radius (ICC 0.84, 0.86, and 0.79, respectively). Other measurements had ICC values of <0.70.

CONCLUSIONS

In an effort to identify the multifactorial nature of CAI, both the fibular position and the talar radius measurements showed good observer reliability, and will be implemented in a future risk assessment models. The other measurements are too prone for measurement errors, for future reference.

LEVEL OF EVIDENCE

IV Case Series.

Diagnostic performance of MRI for assessment of response to neoadjuvant chemoradiotherapy in oesophageal cancer

Background

Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non‐surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2‐weighted (T2W) and diffusion‐weighted (DW) MRI.

Methods

Patients with locally advanced oesophageal cancer who underwent T2W‐ and DW‐MRI (1·5 T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five‐point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW‐MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated.

Results

Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W‐MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W + DW‐MRI were 90–97 and 42–50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W‐MRI, and 0·71, 0·70 and 0·70 on T2W + DW‐MRI (P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively). The κ value for interobserver agreement improved from 0·24–0·55 on T2W‐MRI to 0·55–0·71 with DW‐MRI.

Conclusion

Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.

Metal artifact reduction techniques in musculoskeletal CT-imaging

It is known that metal artifacts can be reduced by modifying standard acquisition and reconstruction, by modifying projection data and/or image data and by using virtual monochromatic imaging extracted from dual-energy CT. In this review we focus on the origin of metal artifacts, technical background of commercially available metal artifact reduction (MAR) algorithms and the value of dual-energy CT and MAR software for different metal hardware in current clinical practice. Virtual monochromatic imaging reduces beam-hardening artifacts, where metal artifact reduction software effectively reduces artifacts caused by extensive photon-starvation. Both techniques have their advantages and disadvantages, and the combination of both techniques is often but not always the best solution regarding metal artifact reduction. Advances in prosthetic imaging are reinforced by advances in prosthetic design. Providing implant specific information prior to scanning is important in order to adjust the metal artifact reduction approach, minimize artifacts and optimize image quality and diagnostic value of CT.

Prognostic implications of MRI-detected lateral nodal disease and extramural vascular invasion in rectal cancer

BACKGROUND

Lateral nodal disease in rectal cancer remains a subject of debate and is treated differently in the East and the West. The predictive value of lateral lymph node and MRI-detected extramural vascular invasion (mrEMVI) features on oncological outcomes was assessed in this study.

METHODS

In this retrospective cohort study, data on patients with cT3-4 rectal cancer within 8 cm from the anal verge were considered over a 5-year period (2009-2013). Lateral lymph node size, malignant features and mrEMVI features were evaluated and related to oncological outcomes.

RESULTS

In total, 192 patients were studied, of whom 30 (15·6 per cent) underwent short-course radiotherapy and 145 (75·5 per cent) received chemoradiotherapy. A lateral lymph node short-axis size of 10 mm or more was associated with a significantly higher 5-year lateral/presacral local recurrence rate of 37 per cent, compared with 7·7 per cent in nodes smaller than 10 mm (P = 0·041). Enlarged nodes did not result in a higher 5-year rate of distant metastasis (23 per cent versus 27·7 per cent in nodes smaller than 10 mm; P = 0·563). However, mrEMVI positivity was related to more metastatic disease (5-year rate 43 versus 26·3 per cent in the mrEMVI-negative group; P = 0·014), but not with increased lateral/presacral recurrence. mrEMVI occurred in 46·6 per cent of patients with nodes smaller than 10 mm, compared with 29 per cent in patients with nodes of 10 mm or larger (P = 0·267).

CONCLUSION

Although lateral nodal disease is more a local problem, mrEMVI mainly predicts distant recurrence. The results of this study showed an unacceptably high local recurrence rate in patients with a short axis of 10 mm or more, despite neoadjuvant (chemo)radiotherapy.

Orgaran (Org 10172) or Heparin for Preventing Venous Thrombosis after Elective Surgery for Malignant Disease? A Double-Blind, Randomised, Multicentre Comparison

This double-blind, randomised, multicentre trial in 513 patients having elective surgery for intra-abdominal or intrathoracic malignancy compared the efficacy and safety of venous thrombosis (VT) prophylaxis using 750 anti-factor Xa units of Orgaran (a mixture of low molecular weight heparinoids) given subcutaneously (sc) twice-daily with that of twice-daily injections of 5,000 units Standard heparin. The main study endpoints were the development of postoperative VT detected by 125I-fibrinogen leg scanning, and the onset of clinically significant venous thromboembolism or bleeding. “Intent to treat” analysis showed a statistically non-significant trend towards less VT during Orgaran prophylaxis (10.4%) than after heparin (14.9%) and there was no difference in bleeding complications between the two study groups. Results remained similar if only patients who completed the intended course of therapy (“compliant patients”) were analysed. Other trials have shown that Orgaran prevents VT after hip surgery and stroke. We now show it is also safe and effective in patients having major surgery for cancer.

Effect of divalent versus monovalent cations on the MS2 retention capacity of amino-functionalized ceramic filters

Ceramic capillary membranes conditioned for virus filtration via functionalization with n-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA) are analyzed with respect to their virus retention capacity when using feed solutions based on monovalent and divalent salts (NaCl, MgCl2). The log reduction value (LRV) by operating in dead-end mode using the model bacteriophage MS2 with a diameter of 25 nm and an IEP of 3.9 is as high as 9.6 when using feeds containing MgCl2. In contrast, a lesser LRV of 6.4 is observed for feed solutions based on NaCl. The TPDA functionalized surface is simulated at the atomistic scale using explicit-solvent molecular dynamics in the presence of either Na+ or Mg2+ ions. Computational prediction of the binding free energy reveals that the Mg2+ ions remain preferentially adsorbed at the surface, whereas Na+ ions form a weakly bound dissolved ionic layer. The charge shielding between surface and amino groups by the adsorbed Mg2+ ions leads to an upright orientation of the TPDA molecules as opposed to a more tilted orientation in the presence of Na+ ions. The resulting better accessibility of the TPDA molecules is very likely responsible for the enhanced virus retention capacity using a feed solution with Mg2+ ions.

Does X-ray imaging by GPC at emergency care access points in the Netherlands change patient flow and reduce ED crowding? A cohort study

OBJECTIVE

Organizing out-of-hours emergency care is a challenge in many countries. In the Netherlands, general practitioner cooperatives (GPCs) and emergency departments (EDs) are increasingly working together, creating one emergency care access point (ECAP). This has redirected the majority of patients with musculoskeletal problems from the ED to the GPC in out-of-hours care, due to the treatment of self-referrals by the general practitioner (GP). Only a minority of the GPs at ECAPs have the possibility to request X-rays, and expanding these facilities could reduce patient presentations to the ED even more. The aim of our study was to explore patient flow and possible reductions in ED referrals at an ECAP with X-ray facilities for GPs.

METHODS

This retrospective cohort study examines all patients that visited an ECAP at a general city hospital in the Netherlands and had an X-ray imaging requested by the GPC between January 1, 2014 and December 31, 2014. General practitioner cooperatives could request X-rays between 5 pm and 10 pm on weekdays and between 8 am and 10 pm during weekends. Recorded data included sex, age, number and type of X-ray, X-ray abnormalities, referral to the ED, and treatment. The annual number of patients presenting to the GPC and ED in 2014 were gathered. Patient outcome was stated negative when the X-ray revealed no abnormality.

RESULTS

A total of 2243 patients received 2663 X-ray examinations. The mean age was 31 years and 48% was male. A total of 1517 (68%) patients were treated at the GPC without an ED referral, a reduction of 4.5% of the annual ED patients.

CONCLUSIONS

With a majority (68%) of the patients examined and treated at the GPC, X-ray facilities at ECAPs will substantially reduce ED population, change patient flow, and have a positive effect on ED crowding. Implementing 24/7 X-ray facilities at all ECAPs will further enhance these effects.

Wrist cineradiography: a protocol for diagnosing carpal instability

Carpal instability is often related to ruptured or lax carpal ligaments. Wrist cineradiography has been shown to be a good modality for diagnosing carpal instability. To create uniformity in obtaining and assessing wrist cineradiography, a wrist cineradiography protocol is desirable. This protocol will focus on wrist cineradiography for diagnosing carpal instabilities. It describes the pathologic motions of the carpus and correlates these with a clinical diagnosis.

LEVEL OF EVIDENCE

III.