119 The Potential of Low-fidelity Arthroscopic Simulation Training in Trauma and Orthopaedic Surgery: A Systematic Review of Experimental Studies

Aim

In an era of budget tightening and work-hour guideline reductions that have significantly reduced surgical exposure, low-fidelity arthroscopic simulators have an essential role to play in surgical training. The COVID-19 pandemic has only further amplified the need for alternative training models, as 91% of orthopaedic trainees have had elective procedures cancelled. The purpose of this systematic review is to synopsise the limited literature regarding the effectiveness of low-fidelity training models in the instruction of novices, and to formulate recommendations for future studies.

Method

The Embase, PubMed, Web of Science and Scopus databases were electronically searched. Studies from any year that described the use of orthopaedic, low-fidelity arthroscopic training models in novice populations were included. Questionnaires, case studies and review studies were excluded. Risk of bias assessments were also conducted for all studies.

Results

16 studies were identified. Using the PRISMA algorithm, 6 studies were deemed relevant. A cross-study comparison revealed low-fidelity arthroscopic simulators reduced time to completion outcomes (P < 0.05), increased ASSET scores (P < 0.01) and confirmed face validity and transfer of skills (cadaver, live patients).

Conclusions

Low-fidelity simulator training significantly improves the arthroscopic performance of novices, without the high setup costs and practical constraints of high-fidelity equivalents. Low-fidelity arthroscopic simulators remain a promising training apparatus in an era of reduced surgical exposure (COVID-19). We have identified the need for consistent outcome measures with greater sample sizes across future studies. We recommend the use of standardised pre-intervention teaching (e.g., ABOS curriculum) and further transference, construct, and face validity evaluations to support future result interpretations.

1393 The Impact of Using A Virtual Reality Surgical Curriculum to Train Scrub Practitioners in Complex Orthopaedic Surgery

Background

The training scrub practitioners receive varies considerably in comparison to their surgical counterpart, although their performance is key to a proficient surgical team. For infrequent procedures that require specific and often intricate equipment such as revision total knee arthroplasty (RTKA), their training may be limited to an initial guidance session by company representatives. This study aims to evaluate the impact of using a virtual reality (VR) curriculum to train scrub practitioners in the performance of a RTKA.

Method

Ten orthopaedic scrub practitioners were enrolled into VR training across four sessions. Each VR session consisted of training where participants were guided through the assembly of equipment and steps of the surgery. In the concluding three sessions, each training session was supplemented by an assessment session in VR without guidance. The outcomes measured in VR assessment were incorrect procedural sequence, duration of surgery and efficiency of movement. The transfer of skills outside VR were assessed pre-training and post-training by the participants performance in a sequence of tasks using real equipment.

Results

All participants enhanced their surgical performance in successive assessed VR sessions reducing their operative time by 47%, assistive prompts by 75% and dominant hand motion by 28%. Improvements in VR showed effective transfer when assessed using real equipment with participants achieving superior scores post-training (11.3% versus 83.5%).

Conclusions

VR enables safe learning and provides measurable feedback of procedural steps and technical skills of complex orthopaedic surgery. VR is an effective training tool for scrub practitioners, with transfer to the real world.

P07.04 Rapid-CNS2: Rapid comprehensive adaptive nanopore-sequencing of CNS tumors, a proof of concept study

BACKGROUND

The WHO classification 2021 includes multiple molecular markers for routine diagnostics in addition to histology. Sequencing setup for complete molecular profiling requires considerable investment, while batching samples for sequencing and methylation profiling can delay turnaround time. We introduce RAPID-CNS2, a nanopore adaptive sequencing pipeline that enables comprehensive mutational, methylation and copy number profiling of CNS tumours with a single third generation sequencing assay. It can be run for single samples and offers highly flexible target selection requiring no additional library preparation.

MATERIAL AND METHODS

Utilising ReadFish, a toolkit enabling targeted nanopore sequencing, we sequenced DNA from 22 diffuse glioma patient samples on a MinION device. Target regions comprised our Heidelberg brain tumour NGS panel and pre-selected CpG sites for methylation classification by an adapted random forest classifier. Pathognomonic alterations, copy number profiles, and methylation classes were called using a custom bioinformatics pipeline. Results were compared to their corresponding NGS panel-seq and EPIC array outputs.

RESULTS

Complete concordance with the EPIC array was found for copy number profiles from RAPID-CNS2. 94% pathognomonic mutations were congruent with NGS panel-seq. MGMT promoter status was correctly identified in all samples. Methylation families were detected with 96% congruence. Among the alterations decisive for rendering a classification-compatible integrated diagnosis, 97% of the alterations were consistent over the entire cohort (completely congruent in 19/22 cases and sufficient for unequivocal diagnosis in all).

CONCLUSION

RAPID-CNS2 provides a swift and highly flexible alternative to conventional NGS and array-based methods for SNV/Indel analysis, detection of copy number alterations and methylation classification. The turnaround time of ~4 days can be further shortened to <12h by altering target sizes. It offers a low-capital approach that would be cost-efficient for low throughput settings and invaluable in cases requiring immediate diagnoses.

Future Tail Tales: A Forward-Looking, Integrative Perspective on Tail Research

Synopsis Tails are a defining characteristic of chordates and show enormous diversity in function and shape. Although chordate tails share a common evolutionary and genetic-developmental origin, tails are extremely versatile in morphology and function. For example, tails can be short or long, thin or thick, and feathered or spiked, and they can be used for propulsion, communication, or balancing, and they mediate in predator-prey outcomes. Depending on the species of animal the tail is attached to, it can have extraordinarily multi-functional purposes. Despite its morphological diversity and broad functional roles, tails have not received similar scientific attention as, for example, the paired appendages such as legs or fins. This forward-looking review article is a first step toward interdisciplinary scientific synthesis in tail research. We discuss the importance of tail research in relation to five topics: (1) evolution and development, (2) regeneration, (3) functional morphology, (4) sensorimotor control, and (5) computational and physical models. Within each of these areas, we highlight areas of research and combinations of long-standing and new experimental approaches to move the field of tail research forward. To best advance a holistic understanding of tail evolution and function, it is imperative to embrace an interdisciplinary approach, re-integrating traditionally siloed fields around discussions on tail-related research.

Administration and monitoring of clofazimine for NTM infections in children with and without cystic fibrosis

Few studies have evaluated clofazimine (CLOF) drug monitoring and safety in children. We treated 10 children, 8 with CF, for NTM infection with multiple antimicrobials, including CLOF. All had serial blood CLOF concentrations measured and were followed for adverse events. Despite CLOF dose escalation, most children with CF did not reach a target CLOF concentration. Our data suggest that children with CF may require earlier initiation of CLOF at higher doses than is currently recommended.

Comparison between conventional CT and grayscale inversion CT images in the assessment of the post-operative spinal orthopaedic implants

AIM

To compare the accuracy of the inverted greyscale CT versus the conventional CT in the assessment of post-operative spinal orthopaedic implants and osseous fusion.

METHODS

50 patients who had CT as part of their routine spinal implant follow up were evaluated for the presence of fusion, fracture and loosening with conventional CT and with greyscale inverted CT images. 3 independent observers assessed the images 2 months apart. Diagnostic performance (sensitivity and specificity) of the conventional and greyscale inversion images relative to the reference standard were calculated. Agreement with the reference standard was assessed using Cohen's kappa for conventional and greyscale inversion images.

RESULTS

Correct classifications increased when using the greyscale inverted CT images for each reader compared to conventional CT images (40-46, 39 to 42 and 41 to 44 (out of 50)). Inverted images demonstrated better agreement with the reference standard than conventional grayscale images for assessment of fusion (kappa of 0.588 for inverted CT versus 0.484 for conventional CT) and loosening (kappa 0.386 for inverted versus 0.293 for conventional). Sensitivity was increased for assessment of fusion and loosening. McNemar's test performed for assessment of sensitivity differences showed statistical significance (p = 0.038 for fusion and p = 0.0313 for loosening).

CONCLUSION

Greyscale inversion CT is a useful adjunct which has advantages (improved sensitivity and better agreement) over conventional CT imaging in cases of fusion and loosening of metallic implants following spinal instrumentation. We recommend the use of both the greyscale inversion CT images and conventional CT imaging when assessing post-operative spinal orthopaedic implants.

Impact of enhanced personal protective equipment on surgeon workload and intraoperative patient outcomes

This work shows the need for targeted improvement to mitigate communication challenges associated with use of enhanced personal protective equipment. The data provide reassurance to surgeons and patients that there is no negative impact on surgeon workload or patient outcomes from use of enhanced personal protective equipment in the operating theatre.

GJB5 association with BRAF mutation and survival in cutaneous malignant melanoma

BACKGROUND

Gap junctional intercellular communication is crucial for epidermal cellular homeostasis. Inability to establish melanocyte-keratinocytes contacts and loss of intercellular junction's integrity may contribute to melanoma development. Connexins, laminins and desmocollins have been implicated in the control of melanoma growth, where their reduced expression has been reported in metastatic lesions.

OBJECTIVES

The aim of this study was to investigate Connexin 31.1 (GJB5) expression and identify any association with BRAF mutational status, melanoma patient prognosis and MAPK inhibitors (MAPKi) treatment.

MATERIAL AND METHODS

GJB5 expression was measured at RNA and protein level in melanoma clinical samples and established cell lines treated or not with BRAF and MEK inhibitors, as well as in cell lines which developed MAPK inhibitors resistance. Findings were further validated and confirmed by analysis of independent datasets.

RESULTS

Our analysis reveals significant downregulation of GJB5 expression in metastatic melanoma lesions compared to primary ones and in BRAF mutated versus BRAF wild-type melanomas. Likewise, GJB5 expression is significantly lower in BRAF^V600E compared with BRAF^WT cell lines and increases upon MAPKi treatment. MAPKi-resistant melanoma cells display a similar expression pattern compared to BRAF^WT cells, with increased GJB5 expression associated with morphological changes. Enhancement of BRAF^V600E expression in BRAF^WT melanoma cells significantly upregulates miR-335-5p expression with consequent downregulation of GJB5, one of its targets. Furthermore, overexpression of miR-335-5p in two BRAF^WT cell lines confirms specific GJB5 protein downregulation. RT-qPCR analysis also revealed upregulation of miR-335 in BRAF^V600E melanoma cells, which is significantly downregulated in cells resistant to MEK inhibitors. Our data were further validated using the TCGA-SKCM dataset, where BRAF mutations associate with increased miR-335 expression and inversely correlate with GJB5 expression. In clinical samples, GJB5 underexpression is also associated with patient overall worse survival, especially at early stages.

CONCLUSION

We identified a significant association between metastases / BRAF mutation and low GJB5 expression in melanoma. Our results identify a novel mechanism of Gap-junctional protein regulation, suggesting a prognostic role for GJB5 in cutaneous melanoma.

From benchtop to clinic: a translational analysis of the immune response to submicron topography and its relevance to bone healing

Proper regulation of the innate immune response to bone biomaterials after implantation is pivotal for successful bone healing. Pro-inflammatory M1 and anti-inflammatory M2 macrophages are known to have an important role in regulating the healing response to biomaterials. Materials with defined structural and topographical features have recently been found to favourably modulate the innate immune response, leading to improved healing outcomes. Calcium phosphate bone grafts with submicron-sized needle-shaped surface features have been shown to trigger a pro-healing response through upregulation of M2 polarised macrophages, leading to accelerated and enhanced bone regeneration. The present review describes the recent research on these and other materials, all the way from benchtop to the clinic, including in vitro and in vivo fundamental studies, evaluation in clinically relevant spinal fusion models and clinical validation in a case series of 77 patients with posterolateral and/or interbody fusion in the lumbar and cervical spine. This research demonstrates the feasibility of enhancing biomaterial-directed bone formation by modulating the innate immune response through topographic surface features.

Myositis ossificans revisited - The largest reported case series

INTRODUCTION

Myositis ossificans (MO) is a condition characterised by the formation of non-neoplastic heterotropic ossification in extraskeletal soft tissues.

MATERIAL AND METHODS

We performed a retrospective study of our radiology databases within our tertiary orthopaedic centre to identify all cases of MO, reported on X ray, Magnetic resonance imaging (MRI) and Computed tomography (CT) over the past 13 years (2007-2020).

RESULTS

We identified 68 cases of MO, which were included into our cohort. The average age of our patients was 36 years (range 4-84 years). 73% of cases (n = 50) were found to affect the lower limb muscles with the majority in the quadriceps.

CONCLUSION

We report the largest case series of MO and discuss the demographics, diagnoses and management.

EPCT-21. NEXT-GENERATION SEQUENCING OF CEREBROSPINAL FLUID FOR CLINICAL MOLECULAR DIAGNOSTICS IN ADOLESCENT AND YOUNG ADULT (AYA) BRAIN TUMOR PATIENTS

Purpose

Pediatric central nervous system tumors remain a leading cause of cancer-related death in children and adolescents. Safe sampling of tumor tissue for diagnostic purposes may be challenging. Subclinical detection of disease prior to clinical or imaging progression may provide opportunity for earlier intervention and ultimately improve overall survival. Additionally, our understanding of molecular evolution in response to therapy remains limited, given the rarity of serial sampling of tumor tissue.

Methods

We report our experience with minimally invasive molecular diagnostics using a validated next generation sequencing assay for sequencing of cerebrospinal fluid (CSF) cell-free DNA (cfDNA) obtained at the time of surgery, by intraventricular catheter or lumbar puncture. All CSF samples were collected as part of clinical care, and results reported to both clinicians and patients/families.

Results

We analyzed 64 CSF samples from 45 pediatric and adolescent and young adult (AYA) patients (pediatric=25; AYA=20) with primary and recurrent brain tumors across 12 histopathological subtypes including high-grade glioma (n=10), medulloblastoma (n=10), pineoblastoma (n=5), low grade glioma (n=4), diffuse leptomeningeal glioneuronal tumor (DLGNT) (n=4), metastatic retinoblastoma (n=4), ependymoma (n=3), and other (n=5). Somatic alterations were detected in 28/64 samples (44.4%) and in at least one sample per unique patient in 22/45 patients (48.8%). CSF cfDNA positivity was strongly associated with the presence of disseminated disease at the time of collection (86.3%). No association was seen between CSF cfDNA positivity and the timing of CSF collection during the patient’s disease course.

Conclusion

We identified four general categories where CSF cfDNA testing provided additional relevant diagnostic, prognostic, and/or therapeutic information, impacting clinical assessment and decision making: 1) diagnosis; 2) identification of actionable alterations; 3) track response to therapy; and 4) monitoring tumor evolution. Our findings support broader implementation of clinical CSF cfDNA testing in this population that may improve care.

Spinal collision lesions

Collision lesions are rare neoplasms often described in the hepatobiliary system, genitourinary system and adrenal glands. Vertebral haemangiomas (VH) are the most common lesions involving the vertebral bodies. VHs are usually asymptomatic and considered as "Do not touch" lesions. Rarely they can be symptomatic. Imaging findings of typical and atypical haemangiomas, variant forms of haemangioma such as aggressive haemangiomas are well known. Collision lesions involving VHs are extremely rare. This article presents a series of cases with collision lesions of the vertebral body involving VHs.

ADVANCES IN KNOWLEDGE

This Case series demonstrates the various collision lesions in spinal haemangioma.

617 Does Wearing Enhanced Personal Protective Equipment (PPE) In Theatre Increase Surgeon Workload and Patient Morbidity?

Introduction

Delivery of surgical services during the Covid-19 pandemic has required the use of enhanced PPE in the operating theatre. We sought to evaluate the impact of this change on surgeon workload and intraoperative patient outcomes.

Method

Surgeons performing as primary operator completed an online procedure-specific questionnaire on workload ratings for each operative case, using an extension of the validated Surgeon Task Load Index (SURG-TLX) tool (reported on a 20-point scale), together with operative details. Local approval was obtained at individual sites. Data was analysed in Stata SE v16.

Results

118 responses (17 surgeons, 7 specialties) were collected from June to September 2020. 77.1% used enhanced PPE. There was no association between enhanced PPE use and overall workload (p = 0.151) as measured with SURG-TLX, although surgeons wearing enhanced PPE commonly reported finding individual procedures harder than expected (37% vs 0%, p < 0.001). Communication was rated worse when using enhanced PPE use (MD -4.38, 95%CI -6.74 to 02.03; p < 0.001). There was no association between enhanced PPE use and intraoperative complications (p = 0.745).

Conclusions

The use of enhanced PPE is not associated with complications or increased surgeon workload assessed by SURG-TLX. It is, however, associated with difficulty in communicating, and subjectively experiencing more procedural challenge than anticipated.

25 Operative Delay in Neck of Femur Fracture Management During the COVID 19 Pandemic Lockdown; Reasons and Impact

All NOF patients beyond 24-hour window over the COVID Lockdown period From April 2020 to July 2020 were identified and causes of delay to theatre were stratified. Manual Data collection over a time period of April 2020 to July 2020, when lockdown was introduced. All patients with NOF who had surgery within 24 hours were excluded. Cases not within 24 hours were included. A total of 70 patients were included in the study. Cause for Delay beyond 24 hours included No list space 30, Medically unfit 20, Anticoagulation 18, COVID related 2 needing ventilatory support. Causes of medical Delay include chest infection (not COVID related), High anaesthetic risk, Cardiac, Anaemia, Electrolyte imbalance. Covid19 accounted for 2 % of operative delays of NOF patients. Other causes include medical optimization, theatre efficiency and use of anticoagulation. However, our study proved there is a vital requirement for robust protocols and pathways in the management of NOF especially during a global pandemic. This is important for the reduction of overall Morbidity and Mortality. Local Strategies should be put in place to address these with the importance of a MDT approach including the Anaesthetic and Orthogeriatic team.

23 Reaudit and Completing the Audit Cycle of Quality of Informed Consent for Surgery on Neck of Femur Fracture in Royal Stoke University Hospital

Using guidelines highlighted by the British Orthopaedic Association an reaudit was performed within our department to assess the adequacy of informed consent for NOF fractures to complete the audit cycle. 50 patients were included in the Audit and reaudit. Risk was classified as common, less common, rare and ‘other’. The adequacy of informed consent was evaluated by assessing the quality and accuracy of documentation. Infection, bleeding risks, clots and anaesthetic risks were documented in all patients (100%). Areas of improvement were seen in the documentation of neurovascular injuries (98%), pain (90%) and altered wound healing (87%). There was no significant change in the documentation of failure of surgery (83%) and neurovascular injuries (98%). The Poorly documented risk factors from the initial audit were seen to improve which included mortality (70%), prosthetic dislocation (90%) and limb length discrepancy (50%). There has been a significant improvement in the quality of Informed consent in the department and this could be attributed to the installation of ward posters and verbal dissemination of information to junior doctors. Recommendation for interventions would be to present in the next clinical governance meeting and presenting at the new junior doctors’ induction at August.

240 Aetiology and Outcomes of Head and Neck Free Flaps in Patients Aged ≥ 65 Years: The Cambridge Experience

Introduction

Elderly patients often present to the Head & Neck Plastic Surgery department with complex reconstructive needs, for which free flaps are the gold-standard management. In order to provide appropriate, patient-centred care, it is imperative to understand how increasing age and related factors affect long-term free flap outcomes.

Method

The authors carried out a retrospective review of all patients 65+ years who underwent free flap surgery at Addenbrooke’s Hospital from 2008-2019. Patient, operative, and flap characteristics, and outcomes, were analysed using Excel and RStudio.

Results

163 patients were identified (54F, 109M). The majority were ALT (n = 74), radial forearm (n = 35), and fibula flaps (n = 23).

Of pre-operative comorbidities, only neurological comorbidities (n = 16), were significantly associated with long-term flap failure (p = 0.016). There was no significant association between number of comorbidities and flap outcome. There was no association between age group and length of stay.

Flap site complications, and particularly venous complications, were significantly associated with later failure (p = 0.001). No other complications were statistically associated with flap failure.

Conclusions

The high success rate supports the use of free flaps in the 65+ population. This data supports a case-by-case approach to assessing fitness for free flap surgery rather than excluding patients on the basis of age or specific comorbidities.