Cost-Utility Analysis of Total Ankle Replacement Compared with Ankle Arthrodesis for Patients Aged 50-85 Years with End-Stage Ankle Osteoarthritis: The TARVA Study

BACKGROUND

Patients with end-stage ankle osteoarthritis suffer from reduced mobility and quality of life and the main surgical treatments are total ankle replacement (TAR) and ankle fusion (AF).

OBJECTIVES

Our aim was to calculate the mean incremental cost per quality-adjusted life-year (QALY) of TAR compared with AF in patients with end-stage ankle osteoarthritis, over 52 weeks and over the patients' lifetime.

METHOD

We conducted a cost-utility analysis of 282 participants from 17 UK centres recruited to a randomised controlled trial (TARVA). QALYs were calculated using index values from EQ-5D-5L. Resource use information was collected from case report forms and self-completed questionnaires. Primary analysis was within-trial analysis from the National Health Service (NHS) and Personal Social Services (PSS) perspective, while secondary analyses were within-trial analysis from wider perspective and long-term economic modelling. Adjustments were made for baseline resource use and index values.

RESULTS

Total cost at 52 weeks was higher in the TAR group compared with the AF group, from the NHS and PSS perspective (mean adjusted difference £2539, 95% confidence interval [CI] £1142, £3897). The difference became very small from the wider perspective (£155, 95% CI -  £1947, £2331). There was no significant difference between TAR and AF in terms of QALYs (mean adjusted difference 0.02, 95% CI -  0.015, 0.05) at 52 weeks post-operation. The incremental cost-effectiveness ratio (ICER) was £131,999 per QALY gained 52 weeks post-operation. Long-term economic modelling resulted in an ICER of £4200 per QALY gained, and there is a 69% probability of TAR being cost effective at a cost-effectiveness threshold of £20,000 per QALY gained.

CONCLUSION

TAR does not appear to be cost effective over AF 52 weeks post-operation. A decision model suggests that TAR can be cost effective over the patients' lifetime but there is a need for longer-term prospectively collected data. Clinical trial registration ISRCTN60672307 and ClinicalTrials.gov NCT02128555.

Randomized Controlled Trial Comparing Early Mobilization vs Six Weeks of Immobilization in a Walking Cast Following Total Ankle Replacement

Rehabilitation for patients after total ankle replacement traditionally involves weeks of immobilization in a plaster cast followed by progressive mobilization. In a small randomized trial, we compared teh outcomes of patients who received a 3-component cementless, unconstrained, mobile-bearing prosthesis and were initially immobilised in a plaster cast for 6 weeks to thoese who received the same prosthesis but were allowed to mobilise early. Gait, clinical, patient-reported, and radiologic outcomes were measured. The study included 20 patients, 10 in the plaster cast group and 10 in the early mobilization group, and the demographics of the groups did not differ significantly. All patients were followed-up for 24 months. There were no significant differences between the 2 groups 2 years after surgery in ankle dorsiflexion, spatiotemporal gait characteristics, American Orthopaedic Foot and Ankle Society ankle-hindfoot scores, Timed Up and Go Test times, WOMAC (pain, stiffness, function) scores, SF-36 (quality-of-life) scores, or patient satisfaction (pain relief, daily-living, recreational activities, and overall) (all p > .05). Bone mineral density decrease of the medial malleolus and increase at middle tibia, calculated with DEXA scans, was significantly better in early mobilization than plaster cast group at one and 2 years postoperatively, but this was also the case preoperatively. The lack of differences in outcomes suggests that early ankle mobilization may be a safe and reliable method to enhance recovery following ankle arthroplasty with a 3-component cementless, unconstrained, mobile-bearing prosthesis. Compared to traditional plaster casting, patients who are engaged in early mobilization after arthroplasty may enjoy similar functional, mobility, quality-of-life, pain relief, activity level, and satisfaction outcomes.

Total Ankle Replacement Versus Arthrodesis for End-Stage Ankle Osteoarthritis: A Randomized Controlled Trial

BACKGROUND

End-stage ankle osteoarthritis causes severe pain and disability. There are no randomized trials comparing the 2 main surgical treatments: total ankle replacement (TAR) and ankle fusion (AF).

OBJECTIVE

To determine which treatment is superior in terms of clinical scores and adverse events.

DESIGN

A multicenter, parallel-group, open-label randomized trial. (ISRCTN registry number: 60672307).

SETTING

17 National Health Service trusts across the United Kingdom.

PATIENTS

Patients with end-stage ankle osteoarthritis, aged 50 to 85 years, and suitable for either procedure.

INTERVENTION

Patients were randomly assigned to TAR or AF surgical treatment.

MEASUREMENTS

The primary outcome was change in Manchester-Oxford Foot Questionnaire walking/standing (MOXFQ-W/S) domain scores between baseline and 52 weeks after surgery. No blinding was possible.

RESULTS

Between 6 March 2015 and 10 January 2019, a total of 303 patients were randomly assigned; mean age was 68 years, and 71% were men. Twenty-one patients withdrew before surgery, and 281 clinical scores were analyzed. At 52 weeks, the mean MOXFQ-W/S scores improved for both groups. The adjusted difference in the change in MOXFQ-W/S scores from baseline was -5.6 (95% CI, -12.5 to 1.4), showing that TAR improved more than AF, but the difference was not considered clinically or statistically significant. The number of adverse events was similar between groups (109 vs. 104), but there were more wound healing issues in the TAR group and more thromboembolic events and nonunion in the AF group. The symptomatic nonunion rate for AF was 7%. A post hoc analysis suggested superiority of fixed-bearing TAR over AF (-11.1 [CI, -19.3 to -2.9]).

LIMITATION

Only 52-week data; pragmatic design creates heterogeneity of implants and surgical techniques.

CONCLUSION

Both TAR and AF improve MOXFQ-W/S and had similar clinical scores and number of harms. Total ankle replacement had greater wound healing complications and nerve injuries, whereas AF had greater thromboembolism and nonunion, with a symptomatic nonunion rate of 7%.

PRIMARY FUNDING SOURCE

National Institute for Health and Care Research Heath Technology Assessment Programme.

Constructing custom-made radiotranscriptomic signatures from CT angiograms: an application in COVID-19 vascular inflammation

Background

Advances in computational methodologies have enabled processing of large datasets originating from imaging studies. However, most imaging biomarkers suffer from a lack of direct links with underlying biology, as they are only observationally correlated with pathophysiology.

Purpose

To develop and validate a novel AI-assisted image analysis platform, by applying quantitative radiotranscriptomics that quantifies cytokine-driven vascular inflammation from routine CT angiograms (CTA) performed as part of clinical care in COVID-19.

Methods

We used this platform to train the radiotranscriptomic signature C19-RS, derived from the perivascular space around the aorta and the internal mammary artery in routine chest CTAs, to best describe cytokine-driven vascular inflammation, defined using transcriptomic profiles from RNA sequencing data from human arterial biopsies (A). This signature was validated externally in 358 clinically indicated CT pulmonary angiograms from patients with or without COVID-19 from 3 different geographical regions.

Results

First, 22 patients who had a CTA before the pandemic underwent repeat CTA <6 months post COVID-19 infection (B). Compared with 22 controls (matched for age, gender, and BMI) C19-RS was increased only in the COVID-19 group (C). Next, C19-RS was calculated in a cohort of 331 patients hospitalised during the pandemic, and was higher in COVID-19 positives (adjusted OR=2.97 [95% CI: 1.43–6.27], p=0.004, D). C19-RS had prognostic value for in-hospital mortality in COVID-19, with HR=3.31 ([95% CI: 1.49–7.33], p=0.003) and 2.58 ([95% CI: 1.10–6.05], p=0.028) in two testing cohorts respectively (E, F), adjusted for clinical factors and biochemical biomarkers of inflammation and myocardial injury. The corrected HR for in-hospital mortality was 8.24 [95% CI: 2.16–31.36], p=0.002 for those who received no treatment with dexamethasone, but only 2.27 [95% CI: 0.69–7.55], p=0.18 in those who received dexamethasone subsequently to the C19-RS based image analysis, suggesting that vascular inflammation may have been a therapeutic target of dexamethasone in COVID-19. Finally, C19-RS was strongly associated (r=0.61, p=0.0003) with a whole blood transcriptional module representing dysregulation of coagulation and platelet aggregation pathways.

Conclusion

We present the first proof of concept study that combines transcriptomics with radiomics to provide a platform for the development of machine learning derived radiotranscriptomics analysis of routine clinical CT scans for the development of non-invasive imaging biomarkers. Application in COVID-19 produced C19-RS, a marker of cytokine-driven inflammation driving systemic activation of coagulation, that predicts in-hospital mortality and identifies people who will have better response to anti-inflammatory treatments, allowing targeted therapy. This AI-assisted image analysis platform may have applications across a wide range of vascular diseases, from infections to autoimmune diseases.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): EPSRC, British Heart Foundation, NIHR

Automated deep learning quantification of epicardial adiposity on cardiac CT predicts atrial fibrillation risk immediately following cardiac surgery and long-term

Introduction

Epicardial adipose tissue (EAT) is a visceral fat deposit within the pericardial sac which surrounds the heart myocardium and coronary arteries. The automated quantification of EAT volume is possible from routine CCTA scans via a deep-learning approach. The use of automated EAT quantification for the assessment of atrial fibrillation (AF) risk in the post-operative period, and longer-term, has not been previously investigated.

Purpose

To apply a deep-learning approach for automated segmentation of EAT from routine CCTA scans to assess the immediate post-operative and long-term risk of AF conveyed by EAT.

Methods

A deep-learning automated EAT segmentation tool using a 3D Residual-U-Net neural network architecture for 3D volumetric segmentation of CCTA data was created and trained on over 2800 consecutive CCTA performed as part of clinical care in patients with stable chest pain from 2015 onwards within the European arm of the Oxford Risk Factors And Non Invasive Imaging (ORFAN) Study. External validation in 817patients demonstrated excellent correlation between machine and human expert (CCC = 0.972). The prognostic value of deep-learning derived EAT volume was assessed in the AdipoRedOx Study (n=253; UK patients undergoing cardiac surgery) against both immediate in-hospital outcomes and longer-term outcomes from UK-wide NHS data, with adjustment for AF risk factors.

Results

There were 97 cases of new-onset AF in the immediate post-operative period (38.3%). EAT volume was found to be an independent predictor of post-operative AF regardless of body mass index. Utilising the median EAT volume as the cut point, the adjusted hazard ratio (HR [95% CI]) for risk of new-onset post-operative AF in-hospital was 1.56 [1.09–3.85], p&lt;0.01 (Figure 1A). In receiver-operator characteristic analysis EAT volume added significant incremental prognostic power for the discrimination of in-hospital post-operative AF over a traditional risk factor model ΔAUC=0.101, p&lt;0.01 (Figure 1B).

Over a median follow-up period of 89 months there were 48 unique cases (19%) of confirmed AF found in nation-wide NHS hospital episode statistics data for the AdipoRedOx cohort. EAT volume was found to be a significant independent predictor of long-term AF. Utilising the median EAT volume as the cut point, the adjusted HR for risk of new-onset long-term AF following cardiac surgery was 1.25 [1.08–3.17], p&lt;0.01 (Figure 1C).

Conclusions

Automatically segmented EAT volume measured using a deep learning network predicts risk of both short-term new onset AF following cardiac surgery, and long-term risk of AF in the 7 years following the surgery independently of BMI and AF risk factors. This suggests that EAT is a potent mediator of AF risk in the post cardiac surgery setting.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation - TG/19/2/34831EU Commission - 965286

Scanning 2d barcodes on vaccine vials to link vials to immunized child, a pilot study

Background

Vaccine stockouts contribute to millions of children missing their routine immunizations globally. This is often due to inadequate forecasting and management of vaccine stocks, especially in low and middle-income countries, such as Pakistan, already characterized by suboptimal coverage. Tracking vaccines via 2D barcodes on each vial, could improve management of vaccine stocks. Vial level data can then be linked to Electronic Immunisation Registry (EIR) data (2D Bar codes already used), facilitating data quality improvements which could unlock programmatic gains. Our aim was to test feasibility and acceptability of scanning vaccine vials in a “live” setting.

Methods

We conducted a pilot in 12 vaccination sites in Karachi/Pakistan. Vaccinators were divided into 3 groups and allocated to use one of the following: their existing android phone (government of Sindh's Zindagi Mehfooz [Safe life; ZM-EIR]); a Zebra touch computer; a handheld scanner. The box of dummy vaccine vials of pneumococcal conjugate vaccine (PCV) and oral polio vaccine (OPV) each with a 2D barcode on it, was scanned by the stockroom manager prior to deployment. Vaccinators were required to scan the corresponding dummy vial and immunization cards while working. We integrated the OneScanTM API on the ZM-EIR to link vial to child data and evaluated the vaccinator's experience through thematic analysis of interviews.

Results

2,310 vaccine vials were scanned and linked to immunized children (Zebra Touch Computer 72.6%, Android phone 19%, Handheld device 8.4%). Overall, vaccinators gave positive feedback and highlighted that scanning vials would simplify their work and save time, contingent on the program going paperless. Likewise, managers outlined digitally tracked vials would greatly reduce stock mismanagement.

Conclusions

Linking vaccine vial to child is a feasible and effective solution for vaccine stock management, acceptable by both vaccinators and stock managers.

Key messages

Linking vial to child is an acceptable method for accurate vaccine stock management and usage, improving forecasting and reducing stock outs. Linking vial to child will better facilitate rapid tracking of reported adverse events from vaccinated child back to the exact vaccine vial.

1-year impact of COVID-19 on childhood immunizations in Pakistan: analysis of &gt; 3.7 million children

 

Covid-19 has universally disrupted primary health care, but routine childhood immunizations are one the most affected services. We analyzed big data in vaccines for measuring the 1-year impact of Covid-19 on outline childhood immunizations for the 48 million population in the Sindh province of Pakistan. We extracted and analyzed >3.7m real-time immunization records of 0-23 months old children from the Sindh Government's Electronic Immunization Registry (EIR). Using a 6-month baseline preceding the COVID-19 lockdown, we quantified the lockdown's (March 23-May 9, 2020) impact on daily immunization rates by geographical area and the change in coverage rates at the one-year mark since the lockdown. The lockdown resulted in 53% drop in the number of immunizations. The impact in rural areas as more than in urban areas (54.9% decline vs 47.5% decline from baseline), and slums had a slightly larger decrease in immunization coverage than non-slum areas (53.8% vs. 51.3%). Of 1,246,321 children who missed immunizations during first year of the pandemic, 76% of these children were eventually vaccinated by the end of March 2021. Similarly, of the 417,553 children who had dropped out during the initial 7-week national lockdown (March 23-May 10, 2020), 79% were immunized by March 2021. Our analysis of EIR data shows that the catch-up and recovery of coverage rates have primarily been driven through intensive outreach vaccination efforts instead of an increase in demand. One year since the onset of the pandemic, the average daily immunization doses administered through outreach increased by 121 percent above baseline estimates. In contrast, vaccines administered at immunization clinics were still 22 percent below baseline. The example of Pakistan shows LMICs can successfully deploy mitigation strategies to catch up with missed children during Covid-19 and sustain routine childhood immunizations to close immunity gaps.

Key messages

Although the lockdown resulted in a 53% drop in immunizations, at the 1-year mark since the pandemic started, 76% of children who missed immunizations are vaccinated.

Pakistan data shows LMICs can rectify routine immunization coverage and immunity gaps and rebound successfully to their pre-COVID-19 coverage rates.

Automated quantification of epicardial adipose tissue on CCTA via deep-learning detection of the pericardium: clinical implications

Background

Epicardial adipose tissue (EAT) is a visceral fat deposit within the pericardial sac which surrounds the heart myocardium and coronary arteries. EAT volume has been demonstrated to be strongly associated with the development and prognosis of cardiovascular diseases, but its measurement is subjective and challenging in practice.

Purpose

To develop a deep-learning approach for automated segmentation of EAT from routine CCTA scans, that could assist clinical interpretation of CCTA.

Methods

A deep-learning method using a 3D Residual-U-Net neural network architecture for 3D volumetric segmentation of CCTA data was created. The network was trained on a diverse sample of 1900 CCTAs, each manually segmented by a single expert, drawn from the UK sites of the Oxford Risk Factors And Non-invasive imaging (ORFAN) Study. Three iterations of feedback learning were used to fine tune the algorithm for the segmentation of the whole heart within the bounds of the pericardium. In each iteration, the machine analysed sets of 100–250 unannotated CCTAs unseen by the machine which were then corrected by experts. EAT volumes were calculated by automated thresholding of adipose tissue (−190HU through −30HU) from within the bound of the pericardial segment (Figure 1). The network was then applied to 817 unseen CCTAs from US sites of the ORFAN Study. These scans were also segmented for ground truth by two experts blind to all other data. Comparisons between machine vs expert total pericardial volume and EAT volume were made using Lin's concordance correlation coefficient (CCC). The algorithm was then applied externally in 1588 CCTAs from the SCOTHEART trial (UK), and the EAT volume was automatically calculated for each case. Cross-sectional associations between standardised EAT volumes and prevalent AF and CAD were performed.

Results

Within both the internal (UK ORFAN sites) and external (USA ORFAN sites) validation cohorts correlation between human and machine segmented total pericardium and EAT was excellent, with CCC of 0.97 for both volumes (external validation cohort shown in Figure 2A). Utilising SCOTHEART CCTAs with automatically segmented EAT volumes, a multivariable-adjusted logistic regression model accounting for risk factors of age, sex, BMI, hypertension, diabetes mellitus, valvular disease, and previous heart surgery found that EAT volumes were significantly associated with prevalent AF, with odds ratio (OR) per 1 SD increase of EAT volume of 1.20 (95% CI, 1.06 to 1.44; P=0.03). A similar model for prevalent CAD, adjusted for age, sex, BMI, hypertension, non-HDL cholesterol, diabetes mellitus, and coronary artery calcium score resulted in an OR per 1 SD increase of EAT volume of 1.26 (95% CI, 1.10 to 1.45; P=0.001) (Figure 2B).

Conclusion

Highly accurate, reproducible, and instantaneous EAT volume quantification is possible utilising deep-learning detection of the whole human heart within the pericardial sac.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): British Heart FoundationNational Institute for Health Research - Oxford University Hospitals Biomedical Research Centre Figure 1Figure 2

A human arterial transcriptomic signature predicts major adverse cardiac events and identifies novel, redox-related therapeutic targets within the vascular wall

Background

The transcriptomic profile of the human vascular wall is implicated in a range of pathologies. RNA sequencing technologies allow for interrogation of gene expression patterns that are associated with clinical outcomes and can guide future research and drug development.

Purpose

To apply discovery network transcriptomics to internal mammary arteries (IMAs) obtained from patients undergoing cardiac surgery, in order to identify redox-related molecular pathways within the vascular wall that can be treated therapeutically.

Methods

Arm 1 included 377 patients in whom segments of IMA were used for ex-vivo quantification of NADPH-stimulated superoxide production by lucigenin-enhanced chemiluminescence. Arm 2 included 205 patients in whom bulk RNA sequencing was performed in RNA isolated from IMA, and the WGCNA package used for the analyses. The association with future incidence of major adverse cardiac events (MACE: cardiovascular death, non-fatal myocardial infarction, and stroke) was assessed using Cox regression models (adjusted for age, sex, hypertension, dyslipidaemia, diabetes mellitus, body mass index, smoking, and plasma TNFa).

Results

Over a median follow-up of 4.84 years [IQR: 2.03–7.14], 38 (11.2%) MACE occurred in Arm 1. High arterial NADPH-stimulated superoxide was independently associated with MACE risk (Adj. HR [95% CI]: 2.62 [1.13–6.07] high group, p=0.02). Unsupervised transcriptomic analysis in Arm 2 allowed identification of 10 coexpressed gene “modules”. Eigengenes summarising modular coexpression signatures were then correlated with NADPH-stimulated superoxide revealing the red module (a) as the most significant (rho=0.19, p=0.01). In survival analysis the red module showed significant correlation with MACE (Adj. HR [95% CI]: 1.40 [1.00–1.95] per SD, p=0.04). For an optimal cut-off, patients with high eigengene values for the red module showed a 4-fold higher risk of MACE (b), and significantly higher arterial oxidative stress (c). Enrichment analysis (performed with Enrichr) of genes in the red module revealed “Electron Transport Chain”, “Oxidative phosphorylation”, “Striated Muscle Contraction Pathway”, and “Glycolysis and Gluconeogenesis” amongst the top enriched pathways (d).

Conclusion

We present for the first time a novel human arterial transcriptomic signature reflecting changes in redox state, which identifies long-term cardiovascular risk. Targeting pathways in the vasculature related with the mitochondrial electron transport chain, the contractile mechanism, or glucose metabolism may lead to the development of novel therapeutics in cardiovascular disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): EPSRC-EP/N509711/1-2119518British Heart Foundation Figure 1

Barriers to recruitment to an orthopaedic randomized controlled trial comparing two surgical procedures for ankle arthritis : a qualitative study

Aims

A multicentre, randomized, clinician-led, pragmatic, parallel-group orthopaedic trial of two surgical procedures was set up to obtain high-quality evidence of effectiveness. However, the trial faced recruitment challenges and struggled to maintain recruitment rates over 30%, although this is not unusual for surgical trials. We conducted a qualitative study with the aim of gathering information about recruitment practices to identify barriers to patient consent and participation to an orthopaedic trial.

Methods

We collected 11 audio recordings of recruitment appointments and interviews of research team members (principal investigators and research nurses) from five hospitals involved in recruitment to an orthopaedic trial. We analyzed the qualitative data sets thematically with the aim of identifying aspects of informed consent and information provision that was either unclear, disrupted, or hindered trial recruitment.

Results

Recruiters faced four common obstacles when recruiting to a surgical orthopaedic trial: patient preferences for an intervention; a complex recruitment pathway; various logistical issues; and conflicting views on equipoise. Clinicians expressed concerns that the trial may not show significant differences in the treatments, validating their equipoise. However, they experienced role conflicts due to their own preference and perceived patient preference for an intervention arm.

Conclusion

This study provided initial information about barriers to recruitment to an orthopaedic randomized controlled trial. We shared these findings in an all-site investigators’ meeting and encouraged researchers to find solutions to identified barriers; this led to the successful completion of recruitment. Complex trials may benefit for using of a mixed-methods approach to mitigate against recruitment failure, and to improve patient participation and informed consent.

Cite this article: Bone Jt Open 2021;2(8):631–637.

Total Joint Replacement of Ankle, Knee, and Hip: How Do Patients Perceive Their Operative Outcomes at 10 Years?

Background:

Patient-reported outcomes (PROMs) are an integral part of national joint registers in measuring outcomes of operative procedures and improving quality of care. There is lack of literature comparing outcomes of total ankle replacement (TAR) to total knee replacement (TKR) and total hip replacement (THR). The aim of this study was to compare PROMs between TAR, TKR, and THR patient groups at 1, 5, and 10 years.

Methods:

Prospective PROMs from patients who underwent a TAR, TKR, or THR procedure between 2003 and 2010 were studied. Patients were divided into 3 groups based on their index joint replacement (hip, knee, or ankle). Patient demographics (age, gender, body mass index), patient-reported outcome scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], 36-Item Short Form Health Survey [SF-36]) and patient satisfaction scores (4-point Likert scale) at follow-up were compared between the 3 groups.

Results:

Data was available on 1797 THR, 2475 TKR, and 146 TAR patients. TAR patients were younger and reported fewer number of comorbidities. All 3 groups improved significantly from preoperative to 10 years for WOMAC scores (P < .001). For SF-36 scores at 10 years, the THR group (32.2% follow-up) scored the highest for 3 domains (P = .031) when compared to the TKR group (29.1% follow-up). All 3 groups had similar outcomes for 5 of 8 domains; P < .05). For patient satisfaction, the THR group reported overall 95.1% satisfaction followed by 89.8% for the TKR group and 83.9% in the TAR group (42.4% follow-up).

Conclusion:

In this cohort with diminishing numbers over the decade of time the patients were followed up we found that patients are equally happy with functional and general health outcomes from total ankle replacement vs other major lower extremity joint replacement. TAR surgery should be considered as a viable treatment option in this patient group.

Level of Evidence:

Level III, retrospective case series.

A novel arterial redox-specific machine learning-derived radiomic signature of perivascular adipose tissue predicts cardiac mortality from routine CCTA

Background

Vascular oxidative stress is involved in inflammation and atherogenesis. Vascular inflammation induces spatial changes in perivascular adipose tissue (PVAT) composition, which can be detected by radiomic analysis of coronary computed tomography angiography (CCTA) images.

Purpose

To explore the association of arterial oxidative stress with long-term risk of major adverse cardiovascular events (MACE). To develop a radiomic signature to identify high oxidative stress non-invasively using CCTA. Finally, to assess the ability of this signature to predict future cardiac risk.

Methods

Arm 1 included 272 patients undergoing cardiac surgery. Segments of internal mammary artery (IMA) were used for ex-vivo quantification of NADPH-stimulated and Vas2870 (pan-NOX inhibitor) inhibitable superoxide production by lucigenin-enhanced chemiluminescence. Eighty-two of these patients with CCTA scans available constituted Arm 2. Peri-IMA PVAT was segmented and used to extract 1,616 radiomic features, which, after filtering (40 final features), were utilised to train extreme gradient boosting, a machine learning algorithm, to predict high arterial oxidative stress. Arm 3 included a nested cohort of 308 participants (41 suffering cardiac death and 267 matched controls) from the CRISP-CT (Cardiovascular RISk Prediction using Computed Tomography) study to externally validate the redox-specific signature developed in Arm 2 for cardiac risk prediction.

Results

Over a median follow-up of 40 months, 18 (6.6%) MACE (cardiovascular death, non-fatal myocardial infarction, and stroke) occurred in Arm 1. High arterial NADPH-stimulated superoxide was independently associated with MACE risk (Adj. HR[95% CI]: 1.61 [1.04–2.53] per SD, p=0.03, adjusted for age, sex, diabetes, hypertension, hyperlipidemia, smoking, obesity, and plasma TNFa). Unsupervised hierarchical clustering of radiomic features from peri-IMA PVAT segments in Arm 2 identified two distinct clusters (A) that differed in NADPH stimulated (p=0.01) and Vas2870 inhibitable (p=0.04) IMA superoxide (B), supporting the hypothesis that PVAT mapping can capture changes corresponding to differential levels of underlying vascular redox state. This prompted the development of a radiomic signature specific to PVAT alterations associated with high vascular oxidative stress, which was validated in Arm 3 (AUC:0.61, p=0.026, C). The novel signature was able to stratify cardiac risk in the validation set, independently of the Fat Attenuation Index, epicardial adipose tissue volume, high-risk plaque features, and obstructive CAD (Adj. HR [95% CI]:2.56 [1.35–4.87], p=0.004, D).

Conclusion

Increased arterial oxidative stress predicts cardiac risk in patients with advanced atherosclerosis. We present for the first time a novel, non-invasive CCTA imaging biomarker reflecting changes in vascular redox state by radiomic phenotyping of perivascular space, which stratifies cardiac risk beyond standard and newer risk assessment methods.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation, National Institute of Health Research, Oxford Biomedical Research Centre

Using mobile immunization vans to cover under-served populations in hard-to-reach areas

Background

In Pakistan, only 66% of children receive their basic vaccinations. However, the figure masks significant inequalities in vaccine coverage between urban and rural residences, slums and areas distantly located from EPI centers. Frequent outbreaks of vaccine-preventable diseases such as polio and measles, in urban cities like Karachi, signal the need for expanding vaccine services to underserved areas. In Apr'19, we introduced the Mobile Immunization Van initiative in Karachi in collaboration with EPI Sindh. Currently, two vans are deployed in hard-to-reach areas and slums to immunize under-2 children for routine vaccines.

Methods

Before the van visit, mobilization efforts are conducted in targeted areas to encourage caretakers to bring their child for vaccination. On the day of visit, the van is parked at a central location, and announcements are played on a loudspeaker to attract caregivers. All vaccinations are administered in the van, and entries are recorded in Government's Digital Immunization Registry along with GIS coordinates of immunized children. The data is then automatically transferred on to a web-dashboard for analysis and tracking.

Results

From Apr'19 to Jan'20, the vans have vaccinated 2,867 children, out of which 50% had never been immunized prior to the van visit. Of those who received their follow-up vaccines from the van, 80% were at least 4 weeks beyond from their vaccine due date. GIS analysis of van data confirmed that immunizations were conducted in slums, and areas distantly located from EPI centers. Moreover, compared to government outreach activity, proportion of BCG, Penta3 and Measles1 administrations in slums was higher through the vans by 5%, 6%, and 4% respectively.

Conclusions

The vans provide an opportunity for immunizing never-vaccinated children and children defaulting on their vaccine schedule, from the most vulnerable geographies, while simultaneously enrolling them in the Government's EPI Program for effective tracking.

Key messages

The mobile vans help achieve universal immunization coverage through provision of vaccine services in slum and rural hard-to-reach areas with limited access to government-provided services. The mobile vans help vaccinate and capture never-immunized children into the Government’s EPI records, reducing the number of children missed through routine services.

AB1183 TERIPARATIDE SWITCH TO BIOSIMILAR - IS IT COST EFFECTIVE?

Background:

Teriparatide is an effective treatment option for osteoporosis however NICE restricts its use to patients with high disease burden. This was based on cost effectiveness evaluation of the originator (Forsteo®) and would be different for recently introduced generic preparation.

Objectives:

We wished to evaluate the current prescribing behaviour prior to a potential switch to generic version and associated cost savings.

Methods:

All patients prescribed Teriparatide since the commencement of specialist osteoporosis service in Aug 2014 at our University teaching hospital covering 350,000 population were included. Data was extracted from electronic database with full access to demographics, population characteristics, disease parameters and medication history.

Results:

113 patients were prescribed Teriparatide over five years. Mean age of participants was 76 yrs (53-96). They had on average three comorbidities (0-8) with most common being hypertension (n=44, 38.9%) and inflammatory arthritis (n=21, 18.5%). Sixteen (14.1%) individuals had concurrent corticosteroids. Median number of fractures prior to therapy were four (0-12). Prior treatments included oral therapy (n= 90,79.6%), IV zoledronate (n=22, 19.4%) and denosumab (n=19, 16.8%). 66 (58.4%) of patients only had one prior bone active medication. Mean duration of prior therapy was 62.4 months (9-192 months). 17 (15.0%) patients had chronic kidney disease with lowest eGFR of 38. 41 (36.2%) had Vit D level between 40-75 nmol/L. Median T score was -3.8 (-2.1 - -6.0) which improved to -3.4 (-2.9 - -3.9) after two years.

Conclusion:

Our real-world study shows that teriparatide is used predominantly in complex, multi-morbid older individuals with several prior fractures. Despite that teriparatide remains effective for a wide range of individuals including those with inflammatory arthritis and/or concurrent steroid use. Neither moderate CKD nor mild Vit D insufficiency seems to impact its efficacy. This is in line with recent meta-analysis of real life teriparatide use in complex osteoporosis with multimorbidity. Our study should enhance clinicians’ confidence in its prescribing. It’s notable that the use is higher than current estimates based on NICE cost effectiveness analysis for eligibility of teriparatide. Instead of annual predicted use of 4.8/100,000 population, it was prescribed to 6.4/100,000. This could potentially have a cost impact however the introduction of a generic version would mitigate against it. We calculated our savings to be over £125,000 if all patients were switched. These savings at national level would hopefully improve access to a wider patient cohort and perhaps allow earlier use in the treatment paradigm.

Disclosure of Interests:

Tahreem Akram: None declared, Maham Siddique: None declared, Hafiz A. Javed: None declared, Julie Begum: None declared, Joanne Fourmy: None declared, Muhammad Khurram Nisar Grant/research support from: Muhammad Nisar undertakes clinical trials and received support (including attendance at conferences, speaker fees and honoraria) from Roche, Chugai, MSD, Abbvie, Pfizer, BMS, Celgene, Novartis and UCB

, Consultant of: Muhammad Nisar undertakes clinical trials and received support (including attendance at conferences, speaker fees and honoraria) from Roche, Chugai, MSD, Abbvie, Pfizer, BMS, Celgene, Novartis and UCB

, Speakers bureau: Muhammad Nisar undertakes clinical trials and received support (including attendance at conferences, speaker fees and honoraria) from Roche, Chugai, MSD, Abbvie, Pfizer, BMS, Celgene, Novartis and UCB

The Effect of Sagittal and Coronal Balance on Patient-Reported Outcomes Following Mobile-Bearing Total Ankle Replacement

Total ankle replacement (TAR) is an established technique for the treatment of end-stage ankle arthritis. The aims of TAR include pain relief, preservation of tibiotalar movement, protection of adjacent joints, and restoration of anatomic alignment in the coronal and sagittal planes. The aims of this study were to determine the relative importance of pre- and post-TAR coronal and sagittal balance on postoperative patient-reported outcome measures (PROMs). A total of 101 ankles in 99 patients were included in this retrospective cohort study. Patients were scored preoperatively and at a minimum of 2 years by using the Foot and Ankle Outcome Score (FAOS), the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle score, the Short Form-36 measures, and a set of radiographic measurements to define the sagittal and coronal alignment. There was no significant difference between the groups regarding the anterior or posterior translation of the talus preoperatively. There were no statistically significant correlations between any preoperative measure and any domain of the PROM data. Significant correlations were observed between postoperative medial distal tibial angle and the function domain of the FAOS and the AOFAS hindfoot-ankle score. Preoperative coronal and sagittal plane deformity are not markedly different, depending on the diagnosis. Preoperative deformity does not appear to correlate significantly with postoperative function, as measured by the PROM scores. Postoperative sagittal plane alignment does not correlate significantly with postoperative function, as measured by PROMs. Coronal plane alignment, as measured by the medial distal tibial angle, may be associated with postoperative function, as measured on the AOFAS hindfoot-ankle and FAOS function subscales.

Non-union Rates in Hind and Midfoot Arthrodesis in Current, Ex-, and Non-smokers

Category:

Hindfoot

Introduction/Purpose:

Arthrodesis is a safe and effective treatment for a number of hind and midfoot conditions. However, non-union rates have historically been reported as high as 41%. A number of factors have been identified that increase non-union rates, the most notable and readily modifiable is a patient’s smoking status. Smoking rates in the UK in 2015 were 19.3% for men and 15.3% for women. We have examined the effect of smoking status (current, ex-smokers and non-smokers) on union rates for a large cohort of patients undergoing hind or midfoot arthrodesis.

Methods:

This is a single surgeon, retrospective cohort study of consecutive cases. The surgeon’s logbook was used to identify patients undergoing any hind and midfoot arthrodesis procedures from January 2010 until September 2016. Revision procedures and charcot arthropathy cases were excluded along with cases with insufficient records available. Demographic data was collected along with: joints involved, surgical implant used, bone grafting, the use of ultrasound bone stimulation (EXOGEN, Bioventus LLC, Durham, USA) therapy, complications and final outcome with regards to union. Patients were divided according to self-reported smoking status at pre-operative assessment; current smokers, ex-smokers and non-smokers. Union outcome was based on clinical notes and included patient symptoms and radiographic evidence. Delayed union was classed as union occurring after 6 months. The effect of smoking status on deep infection rates and the need for EXOGEN therapy was also analysed.

Results:

381 joints were included (see image). The smoking prevalence was 14.0% (accounting for 12.3% of joints) and 32.2% ex-smokers (35.4%). The groups were comparable with regards to gender, diabetes status and BMI. Smokers were younger, had less co-morbidities and were less likely to have had multiple joints fused (p<0.05). Non-union rates were statistically higher in current smokers with a relative risk of 5.81 (95% CI 2.54-13.29, P<0.001), there was no statistically significant difference between ex-smokers and non-smokers. Active smokers had higher rates of deep infection (P=0.05) and the need for EXOGEN use (P<0.001). Within the smoking group there was a trend toward slower union (delayed + non-union) with heavier smoking (p=0.054).

Conclusion:

This large retrospective cohort study confirms previous evidence that smoking has a considerable negative effect on union in arthrodesis (despite other differences between the groups likely to favour union in smokers). A 5.8 relative risk in a modifiable risk factor is extremely high. Arthrodesis surgery should be undertaken with extreme caution in patients who are actively smoking. Our study shows that after cessation of smoking the risk returns to normal, however we have not quantified the time frame. Further research is needed to quantify the necessary time frame for smoking cessation to reduce non-union risk.

Total Ankle Replacement for Osteoarthritis Following Pilon Fracture of the Tibia

BACKGROUND

Outcomes for total ankle replacement (TAR) performed for osteoarthritis following pilon fracture are underreported. We compared the outcomes between different indications for TAR.

METHODS

Patient-reported outcome measures (PROMs) for TAR performed from 2006 to 2014 by a single surgeon were reviewed. Foot and Ankle Outcome Score (FAOS), SF-36, comorbidities, self-reported body mass index (BMI), and patient satisfaction scores were reviewed. Data were collected preoperatively and at 1 and 2 years postoperatively. Clinical notes and radiographs highlighted the indication for TAR. The following subgroups were created: osteoarthritis (OA), rheumatoid arthritis (RA), pilon fracture (PF), ankle fracture (AF), and posttraumatic arthritis without previous fracture (PTOA). PROMs were available for 173 TARs: 89 (51.4%) for OA, 36 (20.8%) for AF, 21 (12.1%) for RA, 15 (8.7%) for PF, and 12 (6.9%) for PTOA. The pilon fracture group were the youngest and had the highest BMI (mean, 56.5 years; mean BMI, 31.6 kg/m²). No difference was found in number of reported comorbidities ( P > .05).

RESULTS

Significant improvement in FAOS scores was seen in all subgroups from preoperatively to 1 year ( P = .01, .05, and .03). SF-36 had similar results for all subgroups with improvement in all parameters by 2 years. Significant improvement in role physical and role emotional domains was seen by 1 year following TAR ( P = .018 and P = .042). Patient satisfaction scores were similar in each group. There was no major difference in any of the reported outcomes between subgroups by 2 years postoperatively.

CONCLUSION

We found similar outcomes for patients who underwent TAR after pilon fracture compared to other indications.

LEVEL OF EVIDENCE

Level III, comparative study.

PROMS and Radiological Outcomes in Mobile Bearing Total Ankle Arthroplasty for Patients with Varus or Valgus Deformity

Category:

Ankle Arthritis

Introduction/Purpose:

There is increasing evidence that outcomes for total ankle arthroplasty (TAA) are not adversely affected by pre-operative varus deformity. There is a sparsity of evidence relating to outcomes in valgus ankle arthritis. We present our outcomes using a mobile bearing prosthesis (Mobility TAA system, DePuy, Raynham, Massachusetts, USA) with a comparison of neutral, varus and valgus ankles.

Methods:

This is a single surgeon, retrospective cohort study of consecutive cases. Cases were identified from a locally held joint registry which routinely records PROMS data pre-operatively and at annual intervals. Patients undergoing primary TAA between March 2006 and June 2014 were included. Rrevision procedures along with those with inadequate radiographic images for deformity analysis were excluded. Patients with inadequate PROMS data were included in the radiological analysis but not the PROMS analysis. Data collected included FAOS (Womac Pain, Function and Stiffness), SF-36 scores and patient satisfaction. Radiological data was gathered from routinely taken AP weight bearing radiographs pre-operatively, immediately post-operatively and at final follow up. Pre-operative deformity was measured between the tibial anatomical axis and a line perpendicular to the talus. Patients were classified as neutral, varus (≥10 degrees varus) or valgus (≥10 degrees valgus).

Results:

230 cases (see image) underwent radiological classification (152 neutral, 60 varus, 18 valgus) and were included in the radiological analysis (mean follow-up 55.9 months). 164 cases were included in the PROMS analysis (mean follow-up 61.6 months). The groups were similar with regards to BMI and length of follow-up but neutral ankles were younger (P<0.001). Baseline scores were equal except physical health with valgus ankles scoring lowest (P=0.045). Valgus ankles had statistically better post-operative pain (P=0.0247) and function (P=0.012) than neutral ankles. Pre to post-operative change did not reach statistical significance except physical health where valgus outperformed neutral and varus (p=0.039). Mean post-operative angle was 3.1 and final angle 3.7 with no significant differences. There was no significant differences in revision rates.

Conclusion:

Our study confirms previous evidence that varus deformity does not affect outcome in TAA. Contrary to this, valgus ankles in our cohort performed better post-operatively than neutral ankles. Post-operative coronal radiological alignment was not affected by pre-operative deformity and was maintained over a number of years. Coronal plane deformity does not negatively impact either radiological or clinical outcomes in TAA should not be considered an absolute contra-indication.

The Prevalence of Degenerative Changes in Foot of Patients Presenting with Ankle Arthritis

Category:

Hindfoot

Introduction/Purpose:

Prevalence of degenerative disease of the joints of the foot is likely to be very low in the general population, as demonstrated by a previous cadaveric study (Muehleman et al. Osteoarthritis and Cartilage, 1997; 5 (1): 23-37). We hypothesised that the prevalence of these changes may be higher in patients presenting with ankle arthritis and we report the prevalence of these additional findings and their effect on patient-reported outcomes (PROMS) at presentation.

Methods:

247 patients presented to our unit with ankle arthritis, which later went on to require total ankle replacement and were therefore included in our local joint replacement registry. Of these, 125 had available pre-operative MRI imaging. These images were reviewed by an orthopaedic resident and consultant radiologist.

Results:

93 patients had evidence of degenerative change to other joints in the foot. The mean number of other joints affected was 1.25. The most common joints affected were the subtalar (67), talonavicular (32), tarsometatarsal (28), naviculocuneiform (21) and calcaneocuboid (5) joints. 92 patients had completed pre-operative FAOS scores. Multiple ANOVA of this data demonstrated no significant difference between the group with only ankle arthritis and those with other degenerative joints in terms of pre-operative FAOS score (p >0.05). In a subset of 19 patients who had pain diagrams available, most patients did not indicate areas of pain in the regions of their other degenerative joints. Pain drawings suggested 0% TMTJ, 25% TNJ and 78% subtalar joints were symptomatic at presentation.

Conclusion:

Most patients presenting with ankle arthritis will have at least one additional area of significant degenerative joint disease somewhere in the foot. Many of these will not be overtly symptomatic at the time of presentation and number and location of other degenerative joints in the foot does not result in significant differences in pre-operative PROMS, from those reported in patients with only ankle arthritis.

Do Pain, Functional Disability, and Gait in End-stage Ankle Arthritis Worsen with Associated Varus Coronal Plane Deformity?

Category:

Ankle Arthritis

Introduction/Purpose:

There is paucity of literature on quantitative gait changes in patients with increased coronal plane deformity along with end stage ankle arthritis. We aimed to study the difference in spatial temporal parameters of gait and patient reported functional measure in patients with end stage arthritis and no coronal plane deformity vs. varus deformity of >10?

Methods:

All patients diagnosed with end stage arthritis between April 2016 and December 2017 underwent an objective gait assessment using Tekscan system (BioSense Medicals, UK) as part of routine clinical practice. Of this cohort, patients with bilateral ankle arthritis, previous reconstructive surgery, inflammatory arthritis, hip and knee arthritis, spinal pathology and underlying neurological conditions were excluded. Patients with unilateral ankle arthritis for a diagnosis of osteoarthritis or post traumatic arthritis were included in this study. These patients were grouped into Group A (no coronal plane deformity) vs. Group B (varus deformity of more than 10?). In these patients differences were studied between the groups for temporal spatial parameters of gait and functional disability levels measured by MOX-FQ scores. Statistical tests included normality tests, student t’tests, chi square evaluation and analysis of variance tests with SPSS.

Results:

Of 33 patients, 22 were in Group A (N=22) and 10 in Group B (N=10). There was no difference in mean age between groups (61.5 vs. 65.07; p=0.335; diagnosis was predominantly OA in both groups MOX-FQ: -  There were similar levels of pain (p=0.570), difficulty with walking / standing (p=0.492) and restriction in social activities (p=0.869) reported Quantitative gait measures: -  For spatial parameters, there was no difference between groups; p>0.05. -  For temporal parameters, there was decreased step time(s) (0.67 vs. 0.61) and mid stance times (0.38 s vs. 0.30 s) in Group B; borderline statistical significance (p=0.052). -  There was increase in stride velocity measured in Group B (79.1 ± 22.7 m/s) compared to Group A (64.0 ± 18.1 m/s), (p=0.05).

Conclusion:

-  Although there were no differences in functional levels of pain, difficulty with walking / standing and restriction in social activities, measured by MOX-FQ, there were differences observed in objective gait parameters. -  Patients in both groups demonstrated antalgic gait patterns; this was slightly increased in varus group. -  There is a trend for reduction in temporal parameters and stride velocity in patients with end stage ankle arthritis and coronal plane deformity >10?, when compared to patients with end stage arthritis and no coronal plane deformity -  Larger clinical study with increased sample size is required to confirm these findings.

Does Hallux Rigidus produce worse functional disability than Hallux Valgus?

Category:

Midfoot/Forefoot

Introduction/Purpose:

There is paucity of literature comparing foot and general health status including quality of life between patients presenting with Hallux Valgus and Hallux Rigidus. We aimed to compare foot specific patient reported disability and general health status including higher functional activities and quality of life reported between patients presenting with Hallux Valgus and Hallux Rigidus.

Methods:

All patients who presented at our hospital foot and ankle clinics (between June 2016 and December 2017) with a diagnosis of primary Hallux Valgus or Hallux Rigidus were included in this prospective study. Patients with associated foot problems, bilateral presentations, h/o previous reconstructive surgeries, and underlying neurological conditions were excluded. These patients were grouped based on diagnosis into Group A (Hallux Valgus) and Group B (Hallux Rigidus). In these patients, differences were studied between groups for scores of MOX-FQ Manchester-Oxford foot questionnaire (Domains: Pain, Walking/Standing, Social activities), EQ-5D EuroQol (UK) and Foot and Ankle outcomes scores (FAOS) (Domains: Pain, symptoms, ADL, Recreation, Quality of Life). Statistical tests between groups included tests for normality, student t’tests and chi square tabulation tests using SPSS software.

Results:

MOX-FQ differences: -  Both groups reported similar level of pain (59.6 ± 22.6 vs. 58.2 ± 23.3); p=0.776; Difficulty with walking/ standing (61.6 vs. 61.4 ); p= 0.960; and restriction with social activity because of foot symptoms (61.6 vs. 59.7 ); p=0.683 EQ-5D: -  For mobility, both groups reported no (21.7% vs. 26.8); slight (28.2% vs. 29.2%) or moderate (34.7% vs. 31.7%) problems; p=0.931. For self-care, pain/discomfort, anxiety/ depression levels, there was no differences between groups; p>0.05. Mean overall general health scores was (71.3 ± 22.8) and (69.5 ± 20.8); p=0.663 FAOS: -  There was no difference in mean pain score (59.6 vs. 58.2; p=0.776), symptoms (70.3 vs. 63.8; p=0.104), ADL score (p=0.587), difficulty with sport/ recreation (p=0.907) or Quality of Life (p=0.662) between groups

Conclusion:

-  There is no difference in foot related quality of life, general health status and higher functional disability levels between patients presenting with Hallux Valgus vs. Hallux Rigidus. -  The impact of these conditions on disability levels remain the same, amidst the difference in pathology

Ankle Arthroplasty

Category:

Ankle Arthritis

Introduction/Purpose:

Total ankle arthroplasty (TAA) has been shown to be an effective treatment for end stage ankle arthritis. Achieving normal anatomical alignment has been shown to be important in long term outcomes and revision rates. Recent data from the British NJR has shown that revision rates are higher in patients with pre-operative fixed equinus. Although there is literature about surgical techniques to deal with pre-operative equinus we are not aware of any papers presenting patient outcomes. We present patient reported outcomes for our cohort of patients with pre-operative fixed equinus compared to those able to achieve a plantigrade ankle.

Methods:

This is a single surgeon, retrospective cohort study of consecutive cases. A mobile bearing prosthesis was used (Mobility TAA system, DePuy, Raynham, Massachusetts, USA). Cases were identified from a locally held joint registry which routinely records PROMS data pre-operatively and at annual intervals post-operatively. Patients undergoing primary TAA between March 2006 and June 2014 were included, revision procedures along with those with inadequate PROMS data were excluded. PROMS scores used were FAOS (WOMAC Pain, Function and Stiffness), SF-36 scores and patient satisfaction. All pre-operative lateral weight bearing xrays were reviewed to screen for potential fixed equinus deformity (tibia-sole angle >90 degrees). Clinical records were then reviewed to confirm clinical diagnosis of fixed equinus deformity.

Results:

259 cases were identified, 95 cases were excluded based on our criteria leaving 164 cases for analysis (mean follow up 61.6 months). 144 were classified as neutral and 20 as fixed equinus. The fixed equinus group were significantly younger (neutral 64.2 vs equinus 53.9, p=0.0002), there was no difference in BMI or length of follow up. There was no difference in baseline scores except WOMAC stiffness, with the fixed equinus group significantly worse (36.9 vs 25.6, p=0.0014). Final PROMS score, change from baseline and patient satisfaction was the same in all domains for both groups. There was no difference in revision rates.

Conclusion:

A pre-operative fixed equinus deformity does not negatively impact on clinical outcomes in patients undergoing TAA. We are not aware of any previous studies to compare results. As expected the equinus group showed higher levels of stiffness pre-operatively. Contrary to the British NJR dataset we did not find a difference in revision rates.

2017 IFFAS Award for Excellence Winner

Category:

Ankle Arthritis

Introduction/Purpose:

Pilon fractures of the distal tibia are high energy injuries often occurring in a young patient cohort. Despite optimal acute fracture management, post traumatic osteoarthritis of the tibiotalar joint is a common corollary. Standard treatment is by way of tibiotalar arthrodesis, however the lack of motion at the ankle afforded by this treatment is often poorly tolerated by patients and can lead to arthrosis of adjacent joints. Total ankle replacement (TAR) offers an attractive pain relieving and motion preserving option for this patient subgroup. Here we report the two-year patient reported outcome measures for a cohort of patients undergoing TAR for osteoarthritis secondary to tibial pilon fracture and compare them to the outcomes for other indications for total ankle replacement.

Methods:

The results of patient-reported outcome measures (PROMs) for TAR performed between March 2006 and November 2014 by a single surgeon at a single institution in the United Kingdom were reviewed. Data collected included Foot and Ankle Outcome Scores (FAOS) (WOMAC pain/stiffness/function); SF-36 General Health Questionnaire; number of comorbidities; self- reported BMI and patient satisfaction scores. Time points for data collection were pre-operatively and then at one and two years post-operatively. Clinical notes and radiographs were reviewed to highlight the indication for TAR and were categorised into the following sub-groups: osteoarthritis (OA); rheumatoid arthritis (RA); arthritis following pilon fracture; arthritis following ankle fracture; and post-traumatic arthritis without previous fracture (PTOA). FAOS and SF-36 were analysed using a general linear model to assess variance and by way of repeated measures ANOVA. Demographic data was assessed using student t-test and chi- squared analysis. Patient satisfaction scores were evaluated using cross-tabulation and chi-squared examination.

Results:

The pilon fracture group had the youngest average age and highest BMI (56.5 years; mean BMI 31.6). There was no statistically significant difference in number of reported comorbidities between subgroups (p>0.05). Significant improvement in FAOS pain, function and stiffness scores was seen in all subgroups from pre-operatively to one year post-operatively (p=0.01, 0.05 and 0.03 respectively). No further statistically significant improvement in the same scores was seen at two years. SF-36 analysis demonstrated similar results for all subgroups. There was general improvement in all parameters except for general health (p=0.890 at one year) and reduction in physical function in the RA group from first to second post-operative years (p=0.046). Patient satisfaction survey showed similar results for all subgroups.

Conclusion:

Our study has demonstrated that statistically significant improvement is seen in FAOS pain, function and stiffness scores in all subgroups of patients undergoing TAR by one year post surgery and that this improvement is maintained by two year follow up. There was no major difference in any of the reported outcomes between subgroups by two years post-operatively, suggesting that TAR performed for arthritis secondary to pilon fracture is a realistic alternative to tibio-talar arthrodesis.

Is Ankle Arthritis More Disabling than Midfoot Arthritis and 1st MTPJ Arthritis?

Category:

Ankle Arthritis, Midfoot/Forefoot

Introduction/Purpose:

There is wide array of outcome tools available for assessment of level of pain and symptoms in osteoarthritis, there are less disease and region specific outcome measures to evaluate the level of disability caused by arthritis in ankle, mid foot arthritis (including Talo-navicular joint, Calcaneo-cuboid joint and tarso metatarsal joints) and 1st Metatarso phalangeal joints. We aimed to measure the level of disability incorporating elements of physical, mental and social well-being using patient reported outcome measures as recommended by the International classification of Functioning, disability and health (ICF)

Methods:

This is a prospective data series, patients with arthritis of ankle, mid foot or 1st MTPJ who were diagnosed in new patient clinic were asked to take part in this survey. They completed a questionnaire consisting of MOX-FQ (Manchester Oxford Foot Questionnaire), EQ-5D (General Health Status) and FAOS (Foot and Ankle Outcome Scores). Patients were grouped in to 3 groups (Group A - ankle arthritis. Group B - midfoot arthritis (either Talo navicular, Calcaneo-cuboid or TMT joint); Group C - arthritis of 1st Metatarso-phalangeal joint of the foot). The results of summary scores were calculated for responses to individual questions and compared between the groups. Demographic factors were included in the statistical analysis carried out using SPSS Version 22, Illinois. Results are reported as follows

Results:

There were 26 patients in (Group A); 12 patients in (Group B) and 19 patients in (Group C). There was no difference in mean age of patients between groups (p>0.05) For components in MOX-FQ, there was no difference in pain scores (p=0.353) between the groups. For difficulty with walking/standing, Group A patients reported significantly worse scores (77 ± 19.4) when compared to Group C (53.7 ± 35.5). There was no difference in scores between groups for social function component of MOX- FQ (p=0.487). For EQ-5D, although Group C patients reported higher scores they failed to achieve statistical significance (p>0.05). For FAOS, Group A patients reported significantly lower scores for pain and symptoms, ADL, ability to take part in Sports/Recreation (p=0.008) and Quality of Life (p=0.003).

Conclusion:

In conclusion, although patients with ankle arthritis, mid foot arthritis and 1st MTP joint arthritis report similar level of disability in terms of general health and social function, patients with ankle arthritis reported higher level of disability in terms of pain, difficulty with standing/ Walking, ability to do Activities of Daily living, ability to take part in recreational activities and overall Quality of Life.

Topographic Pain Mapping versus Radiological Inter-observer Variation in Ankle Arthritis

Category:

Ankle, Ankle Arthritis

Introduction/Purpose:

Topographic pain mapping has gained popularity during 20th century, providing opportunities for patients to demonstrate spatial distribution of pain. Despite this, evidence of clinical application in orthopaedics remains largely limited to spinal pathologies. We investigate how clinician interpretation of routine radiological studies compares to patient pain mapping in ankle arthritis.

Methods:

Between 2014 and 2016 we identified 21 patients ultimately diagnosed with ankle arthritis, who underwent comprehensive gait analysis (including topographic pain mapping) on referral to our institution. Patients were requested to map up to three pain areas, assigning a visual analogue score (VAS) of 0-10, to signify severity of pain in each area. A consultant orthopaedic foot and ankle surgeon, and orthopaedic trainees undertook blinded evaluation of relevant radiological studies, estimating patients’ mapping and VAS scores on the basis of radiological pathology. For the purpose of analysis findings were applied to five distinct regions around the ankle: three anterior (antero-medial; central; and antero-lateral), lateral and medial. Results were correlated between the different assessors, as well as to the patients’ pain mapping, using Spearman’s Rho & Kendall Tau correlation statistics, significance taken as p=<0.05.

Results:

There is a strong radiological inter-observer correlation for anterior ankle pain in ankle arthritis [Antero-lateral 0.751(p=0.012); Central 0.912(p=<0.001)]. These findings also correlate well with patient pain mapping [Central consultant-patient 0.920(p=<0.001); trainee-patient 0.982(p=<0.001)]. Assessment of medial (tibialis posterior) and lateral (subtalar/peroneal) pathology demonstrates poorer inter-observer correlations (p>0.05). Correlation to patient pain mapping was even poorer, with radiological assessment consistently over- estimating symptom severity (p=>0.05).

Conclusion:

There is a statistically strong correlation between topographic pain mapping and radiological evaluation of ankle arthritis. We strongly recommend that additional pathology around the ankle is excluded by use of pre-operative MRI imaging prior to surgery for ankle arthritis. Pain from ankle arthritis appears to mask additional soft tissue pathology surrounding the ankle noted on MRI scan.

Iron–manganese–titanium (1 : 1 : 2) oxide composite thin films for improved photocurrent efficiency

Fe₂MnTi₃O₁₀–MnTiO₃ composite thin films with a photocurrent density of 1.88 mA cm⁻² at 0.2 V have been deposited through AACVD.

Relationships of body habitus and SUV indices with signal-to-noise ratio of hepatic (18)F-FDG PET

OBJECTIVE

Tissue accumulation of (18)F-FDG is quantified as standardised uptake value (SUV), which may be expressed as the voxel maximum (SUVmax) or mean (SUVmean). SUVmax/SUVmean may be a marker of hepatic steatosis, while the coefficient of variation (CV) of SUV may be a marker of hepatic fat distribution heterogeneity (HFDH). Alternatively, they may reflect low signal-to-noise ratio ('noise') in obese persons in whom hepatic steatosis is common. The study aim was to compare the impact of body size on noise versus SUV and CT density (CTD).

METHODS

Dynamic PET was performed (30×1min frames) following FDG injection in 60 patients undergoing routine PET/CT. Hepatic FDG clearance was measured using Patlak-Rutland graphical analysis with abdominal aorta as input. Noise was quantified as the standard deviation (SD) of the plot residuals (ignoring the first 2 frames), normalised to the intercept (NRMSD). SUVmax, SUVmean and CTD were measured from 60min whole body PET/CT. CV of SUV and SD of CTD were quantified in 28/60 patients using texture analysis.

RESULTS

NRMSD correlated with weight (r=0.49; p<0.0001) and BMI (r=0.48; p=0.0001). SUVmax, SUVmean, SUVmax/SUVmean, CV of SUV, CTD, and SD of CTD all correlated strongly with weight and BMI (p<0.0001). However, they correlated weakly with NRMSD, the strongest being SUVmax (r=0.34; p=0.008) and SD of CTD (r=0.42; n=28; p=0.026).

CONCLUSIONS

Noise is increased in overweight/obese persons but has little effect on SUV indices, CTD and their variabilities. SUVmax/SUVmean and CV of SUV are therefore, to some extent, markers of hepatic steatosis and HFDH, respectively.

Radiographic Severity of Arthritis Affects Functional Outcome in Total Ankle Replacement (TAR)

BACKGROUND

It has been previously demonstrated that radiographic severity of arthritis predicts outcome following knee replacement. In certain circumstances, patients may undergo arthroplasty without severe radiographic disease. An example may be the patient with significant chondral damage unsuccessfully treated with arthroscopy. This patient may proceed to joint replacement when their radiographs would not normally merit such intervention. We investigated whether these findings were also applicable to total ankle replacements (TARs).

METHODS

We retrospectively reviewed a single-surgeon, single-implant series of 178 TARs in 170 patients. Of them, 124 patients who took part in the hospital joint registry with a minimum 2-year follow-up were included for this study. The radiographic severity of arthritis was graded using the Kellgren-Lawrence classification. Preoperative weight-bearing radiographs were reviewed for severity of arthritis by 2 blinded observers: the first author and an independent colleague from the radiology department. Patients were grouped into 4 subgroups based on degree of severity of radiographic grading for arthritis-A, B, C, and D (for grades 1, 2, 3, and 4 grades, respectively). Data collected included Foot and Ankle Outcome Score (FAOS; pain, function, and stiffness), MOS 36-item Short-Form Health Survey (SF-36) scores, and patient satisfaction scores collected prospectively and at 1 and 2 years postoperation.

RESULTS

Groups were similar in terms of demographic data (P > .1) and preoperative FAOS scores (P > .89) for pain, function and stiffness. Group D had the biggest improvement in all domains of FAOS. This reached significance in each domain when compared to group C. No significant differences were demonstrated in SF-36 scores. Overall, 91.1% of patients in group D were satisfied at 2 years, compared with 50.0% of patients in groups A, B, and C (P < .001). In addition, 93.9% of patients in group D felt that their quality of life had been improved by the surgery, compared to 47% of patients with groups A, B, and C (P < .001). Further, 77.3% of patients from group D said they would have the operation again, vs only 52.2% of patients with grade III or less (P = .014). Patients who were "very satisfied" or "somewhat satisfied" postoperatively had an average Kellgren-Lawrence (KL) grade of 3.9 preoperatively. In contrast the "very dissatisfied" and "somewhat dissatisfied" patients had an average KL grade of 2.9 (P < .05).

CONCLUSION

Although this study does not explain all of the dissatisfaction in TAR, radiologic severity is an important factor that surgeons must consider when planning how best to treat their patients. There may be a different pathophysiology in this patient group that is not well served by arthroplasty.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Investigation on the structural, dielectric and impedance analysis of manganese substituted cobalt ferrite i.e., Co1−xMnxFe2O4 (0.0 ≤ x ≤ 0.4)

The microstructure and cation distribution of Co_1−xMnxFe₂O₄ were investigated and correlated with their electrical properties. Here, Mn substitution enhances the resistive properties which make them favorable for high-frequency applications.

Early results of a novel technique: Hindfoot fusion in talus osteonecrosis prior to ankle arthroplasty: A case series

BACKGROUND

The purpose of this study was to evaluate the clinical outcome of a two staged approach of subtalar arthrodesis followed by TAR for patients with ankle arthritis and AVN talus.

METHODS

Out of total 210 TARs performed at our institute; 7 patients underwent a two staged procedure between 2006 and 2010. All patients had over 3 years of follow up (except one). The clinical results were assessed using AOFAS, WOMAC, SF-36 and patient satisfaction scores.

RESULTS

The mean follow up was 3 years. There was significant improvement in AOFAS and WOMAC (pain and stiffness) from pre-op to 3 years post-op (P<0.05). SF 36 scores improved from pre-op to 3 years post-op for 6/8 domains. 5 patients were satisfied at 3 years for overall surgical outcomes, 4 were satisfied with pain relief. Radiological signs of talar subsidence were noted in 2 patients at year 1. This did not progress at 3 years and did not deteriorate clinical outcome.

CONCLUSION

We recommend our two staged approach to deal with this difficult clinical problem. We believe this approach is safe for TAR surgery where talar vascularity and bone quality is questionable leading to reduced talar subsidence, ischaemic pain and improvement in longevity of TAR.

LEVEL OF EVIDENCE

Evidence IV (Retrospective case series).

Texture analysis of (125)I-A5B7 anti-CEA antibody SPECT differentiates metastatic colorectal cancer model phenotypes and anti-vascular therapy response

BACKGROUND

We aimed to test the ability of texture analysis to differentiate the spatial heterogeneity of (125)I-A5B7 anti-carcinoembryonic antigen antibody distribution by nano-single photon emission computed tomography (SPECT) in well-differentiated (SW1222) and poorly differentiated (LS174T) hepatic metastatic colorectal cancer models before and after combretastatin A1 di-phosphate anti-vascular therapy.

METHODS

Nano-SPECT imaging was performed following tail vein injection of 20 MBq (125)I-A5B7 in control CD1 nude mice (LS174T, n=3 and SW1222, n=4), and CA1P-treated mice (LS174T, n=3; SW1222, n=4) with liver metastases. Grey-level co-occurrence matrix textural features (uniformity, homogeneity, entropy and contrast) were calculated in up to three liver metastases in 14 mice from control and treatment groups.

RESULTS

Before treatment, the LS174T metastases (n=7) were more heterogeneous than SW1222 metastases (n=12) (uniformity, P=0.028; homogeneity, P=0.01; contrast, P=0.045). Following CA1P, LS174T metastases (n=8) showed less heterogeneity than untreated LS174T controls (uniformity, P=0.021; entropy, P=0.006). Combretastatin A1 di-phosphate-treated SW1222 metastases (n=11) showed no difference in texture features compared with controls (all P>0.05).

CONCLUSIONS

Supporting the potential for novel imaging biomarkers, texture analysis of (125)I-A5B7 SPECT shows differences in spatial heterogeneity of antibody distribution between well-differentiated (SW1222) and poorly differentiated (LS174T) liver metastases before treatment. Following anti-vascular treatment, LS174T metastases, but not SW1222 metastases, were less heterogeneous.

Routine histological analysis of a macroscopically normal gallbladder--a review of the literature

BACKGROUND

70,000 cholecystectomies were performed in the United Kingdom in 2011-2012. Currently it is standard practice to submit all gallbladder specimens for routine histology to exclude malignancy. The aim of this systematic review was to establish whether a normal macroscopic appearance to the gallbladder at the time of cholecystectomy is sufficient to rule out malignancy and therefore negate the need for routine histology.

METHODS

Relevant articles that were published between 1966 and January 2013 were identified through electronic databases.

RESULTS

21 studies reported on 34,499 histologically analysed specimens. 172/187 (92%) of gallbladder cancers demonstrated intra-operative macroscopic abnormality. Studies that opened the specimens intra-operatively identified all cancers, whereas gross macroscopic visualization resulted in 15 potentially missed cancers (p = 0.10). In patients of European ethnicity, gallbladder cancer in a macroscopically normal looking gallbladder was identified in only one study; however all of these patients were above the age of 60. The incidence of gallbladder cancer was significantly raised in ethnic groups from high risk areas (p = 0.0001).

CONCLUSIONS

A macroscopically normal gallbladder in patients of European ethnicity under the age of 60 may not require formal histopathology. The best method for intra-operative examination may involve opening the specimen to allow inspection of the mucosa and wall, however this needs further investigation. In the context of the volume of gallbladder surgery being performed there is the potential for significant cost and time savings.

Differences in regional bone metabolism at the spine and hip: a quantitative study using (18)F-fluoride positron emission tomography

SUMMARY

This study showed that regional bone blood flow and (18)F-fluoride bone plasma clearance measured by positron emission tomography are three times lower at the hip than the lumbar spine.

INTRODUCTION

Measurements of effective bone plasma flow (K (1)), bone plasma clearance (K ( i )) and standardised uptake values (SUV) using (18)F-fluoride positron emission tomography ((18)F-PET) provide a useful means of studying regional bone metabolism at different sites in the skeleton. This study compares the regional (18)F-fluoride kinetics and SUV at the hip and lumbar spine (LS).

METHODS

Twelve healthy postmenopausal women with no history of metabolic bone disease apart from two with untreated osteoporosis were recruited. Each subject underwent 60-min dynamic (18)F-PET scans at the LS and proximal femur two weeks apart. K (1), K ( i ) and SUV were measured at the LS (mean of L(1)-L(4)), femoral neck (FN), total hip (TH) and femoral shaft (FS). Differences between sites were assessed using the nonparametric Kruskal-Wallis test with a Bonferroni correction for multiple comparisons.

RESULTS

Values of K (1), K ( i ) and SUV at the FN, TH and FS were three times lower than at the LS (p = 0.003). Amongst the proximal femur sites, K ( i ) and SUV were lower at the FS compared with the FN and TH, and SUV was lower at the TH compared with the FN (all p < 0.05). The volume of distribution was lower at the TH and FS compared with the LS (p < 0.05).

CONCLUSION

The lower values of K (1), K ( i ) and SUV at the hip suggest that lower bone blood flow in the proximal femur is an important factor explaining the principal reason for the differences in bone fluoride kinetics between the LS and hip sites.

Precision of ¹⁸F-fluoride PET skeletal kinetic studies in the assessment of bone metabolism

We assessed the precision of lumbar spine (18)F-PET measurements based on 58 scans performed on 20 postmenopausal women. The percentage coefficient of variation (%CV) (95% confidence interval) was 9.2% (7.5-11.8) for standardised uptake values, 11.7% (9.5-14.9) for plasma clearance measurements using the Patlak method and 14.5% (11.7-18.5) for plasma clearance measurements using the Hawkins three-compartment model.

INTRODUCTION

(18)F-Fluoride positron emission tomography ((18)F-PET) is a non-invasive technique that allows the assessment of regional bone turnover in patients with metabolic bone disease. Knowledge of the precision errors of (18)F-PET measurements is important for planning the number of subjects required for research studies.

METHODS

Twenty osteoporotic postmenopausal women had (18)F-PET scans of the lumbar spine at 0, 6 and 12 months after stopping long-term bisphosphonate treatment. No significant changes in the PET measurements were seen over the 12-month period, and the data were deemed suitable for a precision study. Precision errors were evaluated for standardised uptake values (SUVs) and for the fluoride plasma clearance to bone mineral (K (i)) determined using the Patlak and Hawkins methods. Precision errors were expressed as the %CV and were calculated for the mean L1-L4 region and for individual vertebrae.

RESULTS

%CV (95% confidence interval) for the L1-L4 region was 9.2% (7.5-11.8) for SUV, 11.7% (9.5-14.9) for K (i) measured using the Patlak method and 14.5% (11.7-18.5) for K (i) measured using the Hawkins method. There was no significant difference between precision errors obtained for the L1-L4 region and those obtained for a single vertebra.

CONCLUSIONS

SUV measurements showed the smallest precision error followed by the Patlak method, while the Hawkins method gave the largest error. Measuring a smaller region of interest did not increase the precision error, suggesting that the factor determining the errors may be scanner calibration.