The Effect of Surgeon Volume on Revision for Periprosthetic Joint Infection: An Analysis of 602,919 Primary Total Knee Arthroplasties

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication of total knee arthroplasty (TKA). An association between low surgeon volume and higher rates of infection following primary TKA has been suggested. The purpose of the present study was to determine if there was a relationship between surgeon volume and the rate of revision for infection after primary TKA.

METHODS

We searched the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) to identify all primary TKA procedures that were performed for the treatment of osteoarthritis from September 1, 1999, to December 31, 2020, and were subsequently revised because of infection. Surgeon volume was defined as the annual volume of procedures performed by a surgeon during the same year in which the primary TKA (which was subsequently revised for infection) was performed. Surgeon volume was defined as <25, 25 to 49, 50 to 74, 75 to 99, or ≥100 primary TKA procedures/year. The cumulative percent revision (CPR) for infection was determined with use of Kaplan-Meier estimates. Cox proportional hazards methods were used to compare rates of revision for infection by surgeon volume, with subanalyses for patellar resurfacing and polyethylene use. Further analyses for patients <65 years of age and male patients were undertaken.

RESULTS

Overall, 602,919 primary TKA procedures were performed for the treatment of osteoarthritis, of which 5,295 were revised because of infection. High-volume surgeons (≥100 TKAs/year) had a significantly lower rate of revision for infection, with a CPR at 1 and 19 years of 0.4% (95% confidence interval [CI], 0.3 to 0.4) and 1.5% (95% CI, 1.2 to 2.0), respectively, compared with 0.6% (95% CI, 0.5 to 0.7) and 2.1% (95% CI, 1.8 to 2.3), respectively, for low-volume surgeons (<25 TKAs/year). Hazard ratios (HRs), adjusted for age and sex, comparing these 2 groups varied, depending on the time point, between 3.07 (95% CI, 2.02 to 4.68) and 1.44 (95% CI, 1.26 to 1.63) but remained significant (p < 0.001). When the analysis was adjusted for age, sex, American Society of Anesthesiologists (ASA) classification, and body mass index (BMI), there remained an increased risk of revision for PJI for all lower surgeon volume levels in comparison with the high- surgeon-volume group (≥100 TKAs/year). The results were similar when stratified by patellar resurfacing and cross-linked polyethylene (XLPE) and adjusted for age and sex.

CONCLUSIONS

High-volume surgeons had lower rates of revision for infection. A better understanding of how surgical volume contributes to decreasing this complication is important and requires in-depth study.

LEVEL OF EVIDENCE

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

Search for the Lepton Flavor Violating Decays B^{+}→K^{+}τ^{±}ℓ^{∓} (ℓ=e, μ) at Belle

We present a search for the lepton flavor violating decays B^{+}→K^{+}τ^{±}ℓ^{∓}, with ℓ=(e,μ), using the full data sample of 772×10^{6}  BB[over ¯] pairs recorded by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. We find no evidence for B^{±}→K^{±}τℓ decays and set upper limits on their branching fractions at the 90% confidence level in the (1-3)×10^{-5} range. The obtained limits are the world's best results.

First Observation of Λπ^{+} and Λπ^{-} Signals near the K[over ¯]N(I=1) Mass Threshold in Λ_{c}^{+}→Λπ^{+}π^{+}π^{-} Decay

Using the data sample of 980  fb^{-1} collected with the Belle detector operating at the KEKB asymmetric-energy e^{+}e^{-} collider, we present the results of an investigation of the Λπ^{+} and Λπ^{-} invariant mass distributions looking for substructure in the decay Λ_{c}^{+}→Λπ^{+}π^{+}π^{-}. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Λπ^{+} (Λπ^{-}) combination a mass of 1434.3±0.6(stat)±0.9(syst)  MeV/c^{2} [1438.5±0.9(stat)±2.5(syst)  MeV/c^{2}], an intrinsic width of 11.5±2.8(stat)±5.3(syst)  MeV/c^{2} [33.0±7.5(stat)±23.6(syst)  MeV/c^{2}] with a significance of 7.5σ (6.2σ). As these two signals are very close to the K[over ¯]N threshold, we also investigate the possibility of a K[over ¯]N cusp, and find that we cannot discriminate between these two interpretations due to the limited size of the data sample.

Gradual Decline of Japanese Beetle (Coleoptera: Scarabaeidae) Populations in Michigan Follows Establishment of Ovavesicula popilliae (Microsporidia)

The purpose of this research was to document the incidence of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), infection by the microsporidian pathogen, Ovavesicula popilliae Andreadis & Hanula (Microsporida: Pleistophoridae) while monitoring Japanese beetle populations at nine golf courses in Michigan from 1999 to 2018. We also compared the current distribution of the pathogen in Michigan to the known distribution in 1999. Beetles were sampled a total of seven different years, in three time periods: 1999-2000, 2005-2007, and 2015-2018. At these nine golf courses, O. popilliae infection rates of adults increased from 0.39% in 2000 to 29.5% in 2018, while Japanese beetle adult populations declined 73.2%, and Japanese beetle larval density declined 78.6% (from 1999 to 2018). In previous research, larval infection rates averaged at least twice the infection rates of adults, because all infections originate in the larval stage, and at least 75% of infected larvae die before pupation. This means that an adult infection rate of 29.5%, combined with previously observed 50% reductions in egg production by infected females, are consistent with the observed population declines. The current distribution of O. popilliae in southern Michigan was determined by sampling Japanese beetle larvae and adults at 38 sites in 2017 and 2018. Ovavesicula popilliae was found at 21 of 38 sites and in 16 of 21 counties, compared with two sites in one of 16 counties when it was first detected in Michigan in 1999 and 2000.

173 Debridement, Antibiotics and Implant Retention (DAIR) in the Management of Prosthetic Joint Infections Following Primary Hip and Knee Arthroplaty: A DGH Experience

Aim

Prosthetic joint infections (PJI) are a devastating complication of arthroplasty surgery. Current gold standard one or two-stage revision, poses sincere surgical challenges and carry significant patient morbidity. If diagnosed promptly, a debridement, antibiotics, and implant retention (DAIR) procedure can be performed. We report the results of our experience with the DAIR procedure in a District General Hospital setting.

Method

Our study comprises of a single centre retrospective review of a prospectively updated database. All patients who underwent a DAIR procedure following hip or knee arthroplasty from August 2012 to July 2019 were included in the study with no exclusions.

Results

Four total knee replacements, sixteen total hip replacements (THR), two revision THR and three hemiarthroplasties were included in the study. Average duration from onset of symptoms to DAIR was 22 days for immediate post-operative patients and 6 days in patients presenting later with an acute infection. All patients had exchange of modular components during the DAIR procedure. Out of 25 DAIR procedures, 23 identified a positive microbiology culture. Most common causative organisms identified were Staphylococcos aureus (23%) and Staphylococcus epidermidis (23%). Average follow up in clinic was 55 months. 76% of patients had a stable post-operative recovery with no recurrence of infection. One patient required a revision THR for aseptic loosening; one patient required a knee arthrodesis and four patients died.

Conclusions

Infection was successfully eradicated in 19 patients. The success reported within the literature stem predominantly from tertiary units. Our study reflects this success in a DGH setting.

Validation of the Kinetik Blood Pressure Monitor-Series 1 for use in adults at home and in clinical settings, according to the 2002 European Society of Hypertension International Protocol on the validation of blood pressure devices

The aim of this study was to assess the blood pressure (BP) measurement accuracy of the Kinetik Blood Pressure Monitor-Series 1 (BPM-1) for use in home or clinical settings according to the 2002 European Society of Hypertension International Protocol (ESH-IP). Forty-two participants were recruited to fulfil the required number of systolic and diastolic BP measurements according to the ESH-IP. Nine sequential same-arm BP readings were measured and analysed for each participant using the test device and observer mercury standard readings according to the 2002 ESH-IP. Forty one participants were used to obtain 33 sets of systolic and diastolic BP readings and were included in the analysis. Mean difference between the device measurements and the observer (mercury standard) measurements was 1.1 ± 7.2/1.1 ± 6.8 mmHg (mean ± standard deviation; systolic/diastolic). The number of systolic BP differences between the test and observer measurements that fell within 5, 10 and 15 mmHg was 65, 86 and 92. For diastolic readings, the number of test-observer measurement differences within 5, 10 and 15 mmHg was 77, 91 and 94. The number of participants with at least two out of three differences within 5 mmHg was 28 for systolic and 40 for diastolic BP readings. Three participants had no differences between the test and observer measurements within 5 mmHg in both the systolic and diastolic measurement categories. The Kinetik BPM-1 device fulfilled the requirements of the ESH-IP validation procedure and can be recommended for clinical use and self-measurement within the home.

Evidence for X(3872)→J/ψπ^{+}π^{-} Produced in Single-Tag Two-Photon Interactions

We report the first evidence for X(3872) production in two-photon interactions by tagging either the electron or the positron in the final state, exploring the highly virtual photon region. The search is performed in e^{+}e^{-}→e^{+}e^{-}J/ψπ^{+}π^{-}, using 825  fb^{-1} of data collected by the Belle detector operated at the KEKB e^{+}e^{-} collider. We observe three X(3872) candidates, where the expected background is 0.11±0.10 events, with a significance of 3.2σ. We obtain an estimated value for Γ[over ˜]_{γγ}B(X(3872)→J/ψπ^{+}π^{-}) assuming the Q^{2} dependence predicted by a cc[over ¯] meson model, where -Q^{2} is the invariant mass squared of the virtual photon. No X(3915)→J/ψπ^{+}π^{-} candidates are found.

Processes of consent in research for adults with impaired mental capacity nearing the end of life: systematic review and transparent expert consultation (MORECare_Capacity statement)

BACKGROUND

Involving adults lacking capacity (ALC) in research on end of life care (EoLC) or serious illness is important, but often omitted. We aimed to develop evidence-based guidance on how best to include individuals with impaired capacity nearing the end of life in research, by identifying the challenges and solutions for processes of consent across the capacity spectrum.

METHODS

Methods Of Researching End of Life Care_Capacity (MORECare_C) furthers the MORECare statement on research evaluating EoLC. We used simultaneous methods of systematic review and transparent expert consultation (TEC). The systematic review involved four electronic databases searches. The eligibility criteria identified studies involving adults with serious illness and impaired capacity, and methods for recruitment in research, implementing the research methods, and exploring public attitudes. The TEC involved stakeholder consultation to discuss and generate recommendations, and a Delphi survey and an expert 'think-tank' to explore consensus. We narratively synthesised the literature mapping processes of consent with recruitment outcomes, solutions, and challenges. We explored recommendation consensus using descriptive statistics. Synthesis of all the findings informed the guidance statement.

RESULTS

Of the 5539 articles identified, 91 met eligibility. The studies encompassed people with dementia (27%) and in palliative care (18%). Seventy-five percent used observational designs. Studies on research methods (37 studies) focused on processes of proxy decision-making, advance consent, and deferred consent. Studies implementing research methods (30 studies) demonstrated the role of family members as both proxy decision-makers and supporting decision-making for the person with impaired capacity. The TEC involved 43 participants who generated 29 recommendations, with consensus that indicated. Key areas were the timeliness of the consent process and maximising an individual's decisional capacity. The think-tank (n = 19) refined equivocal recommendations including supporting proxy decision-makers, training practitioners, and incorporating legislative frameworks.

CONCLUSIONS

The MORECare_C statement details 20 solutions to recruit ALC nearing the EoL in research. The statement provides much needed guidance to enrol individuals with serious illness in research. Key is involving family members early and designing study procedures to accommodate variable and changeable levels of capacity. The statement demonstrates the ethical imperative and processes of recruiting adults across the capacity spectrum in varying populations and settings.

Survival of Japanese beetle, Popillia japonica Newman, larvae in field plots when infected with a microsporidian pathogen, Ovavesicula popilliae

Japanese beetle, Popillia japonica Newman, is an important invasive pest that causes significant damage to golf courses, blueberries, raspberries, hops and many other crops and ornamentals in the eastern United States. This study was conducted to determine the survival of Ovavesicula popilliae-infected larvae compared with uninfected larvae from October to May. Larvae were collected from two sites, one where O. popilliae was active and one where it had not yet been detected. Larvae were placed into plastic sleeve-pots containing 15 cm-diameter cores of turfgrass with roots and soil intact. Larvae collected from both locations were put into sleeve-pots at both locations to account for soil and site factors. Results of this experiment in both years confirm that Japanese beetle larvae infected with O. popilliae do not survive well from October to May. We estimate that at an epizootic location where the pathogen has been active for several years, at least 76.5% of the Japanese beetle larvae infected in October do not survive until May. When the observed amount of population reduction (27-29%) due to natural pathogen infection of larvae in our field plots is combined with a 50% reduction in eggs produced by infected females as previously reported, annual population declines due to O. popilliae would average 40% (assuming a typical adult female infection rate of 25%). This rate of population reduction is consistent with previous reports of Japanese beetle population decline over a period of several years at O. popilliae epizootic sites.

Observation of the Radiative Decays of ϒ(1S) to χ_{c1}

We report the first observation of the radiative decay of the ϒ(1S) into a charmonium state. The significance of the observed signal of ϒ(1S)→γχ_{c1} is 6.3 standard deviations including systematics. The branching fraction is calculated to be B[ϒ(1S)→γχ_{c1}]=[4.7_{-1.8}^{+2.4}(stat)_{-0.5}^{+0.4}(sys)×10^{-5}]. We also searched for ϒ(1S) radiative decays into χ_{c0,2} and η_{c}(1S,2S), and set upper limits on their branching fractions. These results are obtained from a 24.9  fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider at a center-of-mass energy equal to the ϒ(2S) mass using ϒ(1S) tagging by the ϒ(2S)→ϒ(1S)π^{+}π^{-} transitions.

2229. Relative Bioavailability of a Single Oral Dose of SUBA-Itraconazole 65 mg Capsule Compared with Conventional Itraconazole 100 mg Capsule Administered Under Fasted and Fed Conditions in Healthy Adult Volunteers

Background

Conventional itraconazole (CI) absorption from capsules even under fed conditions is suboptimal (~55%), let alone when fasted. SUBA-itraconazole (SI) is ~1.8x’s more bioavailable than CI at steady-state in a fed condition. There are, however, no data comparing these formulations under a fasted state. A single-dose PK study was performed comparing bioavailability of 65mg SI to 100mg CI under fasted or fed conditions.

Methods

This was an open-label, single-dose, randomized, four-period, four-treatment, four-sequence, crossover bioequivalence study under fasted and fed conditions in healthy adults. Subjects were administered a single dose of SI (1 × 65 mg) and CI (1 × 100 mg). Under fasted condition, subjects were administered SI or CI following an overnight fast of at least 10 hours. Subjects under fed condition were administered SI or CI after 30 minutes of consuming a standardized high fat breakfast preceded by an overnight fast of at least 10 hours. After dosing, all subjects fasted for at least 4 hours post-dose in all periods. Blood samples were collected prior to dosing and then from 1 to 120 hours. Analysis of itraconazole (IZ) and hydoxyitraconazole (HIZ) serum levels was by least-squares-geometric means of PK parameters.

Results

Under fasted condition, C_max and AUC_tau of IZ for SI were substantially higher compared with CI (Table, Figure 1). Under fed conditions, however, the C_max and AUC_tau of IZ for SI was 20% and 10% lower, respectively (table, Figure 2). Similar results were found for HIZ. The T_max for IZ and HIZ of SI and CI were similar under a fasted condition but extended by over 2 hours for SI vs. CI under fed conditions. Study drugs were well-tolerated under fasted and fed conditions. All TEAEs were mild and resolved at the end of the study. Fifty of 52 subjects enrolled completed the study. Two subjects did not complete the study due to not being able to finish a high fat meal and noncompliance. No SAEs were reported.

Conclusion

Total and peak IZ/HIZ exposure was substantially higher for SI under fasted conditions compared with CI, but slightly lower under fed conditions with similar safety profiles. This study demonstrates the unique nature of the SI formulation compared with CI under fasted conditions and may lead to less variability if patients are not adherent to dietary requirements when taking itraconazole.

Disclosures

All authors: No reported disclosures.

Abstract B141: Anti-tumor immune responses elicited by mesothelin virus-like particles vaccine effectively controls pancreatic cancer in animal models

Pancreatic cancer is the 12th most common cancer, but is the 3rd leading cause of cancer death in America. This disparity is directly related to three factors: the difficulty in early detection of the disease, pancreatic cancer’s resistance to chemotherapy, and a tendency for the cancer to metastasize early and quickly. Here, we propose a novel immunotherapy to bypass pancreatic cancer’s resistance to standard chemotherapy. We have developed a virus-like particle (VLP) based on an HIV backbone Gag and pancreatic cancer-associated protein mesothelin (MSLN). Vaccination of C57BL/6 mice with MSLN VLP can efficiently activate the immune system and reduce and in some cases eliminate the host’s pancreatic cancer. Our results show that MSLN VLPs induce both humoral and cytotoxic specific response against MSLN in mouse pancreatic cancer models. Specifically, after vaccination with MSLN VLPs, significant increases in CD8+ MSLN specific T-cells and increases in serum anti-MSLN IgG were detected. Furthermore, we observed an increase in the serum of pro-inflammatory cytokine IFN-γ and B cell stimulator IL-5. Consistent with the increased IL-5, we observed a significant increase in tumor infiltrating B cells in the MSLN VLP immunized groups, but neither Gag VLP control nor unimmunized mice. Furthermore, while all tumor-bearing mice generated some antibodies towards MSLN, our MSLN VLP immunized mice had significantly higher serum titers of IgG1, IgG2B, and IgG3. Both Gag VLP and MSLN VLP immunized mice had a decreased tumor volume compared to control, but passive transfer of sera only from MSLN VLP immunized mice decreased tumor volume and increased survival of unimmunized tumor bearing mice, while Gag VLP immunized mice had much less effect. Overall, we have developed a promising vaccine for pancreatic cancer warranting additional studies with adjuvants and combination treatments with standard-of-care chemotherapy.

Citation Format: Qizhi Cathy Yao, Ethen Poteet, Zhengdong Liang, Phoebe Lewis, Zhiyin Yu, Changyi Chen. Anti-tumor immune responses elicited by mesothelin virus-like particles vaccine effectively controls pancreatic cancer in animal models [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B141.

Practice variation in total hip arthroplasty versus hemiarthroplasty for treatment of fractured neck of femur in Australia

Aims

Displaced femoral neck fractures (FNF) may be treated with partial (hemiarthroplasty, HA) or total hip arthroplasty (THA), with recent recommendations advising that THA be used in community-ambulant patients. This study aims to determine the association between the proportion of FNF treated with THA and year of surgery, day of the week, surgeon practice, and private versus public hospitals, adjusting for known confounders.

Patients and Methods

Data from 67 620 patients in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 1999 to 2016 inclusive were used to generate unadjusted and adjusted analyses of the associations between patient, time, surgeon and institution factors, and the proportion of FNF treated with THA.

Results

Overall, THA was used in 23.7% of patients. THA was more frequently used over time, in younger patients, in healthier patients, in cases performed on weekdays (adjusted odds ratio (OR) 1.27; 95% confidence interval (CI) 1.14 to 1.41), in private hospitals (adjusted OR 4.34; 95% CI 3.94 to 4.79) and by surgeons whose hip arthroplasty practice has a relatively higher proportion of elective patients (adjusted OR 1.65; 95% CI 1.49 to 1.83).

Conclusion

Practice variation exists in the proportion of FNF patients treated with THA due to variables other than patient factors. This may reflect variation in resources available and surgeon preference, and uncertainty regarding the relative indication.

Investigator Assessment of the Utility of the TruGraf Molecular Diagnostic Test in Clinical Practice

BACKGROUND

TruGraf v1 is a well-validated DNA microarray-based test that analyzes blood gene expression profiles as an indicator of immune status in kidney transplant recipients with stable renal function.

METHODS

In this study, investigators assessed clinical utility of the TruGraf test in patient management. In a retrospective study, simultaneous blood tests and clinical assessments were performed in 192 patients at 7 transplant centers, and in a prospective observational study they were performed in 45 subjects at 5 transplant centers.

RESULTS

When queried regarding whether or not the TruGraf test result impacted their decision regarding patient management, in 168 of 192 (87.5%) cases the investigator responded affirmatively. The prospective study indicated that TruGraf results supported physicians' decisions on patient management 87% (39/45) of the time, and in 93% of cases physicians indicated that they would use serial TruGraf testing in future patient management. A total of 21 of 39 (54%) reported results confirmed their decision that no intervention was needed, and 17 of 39 (44%) reported that results specifically informed them that a decision not to perform a surveillance biopsy was correct.

CONCLUSIONS

TruGraf is the first and only noninvasive test to be evaluated for clinical utility in determining rejection status of patients with stable renal function and shows promise of providing support for clinical decisions to avoid unnecessary surveillance biopsies with a high degree of confidence. TruGraf is an invaluable addition to the transplant physician's tool kit for managing patient health by avoiding painful and invasive biopsies, reducing health care costs, and enabling frequent assessment of patients with stable renal function to confirm immune quiescence.

2 Combat use of opioid analgesia and its complications: a retrospective review of data from OP herrick

Background

On the battlefield, acute pain, particularly secondary to trauma, is a common condition which requires treatment in the pre-hospital, evacuation and hospital settings. The use of morphine to manage pain during combat has been well established since the 19th century. Despite this, there are relatively few papers reviewing analgesia use in a combat environment. This study aims to review the use and complications from morphine and other opioids during Op HERRICK.

Methods

A database search of the Joint Theatre Trauma Registry (JTTR) was carried out looking for all incidences of administration of either morphine, fentanyl or naloxone from January 2007 to September 2014. Microsoft Excel was then used to analyse the dataset and perform descriptive statistics on the data retrieved.

Results

Opioid analgesia was administered to 5801 casualties. Morphine was administered 6742 times to 3808 patients. Fentanyl was administered 9672 times to 4318 patients. Naloxone was used 18 times on 14 patients, giving a complication rate of 0.24%. Opioid doses prior to naloxone administration range from 0–72 mg of morphine and 0–100 mcg of fentanyl. 4 casualties (2 local civilian and 2 coalition forces) received naloxone despite no recorded opioids being administered. Opium abuse was prevalent amongst the local population in Afghanistan, and this could explain the rationale behind 2 local national casualties receiving naloxone without any documented opioids being given.

Conclusion

The use of opioids in a battlefield environment is extremely safe, with very few incidences of complications requiring the use of naloxone. Complication rates are comparable to previously published research. We are unable to comment on the effectiveness of opioids in relieving pain in this study, and further research is needed, particularly following the introduction of oral transmucosal fentanyl citrate (OTFC) and the availability of non-opioid analgesia.

"Solid Red Line": An Observational Study on Death from Refractory Intracranial Hypertension

The index of cerebrovascular pressure reactivity (PRx) correlates independently with outcome after traumatic brain injury (TBI). However, as an index plotted in the time domain, PRx is rather noisy. To "organise" PRx and make its interpretation easier, the colour coding of values, with green when PRx <0 and red when PRx> 0.3, has been introduced as a horizontal colour bar on the ICM+ screen. In rare cases of death from refractory intracranial hypertension, an increase in intracranial pressure (ICP) is commonly preceded by values of PRx >0.3, showing a "solid red line".Twenty patients after TBI and one after traumatic subarachnoid haemorrhage (SAH) from six centres in Europe and Australia have been studied. All of them died in a scenario of refractory intracranial hypertension. In the majority of cases the initial ICP was below 20 mmHg and finally increased to values well above 60 mmHg, resulting in cerebral perfusion pressure less than 20 mmHg. In three cases initial ICP was elevated at the start of monitoring. A solid red line was observed in all cases preceding an increase in ICP above 25 mmHg by minutes to hours and in two cases by 2 and 3 days, respectively. If a solid red line is observed over a prolonged period, it should be considered as an indicator of deep cerebrovascular deterioration.

International consensus on the definition and classification of fibrosis of the knee joint

AIMS

The aim of this consensus was to develop a definition of post-operative fibrosis of the knee.

PATIENTS AND METHODS

An international panel of experts took part in a formal consensus process composed of a discussion phase and three Delphi rounds.

RESULTS

Post-operative fibrosis of the knee was defined as a limited range of movement (ROM) in flexion and/or extension, that is not attributable to an osseous or prosthetic block to movement from malaligned, malpositioned or incorrectly sized components, metal hardware, ligament reconstruction, infection (septic arthritis), pain, chronic regional pain syndrome (CRPS) or other specific causes, but due to soft-tissue fibrosis that was not present pre-operatively. Limitation of movement was graded as mild, moderate or severe according to the range of flexion (90° to 100°, 70° to 89°, < 70°) or extension deficit (5° to 10°, 11° to 20°, > 20°). Recommended investigations to support the diagnosis and a strategy for its management were also agreed.

CONCLUSION

The development of standardised, accepted criteria for the diagnosis, classification and grading of the severity of post-operative fibrosis of the knee will facilitate the identification of patients for inclusion in clinical trials, the development of clinical guidelines, and eventually help to inform the management of this difficult condition. Cite this article: Bone Joint J 2016;98-B:1479-88.

Toll-like receptor 3 adjuvant in combination with virus-like particles elicit a humoral response against HIV

Human Immunodeficiency Virus (HIV) Virus-Like Particles (VLPs) composed of HIV_IIIB Gag and HIV_BaL gp120/gp41 envelope are a pseudovirion vaccine capable of presenting antigens in their native conformations. To enhance the immunogenicity of the HIV Env antigen, VLPs were coupled to VesiVax Conjugatable Adjuvant Lipid Vesicles (CALV) containing one of four toll-like-receptor (TLR) ligands, each activating a receptor with distinct cellular localization and downstream pathways. C57BL/6 mice were vaccinated by intranasal prime followed by two sub-cheek boosts and their sera immunoglobulin and neutralizing potency were measured over a duration of 3months after vaccination. PBS control, VLPs alone, CALV+VLPs, and VLPs complexed with CALV and ligands for TLR2 (PAM3CAG), TLR3 (dsRNA), TLR4 (MPLA), or TLR7/8 (resiquimod) were evaluated based on antibody titer, IgG1 and IgG2c class switching, germinal center formation, T follicular cells and potency of neutralizing antibodies. Consistently, the TLR3 ligand dsRNA complexed to CALV and in combination with VLPs (CALV(dsRNA)+VLPs) induced the strongest response. CALV(dsRNA)+VLPs induced the highest titers against the recombinant vaccine antigens clade B Bal gp120 and pr55 Gag. Additionally, CALV(dsRNA)+VLPs induced cross-clade antibodies, represented by high titers of antibody to clade c 96ZM651 gp120. CALV(dsRNA)+VLPs induced predominantly IgG2c over IgG1, a response associated with T helper type 1 (Th1)-like cytokines. In turn, CALV(dsRNA)+VLP immunized mice generated the most potent neutralizing antibodies against HIV strain MN.3. Finally, at time of sacrifice, a significant increase in germinal center B cells and T follicular cells was detected in mice which received CALV(dsRNA)+VLPs compared to PBS. Our results indicate that CALV(dsRNA) is a superior adjuvant for HIV VLPs in generating a Th1-like immunoglobulin profile, while prolonging lymph node germinal centers, T follicular cells and generating neutralizing antibodies to a highly sensitive tier 1A variant of HIV.

Sex differences in murine sternohyoid muscle tolerance of acute severe hypoxic stress

Given that sex differences inherent to muscle might at least contribute to male risk for obstructive sleep apnoea syndrome (OSAS), our objective was to test the hypothesis that male sternohyoid muscle exhibits greater susceptibility to severe hypoxic stress compared with female muscle. Adult male and female C57Bl6/J mouse sternohyoid isometric and isotonic functional properties were examined ex vivo at 35 °C in tissue baths under control and severe hypoxic conditions. Hypoxia was detrimental to peak force (Fmax), work (Wmax) and power (Pmax), but not shortening velocity (Vmax). Two-way analysis of variance revealed a significant sex x gas interaction for Fmax (p<0.05), revealing inferior hypoxic tolerance in male sternohyoid muscle. However, increases in male shortening velocity in severe hypoxia preserved power-generating capacity which was equivalent to values determined in female muscle. Fmax decline in hypoxic female sternohyoid was considerably less than in male muscle, illustrating an inherent tolerance of force-generating capacity mechanisms to hypoxic stress in female airway dilator muscle. We speculate that this could confer a distinct advantage in vivo in terms of the defense of upper airway caliber.

First Observation of the Hadronic Transition ϒ(4S)→ηh(b)(1P) and New Measurement of the h(b)(1P) and η(b)(1S) Parameters

Using a sample of 771.6×10(6) ϒϒ(4S) decays collected by the Belle experiment at the KEKB e(+)e(-) collider, we observe, for the first time, the transition ϒ(4S)→ηh(b)(1P) with the branching fraction B[ϒ(4S)→ηh(b)(1P)]=(2.18±0.11±0.18)×10(-3) and we measure the h(b)(1P) mass M(h(b)(1P))=(9899.3±0.4±1.0)  MeV/c(2), corresponding to the hyperfine (HF) splitting ΔM(HF)(1P)=(0.6±0.4±1.0)  MeV/c(2). Using the transition h(b)(1P)→γη(b)(1S), we measure the η(b)(1S) mass M(η(b)(1S))=(9400.7±1.7±1.6)  MeV/c(2), corresponding to ΔM(HF)(1S)=(59.6±1.7±1.6)  MeV/c(2), the η(b)(1S) width Γ(η(b)(1S))=(8(-5)(+6)±5)  MeV/c(2) and the branching fraction B[h(b)(1P)→γη(b)(1S)]=(56±8±4)%.

First Observation of CP Violation in B[over ¯]^{0}→D_{CP}^{(*)}h^{0} Decays by a Combined Time-Dependent Analysis of BABAR and Belle Data

We report a measurement of the time-dependent CP asymmetry of B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays, where the light neutral hadron h^{0} is a π^{0}, η, or ω meson, and the neutral D meson is reconstructed in the CP eigenstates K^{+}K^{-}, K_{S}^{0}π^{0}, or K_{S}^{0}ω. The measurement is performed combining the final data samples collected at the ϒ(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6} BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6} BB[over ¯] pairs recorded by the Belle detector. We measure the CP asymmetry parameters -η_{f}S=+0.66±0.10(stat)±0.06(syst) and C=-0.02±0.07(stat)±0.03(syst). These results correspond to the first observation of CP violation in B[over ¯]^{0}→D_{CP}^{(*)}h^{0} decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations.

A Novel Prime and Boost Regimen of HIV Virus-Like Particles with TLR4 Adjuvant MPLA Induces Th1 Oriented Immune Responses against HIV

HIV virus-like particles (VLPs) present the HIV envelope protein in its native conformation, providing an ideal vaccine antigen. To enhance the immunogenicity of the VLP vaccine, we sought to improve upon two components; the route of administration and the additional adjuvant. Using HIV VLPs, we evaluated sub-cheek as a novel route of vaccine administration when combined with other conventional routes of immunization. Of five combinations of distinct prime and boost sequences, which included sub-cheek, intranasal, and intradermal routes of administration, intranasal prime and sub-cheek boost (IN+SC) resulted in the highest HIV-specific IgG titers among the groups tested. Using the IN+SC regimen we tested the adjuvant VesiVax Conjugatable Adjuvant Lipid Vesicles (CALV) + monophosphoryl lipid A (MPLA) at MPLA concentrations of 0, 7.5, 12.5, and 25 μg/dose in combination with our VLPs. Mice that received 12.5 or 25 μg/dose MPLA had the highest concentrations of Env-specific IgG2c (20.7 and 18.4 μg/ml respectively), which represents a Th1 type of immune response in C57BL/6 mice. This was in sharp contrast to mice which received 0 or 7.5 μg MPLA adjuvant (6.05 and 5.68 μg/ml of IgG2c respectively). In contrast to IgG2c, MPLA had minor effects on Env-specific IgG1; therefore, 12.5 and 25 μg/dose of MPLA induced the optimal IgG1/IgG2c ratio of 1.3. Additionally, the percentage of germinal center B cells increased significantly from 15.4% in the control group to 31.9% in the CALV + 25 μg MPLA group. These mice also had significantly more IL-2 and less IL-4 Env-specific CD8⁺ T cells than controls, correlating with an increased percentage of Env-specific central memory CD4⁺ and CD8⁺ T cells. Our study shows the strong potential of IN+SC as an efficacious route of administration and the effectiveness of VLPs combined with MPLA adjuvant to induce Env specific Th1-oriented HIV-specific immune responses.

Search for the dark photon and the dark Higgs boson at belle

The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical constituents featured in a number of recently proposed dark sector models. Assuming prompt decays of both dark particles, we search for their production in the so-called Higgstrahlung channel e^{+}e^{-}→A^{'}h^{'}, with h^{'}→A^{'}A^{'}. We investigate ten exclusive final states with A^{'}→e^{+}e^{-}, μ^{+}μ^{-}, or π^{+}π^{-} in the mass ranges 0.1  GeV/c^{2} <m_{A^{'}}<3.5  GeV/c^{2} and 0.2  GeV/c^{2} <m_{h^{'}}<10.5  GeV/c^{2}. We also investigate three inclusive final states 2(e^{+}e^{-})X, 2(μ^{+}μ^{-})X, and (e^{+}e^{-})(μ^{+}μ^{-})X, where X denotes a dark photon candidate detected via missing mass, in the mass ranges 1.1  GeV/c^{2} <m_{A^{'}}<3.5  GeV/c^{2} and 2.2  GeV/c^{2} <m_{h^{'}}<10.5  GeV/c^{2}. Using the entire 977  fb^{-1} data set collected by Belle, we observe no significant signal. We obtain individual and combined 90% credibility level upper limits on the branching fraction times the Born cross section, B×σ_{Born}, on the Born cross section σ_{Born}, and on the dark photon coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}×ε^{2}. These limits improve upon and cover wider mass ranges than previous experiments. The limits from the final states 3(π^{+}π^{-}) and 2(e^{+}e^{-})X are the first placed by any experiment. For α_{D} equal to 1/137, m_{h^{'}}< 8  GeV/c^{2}, and m_{A^{'}}<1  GeV/c^{2}, we exclude values of the mixing parameter ε above ∼8×10^{-4}.

Study of CP asymmetry in B^{0}-B[over ¯]^{0} mixing with inclusive dilepton events

We present a measurement of the asymmetry A_{CP} between same-sign inclusive dilepton samples ℓ^{+}ℓ^{+} and ℓ^{-}ℓ^{-} (ℓ=e, μ) from semileptonic B decays in ϒ(4S)→BB[over ¯] events, using the complete data set recorded by the BABAR experiment near the ϒ(4S) resonance, corresponding to 471×10^{6} BB[over ¯] pairs. The asymmetry A_{CP} allows comparison between the mixing probabilities P(B[over ¯]^{0}→B^{0}) and P(B^{0}→B[over ¯]^{0}), and therefore probes CP and T violation. The result, A_{CP}=[-3.9±3.5(stat)±1.9(syst)]×10^{-3}, is consistent with the standard model expectation.

Search for a dark photon in e(+)e(-) collisions at BABAR

Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} using 514  fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10^{-4}-10^{-3} for dark photon masses in the range 0.02-10.2  GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.

Gamma ray measurements with photoconductive detectors using a dense plasma focus

Photons in the MeV range emitted from the dense plasma focus (DPF) at the NSTec North Las Vegas Facility have been measured with both neutron-damaged GaAs and natural diamond photoconductive detectors (PCDs). The DPF creates or "pinches" plasmas of various gases (e.g., H2, D2, Ne, Ar., etc.) that have enough energy to create MeV photons from either bremsstrahlung and/or (n,n(')) reactions if D2 gas is used. The high bandwidth of the PCDs enabled the first ever measurement of the fast micro-pinches present in DPF plasmas. Comparisons between a slower more conventional scintillator/photomultiplier tube based nuclear physics detectors were made to validate the response of the PCDs to fast intense MeV photon signals. Significant discrepancies in the diamond PCD responses were evident.

A pilot study investigating the use of at-home, web-based questionnaires compiling patient-reported outcome measures following total hip and knee replacement surgeries

Patient-reported outcome measures (PROMs) are used routinely in NHS. Traditional pen-and-paper questionnaire collection can be time-consuming for both patients and clinic staff. The purpose of the current study was to determine whether a web-based PROMs system has the potential to provide satisfactory patient compliance and whether compiled data are equivalent to pen-and-paper PROMs data. A series of 82 patients who had joint replacement surgery was identified. Each patient was contacted by letter to register on the myClinicalOutcomes.co.uk website and to follow the instructions to render an Oxford score. A second request was sent to those failing to initially register. Telephone contact was then made with non-responders to identify the reason for failed registration. Successfully collated online Oxford scores were compared with previously recorded pen-and-paper scores for each patient from a prospectively updated database. Of the 82 patients identified, 61 (74%) received a letter or were otherwise contacted by telephone. Of these, 27 (44%) patients confirmed that they had access to the Internet. A total of 21 complete sets of data were collected. On review, the available secure online Oxford outcome scores demonstrated a mean of 30.1 (SD 11.4, range: 9-47). This mean score was comparable to the pen-and-paper database mean score of 29.1 (SD 11.8, range: 9-48) for the respective patients. Of the 27 respondents with Internet access, 21 (78%) produced complete scores that were available for real-time review. Available online scores were comparable to those collected via traditional means. With increased Internet availability and improved communication, remote web-based collection of patient reported outcomes may facilitate enhanced and efficient follow-up of patients.

Review of health-related quality of life data in multiple myeloma patients treated with novel agents

In multiple myeloma (MM), health-related quality of life (HRQoL) data is becoming increasingly important, owing to improved survival outcomes and the impact of treatment-related toxicity on HRQoL. Researchers are more frequently including HRQoL assessments in clinical trials, but analysis and reporting of this data has not been consistent. A systematic literature review assessed the effect of novel agents (thalidomide, bortezomib and lenalidomide) on HRQoL in MM patients, and evaluated the subsequent reporting of these HRQoL results. A relatively small body of literature addresses HRQoL data in MM patients treated with novel MM therapeutic agents: 9 manuscripts and 15 conference proceedings. The literature demonstrates the complementary value of HRQoL when assessing clinical response, progression, overall survival and toxicity. However, weaknesses and inconsistencies in analysis and presentation of HRQoL data were observed, often complicating interpretation of the impact of treatment on HRQoL in MM. Further evaluation of HRQoL in MM patients treated with novel agents is required in larger cohorts, and ideally in head-to-head comparative studies. Additionally, the development of standardised MM-specific best practice guidelines in HRQoL data collection and analysis is recommended. These would ensure that future data are more useful in guiding predictive models and clinical decisions.

Chronic wound and postamputation claudication pain in a diabetic patient

Underlying ischaemic disease should be excluded in patients with delayed wound healing. Contrast angiography is a useful imaging method for assessing the specific cause of wound chronicity and may also be helpful in assessing the aetiology of unexplained pain symptoms. Angioplasty provides a practical alternative to more invasive techniques in addressing peripheral ischaemia. Our patient suffered claudication-type pain in his thigh and a non-healing stump wound following below-knee amputation. Magnetic resonance angiography confirmed the presence of arterial stenoses and an angioplasty was successfully performed to improve patency of the profunda femoris vessel. Following the operation, the claudication pain symptoms were significantly reduced and the stump wound went on to heal.

Measurement of the D*(2010)+ meson width and the D*(2010)+ - D0 mass difference

We measure the mass difference Δm0 between the D*(2010)+ and the D0 and the natural linewidth Γ of the transition D*(2010)+ → D0π+. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(4S) resonance, and correspond to an integrated luminosity of approximately 477  fb(-1). The D0 is reconstructed in the decay modes D0 → K- π+ and D0 → K- π+ π- π+. For the decay mode D0 → K- π+ we obtain Γ = (83.4±1.7±1.5)  keV and Δm0 = (145425.6±0.6±1.7)  keV, [corrected] where the quoted errors are statistical and systematic, respectively. For the D0 → K- π+ π- π+ mode we obtain Γ = (83.2±1.5±2.6)  keV and Δm0 = (145426.6±0.5±1.9)  keV. [corrected] The combined measurements yield Γ = (83.3±1.2±1.4)  keV and Δm0 = (145425.9±0.4±1.7)  keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.

Search for CP violation in B0-B0 mixing using partial reconstruction of B0→D*- Xℓ+ νℓ and a kaon tag

We present results of a search for CP violation in B0- B0 mixing with the BABAR detector. We select a sample of B0→D*- Xℓ+ ν decays with a partial reconstruction method and use kaon tagging to assess the flavor of the other B meson in the event. We determine the CP violating asymmetry ACP≡[N(B0B0)-N(B0B0)]/[N(B0B0)+N(B0B0)]=(0.06±0.17(-0.32)(+0.38))%, corresponding to ΔCP=1-|q/p|=(0.29±0.84(-1.61)(+1.88))×10(-3).