Vertebral Dose Sparing during Lung and Esophageal Radiation Therapy

PURPOSE/OBJECTIVE(S)

The vertebral bodies contain approximately 20-25% of all bone marrow in the body. Lymphopenia is a known negative prognostic factor in thoracic malignancies. Studies have previously demonstrated that patients receiving radiation to the lumbar spine and/or pelvis have shown increased fat deposition/bone marrow scarring following therapy, which leads to long term immunosuppressive effects. In anticipation for an open clinical trial, and based on previously published work, we explored whether retrospectively constraining the thoracic bone marrow is practically feasible and leads to minimal increase in dose to the remaining OARs (Organs at Risk).

MATERIALS/METHODS

Patients with previously treated thoracic cancer were included in this study. The thoracic bone marrow was contoured using PET scan to verify avid areas and a new plan was created. Guideline constraints for the thoracic bone marrow were V10 (<300cc), V20 (<200 cc), and V30 (<150cc). If bone marrow optimization caused a violation of standard OAR guidelines, then the bone marrow constraints were not met. The median changes in thoracic bone marrow and OARs (lung, heart, spinal cord) were compared with the Wilcoxon sign rank test for non-parametric paired samples.

RESULTS

We included 20 patients, 10 with esophageal cancer and 10 with NSCLC (Non-Small Cell Lung Cancer). Only three cases were able to meet the prespecified bone marrow constraints after optimization (15%). Bone marrow median V10 was reduced by 20cc (-8.16%). Larger changes were seen in V20 and V30 dose-volume reductions, with decreases of 35.3 and 32.3 cc (-16.4% and -21.3%), respectively. There was a significant reduction (p<0.001) for V30, V20, and V10. Though most experienced a decrease in mean heart dose, there was an overall median increase of 21.00 cGy, attributable to a single outlier (P = 1). Median cord dose was decreased by 418.5 cGy. There was a minimal non-significant increase in median Lung V20 of 0.76% as well as minimal median increase in the mean lung dose (7 cGy).

CONCLUSION

This retrospective dosimetric analysis reveals that bone marrow can be optimized. While not able to meet thresholds predictive of minimizing Grade 4 lymphopenia, dose reduction can safely be done with minimal increase in values known to cause toxicity in the heart, lungs, and cord. Though radiation dosage to the thoracic vertebrae was not eliminated entirely, significant decreases in median dosages were achieved without compromising OAR dose. Bone marrow sparing should be considered when feasible and this planning technique is currently being used in an open prospective trial.

Attaching protein-adsorbing silica particles to the surface of cotton substrates for bioaerosol capture including SARS-CoV-2

The novel coronavirus pandemic (COVID-19) has necessitated a global increase in the use of face masks to limit the airborne spread of the virus. The global demand for personal protective equipment has at times led to shortages of face masks for the public, therefore makeshift masks have become commonplace. The severe acute respiratory syndrome caused by coronavirus-2 (SARS-CoV-2) has a spherical particle size of ~97 nm. However, the airborne transmission of this virus requires the expulsion of droplets, typically ~0.6-500 µm in diameter (by coughing, sneezing, breathing, and talking). In this paper, we propose a face covering that has been designed to effectively capture SARS-CoV-2 whilst providing uncompromised comfort and breathability for the wearer. Herein, we describe a material approach that uses amorphous silica microspheres attached to cotton fibres to capture bioaerosols, including SARS CoV-2. This has been demonstrated for the capture of aerosolised proteins (cytochrome c, myoglobin, ubiquitin, bovine serum albumin) and aerosolised inactivated SARS CoV-2, showing average filtration efficiencies of ~93% with minimal impact on breathability.

Prevalence and Burden of Migraine in Switzerland: Cross-Sectional Study in ten Specialised Headache Centres from the BECOME Study

INTRODUCTION

There is limited real-world evidence on the burden of migraine among patients with prior preventive treatment failure (PPTF). In the BECOME Swiss subanalysis, we aimed to assess current prevalence of PPTF in patients with migraine seen at specialised headache centres in Switzerland and burden of migraine in these patients. Furthermore, we assessed this burden in subgroups stratified by monthly migraine days (MMDs) and number of PPTFs.

METHODS

BECOME was a prospective, multicentre, non-interventional two-part study conducted in 17 countries across Europe and Israel. This subanalysis includes patients visiting ten headache specialist centres in Switzerland. In part 1, patients visiting the centres over 3 months were screened by physicians for frequency of PPTF, MMD and other migraine characteristics. Patients with ≥ 1 PPTF and ≥ 4 MMDs were invited to take part in part 2. The primary endpoint was the proportion of patients with ≥ 1 PPTF (part 1). Other endpoints included proportion of patients specified by number of PPTF and MMD (part 1, part 2), and impact of migraine on patient-reported outcomes (PROs; part 2).

RESULTS

Patients (1677) from ten Swiss centres were included in part 1, of which 855 (51.0%) reported ≥ 1 PPTF. One hundred fifty-five patients were included in part 2: 6.5% reported ≥ 4 PPTFs and 43.2% reported ≥ 15 MMDs. Mean EuroQoL 5 and EuroQoL visual analogue scale (EQ-VAS) were 0.8 ± 0.2 and 69.6 ± 20.2, respectively, suggesting a mild level of impairment in the daily functioning and self-reported health of the patients. Mean six-item Headache Impact Test (HIT-6) and modified Migraine Disability Assessment (mMIDAS) scores were 63.3 ± 6.5 and 22.7 ± 21.8, respectively, corresponding to severe migraine burden. Patients also reported impairment in work-related productivity and general activities (48.6 ± 22.8) but no associations of anxiety (7.2 ± 4.4) or depression (6.0 ± 4.4) with migraine were noted. Burden of migraine increased with increasing frequency of PPTF and MMD.

CONCLUSIONS

Migraine-related quality of life, as well as work productivity are significantly affected in Swiss patients with migraine. Increasing migraine burden is associated with increasing migraine frequency and prior treatment failures.

Lateral Extra-Articular Tenodesis Combined With Anterior Cruciate Ligament Reconstruction Is Effective in Knees With Additional Features of Lateral, Hyperextension, or Increased Rotational Laxity: A Matched Cohort Study

PURPOSE

To investigate the patient-reported outcome measures (PROMs) and graft survival of combined anterior cruciate ligament reconstruction (ACLR) and lateral extra-articular tenodesis (ACLR-LET) compared with a matched cohort having ACLR alone.

METHODS

Patients were retrospectively recruited from a consecutive series of primary ACLR-LET, between 1996 and 2015, with a minimum postsurgical time of 4 years. ACLR-LET were matched with isolated ACLR for age, gender, and operation year. The indications for adding lateral extra-articular tenodesis were lateral laxity of grade 1 or 2, hyperextension laxity, and/or increased rotational laxity of 5° to 10°. The technique used involved detaching a strip of iliotibial band proximally, before being passed deep to the lateral collateral ligament, looped through Kaplan's fibers, and sutured back onto itself at physiological tension. The PROMs used were the Lysholm Knee Scoring Scale, Tegner Activity Scale, Oxford Knee Score, and International Knee Documentation Committee subjective knee form. Failure was defined as graft rupture. Student's t-test was used to compare the matched groups and Kaplan-Meier analysis for survivorship.

RESULTS

Eighty-three patients had ACLR-LET between 1996 and 2015. Nine revision cases and 2 with less than 4 years follow-up were excluded. The remaining 72 ACLR-LET patients were matched and included in the survival analysis. Seventy percent of patients completed the PROMs. In both groups, 76% were males, and the mean age was 25 years (standard deviation ± 8.5). The median follow-up was 10 years (interquartile range, 6.7 years). There was no significant change of PROMs (Lysholm Knee Scoring Scale: P = .82, 95% confidence interval (CI) -13 to 11; International Knee Documentation Committee: P = .07, CI -1 to 24; Oxford Knee Score: P = .5, CI -8 to 4; Tegner Activity Scale: P = .5, CI -1 to 3) between the groups. The pre- to postoperative PROMs, except the Tegner Activity Scale, improved significantly, clinically and statistically. There was no statistically significant difference in graft failure between the ACLR-LET group (n = 4, 5%) and the ACLR group (n = 9, 11%) (log-rank P = .099).

CONCLUSION

ACLR-LET shows good graft survival and PROMs in a high-risk population. This suggests that lateral extra-articular tenodesis is an effective technique to restore joint stability to a knee with additional features of laxity.

LEVEL OF EVIDENCE

III, matched cohort study.

Silica Microspheres-in-Pores Composite Monoliths with Fluorescence and Potential for Water Remediation

Water pollution is a severe worldwide issue. Constructing advanced porous composite materials has been an efficient route to water remediation via adsorption. In this study, a unique microspheres-in-pores monolithic structure was fabricated. An emulsion-templated polymer monolith was first prepared and silica microspheres were subsequently formed in the porous polymer. A silica precursor was modified with a fluorescent dye and co-condensed with other precursors to fabricate porous composites with fluorescent properties, which were enhanced by the presence of Ag nanoparticles in the polymer matrix. This unique material showed good promise in water remediation by removing organic dyes and heavy metal ions from wastewater via a flowing filter or monolithic column separation.

Homozygous GRN mutations: new phenotypes and new insights into pathological and molecular mechanisms

Homozygous mutations in the progranulin gene (GRN) are associated with neuronal ceroid lipofuscinosis 11 (CLN11), a rare lysosomal-storage disorder characterized by cerebellar ataxia, seizures, retinitis pigmentosa, and cognitive disorders, usually beginning between 13 and 25 years of age. This is a rare condition, previously reported in only four families. In contrast, heterozygous GRN mutations are a major cause of frontotemporal dementia associated with neuronal cytoplasmic TDP-43 inclusions. We identified homozygous GRN mutations in six new patients. The phenotypic spectrum is much broader than previously reported, with two remarkably distinct presentations, depending on the age of onset. A childhood/juvenile form is characterized by classical CLN11 symptoms at an early age at onset. Unexpectedly, other homozygous patients presented a distinct delayed phenotype of frontotemporal dementia and parkinsonism after 50 years; none had epilepsy or cerebellar ataxia. Another major finding of this study is that all GRN mutations may not have the same impact on progranulin protein synthesis. A hypomorphic effect of some mutations is supported by the presence of residual levels of plasma progranulin and low levels of normal transcript detected in one case with a homozygous splice-site mutation and late onset frontotemporal dementia. This is a new critical finding that must be considered in therapeutic trials based on replacement strategies. The first neuropathological study in a homozygous carrier provides new insights into the pathological mechanisms of the disease. Hallmarks of neuronal ceroid lipofuscinosis were present. The absence of TDP-43 cytoplasmic inclusions markedly differs from observations of heterozygous mutations, suggesting a pathological shift between lysosomal and TDP-43 pathologies depending on the mono or bi-allelic status. An intriguing observation was the loss of normal TDP-43 staining in the nucleus of some neurons, which could be the first stage of the TDP-43 pathological process preceding the formation of typical cytoplasmic inclusions. Finally, this study has important implications for genetic counselling and molecular diagnosis. Semi-dominant inheritance of GRN mutations implies that specific genetic counselling should be delivered to children and parents of CLN11 patients, as they are heterozygous carriers with a high risk of developing dementia. More broadly, this study illustrates the fact that genetic variants can lead to different phenotypes according to their mono- or bi-allelic state, which is a challenge for genetic diagnosis.

Furo[3,2-c]coumarin-derived Fe3+ Selective Fluorescence Sensor: Synthesis, Fluorescence Study and Application to Water Analysis

Furocoumarin (furo[3,2-c]coumarin) derivatives have been synthesized from single step, high yielding (82-92%) chemistry involving a 4-hydroxycoumarin 4 + 1 cycloaddition reaction. They are characterized by FTIR, 1H-NMR, and, for the first time, a comprehensive UV-Vis and fluorescence spectroscopy study has been carried out to determine if these compounds can serve as useful sensors. Based on the fluorescence data, the most promising furocoumarin derivative (2-(cyclohexylamino)-3-phenyl-4H-furo[3,2-c]chromen-4-one, FH), exhibits strong fluorescence (ФF = 0.48) with long fluorescence lifetime (5.6 ns) and large Stokes' shift, suggesting FH could be used as a novel fluorescent chemosensor. FH exhibits a highly selective, sensitive and instant turn-off fluorescence response to Fe3+ over other metal ions which was attributed to a charge transfer mechanism. Selectivity was demonstrated against 13 other competing metal ions (Na+, K+, Mg2+, Ca2+, Mn2+, Fe2+, Al3+, Ni2+, Cu2+, Zn2+, Co2+, Pb2+ and Ru3+) and aqueous compatibility was demonstrated in 10% MeOH-H2O solution. The FH sensor coordinates Fe3+ in a 1:2 stoichiometry with a binding constant, Ka = 5.25 × 103 M-1. This novel sensor has a limit of detection of 1.93 µM, below that of the US environmental protection agency guidelines (5.37 µM), with a linear dynamic range of ~28 (~2-30 µM) and an R2 value of 0.9975. As an exemplar application we demonstrate the potential of this sensor for the rapid measurement of Fe3+ in mineral and tap water samples demonstrating the real-world application of FH as a "turn off" fluorescence sensor.

White Light Emission from a Simple Mixture of Fluorescent Organic Compounds

Three fluorescent organic compounds—furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)—are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d’Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.

Distinct chromatin structures at the monoamine oxidase-A promoter correlate with allele-specific expression in SH-SY5Y cells

Monoamine oxidase-A (MAOA) metabolises monoamines and is implicated in the pathophysiology of psychiatric disorders. A polymorphic repetitive DNA domain, termed the uVNTR (upstream variable number tandem repeat), located at the promoter of the MAOA gene is a risk factor for many of these disorders. MAOA is on the X chromosome suggesting gender could play a role in regulation. We analysed MAOA regulation in the human female cell line, SH-SY5Y, which is polymorphic for the uVNTR. This heterozygosity allowed us to correlate allele-specific gene expression with allele-specific transcription factor binding and epigenetic marks for MAOA. Gene regulation was analysed under basal conditions and in response to the mood stabiliser sodium valproate. Both alleles were transcriptionally active under basal growth conditions; however, the alleles showed distinct transcription factor binding and epigenetic marks at their respective promoters. Exposure of the cells to sodium valproate resulted in differential allelic expression which correlated with allele-specific changes in distinct transcription factor binding and epigenetic marks at the region encompassing the uVNTR. Biochemically our model for MAOA promoter function has implications for gender differences in gene × environment responses in which the uVNTR has been implicated as a genetic risk.

Meniscal allograft transplantation: undersizing grafts can lead to increased rates of clinical and mechanical failure

PURPOSE

To assess mid-term survivorship of meniscal allograft transplantation (MAT) and determine the effect that pre-operative meniscal sizing has upon functional outcome and mechanical survivorship.

METHODS

A prospectively collected database of patients receiving MAT from 2001 to 2017 was analysed. Data include demographics; sizing measurements, complications, further surgery, and patient-reported outcome measures (PROMs). Allografts were fresh frozen, non-irradiated, and sized using the Pollard technique.

RESULTS

Seventy-three MATs were performed in 67 patients; mean age at MAT was 34 years (range 14-52 years). 56% were male and 62% were medial. The mean follow-up was 75 months (6.25 years). Mechanical survival at 5 and 10 years was 96% and 89.4%, respectively. There were statistically significant improvements in all PROMs; mean Lysholm score improved by 17.5 points [95% confidence interval (CI) 22.2-12.9, p < 0.001]; mean IKDC score improved significantly by 13.3 points (CI 19.3-7.4, p < 0.001); mean OKS improved by 5.6 points (CI 9.2-2.2, p < 0.002); and the median Tegner improved by 1 point. Forty-one MATs (56%) were undersized for width (range 1-11 mm). Seven MATs (10%) were undersized for length (range 1-4 mm). There was no statistically significant difference in mechanical survivorship or clinical outcomes between undersized, matched, or oversized grafts overall; however, sub-group analysis demonstrated increased failure when allografts were undersized by more than 5 mm in width.

CONCLUSIONS

MAT is an effective treatment to improve function and alleviate pain with excellent survivorship in this series. Accepting an allograft that is more than 5 mm smaller in width than pre-operative templating increases the likelihood of clinical and mechanical failure. We, therefore, urge surgeons to be familiar with the measuring process used by their individual tissue bank provider to avoid graft-host mismatch that could affect outcome.

What Is the Risk of Repeat Revision When Patellofemoral Replacement Is Revised to TKA? An Analysis of 482 Cases From a Large National Arthroplasty Registry

BACKGROUND

Patellofemoral replacements (PFRs) have a higher rate of revision than unicompartmental knee arthroplasty or TKA. However, there is little information regarding why PFRs are revised, the components used for these revisions, or the outcome of the revision procedure. Some contend that PFR is a bridging procedure that can easily be revised to a TKA with similar results as a primary TKA; however, others dispute this suggestion.

QUESTIONS/PURPOSES

(1) In the setting of a large national registry, what were the reasons for revision of PFR to TKA and was the level of TKA constraint used in the revision associated with a subsequent risk of rerevision? (2) Is the risk of revision of the TKA used to revise a PFR greater than the risk of revision after a primary TKA and greater than the risk of rerevision after revision TKA?

METHODS

Data were obtained from the Australian Orthopaedic Association Joint Replacement Registry through December 31, 2016, for TKA revision procedures after PFR. Because revisions for infection may be staged procedures resulting in further planned operations, for the revision analyses, these were excluded. There were 3251 PFRs, 482 of which were revised to TKA during the 17-year study period. The risk of second revision was calculated using Kaplan-Meier estimates of survivorship for PFRs revised to TKAs, and that risk was compared with the risk of first revision after TKA and also with the risk of a second revision after revision TKA. Hazard ratios (HRs) from Cox proportional hazards models were used to compare second revision rates among the different levels of prosthesis constraint used in the index revision after PFR (specifically, cruciate-retaining versus cruciate-substituting).

RESULTS

The main reasons for revising a PFR to TKA were progression of disease (56%), loosening (17%), and pain (12%). With the numbers available for analysis, there was no difference in the risk of a second revision when a PFR was revised to a cruciate-retaining TKA than when it was revised to a cruciate-substituting TKA (HR, 1.24 [0.65-2.36]; p = 0.512). A total of 204 (42%) of the PFR revisions had the patella component revised when the PFR was converted to a TKA. There difference in rates of second revision when the patella component was revised or not revised (HR, 1.01 [0.55-1.85]; p = 0.964). When we eliminated the devices that ceased to be used before 2005 (older devices), we found no change in the overall risk of repeat revision. The risk of a PFR that was revised to a TKA undergoing a second revision was greater than the risk of TKA undergoing a first revision (HR, 2.39 [1.77-3.24]; p < 0.001), but it was less than the risk of a revision TKA undergoing a second revision (HR, 0.60 [0.43-0.81]; p = 0.001).

CONCLUSIONS

The risk of second revision when a PFR is revised is not altered if cruciate-retaining or posterior-stabilized TKA is used for the revision nor if the patella component is revised or not revised. The risk of repeat revision after revision of a PFR to a TKA was much higher than the risk of revision after a primary TKA, and these findings did not change when we analyzed only devices in use since 2005. When PFR is used for the management of isolated patellofemoral osteoarthritis, patients should be counselled not only about the high revision rate of the primary procedure, but also the revision rate after TKA. Further studies regarding the functional outcomes of these procedures may help clarify the value of PFRs and subsequent revisions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Abstract P4-11-01: Effects of high anxiety scores on surgical and overall treatment plan in breast cancer patients treated with neoadjuvant therapy

Introduction:

Anxiety is a common symptom in patients with newly diagnosed cancer. Patients with high levels of anxiety have been shown to choose more invasive surgeries in various cancer settings. Rates of contralateral prophylactic mastectomy in the adjuvant setting remain high, despite offering no survival advantage. In the neoadjuvant setting, patients have more time for decisions regarding final surgery. If anxiety is playing a role in their decisions, this could be addressed while on neoadjuvant therapy (NAT). However, the impact of anxiety at initial diagnosis on surgical decision making in this setting has not yet been studied.

Methods:

Data collected from a prospective institutional database of breast cancer patients treated with NAT at the British Columbia Cancer Agency (BCCA) were utilized to identify all patients. Information was extracted from this database with regards to patient and tumour characteristics, initial surgical plan, and final surgery performed. This was cross referenced with patient self-reported anxiety, which was extracted from the Edmonton Symptom Assessment System (ESAS) and the Psychosocial Screen for Cancer (PSSCAN) forms administered at initial consultation. Patients were assigned a score of 0 to 3 based on their answers to the ESAS anxiety scale and the PSSCAN anxiety questions, and whether or not they had any concerns related to their care. Patients were excluded if they had bilateral breast cancer, BRCA mutation or referral to the Hereditary Cancer Program, did not receive NAT or undergo breast surgery, or did not complete the forms. Fisher's exact tests were applied for statistical analysis.

Results:

From 2012-2016, 361 potential patients were identified for this study. A total of 203 patients met eligibility criteria. 93 patients (46%) had low anxiety (score 0 or 1) and 110 patients (54%) had high anxiety (score 2 or 3). Patients with high self-reported anxiety at initial consultation were significantly more likely to undergo bilateral mastectomy for unilateral disease and mastectomy for breast conserving surgery (BCS) eligible disease than those with low self-reported anxiety at initial consultation (37.3% VS 18.3%; p=0.003). No significant differences in treatment times (time interval between biopsy to chemotherapy, chemotherapy to surgery, and surgery to radiation) or investigations were identified when comparing high and low anxiety patients.

Anxiety level and type of surgery performedType of SurgeryAnxiety Level  Low (n=93)High (n=110) Bilateral Mastectomy and Mastectomy for BCS eligible disease17 (18.3%)41 (37.3%) BCS and Mastectomy for non-BCS eligible disease76 (81.7%)69 (62.7%)    p = 0.0031

Conclusion:

High anxiety scores lead to a 19% increase in bilateral mastectomies in patients without bilateral disease and mastectomies in patients eligible for BCS compared to patients with low anxiety (p = 0.003). These findings suggest that self-reported anxiety levels can inform and assist physicians to identify patients who are more likely to undergo aggressive surgery and may need further counselling and support services. Future work should examine the effects of counselling intervention in patients with high anxiety on surgical decisions.

Citation Format: Li H, Cheung W, Myers P, McKevitt E, Willemsma K, Deruchie Tan A, Chia S, Simmons C. Effects of high anxiety scores on surgical and overall treatment plan in breast cancer patients treated with neoadjuvant therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-11-01.

Meniscal transplantation: procedures, outcomes, and rehabilitation

Meniscal allograft transplantation (MAT) is a possible treatment option for patients with joint pain after meniscectomy. It is necessary that the joint be aligned and stable. Current evidence shows that MAT improves pain and mechanical function in the mid to long term with patients reporting significantly improved outcomes at up to 15 years following surgery. Studies on survivorship showed up to 76% graft survival at 10 years. Recent studies have suggested a chondroprotective effect, but there is, at present, no evidence to support MAT in the prevention of osteoarthritis. This review article reported the current evidence for MAT showing support for fresh frozen, nonirradiated allografts. However, further research is required to determine the ideal indications for MAT, the optimal graft fixation method, and the safest rehabilitation protocol.

International Meniscus Reconstruction Experts Forum (IMREF) 2015 Consensus Statement on the Practice of Meniscal Allograft Transplantation

Meniscal allograft transplantation (MAT) has become relatively commonplace in specialized sport medicine practice for the treatment of patients with a symptomatic knee after the loss of a functional meniscus. The technique has evolved since the 1980s, and long-term results continue to improve. However, there still remains significant variation in how MAT is performed, and as such, there remains opportunity for outcome and graft survivorship to be optimized. The purpose of this article was to develop a consensus statement on the practice of MAT from key opinion leaders who are members of the International Meniscus Reconstruction Experts Forum so that a more standardized approach to the indications, surgical technique, and postoperative care could be outlined with the goal of ultimately improving patient outcomes.

Twelve-Year Outcomes of an Oxinium Total Knee Replacement Compared with the Same Cobalt-Chromium Design: An Analysis of 17,577 Prostheses from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Oxidized zirconium (Oxinium) was introduced as an alternative bearing surface to cobalt-chromium (CoCr) in an attempt to reduce polyethylene wear and decrease aseptic mechanical failure of total knee replacements. While noncomparative reports have been described as promising, we were aware of no short or long-term clinical studies showing the superiority of Oxinium on polyethylene as a bearing surface. Using data from a comprehensive national joint replacement registry, we compared the long-term outcomes after cruciate-retaining total knee arthroplasty (TKA) with an Oxinium femoral component and those with the same prosthetic design but with a CoCr femoral component.

METHODS

The cohorts consisted of 17,577 cemented Genesis-II cruciate-retaining total knee replacements using non-cross-linked polyethylene, which included 11,608 with CoCr femoral components and 5,969 with Oxinium femoral components. The cumulative percent revision and hazard ratio (HR) for revision risk were estimated for the cemented Genesis-II Oxinium and CoCr cruciate-retaining TKAs performed in Australia from September 1, 1999, to December 31, 2013. In addition, the revision diagnoses and the effects of age and patellar resurfacing were examined.

RESULTS

No difference in the HR for revision risk was found between the Oxinium and CoCr cohorts for any age category for all causes of revision (HR = 0.92 [95% confidence interval (CI), 0.92 to 1.29]; p = 0.329), loosening or lysis, or aseptic causes, except for loosening or lysis in the group of patients who were ≥75 years old (p = 0.033). In these patients, TKA with Oxinium femoral components had a higher rate of revision. Younger patients preferentially received Oxinium femoral components. The revision risk was not affected by patellar resurfacing or nonresurfacing. At 12 years, the cumulative percent revision was 4.8% (95% CI, 4.2% to 5.4%) for the CoCr Genesis-II prosthesis compared with 7.7% (95% CI, 6.2% to 9.5%) for the Oxinium Genesis-II prosthesis.

CONCLUSIONS

In this cohort study involving the same prosthetic design, Oxinium femoral components did not reduce revision rates for all causes, loosening or lysis, or when infection as a cause of revision was removed compared with the same CoCr femoral component across all age groups including patients who were <55 years old. The cumulative percent revision was greater for the Oxinium components than for the CoCr components.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A review of 1000 referrals to Walsall's hospital eye service

BACKGROUND

Referrals to ophthalmology are predominantly made from general practitioners (GPs) and optometrists. These two groups of referrers receive differing types and levels of training and are equipped with different instrumentation. The purpose of this study was to determine whether the quality of referrals to the hospital eye service (HES) differs between GPs and optometrists in Walsall.

METHODS

Referrals into the HES were identified from Q1 2014 retrospectively until 1000 notes had been reached. Each record was scrutinized using a standard template. Data were analysed and summary statistics produced including positive predictive values and interobserver agreement.

RESULTS

We achieved our target of auditing 1000 records. The false-positive rate (patients being discharged from HES with a 'normal vision' diagnosis) was 7.7% of referrals from GPs and 6.2% of referrals from optometrists. Concordance between referred condition and diagnosed condition at HES between optometrists and ophthalmologists was 76.1%, and between GPs and ophthalmologists was 67.2%.

CONCLUSIONS

In view of findings from this study, it is important for commissioners in the new reconfigured National Health Service to ensure that enhanced ophthalmic services are commissioned only on the basis of hard evidence sourced from local data rather than opinion or on data from another geographical area.

Colonization of the Beaver Island Archipelago by deer mice (Peromyscus maniculatus gracilis): mtDNA evidence for multiple origins

The Beaver Island group in Lake Michigan comprises nine islands ranging from 0.3 to 144 km2, lying approximately 30 km west of Michigan’s Lower Peninsula (LP) and 15 km south of the Upper Peninsula (UP). The islands have been isolated from mainland Michigan for most of their postglacial history, but were connected to the mainland LP during the low-water Chippewa stage (ending about 7400 years before present (YBP)). Although plants and animals could have colonized the islands during the Chippewa period, flooding during the subsequent Nipissing high-water stand means that the smaller islands have been colonized more recently. We analyzed 481 bp of mitochondrial D-loop sequences from woodland deer mice (Peromyscus maniculatus (Wagner, 1845)) on six of these islands in northern Lake Michigan to elucidate the mainland origin and minimum number of colonization events for this species. Surprisingly, the distribution of haplotypes on the islands suggests that the populations on most islands likely had separate recent origins on the mainland UP. Approximate Bayesian computation supports a scenario in which individual islands were colonized separately by distinct groups of mice. Together, the data suggest multiple colonization events from the UP, rather than expansion from a bottlenecked population or a single colonization event.

Aligned macroporous monoliths with intrinsic microporosity via a frozen-solvent-templating approach

Aligned macroporous monoliths of an organic cage, a polymer of intrinsic microporosity (PIM-1), and a metal–organic framework (HKUST-1) are prepared by a controlled freezing approach. In addition to macropores, all the monoliths contain the intrinsic micropores.

Synthesis of nanospheres-on-microsphere silica with tunable shell morphology and mesoporosity for improved HPLC

Core-shell particles have a wide range of applications. Most of the core-shell particles are prepared in two or multiple steps. Core-shell silica microspheres, with solid core and porous shell, have been used as novel packing materials in recent years for highly efficient liquid chromatography separation with relatively low back-pressure. These core-shell silica microspheres are usually prepared by the time-consuming layer-by-layer technique. Built on our previous report of one-pot synthesis of core-shell nanospheres-on-microspheres (termed as SOS particles for "spheres-on-spheres"), we describe here a two-stage synthesis for the introduction of shell mesoporosity into SOS particles with tunable shell morphology by co-condensation of tetraethyl orthosilicate (TEOS) with 3-mercaptopropyltrimethoxysilane (MPTMS) in the presence of surfactant in the second stage. With MPTMS as the primary precursor at the first stage, some other silica precursors (apart from TEOS) are also employed at the second stage. Expansion of the surfactant-templated mesopores with swelling agents during the reaction and by hydrothermal postsynthesis treatment is then performed to allow the pore sizes (> 6 nm) suitable for separation of small molecules in liquid chromatography. Compared to the standard SOS silica (both the nanospheres and microspheres contain nearly no mesopores), the introduction of mesoporosity into the nanosphere shell increases the separation efficiency of small molecule mixtures by 4 times as judged by the height equivalent plate number, while the separation of protein mixtures is not negatively affected.

Monodisperse sphere-on-sphere silica particles for fast HPLC separation of peptides and proteins

One-pot synthesis of monodisperse sphere-on-sphere (SOS) silica microspheres is developed for fast separation of peptide and protein mixtures by HPLC.

Hierarchical porous metal–organic framework monoliths

A simple powder-packing synthesis is developed to produce crystalline MOF monoliths containing micropores and highly interconnected macropores. Fast HPLC separation using the monolithic column is demonstrated.

One-pot synthesis of spheres-on-sphere silica particles from a single precursor for fast HPLC with low back pressure

Spheres-on-sphere (SOS) silica particles are prepared in a one-pot scalable synthesis from mercaptopropyltrimethoxysilane with hydrophilic polymer and cationic surfactant under alkaline conditions. The SOS particles exhibit solid-core porous-shell properties. The fast separation of small molecules and proteins with low back pressure are demonstrated by high-performance liquid chromatography (HPLC) for the columns packed with SOS-particles.

SU-E-T-387: Validation of a New System for Patient Specific IMRT QA and Comparison with Other Commerical Systems

PURPOSE

The focus of this project is to compare the Octavius 4D with current commercial available dose validation systems: MatriXX MultiCube and Delta4.

METHODS AND MATERIALS

Many challenges are faced with properly measuring Intensity Modulated Radiotherapy (IMRT). It has become common practice for clinics to use film, arrays, or multiple detectors to validate dose measurements pretreatment for static and dynamic treatments. IMRT QAs for various treatment sites were measured for patients using three different dose validation systems. All measurements were taken on a Varian CLinac 2100 C/D, SN-757, 80 MLC with 6MV. The treatment plans evaluated were Step-N-Shoot. Data analysis was performed using the software provided with each dose validation system. Detailed information was gathered from each system with their perspective advantages. The latest system, Octavius 4D, allows one to calculate the Gamma Index for Coronal, Sagittal, and Transversal views for every slice included in the measurement along with the traditional data analysis provided; histograms, horizontal and vertical profiles, DTA.

RESULTS AND DISCUSSION

The Gamma Index values were observed using the MatriXX Multicube, Delta4, and Octavius 4D. The treatment plan included five fields at various gantry angles. Also the gamma index and profiles were calculated for various treatment sites. Delta 4 and the Octavius 4D appears to be quite comparable. Each device has the ability to allow one to verify segmented and composite fields, measure dose profiles and analysis using the Gamma Method. ConclusionsSimilar IMRT QA measurements will be made for more Step-N-Shoot cases with the addition of SmartArcs. The limitations of each system will be determined for each system using the Gamma Index as a reference while varying the Region of Interest, Threshold, and Gamma Method (local, normalization, and maximum dose), as well as the 2D- profiles for these cases.

SU-E-T-562: Reducing the Arc Span for CSA VMAT Delivery

PURPOSE

To dosimetrically evaluate advantages and disadvantages of using multiple, shorter, sub-arcs versus full arc deliveries for treatment of cranio-spinal axis (CSA) irradiation.

METHODS

Five (n=5) cranio-spinal axis irradiation patients were planned using 2 complete arcs, one superior and one inferior; with gantry rotations from 1 to 359 degrees. Due to supine patient setup, each original full arc was then replanned split into two sub arcs with gantry rotations from 1 to 100 and 260 to 359 degrees creating 4 smaller arcs. The PTV was normalized such that 95% received at least 23.4 Gy in 13 fractions. The PTV was evaluated based on conformity number and homogeneity index. The normal structures were evaluated based on maximum and mean doses. Beam on times and monitor units were compared.

RESULTS

Averaged over all patients, conformity number was calculated to be approximately 0.86 and 0.82 for full arc and sub arc plans respectively. The homogeneity index was approximately 1.07 and 1.06 for full arc and sub arc plans. This indicates better target conformity but less homogeneous dose distribution for full arc plans as compared with sub arc plans. With the exception of the eyes, each normal structure evaluated had lower maximum doses with subarc plans. All normal structures, with the exception of the left kidney, had lower mean doses using sub arc deliveries. Beam on times were shorter on average for full arcs, but the monitor units were lower on average for sub arcs.

CONCLUSIONS

Overall, CSA patients would benefit from the use of sub arc treatment deliveries versus full arc deliveries. Nearly all normal structure doses were lower for sub arcs, while the PTV was still adequately covered and beam on times and monitor units were similar.