CAR T-cells to treat brain tumors

Tremendous success using CAR T therapy in hematological malignancies has garnered significant interest in developing such treatments for solid tumors, including brain tumors. This success, however, has yet to be mirrored in solid organ neoplasms. CAR T function has shown limited efficacy against brain tumors due to several factors including the immunosuppressive tumor microenvironment, blood-brain barrier, and tumor-antigen heterogeneity. Despite these considerations, CAR T-cell therapy has the potential to be implemented as a treatment modality for brain tumors. Here, we review adult and pediatric brain tumors, including glioblastoma, diffuse midline gliomas, and medulloblastomas that continue to portend a grim prognosis. We describe insights gained from different preclinical models using CAR T therapy against various brain tumors and results gathered from ongoing clinical trials. Furthermore, we outline the challenges limiting CAR T therapy success against brain tumors and summarize advancements made to overcome these obstacles.

Anti-glioblastoma activity of monensin and its analogs in an organoid model of cancer

Glioblastoma (GBM) remains the most frequently diagnosed primary malignant brain cancer in adults. Despite recent progress in understanding the biology of GBM, the clinical outcome for patients remains poor, with a median survival of approximately one year after diagnosis. One factor contributing to failure in clinical trials is the fact that traditional models used in GBM drug discovery poorly recapitulate patient tumors. Previous studies have shown that monensin (MON) analogs, namely esters and amides on C-26 were potent towards various types of cancer cell lines. In the present study we have investigated the activity of these molecules in GBM organoids, as well as in a host:tumor organoid model. Using a mini-ring cell viability assay we have identified seven analogs (IC₅₀ = 91.5 ± 54.4–291.7 ± 68.8 nM) more potent than parent MON (IC₅₀ = 612.6 ± 184.4 nM). Five of these compounds induced substantial DNA fragmentation in GBM organoids, suggestive of apoptotic cell death. The most active analog, compound 1, significantly reduced GBM cell migration, induced PARP degradation, diminished phosphorylation of STAT3, Akt and GSK3β, increased ɣH2AX signaling and upregulated expression of the autophagy associated marker LC3-II. To investigate the activity of MON and compound 1 in a tumor microenvironment, we developed human cerebral organoids (COs) from human induced pluripotent stem cells (iPSCs). The COs showed features of early developing brain such as multiple neural rosettes with a proliferative zone of neural stem cells (Nestin+), neurons (TUJ1 +), primitive ventricular system (SOX2 +/Ki67 +), intermediate zone (TBR2 +) and cortical plate (MAP2 +). In order to generate host:tumor organoids, we co-cultured RFP-labeled U87MG cells with fully formed COs. Compound 1 and MON reduced U87MG tumor size in the COs after four days of treatment and induced a significant reduction of PARP expression. These findings highlight the therapeutic potential of MON analogs towards GBM and support the application of organoid models in anti-cancer drug discovery.

Primary acute lymphoblastic leukemia cells are susceptible to microtubule depolymerization in G1 and M phases through distinct cell death pathways

Microtubule targeting agents (MTAs) are widely used cancer chemotherapeutics which conventionally exert their effects during mitosis, leading to mitotic or postmitotic death. However, accumulating evidence suggests that MTAs can also generate death signals during interphase, which may represent a key mechanism in the clinical setting. We reported previously that vincristine and other microtubule destabilizers induce death not only in M phase but also in G1 phase in primary acute lymphoblastic leukemia cells. Here, we sought to investigate and compare the pathways responsible for phase-specific cell death. Primary acute lymphoblastic leukemia cells were subjected to centrifugal elutriation, and cell populations enriched in G1 phase (97%) or G2/M phases (80%) were obtained and treated with vincristine. We found death of M phase cells was associated with established features of mitochondrial-mediated apoptosis, including Bax activation, loss of mitochondrial transmembrane potential, caspase-3 activation, and nucleosomal DNA fragmentation. In contrast, death of G1 phase cells was not associated with pronounced Bax or caspase-3 activation but was associated with loss of mitochondrial transmembrane potential, parylation, nuclear translocation of apoptosis-inducing factor and endonuclease G, and supra-nucleosomal DNA fragmentation, which was enhanced by inhibition of autophagy. The results indicate that microtubule depolymerization induces distinct cell death pathways depending on during which phase of the cell cycle microtubule perturbation occurs. The observation that a specific type of drug can enter a single cell type and induce two different modes of death is novel and intriguing. These findings provide a basis for advancing knowledge of clinical mechanisms of MTAs.

The effect of vitamin D supplementation on outcomes following total hip or knee arthroplasty surgery: a rapid systematic review of current evidence

Purpose

Vitamin D deficiency has been linked to poorer outcomes following hip (THR) and knee (TKR) replacement. We review the effect of peri-operative supplementation on clinical and patient-reported outcomes following THR/TKR.

Methods

This study was registered with PROSPERO (CRD42021238086). Searches of electronic databases were performed from inception to March 2021. All randomised, cohort, or case-controlled studies reported in English of adults undergoing THR/TKR where vitamin D supplementation was given peri-operatively and at least one outcome was reported were included. Studies reporting on vitamin D in relation to osteoporosis and hip fracture were excluded, as were conference abstracts and those involving preclinical models. Risks of bias were performed using the RoB-2 and ROBINS-I tools.

Results

Three studies comprising 413 TKR patients were identified; two were randomised controlled trials and one was a prospective cohort study. No studies meeting the inclusion criteria reported on the outcomes following THR. Supplementation was associated with a statistically significant reduction in the IL6:IL10 ratio at 24- and 48h following surgery, but no effect was noted on Western Ontario and McMaster Universities Osteoarthritis Index scores or the rates of falls. All studies were judged to be limited by bias, with heterogeneity in the supplementation dose and timing of administration, as well as the reported outcome measures used.

Discussion

Further adequately powered randomised-controlled trials using vitamin D supplementation and a specific clinically relevant or patient-reported outcome measure are required to assess if pre-operative vitamin D insufficiency is a modifiable risk factor to improve outcomes following THR/TKR.

A Functional Precision Medicine Pipeline Combines Comparative Transcriptomics and Tumor Organoid Modeling to Identify Bespoke Treatment Strategies for Glioblastoma

Li Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome caused by germline mutations in TP53. TP53 is the most common mutated gene in human cancer, occurring in 30-50% of glioblastomas (GBM). Here, we highlight a precision medicine platform to identify potential targets for a GBM patient with LFS. We used a comparative transcriptomics approach to identify genes that are uniquely overexpressed in the LFS GBM patient relative to a cancer compendium of 12,747 tumor RNA sequencing data sets, including 200 GBMs. STAT1 and STAT2 were identified as being significantly overexpressed in the LFS patient, indicating ruxolitinib, a Janus kinase 1 and 2 inhibitors, as a potential therapy. The LFS patient had the highest level of STAT1 and STAT2 expression in an institutional high-grade glioma cohort of 45 patients, further supporting the cancer compendium results. To empirically validate the comparative transcriptomics pipeline, we used a combination of adherent and organoid cell culture techniques, including ex vivo patient-derived organoids (PDOs) from four patient-derived cell lines, including the LFS patient. STAT1 and STAT2 expression levels in the four patient-derived cells correlated with levels identified in the respective parent tumors. In both adherent and organoid cultures, cells from the LFS patient were among the most sensitive to ruxolitinib compared to patient-derived cells with lower STAT1 and STAT2 expression levels. A spheroid-based drug screening assay (3D-PREDICT) was performed and used to identify further therapeutic targets. Two targeted therapies were selected for the patient of interest and resulted in radiographic disease stability. This manuscript supports the use of comparative transcriptomics to identify personalized therapeutic targets in a functional precision medicine platform for malignant brain tumors.

Single and double modified salinomycin analogs target stem-like cells in 2D and 3D breast cancer models

Breast cancer remains one of the leading cancers among women. Cancer stem cells (CSCs) are tumor-initiating cells which drive progression, metastasis, and reoccurrence of the disease. CSCs are resistant to conventional chemo- and radio-therapies and their ability to survive such treatment enables tumor reestablishment. Metastasis is the main cause of mortality in women with breast cancer, thus advances in treatment will depend on therapeutic strategies targeting CSCs. Salinomycin (SAL) is a naturally occurring polyether ionophore antibiotic known for its anticancer activity towards several types of tumor cells. In the present work, a library of 17 C1-single and C1/C20-double modified SAL analogs was screened to identify compounds with improved activity against breast CSCs. Six single- and two double-modified analogs were more potent (IC50 range of 1.1 ± 0.1-1.4 ± 0.2 µM) toward the breast cancer cell line MDA-MB-231 compared to SAL (IC50 of 4.9 ± 1.6 µM). Double-modified compound 17 was found to be more efficacious than SAL against the majority of cancer cell lines in the NCI-60 Human Tumor Cell Line Panel. Compound 17 was more potent than SAL in inhibiting cell migration and cell renewal properties of MDA-MB-231 cells, as well as inducing selective loss of the CD44+/CD24/low stem-cell-like subpopulation in both monolayer (2D) and organoid (3D) culture. The present findings highlight the therapeutic potential of SAL analogs towards breast CSCs and identify select compounds that merit further study and clinical development.

Inhibition of tryptophan 2,3-dioxygenase impairs DNA damage tolerance and repair in glioma cells

Expression of tryptophan 2,3-dioxygenase (TDO) is a determinant of malignancy in gliomas through kynurenine (KYN) signaling. We report that inhibition of TDO activity attenuated recovery from replication stress and increased the genotoxic effects of bis-chloroethylnitrosourea (BCNU). Activation of the Chk1 arm of the replication stress response (RSR) was reduced when TDO activity was blocked prior to BCNU treatment, whereas phosphorylation of serine 33 (pS33) on replication protein A (RPA) was enhanced—indicative of increased fork collapse. Analysis of quantitative proteomic results revealed that TDO inhibition reduced nuclear 53BP1 and sirtuin levels. We confirmed that cells lacking TDO activity exhibited elevated gamma-H2AX signal and defective recruitment of 53BP1 to chromatin following BCNU treatment, which corresponded with delayed repair of DNA breaks. Addition of exogenous KYN increased the rate of break repair. TDO inhibition diminished SIRT7 deacetylase recruitment to chromatin, which increased histone H3K18 acetylation—a key mark involved in preventing 53BP1 recruitment to sites of DNA damage. TDO inhibition also sensitized cells to ionizing radiation (IR)-induced damage, but this effect did not involve altered 53BP1 recruitment. These experiments support a model where TDO-mediated KYN signaling helps fuel a robust response to replication stress and DNA damage.

Human Rev1 relies on insert-2 to promote selective binding and accurate replication of stabilized G-quadruplex motifs

We previously reported that human Rev1 (hRev1) bound to a parallel-stranded G-quadruplex (G4) from the c-MYC promoter with high affinity. We have extended those results to include other G4 motifs, finding that hRev1 exhibited stronger affinity for parallel-stranded G4 than either anti-parallel or hybrid folds. Amino acids in the αE helix of insert-2 were identified as being important for G4 binding. Mutating E466 and Y470 to alanine selectively perturbed G4 binding affinity. The E466K mutant restored wild-type G4 binding properties. Using a forward mutagenesis assay, we discovered that loss of hRev1 increased G4 mutation frequency >200-fold compared to the control sequence. Base substitutions and deletions occurred around and within the G4 motif. Pyridostatin (PDS) exacerbated this effect, as the mutation frequency increased >700-fold over control and deletions upstream of the G4 site more than doubled. Mutagenic replication of G4 DNA (±PDS) was partially rescued by wild-type and E466K hRev1. The E466A or Y470A mutants failed to suppress the PDS-induced increase in G4 mutation frequency. These findings have implications for the role of insert-2, a motif conserved in vertebrates but not yeast or plants, in Rev1-mediated suppression of mutagenesis during G4 replication.

Abstract PS18-46: Inhibition of breast cancer stem cells in 2- and 3-dimensional culture by novel salinomycin analogs

Breast cancer remains one of the leading cancers among women and an estimated 90% of breast cancer deaths are due to metastasis. Cancer stem cells (CSCs) are a sub-population of cancer cells which are responsible for its initiation, progression and metastasis. CSCs are resistant to conventional chemo- and radio-therapies and therefore therapeutic strategies targeting CSCs hold great potential for novel advances in cancer treatment. Salinomycin (SAL) is a naturally occurring polyether ionophore antibiotic which was shown to effectively target breast CSCs. A library of 17 novel SAL analogs was synthesized and screened to identify compounds with improved selectivity against breast cancer stem cells. SAL analogs were either single modified esters or amides in the C1 position or double-modified C20-oxo derivatives. Eight single- and two double-modified analogs were more potent (IC50 range of 1.13 ± 0.19 to 3.93 ± 0.39 µM) towards the breast cancer cell line MDA-MB-231 compared to parent SAL (IC50 of 4.90 ± 1.60 µM). These analogs induced DNA fragmentation suggestive of apoptotic cell death. Compounds 2 (butyl ester analog of SAL) and 17 (double-modified C20-oxosalinomycin with benzhydroxamic acid) have been chosen for follow-up screening due to their improved activity and selectivity versus parent SAL. This included clonogenic assays to assess the ability of the compounds to affect cell renewal, and wound healing assays to assess cell migratory properties. In both assays, compound 17 showed superior properties over SAL. Furthermore, analog 17 showed improved targeting of breast CSCs in both cell monolayer and organoid culture as assessed in assays measuring the CD44+/CD24- stem cell sub-population. Analogs and parent compound were further studied examining (ADP-ribose) polymerase (PARP) cleavage and Bcl-2 levels by immunoblotting. All three compounds induced loss of 116 kDa PARP expression within 48h, with the highest effect induced by analog 17. In addition, treatment with compound 17 caused a decrease in Bcl-2 expression as early as 24 h. Select analogs were next screened against the NCI-60 Human Tumor Cell Line Panel. The described above double-modified analog was found to be more potent than SAL towards all 6 breast cancer cell lines in the panel as well as other tumor types. The present findings highlight the therapeutic potential of SAL analogs towards breast stem cells and support further research and clinical development of these compounds.

Funding: The present study was funded by grants (to AM and TCC) from the Arkansas Breast Cancer Research Program. Testing was performed by the Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, http://dtp.cancer.gov.

Citation Format: Alicja Joanna Urbaniak, Megan R. Reed, Michał Antoszczak, Michał Sulik, Adam Huczyński, Robert L. Eoff, Melanie C. MacNicol, Timothy C. Chambers, Angus M. MacNicol. Inhibition of breast cancer stem cells in 2- and 3-dimensional culture by novel salinomycin analogs [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS18-46.

LC8/DYNLL1 is a 53BP1 effector and regulates checkpoint activation

The tumor suppressor protein 53BP1 plays key roles in response to DNA double-strand breaks (DSBs) by serving as a master scaffold at the damaged chromatin. Current evidence indicates that 53BP1 assembles a cohort of DNA damage response (DDR) factors to distinctly execute its repertoire of DSB responses, including checkpoint activation and non-homologous end joining (NHEJ) repair. Here, we have uncovered LC8 (a.k.a. DYNLL1) as an important 53BP1 effector. We found that LC8 accumulates at laser-induced DNA damage tracks in a 53BP1-dependent manner and requires the canonical H2AX-MDC1-RNF8-RNF168 signal transduction cascade. Accordingly, genetic inactivation of LC8 or its interaction with 53BP1 resulted in checkpoint defects. Importantly, loss of LC8 alleviated the hypersensitivity of BRCA1-depleted cells to ionizing radiation and PARP inhibition, highlighting the 53BP1-LC8 module in counteracting BRCA1-dependent functions in the DDR. Together, these data establish LC8 as an important mediator of a subset of 53BP1-dependent DSB responses.

Inhibition of Human DNA Polymerases Eta and Kappa by Indole-Derived Molecules Occurs through Distinct Mechanisms

Overexpression of human DNA polymerase kappa (hpol κ) in glioblastoma is associated with shorter survival time and resistance to the alkylating agent temozolomide (TMZ), making it an attractive target for the development of small-molecule inhibitors. We previously reported on the development and characterization of indole barbituric acid-derived (IBA) inhibitors of translesion DNA synthesis polymerases (TLS pols). We have now identified a potent and selective inhibitor of hpol κ based on the indole-aminoguanidine (IAG) chemical scaffold. The most promising IAG analogue, IAG-10, exhibited greater inhibitory action against hpol κ than any other human Y-family member, as well as pols from the A-, B-, and X-families. Inhibition of hpol κ by IAG analogues appears to proceed through a mechanism that is distinct from inhibition of hpol η based on changes in DNA binding affinity and nucleotide insertion kinetics. By way of comparison, both IAG and IBA analogues inhibited binary complex formation by hpol κ and ternary complex formation by hpol η. Decreasing the concentration of enzyme and DNA in the reaction mixture lowered the IC₅₀ value of IAG-10 to submicromolar values, consistent with inhibition of binary complex formation for hpol κ. Chemical footprinting experiments revealed that IAG-10 binds to a cleft between the finger, little finger, and N-clasp domains on hpol κ and that this likely disrupts the interaction between the N-clasp and the TLS pol core. In cell culture, IAG-10 potentiated the antiproliferative activity and DNA damaging effects of TMZ in hpol κ-proficient cells but not in hpol κ-deficient cells, indicative of a target-dependent effect. Mutagenic replication across alkylation damage increased in hpol κ-proficient cells treated with IAG-10, while no change in mutation frequency was observed for hpol κ-deficient cells. In summary, we developed a potent and selective small-molecule inhibitor of hpol κ that takes advantage of structural features unique to this TLS enzyme to potentiate TMZ, a standard-of-care drug used in the treatment of malignant brain tumors. Furthermore, the IAG scaffold represents a new chemical space for the exploration of TLS pol inhibitors, which could prove useful as a strategy for improving patient response to genotoxic drugs.

A randomized controlled trial comparing the Thompson hemiarthroplasty with the Exeter polished tapered stem and Unitrax modular head in the treatment of displaced intracapsular fractures of the hip: the WHiTE 3: HEMI Trial

Aims

This study aimed to compare the change in health-related quality of life of patients receiving a traditional cemented monoblock Thompson hemiarthroplasty compared with a modern cemented modular polished-taper stemmed hemiarthroplasty for displaced intracapsular hip fractures.

Patients and Methods

This was a pragmatic, multicentre, multisurgeon, two-arm, parallel group, randomized standard-of-care controlled trial. It was embedded within the WHiTE Comprehensive Cohort Study. The sample size was 964 patients. The setting was five National Health Service Trauma Hospitals in England. A total of 964 patients over 60 years of age who required hemiarthroplasty of the hip between February 2015 and March 2016 were included. A standardized measure of health outcome, the EuroQol (EQ-5D-5L) questionnaire, was carried out on admission and at four months following the operation.

Results

Of the 964 patients enrolled, 482 died or were lost to follow-up (50%). No significant differences were noted in EQ-5D between groups, with a mean difference at four months of 0.037 in favour of the Exeter/Unitrax implant (95% confidence interval (CI) 0.014 to 0.087, p = 0.156), rising to 0.045 (95% CI 0.007 to 0.098, p = 0.09) when patients who died were excluded. The minimum clinically important difference for EQ-5D-5L used in this study is 0.08, therefore any benefit between implants is unlikely to be noticeable to the patient. There was no difference in mortality or mobility score.

Conclusion

Allowing for the high rate of loss to follow-up, the use of the traditional Thompson hemiarthroplasty in the treatment of the displaced intracapsular hip fracture shows no difference in health outcome when compared with a modern cemented hemiarthroplasty. Cite this article: Bone Joint J 2018;100-B:352-60.

The effect of triclosan-coated sutures on the rate of surgical site infection after hip and knee arthroplasty: a double-blind randomized controlled trial of 2546 patients

Aims

Surgical site infection (SSI) is a common complication of surgery with an incidence of about 1% in the United Kingdom. Sutures can lead to the development of a SSI, as micro-organisms can colonize the suture as it is implanted. Triclosan-coated sutures, being antimicrobical, were developed to reduce the rate of SSI. Our aim was to assess whether triclosan-coated sutures cause a reduction in SSIs following arthroplasty of the hip and knee.

Patients and Methods

This two-arm, parallel, double-blinded study involved 2546 patients undergoing elective total hip (THA) and total knee arthroplasty (TKA) at three hospitals. A total of 1323 were quasi-randomized to a standard suture group, and 1223 being quasi-randomized to the triclosan-coated suture group. The primary endpoint was the rate of SSI at 30 days postoperatively.

Results

The baseline characteristics of age, gender and comorbidities were well matched in the two groups. The rates of superficial SSI were 0.8% in the control group and 0.7% in the intervention group (p = 0.651), and when deep and superficial SSIs were combined the rates were 2.5% and 1.8 (p = 0.266). The length of stay in hospital and the rates of medical complications did not differ significantly between the groups (p = 1.000).

Conclusion

This trial provided no evidence that the use of triclosan-coated sutures at THA and TKA leads to a reduction in the rate of SSI.

Cite this article: Bone Joint J 2018;100-B:296–302.

A Small-Molecule Inhibitor of Human DNA Polymerase η Potentiates the Effects of Cisplatin in Tumor Cells

Translesion DNA synthesis (TLS) performed by human DNA polymerase eta (hpol η) allows tolerance of damage from cis-diamminedichloroplatinum(II) (CDDP or cisplatin). We have developed hpol η inhibitors derived from N-aryl-substituted indole barbituric acid (IBA), indole thiobarbituric acid (ITBA), and indole quinuclidine scaffolds and identified 5-((5-chloro-1-(naphthalen-2-ylmethyl)-1H-indol-3-yl)methylene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione (PNR-7-02), an ITBA derivative that inhibited hpol η activity with an IC₅₀ value of 8 μM and exhibited 5-10-fold specificity for hpol η over replicative pols. We conclude from kinetic analyses, chemical footprinting assays, and molecular docking that PNR-7-02 binds to a site on the little finger domain and interferes with the proper orientation of template DNA to inhibit hpol η. A synergistic increase in CDDP toxicity was observed in hpol η-proficient cells co-treated with PNR-7-02 (combination index values = 0.4-0.6). Increased γH2AX formation accompanied treatment of hpol η-proficient cells with CDDP and PNR-7-02. Importantly, PNR-7-02 did not impact the effect of CDDP on cell viability or γH2AX in hpol η-deficient cells. In summary, we observed hpol η-dependent effects on DNA damage/replication stress and sensitivity to CDDP in cells treated with PNR-7-02. The ability to employ a small-molecule inhibitor of hpol η to improve the cytotoxic effect of CDDP may aid in the development of more effective chemotherapeutic strategies.

Dose optimisation of intravenous tranexamic acid for elective hip and knee arthroplasty: The effectiveness of a single pre-operative dose

Objectives

We have increased the dose of tranexamic acid (TXA) in our enhanced total joint recovery protocol at our institution from 15 mg/kg to 30 mg/kg (maximum 2.5 g) as a single, intravenous (IV) dose. We report the clinical effect of this dosage change.

Methods

We retrospectively compared two cohorts of consecutive patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) surgery in our unit between 2008 and 2013. One group received IV TXA 15 mg/kg, maximum 1.2 g, and the other 30 mg/kg, maximum 2.5 g as a single pre-operative dose. The primary outcome for this study was the requirement for blood transfusion within 30 days of surgery. Secondary measures included length of hospital stay, critical care requirements, re-admission rate, medical complications and mortality rates.

Results

A total of 1914 THA and 2537 TKA procedures were evaluated. In THA, the higher dose of TXA was associated with a significant reduction in transfusion (p = 0.02, risk ratio (RR) 0.74, 95% confidence interval (CI) 0.58 to 0.96) and rate of re-admission (p < 0.001, RR 0.50, 95% CI 0.35 to 0.71). There were reductions in the requirement for critical care (p = 0.06, RR 0.55, 95% CI 0.31 to 1.00), and in the length of stay from 4.7 to 4.3 days (p = 0.02). In TKA, transfusion requirements (p = 0.049, RR 0.64, 95% CI 0.41 to 0.99), re-admission rate (p = 0.001, RR 0.56, 95% CI 0.39 to 0.80) and critical care requirements (p < 0.003, RR 0.34, 95% CI 0.16 to 0.72) were reduced with the higher dose. Mean length of stay reduced from 4.6 days to 3.6 days (p < 0.01). There was no difference in the incidence of deep vein thrombosis, pulmonary embolism, gastrointestinal bleed, myocardial infarction, stroke or death in THA and TKA between cohorts.

Conclusion

We suggest that a single pre-operative dose of TXA, 30 mg/kg, maximum 2.5g, results in a lower transfusion requirement compared with a lower dose in patients undergoing elective primary hip and knee arthroplasty. However, these findings should be interpreted in the context of the retrospective non-randomised study design.

Cite this article: R. J. M. Morrison, B. Tsang, W. Fishley, I. Harper, J. C. Joseph, M. R. Reed. Dose optimisation of intravenous tranexamic acid for elective hip and knee arthroplasty: The effectiveness of a single pre-operative dose. Bone Joint Res 2017;6:499–505. DOI: 10.1302/2046-3758.68.BJR-2017-0005.R1.

Thompson hemiarthroplasty versus modular unipolar implants for patients requiring hemiarthroplasty of the hip: A systematic review of the evidence

Objectives

The objective of this study was to assess all evidence comparing the Thompson monoblock hemiarthroplasty with modular unipolar implants for patients requiring hemiarthroplasty of the hip with respect to mortality and complications.

Methods

A literature search was performed to identify all relevant literature. The population consisted of patients undergoing hemiarthroplasty of the hip for fracture. The intervention was hemiarthroplasty of the hip with a comparison between Thompson and modular unipolar prostheses.

Pubmed, Embase, CINAHL, Web of Science, PROSPERO and the Cochrane Central Register of Controlled Trials.

The study designs included were randomised controlled trials (RCTs), well designed case control studies and retrospective or prospective cohort studies. Studies available in any language, published at any time until September 2015 were considered. Studies were included if they contained mortality or complications.

Results

The initial literature search identified 4757 items for examination. Four papers were included in the final review. The pooled odds ratio for mortality was 1.3 (95% confidence Interval 0.78 to 2.46) favouring modular designs. The pooled odds ratio for post-operative complications was 1.1 (95% CI 0.79 to 1.55) favouring modular designs. Outcomes were reported at 12 or six months. These papers all contained potential sources of bias and significant clinical heterogeneity.

Conclusion

The current evidence comparing monoblock versus modular implants in patients undergoing hemiarthroplasty is weak. Confidence intervals around the pooled odds ratios are broad and incorporate a value of one. Direct comparison of outcomes from these papers is fraught with difficulty and, as such, may well be misleading. A well designed randomised controlled trial would be helpful to inform evidence-based implant selection.

Cite this article: A. L. Sims, A. J. Farrier, M. R. Reed, T. A. Sheldon. Thompson hemiarthroplasty versus modular unipolar implants for patients requiring hemiarthroplasty of the hip: A systematic review of the evidence. Bone Joint Res 2017;6:–513. DOI: 10.1302/2046-3758.68.BJR-2016-0256.R1.

The use of high-dose dual-impregnated antibiotic-laden cement with hemiarthroplasty for the treatment of a fracture of the hip: The Fractured Hip Infection trial

Aims

A fracture of the hip is the most common serious orthopaedic injury, and surgical site infection (SSI) is one of the most significant complications, resulting in increased mortality, prolonged hospital stay and often the need for further surgery. Our aim was to determine whether high dose dual antibiotic impregnated bone cement decreases the rate of infection.

Patients and Methods

A quasi-randomised study of 848 patients with an intracapsular fracture of the hip was conducted in one large teaching hospital on two sites. All were treated with a hemiarthroplasty. A total of 448 patients received low dose single-antibiotic impregnated cement (control group) and 400 patients received high dose dual-antibiotic impregnated cement (intervention group). The primary outcome measure was deep SSI at one year after surgery.

Results

The rate of deep SSI was 3.5% in the control group and 1.1% in the intervention group (p = 0.041; logistic regression adjusting for age and gender). The overall rate of non-infective surgical complications did not differ between the two groups (unadjusted chi-squared test; p > 0.999).

Conclusion

The use of high dose dual-antibiotic impregnated cement in these patients significantly reduces the rate of SSI compared with standard low dose single antibiotic loaded bone cement.

Cite this article: Bone Joint J 2016;98-B:1534–1541.

Performance and learning curve of a surgical care practitioner in completing hip aspirations

INTRODUCTION The roles of non-medically trained practitioners within the NHS are expanding; they are now being employed by many specialties, including surgery, to relieve pressures on healthcare teams. AIMS To investigate the learning curve and competence of an orthopaedic surgical care practitioner (SCP) in performing hip aspirations. METHODS Data were retrospectively collected on 510 orthopaedic hip aspirations, of which 360 were completed by a single SCP and 150 were completed by surgeons before the SCP took over routine aspiration. The 360 aspirations completed by an SCP were separated into groups of 30 by date, so any trend in failure rate could be analysed. Ordinal χ² analysis was used to analyse this trend and Pearson χ² analysis was used to analyse differences in failure rates between professionals. RESULTS The hip aspiration failure rate for the SCP was significantly lower than for the surgeons; 8.6% vs 20.7% (P<0.001). With the experience gained in completing the first 210 procedures, the failure rate of the SCP dropped to 3.3% for the remaining 150 procedures. This downward trend in hip aspiration failure rate, with advancing experience of the SCP, was shown to be statistically significant (P=0.006). DISCUSSION SCPs who complete hip aspirations on a regular basis have significantly lower failure rates than surgeons, probably as a result of the learning curve, which this study demonstrated. Other trusts should consider delegating routine hip aspiration work to a designated SCP to lower failure rates.

STICKS study - Short-sTretch Inelastic Compression bandage in Knee Swelling following total knee arthroplasty - a feasibility study

BACKGROUND

Postoperative knee swelling is common and impairs early postoperative function following total knee arthroplasty. It was hypothesised that the use of a short-stretch, inelastic compression bandage would reduce knee swelling and improve pain and early function. The aim of this study was to provide preliminary data and test feasibility with a view to informing a larger, future trial.

METHODS

Fifty consecutive patients selected for primary total knee arthroplasty underwent distance randomisation to receive a short-stretch, inelastic compression bandage or a standard wool and crepe bandage for the first 24 h postoperatively. Study feasibility including recruitment rates, retention rates and complications were analysed. The Oxford Knee Score, the EQ-5D-3L index score, knee swelling, knee range of motion, visual analogue pain score and length of stay were compared between groups. Analysis of covariance (ANCOVA) was performed adjusting for the preoperative measurement.

RESULTS

Sixty-eight percent of eligible patients were recruited into the trial. The retention rate was 88%. There were no complications regarding compression bandage use. There was a greater mean but non-significant improvement in Oxford Knee Score (p = 0.580; point estimate = 2.1; 95% CI -3.288 to 7.449) and EQ-5D-3L index score (p = 0.057; point estimate = 0.147; 95% CI -0.328 to 0.005) in the compression bandage group at 6 months. There was no significant difference between groups regarding knee swelling, knee range of motion, visual analogue pain score, complications and length of stay.

CONCLUSION

Preliminary data suggests that the use of an inelastic, short-stretch compression bandage following total knee arthroplasty is a safe technique that is acceptable to patients. A larger, multicentre trial is required to determine its effect postoperatively.

TRIAL REGISTRATION

The study was registered with Current Controlled Trials, identifier: ISRCTN86903140 . Registered on 30 May 2013.

Do large pragmatic randomised trials change clinical practice?: assessing the impact of the Distal Radius Acute Fracture Fixation Trial (DRAFFT)

AIMS

Our aim, using English Hospital Episode Statistics data before during and after the Distal Radius Acute Fracture Fixation Trial (DRAFFT), was to assess whether the results of the trial affected clinical practice.

PATIENTS AND METHODS

Data were grouped into six month intervals from July 2005 to December 2014. All patient episodes in the National Health Service involving emergency surgery for an isolated distal radial fracture were included.

RESULTS

Clinical practice in England had not changed in the five years before DRAFFT: 75% of patients were treated with plate fixation versus 12% with Kirschner (K)-wires. After the publication of the trial, the proportion of patients having K-wire fixation rose to 42% with a concurrent fall in the proportion having fixation with a plate to 48%. The proportion of 'other' procedures stayed the same.

TAKE HOME MESSAGE

It appears that surgeons in the United Kingdom do change their practice in response to large, pragmatic, multicentre clinical trials in musculoskeletal trauma.

Evidence That G-quadruplex DNA Accumulates in the Cytoplasm and Participates in Stress Granule Assembly in Response to Oxidative Stress

Cells engage numerous signaling pathways in response to oxidative stress that together repair macromolecular damage or direct the cell toward apoptosis. As a result of DNA damage, mitochondrial DNA or nuclear DNA has been shown to enter the cytoplasm where it binds to "DNA sensors," which in turn initiate signaling cascades. Here we report data that support a novel signaling pathway in response to oxidative stress mediated by specific guanine-rich sequences that can fold into G-quadruplex DNA (G4DNA). In response to oxidative stress, we demonstrate that sequences capable of forming G4DNA appear at increasing levels in the cytoplasm and participate in assembly of stress granules. Identified proteins that bind to endogenous G4DNA in the cytoplasm are known to modulate mRNA translation and participate in stress granule formation. Consistent with these findings, stress granule formation is known to regulate mRNA translation during oxidative stress. We propose a signaling pathway whereby cells can rapidly respond to DNA damage caused by oxidative stress. Guanine-rich sequences that are excised from damaged genomic DNA are proposed to enter the cytoplasm where they can regulate translation through stress granule formation. This newly proposed role for G4DNA provides an additional molecular explanation for why such sequences are prevalent in the human genome.

Linkage via K27 Bestows Ubiquitin Chains with Unique Properties among Polyubiquitins

Polyubiquitination, a critical protein post-translational modification, signals for a diverse set of cellular events via the different isopeptide linkages formed between the C terminus of one ubiquitin (Ub) and the ɛ-amine of K6, K11, K27, K29, K33, K48, or K63 of a second Ub. We assembled di-ubiquitins (Ub2) comprising every lysine linkage and examined them biochemically and structurally. Of these, K27-Ub2 is unique as it is not cleaved by most deubiquitinases. As this remains the only structurally uncharacterized lysine linkage, we comprehensively examined the structures and dynamics of K27-Ub2 using nuclear magnetic resonance, small-angle neutron scattering, and in silico ensemble modeling. Our structural data provide insights into the functional properties of K27-Ub2, in particular that K27-Ub2 may be specifically recognized by K48-selective receptor UBA2 domain from proteasomal shuttle protein hHR23a. Binding studies and mutagenesis confirmed this prediction, further highlighting structural/recognition versatility of polyubiquitins and the potential power of determining function from elucidation of conformational ensembles.

The World Hip Trauma Evaluation Study 3: Hemiarthroplasty Evaluation by Multicentre Investigation - WHITE 3: HEMI - An Abridged Protocol

Background

Approximately half of all hip fractures are displaced intracapsular fractures. The standard treatment for these fractures is either hemiarthroplasty or total hip arthroplasty. The recent National Institute for Health and Care Excellence (NICE) guidance on hip fracture management recommends the use of ‘proven’ cemented stem arthroplasty with an Orthopaedic Device Evaluation Panel (ODEP) rating of at least 3B (97% survival at three years). The Thompsons prosthesis is currently lacking an ODEP rating despite over 50 years of clinical use, likely due to the paucity of implant survival data. Nationally, adherence to these guidelines is varied as there is debate as to which prosthesis optimises patient outcomes.

Design

This study design is a multi-centre, multi-surgeon, parallel, two arm, standard-of-care pragmatic randomised controlled trial. It will be embedded within the WHiTE Comprehensive Cohort Study (ISRCTN63982700). The main analysis is a two-way equivalence comparison between Hemi-Thompson and Hemi-Exeter polished taper with Unitrax head. Secondary outcomes will include radiological leg length discrepancy measured as per Bidwai and Willett, mortality, re-operation rate and indication for re-operation, length of index hospital stay and revision at four months. This study will be supplemented by the NHFD (National Hip Fracture Database) dataset.

Discussion

Evidence on the optimum choice of prosthesis for hemiarthroplasty of the hip is lacking. National guidance is currently based on expert opinion rather than empirical evidence. The incidence of hip fracture is likely to continue to increase and providing high quality evidence on the optimum

Cite this article: A. L. Sims. The World Hip Trauma Evaluation Study 3: Hemiarthroplasty Evaluation by Multicentre Investigation – WHITE 3: HEMI – An Abridged Protocol. Bone Joint Res 2016;5:18–25. DOI: 10.1302/2046-3758.51.2000473

Kynurenine Signaling Increases DNA Polymerase Kappa Expression and Promotes Genomic Instability in Glioblastoma Cells

Overexpression of the translesion synthesis polymerase hpol κ in glioblastomas has been linked to poor patient prognosis; however, the mechanism promoting higher expression in these tumors remains unknown. We determined that activation of the aryl hydrocarbon receptor (AhR) pathway in glioblastoma cells leads to increased hpol κ mRNA and protein levels. We blocked nuclear translocation and DNA binding by AhR in glioblastoma cells using a small-molecule and observed decreased hpol κ expression. Pharmacological inhibition of tryptophan-2,3-dioxygenase (TDO), the enzyme largely responsible for activating AhR in glioblastoma, led to a decrease in the endogenous AhR agonist kynurenine and a corresponding decrease in hpol κ protein levels. Importantly, we discovered that inhibiting TDO activity, AhR signaling, or suppressing hpol κ expression with RNA interference led to decreased chromosomal damage in glioblastoma cells. Epistasis assays further supported the idea that TDO activity, activation of AhR signaling, and the resulting overexpression of hpol κ function primarily in the same pathway to increase endogenous DNA damage. These findings indicate that upregulation of hpol κ through glioblastoma-specific TDO activity and activation of AhR signaling likely contributes to the high levels of replication stress and genomic instability observed in these tumors.

Prophylactic antibiotics in elective hip and knee arthroplasty: an analysis of organisms reported to cause infections and National survey of clinical practice

Objectives

We wanted to investigate regional variations in the organisms reported to be causing peri-prosthetic infections and to report on prophylaxis regimens currently in use across England.

Methods

Analysis of data routinely collected by Public Health England’s (PHE) national surgical site infection database on elective primary hip and knee arthroplasty procedures between April 2010 and March 2013 to investigate regional variations in causative organisms. A separate national survey of 145 hospital Trusts (groups of hospitals under local management) in England routinely performing primary hip and/or knee arthroplasty was carried out by standard email questionnaire.

Results

Analysis of 189 858 elective primary hip and knee arthroplasty procedures and 1116 surgical site infections found statistically significant variations for some causative organism between regions. There was a 100% response rate to the prophylaxis questionnaire that showed substantial variation between individual trust guidelines. A number of regimens currently in use are inconsistent with the best available evidence.

Conclusions

The approach towards antibiotic prophylaxis in elective arthroplasty nationwide reveals substantial variation without clear justification. Only seven causative organisms are responsible for 89% of infections affecting primary hip and knee arthroplasty, which cannot justify such widespread variation between prophylactic antibiotic policies.

Cite this article: Bone Joint Res 2015;4:181–189.

Independent validation of the Nottingham Hip Fracture Score and identification of regional variation in patient risk within England

The Nottingham Hip Fracture Score (NHFS) was developed to assess the risk of death following a fracture of the hip, based on pre-operative patient characteristics. We performed an independent validation of the NHFS, assessed the degree of geographical variation that exists between different units within the United Kingdom and attempted to define a NHFS level that is associated with high risk of mortality. The NHFS was calculated retrospectively for consecutive patients presenting with a fracture of the hip to two hospitals in England. The observed 30-day mortality for each NHFS cohort was compared with that predicted by the NHFS using the Hosmer-Lemeshow test. The distribution of NHFS in the observed group was compared with data from other hospitals in the United Kingdom. The proportion of patients identified as high risk and the mortality within the high risk group were assessed for groups defined using different thresholds for the NHFS. In all 1079 hip fractures were included in the analysis, with a mean age of 83 years (60 to 105), 284 (26%) male. Overall 30-day mortality was 7.3%. The NHFS was a significant predictor of 30-day mortality. Statistically significant differences in the distribution of the NHFS were present between different units in England (p < 0.001). A NHFS ≥ 6 appears to be an appropriate cut-point to identify patients at high risk of mortality following a fracture of the hip.

Cemented Thompson's hemiarthroplasty in patients with intracapsular neck of femur fractures: survival analysis of 1,670 procedures

Cemented Thompson's prostheses have been used to treat elderly patients with displaced intracapsular hip fractures at our two units for the last 15 years, amid growing support for the use of newer implant designs for hip hemiarthroplasty. This provided us with an opportunity to investigate survival of the Thompson's stem in our patients. A retrospective cohort study was set up to review previously collected data on patients who underwent Thompson's hemiarthroplasty over a 7-year period. These were linked to surgical notes, clinical letters and radiographs to record post-operative course and subsequent admissions and procedures. The identifiers were then linked to mortality data from the Office of 'National Statistics. Kaplan-Meier survival analyses were done for implants and patients. A total of 1,632 patients (mean age 82.7 years) underwent 1,670 procedures. Five-year implant survival was 95.4 %. A total of 36 stems were revised, including 14 revisions to total hip arthroplasty and 22 excision arthroplasties. Reasons for revision included infection (2.1 %), dislocation (1.1 %) and aseptic loosening (0.5 %). Symptomatic aseptic loosening and acetabular erosion occurred late (mean time 3.2 and 5.7 years, respectively following surgery). Aseptic loosening and erosion following hemiarthroplasty are relatively late complications.

Infection control hazards associated with the use of forced-air warming in operating theatres

A review is presented of the published experimental and clinical research into the infection control hazards of using forced air-warming (FAW) in operating theatres to prevent inadvertent hypothermia. This evidence has been reviewed with emphasis on the use of ultra-clean ventilation, any interaction it has with different types of patient warming (and FAW in particular), and any related increased risk of surgical site infection (SSI). We conclude that FAW does contaminate ultra-clean air ventilation; however, there appears to be no definite link to an increased risk of SSI based on current research. Nevertheless, whereas this remains unproven, we recommend that surgeons should at least consider alternative patient-warming systems in areas where contamination of the operative field may be critical. Although this is not a systematic review of acceptable randomized controlled clinical trials, which do not exist, it does identify that there is a need for definitive research in this field.

Evidence-base for aspirin as venous thromboembolic prophylaxis following joint replacement

The National Institute for Health and Clinical Excellence (NICE) has thus far relied on historical data and predominantly industry-sponsored trials to provide evidence for venous thromboembolic (VTE) prophylaxis in joint replacement patients. We argue that the NICE guidelines may be reliant on assumptions that are in need of revision. Following the publication of large scale, independent observational studies showing little difference between low-molecular-weight heparins and aspirin, and recent changes to the guidance provided by other international bodies, should NICE reconsider their recommendations?

Cite this article: Bone Joint Res 2014;3:146–9.

Consultant and trainee attitudes towards supervision of operative procedures in the UK and Ireland

The e-logbook is used to monitor progression through training and to assess training within teaching units. We document consultant and trainee opinions with regards to supervision status, and to inform guidelines for trainees and trainers using the e-logbook. A questionnaire was sent to consultants and trainees in the UK and Ireland. Eight theatre scenarios were described and respondents were asked to state what they felt was the appropriate supervision status for the trainee. Significantly more consultants in the UK use the e-logbook than those based in Ireland (58.5%:14.5%). There were differences in consensus response to the scenarios between consultants and trainees, and between Irish and UK based surgeons. We have documented the opinions of consultants and trainees from across the UK and Ireland with regards to supervision status for trainees under certain theatre situations. This information should support formal guidelines for all users of the logbook.

The 2012 ABC orthopaedic fellowship in North America: May 24 to July 2

In May 2012, in airports across the globe, seven orthopaedic surgeons bravely said goodbye to their loved ones, and slowly turned towards their respective aircraft. Filled with expectation and mild trepidation they stepped into the unknown… the ABC fellowship of 2012.

Revision Knee Replacement in England and Wales: An Audit of Hospital Volume

Increasing surgeon and hospital volume improves outcome following a range of surgical procedures, including primary and revision knee surgery. Increasing operative volume leads intuitively to greater familiarity and experience. This is particularly important for those surgeons and centres undertaking complex procedures that are often performed infrequently.

The design of the acetabular component and size of the femoral head influence the risk of revision following 34 721 single-brand cemented hip replacements: a retrospective cohort study of medium-term data from a National Joint Registry

Despite excellent results, the use of cemented total hip replacement (THR) is declining. This retrospective cohort study records survival time to revision following primary cemented THR using the most common combination of components that accounted for almost a quarter of all cemented THRs, exploring risk factors independently associated with failure. All patients with osteoarthritis who had an Exeter V40/Contemporary THR (Stryker) implanted before 31 December 2010 and recorded in the National Joint Registry for England and Wales were included in the analysis. Cox's proportional hazard models were used to analyse the extent to which risk of revision was related to patient, surgeon and implant covariates, with a significance threshold of p < 0.01. A total of 34 721 THRs were included in the study. The overall seven-year rate of revision for any reason was 1.70% (99% confidence interval (CI) 1.28 to 2.12). In the final adjusted model the risk of revision was significantly higher in THRs with the Contemporary hooded component (hazard ratio (HR) 1.88, p < 0.001) than with the flanged version, and in smaller head sizes (< 28 mm) compared with 28 mm diameter heads (HR 1.50, p = 0.005). The seven-year revision rate was 1.16% (99% CI 0.69 to 1.63) with a 28 mm diameter head and flanged component. The overall risk of revision was independent of age, gender, American Society of Anesthesiologists grade, body mass index, surgeon volume, surgical approach, brand of cement/presence of antibiotic, femoral head material (stainless steel/alumina) and stem taper size/offset. However, the risk of revision for dislocation was significantly higher with a 'plus' offset head (HR 2.05, p = 0.003) and a hooded acetabular component (HR 2.34, p < 0.001). In summary, we found that there were significant differences in failure between different designs of acetabular component and sizes of femoral head after adjustment for a range of covariates.

Reducing surgical site infection in arthroplasty of the lower limb: A multi-disciplinary approach

Objectives

To review the current best surgical practice and detail a multi-disciplinary approach that could further reduce joint replacement infection.

Methods

Review of relevant literature indexed in PubMed.

Results

Surgical site infection is a major complication following arthroplasty. Despite its rarity in contemporary orthopaedic practice, it remains difficult to treat and is costly in terms of both patient morbidity and long-term health care resources.

Conclusions

Emphasis on education of patients and all members of the health-care team and raising awareness in how to participate in preventative efforts is imperative.

The effect of surgical factors on early patient-reported outcome measures (PROMS) following total knee replacement

Patient-reported outcome measures (PROMs) are increasingly being used to assess functional outcome and patient satisfaction. They provide a framework for comparisons between surgical units, and individual surgeons for benchmarking and financial remuneration. Better performance may bring the reward of more customers as patients and commissioners seek out high performers for their elective procedures. Using National Joint Registry (NJR) data linked to PROMs we identified 22,691 primary total knee replacements (TKRs) undertaken for osteoarthritis in England and Wales between August 2008 and February 2011, and identified the surgical factors that influenced the improvements in the Oxford knee score (OKS) and EuroQol-5D (EQ-5D) assessment using multiple regression analysis. After correction for patient factors the only surgical factors that influenced PROMs were implant brand and hospital type (both p < 0.001). However, the effects of surgical factors upon the PROMs were modest compared with patient factors. For both the OKS and the EQ-5D the most important factors influencing the improvement in PROMs were the corresponding pre-operative score and the patient's general health status. Despite having only a small effect on PROMs, this study has shown that both implant brand and hospital type do influence reported subjective functional scores following TKR. In the current climate of financial austerity, proposed performance-based remuneration and wider patient choice, it would seem unwise to ignore these effects and the influence of a range of additional patient factors.

Comparison of patient-reported outcome measures following total and unicondylar knee replacement

Following arthroplasty of the knee, the patient's perception of improvement in symptoms is fundamental to the assessment of outcome. Better clinical outcome may offset the inferior survival observed for some types of implant. By examining linked National Joint Registry (NJR) and patient-reported outcome measures (PROMs) data, we aimed to compare PROMs collected at a minimum of six months post-operatively for total (TKR: n = 23,393) and unicondylar knee replacements (UKR: n = 505). Improvements in knee-specific (Oxford knee score, OKS) and generic (EuroQol, EQ-5D) scores were compared and adjusted for case-mix differences using multiple regression. Whereas the improvements in the OKS and EQ-5D were significantly greater for TKR than for UKR, once adjustments were made for case-mix differences and pre-operative score, the improvements in the two scores were not significantly different. The adjusted mean differences in the improvement of OKS and EQ-5D were 0.0 (95% confidence interval (CI) -0.9 to 0.9; p = 0.96) and 0.009 (95% CI -0.034 to 0.015; p = 0.37), respectively. We found no difference in the improvement of either knee-specific or general health outcomes between TKR and UKR in a large cohort of registry patients. With concerns about significantly higher revision rates for UKR observed in worldwide registries, we question the widespread use of an arthroplasty that does not confer a significant benefit in clinical outcome.

The effect of aspirin and low-molecular-weight heparin on venous thromboembolism after knee replacement: a non-randomised comparison using National Joint Registry Data

We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or low-molecular-weight heparin (LMWH). Data from the National Joint Registry for England and Wales were linked to an administrative database of hospital admissions in the English National Health Service. A total of 156,798 patients between April 2003 and September 2008 were included and followed for 90 days. Multivariable risk modelling was used to estimate odds ratios adjusted for baseline risk factors (AOR). An AOR < 1 indicates that risk rates are lower with LMWH than with aspirin. In all, 36,159 patients (23.1%) were prescribed aspirin and 120,639 patients (76.9%) were prescribed LMWH. We found no statistically significant differences between the aspirin and LMWH groups in the rate of pulmonary embolism (0.49% vs 0.45%, AOR 0.88 (95% confidence interval (CI) 0.74 to 1.05); p = 0.16), 90-day mortality (0.39% vs 0.45%, AOR 1.13 (95% CI 0.94 to 1.37); p = 0.19) or major haemorrhage (0.37% vs 0.39%, AOR 1.01 (95% CI 0.83 to 1.22); p = 0.94). There was a significantly greater likelihood of needing to return to theatre in the aspirin group (0.26% vs 0.19%, AOR 0.73 (95% CI 0.58 to 0.94); p = 0.01). Between patients receiving LMWH or aspirin there was only a small difference in the risk of pulmonary embolism, 90-day mortality and major haemorrhage. These results should be considered when the existing guidelines for thromboprophylaxis after knee replacement are reviewed.

Changing antibiotic prophylaxis for primary joint arthroplasty affects postoperative complication rates and bacterial spectrum

BACKGROUND

The reduction of Clostridium difficile associated diarrhoea (CDAD) is a national priority. As part of the C. difficile improvement plan in our Trust, antibiotic prophylaxis for primary arthroplasty was changed from cefuroxime to gentamicin. Gentamicin was chosen following a review of the sensitivity profiles of all the organisms isolated from infected primary arthoplasties.

METHODS

From January 2002 to September 2007, 6094 patients (Group 1) undergoing primary hip and knee arthroplasty received three doses of Cefuroxime as prophylaxis; while from October 2007 to February 2009, 2101 patients (Group 2) received single dose Gentamicin (4.5 mg/kg). We studied the rate of CDAD as well as several other postoperative complications, including rate of return to theatre (RTT), before and after the change.

FINDINGS

There was an insignificant fall in CDAD from 0.18% to 0% (p=0.08) in Group 2, however there was a statistically significant increase in pneumonia (0.67-1.33%, p<0.01), acute renal failure (ARF) requiring HDU admission (0.07-0.33%, p<0.01) and RTT (1.08-1.95%, p<0.01) in this group. RTT for proven infection increased from 0.66% to 1.52% (p<0.01).

CONCLUSIONS

We conclude that Gentamicin 4.5 mg/kg alone should not be used as prophylaxis for primary joint arthroplasty as it does not reduce CDAD significantly but increases the risk of other postoperative complications. We have changed our prophylaxis to low dose gentamicin (3 mg/kg) combined with Teicoplanin 400 mg given once.

A national analysis of complications following hemiarthroplasty for hip fracture in older patients

BACKGROUND

There is emerging evidence that patients with fractured neck of femur (FNOF) aged >85 years have different demands on a health-care system when compared to younger patients.

AIM

We sought to better quantify this in terms of comorbidity and complication rates.

DESIGN

Retrospective review of national database.

METHODS

Data on all patients who underwent hip hemiarthroplasty for FNOF between January 2005 and December 2008 were extracted from the English hospital episode statistics database.

RESULTS

There were 41 770 patients aged 65-84 years and 35 321 patients aged ≥85 years. The older cohort was less likely to have diabetes, chronic obstructive pulmonary disease and rheumatoid arthritis. However, they exhibited a significantly higher risk of lower respiratory tract infection [odds ratio (OR) = 1.58, 95% confidence interval (CI) 1.50-1.67)], myocardial infarction (OR = 1.67, 1.52-1.83) and acute renal failure (OR = 1.54, 1.40-1.70) within 30 days of surgery with an inpatient mortality risk at 90 days, double that of the younger age group. Length of stay (LoS) was significantly longer in patients >85 years compared to younger patients (median 18 days vs. 15, P < 0.001).

CONCLUSION

Patients aged ≥85 years admitted for FNOF were found to have a lower incidence of major chronic disease but exhibited a greater incidence of acute events following hemiarthroplasty and their LoS was increased. Targeted medical interventions that focus upon this susceptible patient group may help reduce morbidity and improve survival.

The effect of aspirin and low-molecular-weight heparin on venous thromboembolism after hip replacement: a non-randomised comparison from information in the National Joint Registry

We compared thromboembolic events, major haemorrhage and death after total hip replacement in patients receiving either aspirin or low-molecular-weight heparin (LMWH). We analysed data from the National Joint Registry for England and Wales linked to an administrative database of hospital admissions in the English National Health Service. A total of 108,584 patients operated on between April 2003 and September 2008 were included and followed up for 90 days. Multivariable risk modelling and propensity score matching were used to estimate odds ratios (OR) adjusted for baseline risk factors. An OR < 1 indicates that rates are lower with LMWH than with aspirin. In all, 21.1% of patients were prescribed aspirin and 78.9% LMWH. Without adjustment, we found no statistically significant differences. The rate of pulmonary embolism was 0.68% in both groups and 90-day mortality was 0.65% with aspirin and 0.61% with LMWH (OR 0.93; 95% CI 0.77 to 1.11). With risk adjustment, the difference in mortality increased (OR 0.84; 95% CI 0.69 to 1.01). With propensity score matching the mortality difference increased even further to 0.65% with aspirin and 0.51% with LMWH (OR 0.77; 95% CI 0.61 to 0.98). These results should be considered when the conflicting recommendations of existing guidelines for thromboprophylaxis after hip replacement are being addressed.

Return to theatre following total hip and knee replacement, before and after the introduction of rivaroxaban: a retrospective cohort study

Rivaroxaban has been recommended for routine use as a thromboprophylactic agent in patients undergoing lower-limb arthroplasty. However, trials supporting its use have not fully evaluated the risks of wound complications. This study of 1048 total hip/knee replacements records the rates of return to theatre and infection before and after the change from a low molecular weight heparin (tinzaparin) to rivaroxaban as the agent of chemical thromboprophylaxis in patients undergoing lower-limb arthroplasty. During a period of 13 months, 489 consecutive patients undergoing lower-limb arthroplasty received tinzaparin and the next 559 consecutive patients received rivaroxaban as thromboprophylaxis. Nine patients in the control (tinzaparin) group (1.8%, 95% confidence interval 0.9 to 3.5) returned to theatre with wound complications within 30 days, compared with 22 patients in the rivaroxaban group (3.94%, 95% confidence interval 2.6 to 5.9). This increase was statistically significant (p = 0.046). The proportion of patients who returned to theatre and became infected remained similar (p = 0.10). Our study demonstrates the need for further randomised controlled clinical trials to be conducted to assess the safety and efficacy of rivaroxaban in clinical practice, focusing on the surgical complications as well as the potential prevention of venous thromboembolism.

Pharmacogenetic analysis of the mGlu2/3 agonist LY2140023 monohydrate in the treatment of schizophrenia

The goal of this study was to identify genetic markers associated with LY2140023 monohydrate response in patients with schizophrenia. Variants in eight candidate genes related to the mechanism of action of LY2140023 or olanzapine were investigated in a genetic cohort collected from two clinical trials. Results from this genetic analysis indicate that 23 single nucleotide polymorphisms (SNPs) were associated with a change in Positive and Negative Syndrome Scale total score in response to LY2140023 at 28 days (P<0.01; false discovery rate <0.2). Sixteen of these SNPs were located in the serotonin 2A receptor (HTR2A). Bioinformatic analyses identified a putative antisense nested gene in intron 2 of HTR2A in the region of the genetic markers associated with LY2140023 response. These data suggest a genetic association exists between SNPs in several genes, such as HTR2A, and response to LY2140023 treatment. Additional clinical trials are needed to establish replication of these results.

Does bariatric surgery prior to lower limb joint replacement reduce complications?

Obesity is an increasing health concern in developed world. Bariatric surgery is considered in super-obese patients. Many of these patients will also require lower limb arthroplasty. This study was performed to investigate the complications of hip and knee replacement in patients who had bariatric surgery either before or after their joint replacement. Hospital episode statistics data for English NHS patients undergoing lower limb arthroplasty and bariatric surgery between 2005 and 2009 were analysed. The joint replacement-specific and general medical complications were compared between those undergoing joint replacement prior to bariatric surgery and vice versa, and also with the general English arthroplasty patient. One hundred and forty-three patients underwent bariatric surgery and joint replacement. Bariatric surgery was performed first in 53 and arthroplasty first in 90 patients. The mean age of obese patients was 9 years younger than the general arthroplasty population. Mean in-hospital stay was similar but general medical complications in obese patients appear to be less, possibly because of the lower age at the time of the procedure. Hip dislocation rate at 18 months was higher. Within the two obese groups wound infection rate was 3.5 times lower and readmission to hospital at 30 days appeared to be 7-times lower in patients who had bariatric surgery prior to joint replacement (p = 0.06). In this patient group, the risk of complications following joint replacement appears to be lower if bariatric surgery is performed first.

The impact of national guidelines for the prophylaxis of venous thromboembolism on the complications of arthroplasty of the lower limb

The National Institute for Clinical Excellence (NICE) produces recommendations on appropriate treatment within the National Health Service (NHS) in England and Wales. The NICE guidelines on prophylaxis for venous thromboembolism in orthopaedic surgery recommend that all patients be offered a low molecular weight heparin (LMWH). The linked hospital episode statistics of 219 602 patients were examined to determine the rates of complications following lower limb arthroplasty for the 12-month periods prior to and following the publication of these guidelines. These were compared with data from the National Joint Registry (England and Wales) regarding the use of LMWH during the same periods. There was a significant increase in the reported use of LMWH (59.5% to 67.6%, p < 0.001) following the publication of the guidelines. However, the 90-day venous thromboembolism events actually increased slightly following total hip replacement (THR, 1.69% to 1.84%, p = 0.06) and remained unchanged following total knee replacement (TKR, 1.99% to 2.04%). Return to theatre in the first 30 days for infection did not show significant changes. There was an increase in the number of patients diagnosed with thrombocytopenia, which was significant following THR (0.11% to 0.16%, p = 0.04). The recommendations from NICE are based on predicted reductions in venous thromboembolism events, reducing morbidity, mortality and costs to the NHS. The early results in orthopaedic patients do not support these predictions, but do show an increase in complications.

Trauma experience in the UK and Ireland: analysis of orthopaedic training using the FHI eLogbook

Surgical trainees routinely provide evidence of their training and operative experience for assessment. National comparative data on the number of procedures performed during training was previously unavailable in the UK. Since 2003 every trainee in Trauma and Orthopaedics (T&O) in the UK and Ireland has submitted data recording their operative experience electronically via the Faculty of Health Informatics (FHI) eLogbook. This provides detailed data on trainee, trainer, hospital and training programme performance. This data has been analysed for trauma surgery. By March 2007 there were 1053 T&O Specialist Registrars with operations logged. Trauma operations performed and uploaded during the previous 3 years have been included. Each trainee's work is analysed by 'year-in-training' (YIT, 1-6). Data on levels of supervision and potentially missed opportunities (where the trainee was present but assisted rather than performed the operation) was analysed. The mean number of trauma operations performed annually by trainees was 109, 120, 110, 122, 98 and 84 (total 643) for YIT 1-6, respectively. 22% of the operations at which a trainee was present were potentially missed opportunities. A high level of experience is gained in hip fracture surgery (121 operations performed), intramedullary nailing (38) and ankle (47) stabilisation over the 6 years of training. However, the mean number of tendon repairs (18), tension band wires (13), external fixators (12) and children's supracondylar fracture procedures (9) performed is low. We also report figures for complex fracture stabilisation. The eLogbook remains a powerful tool which can provide accurate information to support in-depth analysis of trainees, trainers, and training programmes. Based on this analysis, we suggest 'standard setting' to identify trainees performing fewer operations than required during their training. We have also established a baseline which can be used to identify the consequences of changes to length of training and working hours.

Tumour necrosis factor inhibitors in ankylosing spondylitis

Ankylosing spondylitis (AS) is the most common form of spondyloarthropathy. Non-steroidal anti-inflammatory medications and exercise are used to manage the chronic inflammatory spinal pain and stiffness. Up to 20% of patients have a peripheral inflammatory arthritis, which is treated with standard disease-modifying anti-rheumatic drugs especially sulfasalazine and methotrexate. Patients may also have extra-articular manifestations, such as anterior uveitis, psoriasiform skin lesions and inflammatory bowel disease. Anti-tumour necrosis (TNF) therapy has been used with great success in rheumatoid arthritis. There are now good data of the efficacy of anti-TNF therapies in the short and medium terms in AS. Etanercept, infliximab and adalimumab have been shown in randomized placebo-controlled trials of short duration to significantly reduce disease activity, including pain and stiffness as well as improving function, spinal movement and quality of life. It is hoped that long-term therapy will prevent radiologic progression and ankylosis and studies of long-term efficacy are awaited. Anti-TNF therapies are generally well tolerated in AS. It is important to screen for latent tuberculosis before the commencement of anti-TNF therapy. The side-effect profile of anti-TNF therapies in AS does not appear different from that in rheumatoid arthritis. Currently, treatment with anti-TNF therapy in AS is indicated in established disease with radiographic damage. There is evidence that response to therapy is greater in patients with earlier disease and less damage. Future developments may see this therapy extended to patients with pre-radiographic AS.