The characteristics and predictors of mortality in periprosthetic fractures around the knee.

Aims: Periprosthetic fractures (PPFs) around the knee are challenging injuries. This study aims to describe the characteristics of knee PPFs and the impact of patient demographics, fracture types, and management modalities on in-hospital mortality. Methods: Using a multicentre study design, independent of registry data, we included adult patients sustaining a PPF around a knee arthroplasty between 1 January 2010 and 31 December 2019. Univariate, then multivariable, logistic regression analyses were performed to study the impact of patient, fracture, and treatment on mortality. Results: Out of a total of 1,667 patients in the PPF study database, 420 patients were included. The in-hospital mortality rate was 6.4%. Multivariable analyses suggested that American Society of Anesthesiologists (ASA) grade, history of peripheral vascular disease (PVD), history of rheumatic disease, fracture around a loose implant, and cerebrovascular accident (CVA) during hospital stay were each independently associated with mortality. Each point increase in ASA grade independently correlated with a four-fold greater mortality risk (odds ratio (OR) 4.1 (95% confidence interval (CI) 1.19 to 14.06); p = 0.026). Patients with PVD have a nine-fold increase in mortality risk (OR 9.1 (95% CI 1.25 to 66.47); p = 0.030) and patients with rheumatic disease have a 6.8-fold increase in mortality risk (OR 6.8 (95% CI 1.32 to 34.68); p = 0.022). Patients with a fracture around a loose implant (Unified Classification System (UCS) B2) have a 20-fold increase in mortality, compared to UCS A1 (OR 20.9 (95% CI 1.61 to 271.38); p = 0.020). Mode of management was not a significant predictor of mortality. Patients managed with revision arthroplasty had a significantly longer length of stay (median 16 days; p = 0.029) and higher rates of return to theatre, compared to patients treated nonoperatively or with fixation. Conclusion: The mortality rate in PPFs around the knee is similar to that for native distal femur and neck of femur fragility fractures. Patients with certain modifiable risk factors should be optimized. A national PPF database and standardized management guidelines are currently required to understand these complex injuries and to improve patient outcomes.

Predictors of mortality in periprosthetic fractures of the hip: Results from the national PPF study.

INTRODUCTION: Periprosthetic fractures (PPFs) around the hip joint are increasing in prevalence. In this collaborative study, we aimed to investigate the impact of patient demographics, fracture characteristics, and modes of management on in-hospital mortality of PPFs involving the hip. METHODS: Using a multi-centre cohort study design, we retrospectively identified adults presenting with a PPF around the hip over a 10-year period. Univariate and multivariable logistic regression analyses were performed to study the independent correlation between patient, fracture, and treatment factors on mortality. RESULTS: A total of 1,109 patients were included. The in-hospital mortality rate was 5.3%. Multivariable analyses suggested that age, male sex, abbreviated mental test score (AMTS), pneumonia, renal failure, history of peripheral vascular disease (PVD) and deep surgical site infection were each independently associated with mortality. Each yearly increase in age independently correlates with a 7% increase in mortality (OR 1.07, p=0.019). The odds of mortality was 2.99 times higher for patients diagnosed with pneumonia during their hospital stay [OR 2.99 (95% CI 1.07-8.37) p=0.037], and 7.25 times higher for patients that developed renal failure during their stay [OR 7.25 (95% CI 1.85-28.47) p=0.005]. Patients with history of PVD have a six-fold greater mortality risk (OR 6.06, p=0.003). Mode of treatment was not a significant predictor of mortality. CONCLUSION: The in-hospital mortality rate of PPFs around the hip exceeds 5%. The fracture subtype and mode of management are not independent predictors of mortality, while patient factors such as age, AMTS, history of PVD, pneumonia, and renal failure can independently predict mortality. Peri-operative optimisation of modifiable risk factors such as lung and kidney function in patients with PPFs around the hip during their hospital stay is of utmost importance.

The British Orthopaedic Oncology Management (BOOM) audit.

Aims: Most patients with advanced malignancy suffer bone metastases, which pose a significant challenge to orthopaedic services and burden to the health economy. This study aimed to assess adherence to the British Orthopaedic Oncology Society (BOOS)/British Orthopaedic Association (BOA) guidelines on patients with metastatic bone disease (MBD) in the UK. Methods: A prospective, multicentre, national collaborative audit was designed and delivered by a trainee-led collaborative group. Data were collected over three months (1 April 2021 to 30 June 2021) for all patients presenting with MBD. A data collection tool allowed investigators at each hospital to compare practice against guidelines. Data were collated and analyzed centrally to quantify compliance from 84 hospitals in the UK for a total of 1,137 patients who were eligible for inclusion. Results: A total of 846 patients with pelvic and appendicular MBD were analyzed, after excluding those with only spinal metastatic disease. A designated MBD lead was not present in 39% of centres (33/84). Adequate radiographs were not performed in 19% of patients (160/846), and 29% (247/846) did not have an up-to-date CT of thorax, abdomen, and pelvis to stage their disease. Compliance was low obtaining an oncological opinion (69%; 584/846) and prognosis estimations (38%; 223/846). Surgery was performed in 38% of patients (319/846), with the rates of up-to-date radiological investigations and oncology input with prognosis below the expected standard. Of the 25% (215/846) presenting with a solitary metastasis, a tertiary opinion from a MBD centre and biopsy was sought in 60% (130/215). Conclusion: Current practice in the UK does not comply with national guidelines, especially regarding investigations prior to surgery and for patients with solitary metastases. This study highlights the need for investment and improvement in care. The recent publication of British Orthopaedic Association Standards for Trauma (BOAST) defines auditable standards to drive these improvements for this vulnerable patient group.

Towards smart glasses for facial expression recognition using OMG and machine learning.

This study aimed to evaluate the use of novel optomyography (OMG) based smart glasses, OCOsense, for the monitoring and recognition of facial expressions. Experiments were conducted on data gathered from 27 young adult participants, who performed facial expressions varying in intensity, duration, and head movement. The facial expressions included smiling, frowning, raising the eyebrows, and squeezing the eyes. The statistical analysis demonstrated that: (i) OCO sensors based on the principles of OMG can capture distinct variations in cheek and brow movements with a high degree of accuracy and specificity; (ii) Head movement does not have a significant impact on how well these facial expressions are detected. The collected data were also used to train a machine learning model to recognise the four facial expressions and when the face enters a neutral state. We evaluated this model in conditions intended to simulate real-world use, including variations in expression intensity, head movement and glasses position relative to the face. The model demonstrated an overall accuracy of 93% (0.90 f1-score)-evaluated using a leave-one-subject-out cross-validation technique.

The anatomical growth of the thoracic cage in adolescents with specific reference to axial growth comparing the right and left hemithorax.

This study has demonstrated the changing volume of both the anterior and posterior thorax in normal adolescents (without spinal or thoracic deformity), differentiating for both sex and age, to further understand how the thorax grows, along with the differences in growth between the anterior and posterior thorax. The thorax was measured on axial CT slices at every vertebral level from T3 to T12 in a series of scans previous taken for routine clinical care. Measurements taken were the anteroposterior thoracic distance and the area of the anterior and posterior rib prominences on either side of the thorax. Data was analyzed per vertebral level, differentiating for age and sex. There were 486 CT scans analyzed (257 males and 229 females) between the ages of 8 and 18 years. The analysis identified that for the anterior thorax, there are three phases of growth with an initial slow increase in volume, followed by a stabilization of little growth, followed by another phase of a more rapid increase in volume. For the posterior thorax, there was a gradual increase in area with increasing age. This study demonstrates that the shape of the thorax is age and sex dependent, with males having both a greater width and depth of thorax compared to females. Of particular note is the difference in patterns of growth between the anterior and posterior thorax. This information will add to the understanding of normal growth, which will aid in the management of conditions where that growth is disturbed.

Outcomes Evaluating Quality of Life and Their Measurement Properties in Early-onset Scoliosis: A Systematic Review.

INTRODUCTION: Early-onset scoliosis (EOS) is a spinal deformity affecting children under the age of 10. Understanding the impact of EOS on quality of life can be achieved through appropriate patient/carer-reported outcome measures (PROMs). The aim of this systematic review was to identify, evaluate and summarize the evidence for the measurement properties of health-related quality of life (HR-QoL) outcome measures in the EOS population. METHODS: A 2-stage search methodology was conducted across the PubMed, MEDLINE, EMBASE, EMCARE, PsychINFO, and CINAHL databases. Search 1 identified PROMs used to evaluate the quality of life in EOS, and search 2 identified studies of the measurement properties of these PROMs. Two reviewers performed searching, study screening and selection and assessed studies for risk of bias using the Consensus-based Standards for the selection of health Measurement INstruments (COSMIN) Risk of Bias checklist. One reviewer performed data extraction. Evidence for each measurement property per PROM was summarized and evaluated using a modified GRADE approach. RESULTS: Search 1 identified 19 (10 disease-specific, 9 generic) PROMs that have been used to assess HR-QoL or a relevant domain in the EOS population. Search 2 identified only one PROM (the 24-item Early-Onset Scoliosis Questionnaire, EOSQ) with eligible studies (n=4) evaluating measurement properties. There is low-quality evidence for sufficient content validity, very low-quality evidence for sufficient reliability and low-quality evidence for sufficient criterion validity, specifically regarding the pulmonary function domain) of the EOSQ. Construct validity and responsiveness were rated as indeterminate. There were no studies on measurement error. CONCLUSIONS: Our search strategy found that measurement properties have only been evaluated for one PROM, the EOSQ. There is low-quality evidence for sufficient measurement properties for the EOSQ in patients under the age of 10 with EOS. Further research is needed to improve the quality of evidence for EOSQ measurement properties and investigate other PROMs in this population. LEVEL OF EVIDENCE: Level II.

Management of Open Ankle Fractures in Elderly Patients With a Fibula Nail is a Safe and Reliable Technique.

BACKGROUND: Ankle fractures are becoming more common in the elderly and their management is frequently challenging. There is increasing evidence of good outcomes following fibula nail fixation in the management of ankle fractures. The use of a fibula nail in open fractures comes with potential advantages such as minimal soft tissue dissection, early rehabilitation, and decreased wound complications. We aimed to assess their use in the management of open ankle fractures in the elderly. METHODS: A review of patients aged 60 years or older with an open ankle fracture treated with a fibular nail at a major trauma center was conducted. All patients were managed with joint Orthopaedic and Plastic Surgical input to determine their optimal management. Functional outcome scores, postoperative complications, and re-operation rates were determined. RESULTS: Fifteen patients were identified with a mean age of 76 years. Patient-reported outcomes (Olerud and Molander Score) were calculated in 73% of patients. Our results demonstrated excellent outcome scores (>91) in 1 patient, good outcome scores (61-90) in 7 patients, and fair outcome scores (31-60) in 3 patients. There were no postoperative complications or re-operations within our study group. CONCLUSION: This article is the largest series presenting the outcomes of fibula nails in the management of open ankle fractures in elderly patients. We conclude that it can be used as a treatment option to safely manage open ankle fractures in the elderly. It provides a stable fixation, early weight-bearing, low risk of postoperative complications while maintaining good patient-reported functional outcomes. LEVEL OF EVIDENCE: Level 4.

Evaluating measures of quality of life in adult scoliosis: a systematic review and narrative synthesis.

PURPOSE: To systematically review and synthesise the evidence on the measurement properties of patient-reported outcome measure (PROMs) used to assess the quality of life in patients with adult scoliosis. METHOD: Based on the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines and a published protocol, a two-stage search was conducted and reported in line with the Preferred Reporting Items for Systematic review and Meta-analysis (PRISMA). Stage one identified all studies of patients with adult scoliosis which included PROMs of health-related quality of life (HR-QOL). Databases including AMED, CINAHL, EMBASE, Medline, PsychINFO and Pubmed were searched from inception until 31st December 2020. This derived list of PROMs, was then utilised for a stage 2 search to identify studies which evaluated the measurement properties of the PROMs. Two reviewers independently performed the searches, study screening, selection and risk of bias assessment using the COSMIN tool. The overall quality of the evidence was assessed using a modified Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Stage one yielded 16 PROMs of HR-QOL with the Oswestry Disability Index (ODI) and Scoliosis Research Society-22 (SRS-22) the most used. Stage two identified three stage one PROMs that fulfilled eligibility criteria: SRS-22, ODI and SRS-22r; with five studies investigating measurement properties in an adult scoliosis population. The SRS-22 was the most comprehensively evaluated PROM in this cohort with very low-quality evidence indicating indeterminate reliability, sufficient construct validity and sufficient responsiveness of the SRS-22. There is very low-quality evidence indicating sufficient responsiveness of the ODI. There is very low-quality evidence indicating indeterminate cross-cultural validity for the SRS-22r. All other measurement properties in the SRS-22, ODI and SRS-22r have not been evaluated. CONCLUSION: A large number of PROMs are being utilised in the adult scoliosis population and of these, the most commonly utilised are the ODI and SRS-22. The SRS-22, ODI and SRS-22r are the only PROMs to have had their measurement properties evaluated in the adult scoliosis population. The findings of this systematic review are that there currently is not sufficient evidence on the measurement properties of any PROMs in adult scoliosis. Further research is now urgently required to assess the measurement properties of these PROMs.

Evaluating measures of quality of life in adult scoliosis: a protocol for a systematic review and narrative synthesis.

BACKGROUND: Adult scoliosis represents a distinct subgroup of scoliosis patients for whom the diagnosis can have a large impact on their health-related quality of life (HR-QOL). Therefore, HR-QOL patient-reported outcome measures (PROMs) are essential to assess disease progression and the impact of interventions. The objective of this systematic review is to evaluate the measurement properties of HR-QOL PROMs in adult scoliosis patients. METHODS: We will conduct a literature search, from their inception onwards, of multiple electronic databases including AMED, CINAHL, EMBASE, Medline, PsychINFO and PubMed. The searches will be performed in two stages. For both stages of the search, participants will be aged 18 and over with a diagnosis of scoliosis. The primary outcome of interest in the stage one searches will be studies which use PROMs to investigate HR-QOL as defined by the Core Outcome Measures in Effectiveness Trials (COMET) taxonomy, the secondary outcome will be to assess the frequency of use of the various PROMs. In stage two, the primary outcome of interest will be studies which assess the measurement properties of the HR-QOL PROMs identified in stage one. No specific measurement property will be given priority. No planned secondary outcomes have been identified but will be reported if discovered. In stage one, the only restriction on study design will be the exclusion of systematic reviews. In Stage two the only restriction on study design will be the exclusion of full-text articles not available in the English language. Two reviewers will independently screen all citations and abstract data. Potential conflicts will be resolved through discussion. The study methodological quality (or risk of bias) will be appraised using the Consensus-based Standards for the selection of Health Measurement Instruments (COSMIN) checklist. The overall strength of the body of evidence will then be assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A narrative synthesis will be provided with information presented in the main text and tables to summarise and explain the characteristics and findings of the included studies. The narrative synthesis will explore the evidence for currently used PROMs in adult scoliosis patients and any areas that require further study. DISCUSSION: The review will help clinicians and researchers identify a HR-QOL PROM for use in patients with adult scoliosis. Findings from the review will be published and disseminated through a peer-reviewed journal and conference presentations. SYSTEMATIC REVIEW REGISTRATION: This systematic review has been registered with the International Prospective Register of Systematic Reviews (PROSPERO), reference number: CRD42020219437.

Outcomes evaluating quality of life and their measurement properties in early-onset scoliosis: protocol for a systematic review.

INTRODUCTION: Early-onset scoliosis (EOS) is a rare spinal deformity affecting children under the age of 10. Both the condition and its treatment have associated morbidity and can impact quality of life. Understanding this impact can be achieved by using appropriate patient-reported and/or carer-reported outcome measures. The aim of the review described in this protocol is to evaluate the evidence on measurement properties relevant to health-related quality of life outcomes in the EOS population. The focus will be on outcome measures relevant to patients undergoing treatment of EOS under the age of 10. METHODS/ANALYSIS: This protocol is reported in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol and COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) methodology. The MEDLINE, EMBASE, EMCARE, PubMed, PsychINFO and CINAHL databases will be searched using a two-stage search strategy. The first stage will identify measures of HRQoL used in EOS through screening of titles and abstracts. The second stage will assess the measurement properties of those measures identified through screening of full-text articles. The measurement properties of interest are the 'reliability', 'validity' and 'responsiveness' of the instrument. Only English language articles will be considered. Two reviewers will independently review the search results against the eligibility criteria, perform data extraction and assess for risk of bias, with disputes handled by a third reviewer. Data will be quantitatively pooled where possible or reported as a narrative synthesis. The summarised results for each measurement property will be rated against the criteria for good measurement properties following the COSMIN methodology. Two reviewers will assess the body of evidence for each measurement property using modified Grading of Recommendations, Assessment, Development and Evaluation guidelines. ETHICS AND DISSEMINATION: No ethical approval is required for this review and the results will be submitted for publication in peer-reviewed publications. PROSPERO REGISTRATION NUMBER: CRD42020219721.

Traumatic hip dislocation in the paediatric population: A case series from a specialist centre.

INTRODUCTION: Traumatic hip dislocation is a rare injury in the paediatric population. It can occur after high energy trauma, but also after lower energy injuries especially in younger children. Posterior dislocation is the most common pattern of hip dislocation. In most cases, closed reduction is successful, but occasionally open reduction is required to achieve concentric reduction. The aim of our study was to present the 10-year experience from a Level-1 Trauma Paediatric Hospital and to comment on how our experience correlates with the current literature. PATIENTS AND METHODS: This is a retrospective case series of all paediatric patients (< 16 years old) with a traumatic hip dislocation presented and/or treated at our institution, between the 1st of January 2010 and 31st August 2020. RESULTS: Thirteen cases of traumatic hip dislocation were identified. There were 7 females. The mean age was 9.8 years. Typically, younger patients were involved in lower energy injuries. The direction of hip dislocation was posterior in ten cases. Associated injuries were seen in eight patients. All cases underwent closed reduction, which was successful in nine cases. Mean time to reduction was 6.8 hours. Post reduction imaging with CT and/or MRI was performed in all cases. There was residual subluxation in three cases, requiring open reduction. In one case with unrecognised undisplaced physeal injury, closed reduction resulted in a Delbet type 1 hip fracture. Two cases developed avascular necrosis (AVN). CONCLUSIONS: Traumatic paediatric hip dislocation is a rare injury. A target of 6 hours for reduction should be employed as this will reduce the risk of AVN in those who have not permanently damaged the vessels at the time of injury. We advocate all attempts for closed reduction to be performed in an operating theatre with the use of an image intensifier to help identifying associated injuries and confirm concentric reduction. If closed reduction fails, open reduction is required. Post-reduction MRI is an important adjunct to recognise associated soft tissue injuries. Follow up of patients should continue for 2 years as a minimum to help detect AVN.

The resting coronal and sagittal stance position of the torso in adolescents with and without spinal deformity.

The purpose of this work is to identify the resting stance of the torso, defined as the position of the C7 vertebral body relative to the sacrum in a 'birds eye view', as the coronal and sagittal offset, in those without spinal deformity, those with pre and post-operative AIS, and those with Scheuermann's kyphosis (SK). Using ISIS2 surface topography, the coronal and sagittal offset were measured in a prospective manner in all groups. With bivariate ellipses, a mean and 95% confidence ellipse of the data was developed. Statistical analyses was performed to examine the distribution of the data from the groups. A graphical representation of the data was developed. There were 829 without spinal deformity, 289 in both the pre and post-operative with AIS and 59 with SK. The results showed that the mean coronal offset for all groups was between 2 and 6 mm and the sagittal offset was 12 and 26 mm. Statistically significance was seen for both measures between the non-scoliotic and both AIS groups, along with the pre-operative AIS coronal offset and post-operative AIS sagittal offset and the SK measures. However, all mean values were within the 95% confidence ellipse for all of the groups. Regardless of the size or type of spinal deformity, the position of the C7 vertebral body and sacrum remain within the 95% confidence ellipse of that seen in those without spinal deformity. This work defines the Minimally Clinically Important Difference for all of the groups.

Management of Native Joint Septic Arthritis, Serial Aspiration vs. Arthroscopic Washout During the COVID-19 Pandemic.

Septic arthritis remains an orthopaedic emergency that requires prompt diagnosis and management. During the 2020 COVID-19 pandemic, British Orthopaedic Association (BOAST) guidelines dictated that medical treatment (closed-needle aspiration + antibiotic therapy) should be offered to patients as first-line management, and operative treatment (arthroscopic joint washout +/- synovectomy) be reserved for patients exhibiting signs of sepsis. Literature has previously shown that for native joint septic arthritis, operative treatment is not superior to medical treatment. During the COVID-19 'lock-down' period (March 2020 to June 2020), we prospectively followed the presentation, diagnosis, management and outcome of a total of six patients who presented with confirmed native joint septic arthritis. All six patients underwent initial medical management of their septic arthritis following their diagnostic aspiration, which involved serial closed-needle aspirations and antibiotic therapy as advised by our microbiology team. Four patients went on to have an arthroscopic washout at an average of eight days following admission (mean 2.5), prior to a consultant-led decision to proceed to arthroscopic washout. The decision for operative management was the patient's clinical deterioration based on physiological (fever, tachycardia) and biochemical (C-reactive protein (CRP), white blood cell (WBC)) parameters. All of the four patients that proceeded to operative treatment failed to provide culture yield at the time of arthroscopic washout. The mean time to discharge was 15.6 days, whilst the mean time to discharge following operative intervention was 12 days. One patient passed away during admission and one patient required a second arthroscopic washout. Medical management of septic arthritis may play a role in symptom control in the palliative setting or in patients where a general anaesthetic is undesirable. We found operative management to be therapeutic clinically, haemodynamically and biochemically as well as facilitative of a faster recovery and shorter inpatient stay.

A case of missed unstable cervical injury during the COVID-19 pandemic.

This case report discusses a patient with a significant, unstable, three-column injury of the cervical spine, which was not initially detected and was subsequently found on reassessment at 2 weeks post injury. The report discusses the imaging findings and the subsequent management of the injury. The report highlights the need for an individualized assessment of each presentation, taking into account the circumstances of injury and any pre-existing degenerative change in the spine.

MRI-LINAC beam profile measurements using a plastic scintillation dosimeter.

Plastic scintillation dosimeters (PSDs) possess many desirable qualities for dosimetry with LINACs. These qualities are expected to make PSDs effective for MRI-LINAC dosimetry, however little research has been conducted investigating their dosimetric performance with MRI-LINACs. In this work, an in-house PSD was used to measure 8 beam profiles with an in-line MRI-LINAC, compared with film measurements. One dimensional global gamma indices (γ) and corresponding γ pass rates were calculated to compare PSD and film profiles for the 1%/1 mm, 2%/2 mm and 3%/3 mm criterion. The mean global pass rates were 85.8%, 97.5% and 99.4% for the 1%/1 mm, 2%/2 mm and 3%/3 mm criteria, respectively. The majority of the γ failures occurred in the penumbral regions. Penumbra widths were measured to be slightly narrower with the PSD compared to film, however, the uncertainties in the measured penumbra widths brought the PSD and film penumbra widths into agreement. Differences in dose were calculated between the PSD and film, and remained within 2.2% global agreement for the central regions and 1.5% global agreement for out of field regions. These values for range of agreement were similar to the those reported in the literature for other dosimeters which are trusted for relative MRI-LINAC dosimetry.

Minimising Tourniquet Time and Post-operative Pain During Carpal Tunnel Decompression.

Background Pain and discomfort at the tourniquet and wound site are recognised complications of carpal tunnel surgery. Studies have shown that longer tourniquet times lead to increased pain, local and systematic complications. We hypothesise that minimising the intraoperative tourniquet time will reduce post-operative pain and complications. Objective Our aim is to present the results of our novel operative technique for carpal tunnel decompression which minimises tourniquet time. Method The study represented a prospective case series in which 55 consecutive and unselected patients with positive nerve conduction study results were operated on by a single surgeon at a single hospital site over a period of 12 months. The patients filled in a questionnaire based on a visual analogue score (VAS) (1-10) for pain at (1) first presentation at the clinic, (2) recovery in theatre post-operatively and (3) on discharge from care at 12 weeks post-operatively. Questions included the perception of pain at the tourniquet site and at the wound site. Results  A total of 55 (female 39 and male 16) patients participated in the study. The average tourniquet time was 5 minutes 50 seconds. 98% of patients had a VAS of 1 at both the wound and tourniquet site post-operatively. One patent had a score of 3 at the tourniquet site. Eleven patients had undergone contralateral carpal tunnel decompression surgery. Of the remaining 43 patients, all said they would have the other side operated on in the same way. Conclusion  We have demonstrated a safe and efficient technique to reduce post-operative pain by minimising tourniquet inflation time. Our patient cohort experienced no significant complications and minimal pain post-operatively.

First measurements with a plastic scintillation dosimeter at the Australian MRI-LINAC.

MRI-LINACs combine MRI and LINAC technologies with the potential for image guided radiation therapy with optimal soft-tissue contrast. In this work, we present the advantages and limitations of plastic scintillation dosimeters (PSDs) for relative dosimetry with MRI-LINACs. PSDs possess many desirable qualities, including magnetic field insensitivity and irradiation angle independence, which are expected to make them suitable for dosimetry with MRI-LINACs. An in-house PSD was used to measure field size output factors as well as a percent depth dose distribution and the beam quality index TPR20/10 at a [Formula: see text] cm2 field size. Measurements were repeated with a Scanditronix/Wellhofer FC65-G ionisation chamber and PTW 60019 microDiamond detector for comparison. Relative differences were calculated between the three detectors, where the mean difference in dose was 1.2% between the PSD and ionisation chamber, 1.9% between the PSD and microDiamond detector and 1.3% between the microDiamond detector and the ionisation chamber. The closeness between the three mean differences in doses suggests that PSDs are feasible for relative dosimetry with MRI-LINACs.

High spatial resolution scintillator dosimetry of synchrotron microbeams.

Microbeam radiation therapy is a novel pre-clinical external beam therapy that uses high-brilliance synchrotron X-rays to deliver the necessary high dose rates. The unique conditions of high dose rate and high spatial fractionation demand a new class of detector to experimentally measure important beam quality parameters. Here we demonstrate the highest spatial resolution plastic scintillator fibre-optic dosimeter found in the literature to date and tested it on the Imaging and Medical Beam-Line at the Australian Synchrotron in a X-ray beam where the irradiation dose rate was 4435 Gy/s. With a one-dimensional spatial resolution of 10 µm the detector is able to resolve the individual microbeams (53.7 ± 0.4 µm wide), and measure the peak-to-valley dose ratio to be 55 ± 17. We also investigate the role of radioluminescence in the optical fibre used to transport the scintillation photons, and conclude that it creates a significant contribution to the total light detected.

An algorithmic approach to single-probe Cherenkov removal in pulsed x-ray beams.

PURPOSE: The removal of Cherenkov light in an optical dosimetry system is an important process to ensure accurate dosimetry without compromising spatial resolution. Many solutions have been presented in the literature, each with advantages and disadvantages. We present a methodology to remove Cherenkov light from a scintillator fiber optic dosimeter in a pulsed megavoltage x-ray beam using the temporal waveform across the pulse. METHODS: A sample waveform of Cherenkov light can be measured by exposing only the fiber to the beam. By assuming that the Cherenkov waveform closely matches the intensity of incident radiation, this waveform can be convoluted with the instantaneous scintillation response function to generate an expected scintillation signal. By finding the least-squares fit between these two functions and the experimental data, the estimated Cherenkov contribution can be subtracted off the net signal. This can be applied for arbitrarily complex Cherenkov waveforms (within the 2 ns timing resolution of the data acquisition), and in fact, the results suggest more fluctuations in the waveforms provide a better fit to data. RESULTS: Four beam profiles for different field sizes and energies were found with this method. They closely matched references data measured with ionization chamber with average differences across the beam no more than 4%. Noisy waveforms are assumed to be the primary cause of differences between the analyzed scintillator and IC results. We propose methods for improving the results and optimizing the data acquisition and analysis processes. CONCLUSIONS: These results demonstrate that it is possible and effective with a single probe to use function fitting of expected data to experimental to remove a complicated Cherenkov signal from the net light signal in pulsed-beam optical dosimetry.

Temporal separation of Cerenkov radiation and scintillation using a clinical LINAC and artificial intelligence.

Convolutional neural network (CNN) type artificial intelligences were trained to estimate the Cerenkov radiation present in the temporal response of a LINAC irradiated scintillator-fiber optic dosimeter. The CNN estimate of Cerenkov radiation is subtracted from the combined scintillation and Cerenkov radiation temporal response of the irradiated scintillator-fiber optic dosimeter, giving the sole scintillation signal, which is proportional to the scintillator dose. The CNN measured scintillator dose was compared to the background subtraction measured scintillator dose and ionisation chamber measured dose. The dose discrepancy of the CNN measured dose was on average 1.4% with respect to the ionisation chamber measured dose, matching the 1.4% average dose discrepancy of the background subtraction measured dose with respect to the ionisation chamber measured dose. The developed CNNs had an average time of 3 ms to calculate scintillator dose, permitting the CNNs presented to be applicable for dosimetry in real time.