Systematic Review and Meta-Analysis of a New Active Transcutaneous Bone Conduction Implant

OBJECTIVE

This review aims to quantify the pooled functional gain (FG) in different types of hearing loss with the transcutaneous hearing device, Osia (Cochlear, Sydney, Australia) in comparison with the unaided state. Secondary outcomes are patient-reported outcomes measures (PROMs) and complication rates.

DATA SOURCES

Medline, Embase, SCOPUS, Cochrane CENTRAL, PROSPERO and Cochrane Library.

REVIEW METHODS

Systematic review and meta-analysis of indexed search terms relating to "Osia," "Osseointegration," "Cochlear Implant," and "Bone-Anchored Prosthesis" was performed from database inception to September 20, 2022.

RESULTS

Of the 168 studies identified, 14 studies with 15 patient cohorts (n = 314) met inclusion criteria for meta-analysis. Pooled overall mean FG for all types of hearing loss was 35.0 dB sound pressure level (SPL) (95% confidence interval [CI] 29.12-40.97) compared against unaided hearing. Pooled FG for conductive/mixed hearing loss was 37.7 dB SPL (95% CI 26.1-49.3). Pooled single-sided deafness (SSD) FG could not be calculated due to the small patient cohort for whom SSD data was reported. There is a trend toward improvements in speech receptiveness threshold, signal to noise ratio, and some PROMs compared with baseline hearing. Early complication rates demonstrate risks similar to other transcutaneous implants, with a low predicted explantation (0.11%, 95% CI 0.00%-1.90%) and wound infection rate (1.92% [95% CI 0.00%-6.17%]). No articles directly comparing transcutaneous devices were identified.

CONCLUSION

The Osia devices demonstrate clear audiologic benefits and a good safety profile for the included patient population. Our study results indicate that frequency-specific gain, PROMs, and the audiological benefit in single-sided deafness may be areas for future prospective research. Laryngoscope, 134:1531-1539, 2024.

Molecular Factors in Carcinoma Ex Pleomorphic Adenoma: Systematic Review and Meta-Analysis

OBJECTIVE

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignant salivary gland tumor. Although multiple reviews have been published on salivary gland malignancies, it has been a decade since the last dedicated systematic review pertaining to CXPA alone was published. This study examines molecular factors in CXPA diagnosis.

DATA SOURCES

MEDLINE, CINAHL, Embase, Scopus, Web of Science (BIOSIS), Cochrane CENTRAL, Health Collection (Informit), OpenDOAR, and GreyNet International.

REVIEW METHODS

Systematic review and meta-analysis from inception to October 31, 2022 for all English language studies pertaining to "carcinoma ex pleomorphic adenoma." Predicted incidence of each biomarker was calculated with meta-analysis. Comparison against pleomorphic adenoma (PA) and salivary duct carcinoma (SDC) when reported within the same study are performed. Risk of bias performed with JBI tool for prevalence studies.

RESULTS

Of 19151 unique studies undergoing abstract screening, 55 studies (n = 1322 patients) underwent data analysis. Biomarkers with >3 studies were p53, HER2, AR, EGFR, PLAG1, ERBB, ER, PR, HMGA2, p16, p63, a-SMA, RAS, PTEN, PDL1, BRAF, PIK3CA, and c-kit. Highest incidence was seen in AR, EGFR, p16, and p53. Significant differences were demonstrated compared with PA and SDC. There was high heterogeneity and overall high risk of bias within studies.

CONCLUSION

Molecular factors are an area of interest in the diagnosis of CXPA. Our study results support examining CXPA as a discrete cohort in future targeted therapy trials. Laryngoscope, 134:1042-1053, 2024.

Risk of malignancy in incidental oropharyngeal lesions exhibiting fluorodeoxyglucose uptake which proceed to tissue biopsy

BACKGROUND

Utilization of positron emission tomography/computed tomography (PET/CT) with fluorodeoxyglucose is increasing in use for a variety of indications, including surveillance of cancer patients. There is a paucity of evidence pertaining to the significance of incidental PET-avid oropharyngeal lesions. This study aims to examine the clinical and radiological features of these incidental oropharyngeal lesions in patients undergoing PET for indications other than head and neck cancer.

METHODS

Retrospective cohort study of three Australian tertiary hospitals, from 2015 to 2021, on adult patients undergoing biopsy of incidental PET-avid oropharyngeal lesions. Primary outcome of interest was the incidence of malignancy. Patients with a previous history of, or undergoing investigations for, head and neck cancer were excluded.

RESULTS

Thirty-one patients were included, wherein 21 patients had tonsillar uptake, and 13 patients had base of tongue uptake. Tonsillar disease was mostly asymmetrical (n = 15/21), bilateral (n = 11/21), and had median SUVmax 9.35 (n = 12, IQR 7.4-11.15). Base of tongue was mostly asymmetrical (n = 7/13, 54%), bilateral (n = 8/13, 62%), and had median SUVmax 8.2 (n = 10, IQR 6.9-12.65). Seven patients had malignancy confirmed on tissue biopsy: five biopsies confirmed the tissue diagnosis of suspected lymphoma, and two incidental findings of unexpected malignancies: one p16 positive tonsillar squamous cell carcinoma, and one metastatic breast cancer.

CONCLUSION

In 31 patients undergoing tissue biopsy for incidental PET-avid oropharyngeal lesions, there were two unexpected malignancies. Our study results indicate that although unexpected malignancies are uncommon, a malignant diagnosis cannot be excluded from clinical features alone.

Systematic Review of Intracochlear Measurements and Effect on Postoperative Auditory Outcomes after Cochlear Implant Surgery

OBJECTIVE

Quality and adequacy of the electrode neuron interface (ENI) is postulated to be a determining factor in affecting auditory outcomes after cochlear implantation. This study aims to review radiological parameters affecting ENI, including angular insertion (AngI), wrapping factor (WF), scalar translocation (ScaT), and electrode-modiolar distance (EMD) and their effect on auditory outcomes.

DATABASES REVIEWED

PubMed, MEDLINE, Embase, Scopus, OpenGrey, and Google Scholar from inception to 01 September 2022.

METHODS

Inclusion criteria were (i) all humans with any cochlear implant (CI); (ii) postoperative cross-sectional imaging with electrode position factors of AngI, ScaT, EMD, and/or WF; and (iii) associated auditory outcomes. Search was restricted to English-language literature. Two independent reviewers performed title and abstract screening, data extraction, and ROBINS-I risk of bias assessment. Formal statistical analysis not performed due to data heterogeneity. PROSPERO (CRD42022359198).

RESULTS

Thirty-one studies (n = 2,887 patients, 3,091 electrodes) underwent qualitative synthesis. Higher AngI (n = 1921 patients) demonstrated positive correlation in 11 studies, no correlation in eight studies, and negative correlation in four studies. ScaT (n = 2,115 patients) demonstrated negative correlation in 12 studies, none in six studies, and one unclear correlation. Larger EMD (n = 240 patients) showed negative correlation in two studies, no correlation in one, and unclear correlation in one study. Smaller WF (n = 369 patients) demonstrated no correlation in three studies and positive correlation in one study.

CONCLUSIONS

Our study finds variable reported relationship between AngI and auditory outcomes. CI electrodes with a ScaT or larger EMD are more likely to exhibit poorer outcomes, and WF does not correlate with outcomes.

A Deep Learning Algorithm to Identify Anatomical Landmarks on Computed Tomography of the Temporal Bone

BACKGROUND

Petrous temporal bone cone-beam computed tomography scans help aid diagnosis and accurate identification of key operative landmarks in temporal bone and mastoid surgery. Our primary objective was to determine the accuracy of using a deep learning convolutional neural network algorithm to augment identification of structures on petrous temporal bone cone-beam computed tomography. Our secondary objective was to compare the accuracy of convolutional neural network structure identification when trained by a senior versus junior clinician.

METHODS

A total of 129 petrous temporal bone cone-beam computed tomography scans were obtained from an Australian public tertiary hospital. Key intraoperative landmarks were labeled in 68 scans using bounding boxes on axial and coronal slices at the level of the malleoincudal joint by an otolaryngology registrar and board-certified otolaryngologist. Automated structure identification was performed on axial and coronal slices of the remaining 61 scans using a convolutional neural network (Microsoft Custom Vision) trained using the labeled dataset. Convolutional neural network structure identification accuracy was manually verified by an otolaryngologist, and accuracy when trained by the registrar and otolaryngologist labeled datasets respectively was compared.

RESULTS

The convolutional neural network was able to perform automated structure identification in petrous temporal bone cone-beam computed tomography scans with a high degree of accuracy in both axial (0.958) and coronal (0.924) slices (P < .001). Convolutional neural network accuracy was proportionate to the seniority of the training clinician in structures with features more difficult to distinguish on single slices such as the cochlea, vestibule, and carotid canal.

CONCLUSION

Convolutional neural networks can perform automated structure identification in petrous temporal bone cone-beam computed tomography scans with a high degree of accuracy, with the performance being proportionate to the seniority of the training clinician. Training of the convolutional neural network by the most senior clinician is desirable to maximize the accuracy of the results.

A Computer Vision Algorithm to Classify Pneumatization of the Mastoid Process on Temporal Bone Computed Tomography Scans

BACKGROUND

Pneumatization of the mastoid process is variable and of significance to the operative surgeon. Surgical approaches to the temporal bone require an understanding of pneumatization and its implications for surgical access. This study aims to determine the feasibility of using deep learning convolutional neural network algorithms to classify pneumatization of the mastoid process.

METHODS

De-identified petrous temporal bone images were acquired from a tertiary hospital radiology picture archiving and communication system. A binary classification mode in the pretrained convolutional neural network was used to investigate the utility of convolutional neural networks in temporal bone imaging. False positive and negative images were reanalyzed by the investigators and qualitatively assessed to consider reasons for inaccuracy.

RESULTS

The overall accuracy of the model was 0.954. At a probability threshold of 65%, the sensitivity of the model was 0.860 (95% CI 0.783-0.934) and the specificity was 0.989 (95% CI 0.960-0.999). The positive predictive value was 0.973 (95% CI 0.904-0.993) and the negative predictive value was 0.935 (95% CI 0.901-0.965). The false positive rate was 0.006. The F1 number was 0.926 demonstrating a high accuracy for the model.

CONCLUSION

The temporal bone is a complex anatomical region of interest to otolaryngologists. Surgical planning requires high-resolution computed tomography scans, the interpretation of which can be augmented with machine learning. This initial study demonstrates the feasibility of utilizing machine learning algorithms to discriminate anatomical variation with a high degree of accuracy. It is hoped this will lead to further investigation regarding more complex anatomical structures in the temporal bone.

Convolutional Neural Networks in ENT Radiology: Systematic Review of the Literature

INTRODUCTION

Convolutional neural networks (CNNs) represent a state-of-the-art methodological technique in AI and deep learning, and were specifically created for image classification and computer vision tasks. CNNs have been applied in radiology in a number of different disciplines, mostly outside otolaryngology, potentially due to a lack of familiarity with this technology within the otolaryngology community. CNNs have the potential to revolutionize clinical practice by reducing the time required to perform manual tasks. This literature search aims to present a comprehensive systematic review of the published literature with regard to CNNs and their utility to date in ENT radiology.

METHODS

Data were extracted from a variety of databases including PubMED, Proquest, MEDLINE Open Knowledge Maps, and Gale OneFile Computer Science. Medical subject headings (MeSH) terms and keywords were used to extract related literature from each databases inception to October 2020. Inclusion criteria were studies where CNNs were used as the main intervention and CNNs focusing on radiology relevant to ENT. Titles and abstracts were reviewed followed by the contents. Once the final list of articles was obtained, their reference lists were also searched to identify further articles.

RESULTS

Thirty articles were identified for inclusion in this study. Studies utilizing CNNs in most ENT subspecialties were identified. Studies utilized CNNs for a number of tasks including identification of structures, presence of pathology, and segmentation of tumors for radiotherapy planning. All studies reported a high degree of accuracy of CNNs in performing the chosen task.

CONCLUSION

This study provides a better understanding of CNN methodology used in ENT radiology demonstrating a myriad of potential uses for this exciting technology including nodule and tumor identification, identification of anatomical variation, and segmentation of tumors. It is anticipated that this field will continue to evolve and these technologies and methodologies will become more entrenched in our everyday practice.

Does intra-operative humidification with warmed CO2 reduce surgical site infection in open colorectal surgery? A randomized control trial

BACKGROUNDS

Surgical site infections (SSI) are a significant cause of postoperative morbidity and mortality, contributing to a considerable financial burden on the healthcare system. Insufflation of the open surgical wound with warm, humidified carbon dioxide (CO₂ ) is a novel measure aimed to reduce SSI. The local atmosphere of warm, humidified CO₂ within the open surgical wound is proposed to decrease airborne contamination, bacterial growth, desiccation, and heat loss while improving tissue oxygenation and perfusion. This randomized controlled trial evaluates the impact of the HumiGard™ surgical humidification system on the incidence of SSI in patients undergoing open colorectal surgery.

METHODS

We conducted a multi-site single-blinded randomized control trial on patients undergoing elective or emergency laparotomy at a single tertiary Colorectal Surgery service. The primary outcome measure was the incidence of SSI, with secondary outcomes including ICU length of stay (LOS), total LOS and mean core temperature.

RESULTS

Patients who received HumiGard™ had a lower incidence of SSI, although this did not reach statistical significance (4.5% for treatment group versus 13.0% for control group; P = 0.092). There was no significant difference in ICU LOS or total LOS between cohorts. The HumiGard™ group had a higher mean core temperature than the control at the end of surgery (P < 0.001).

CONCLUSION

The present study could not confirm that utilization of warm, humidified CO2 with HumiGard™ reduces SSI in open colorectal surgery. Further research is indicated to validate and extend these findings.

Cost-minimisation analysis of polysomnography and pulse oximetry in a risk stratification protocol for paediatric adenotonsillectomy

BACKGROUND

Severe obstructive sleep apnoea (OSA) is associated with increased risk of respiratory compromise in the post-operative period following adenotonsillectomy (AT). This study analyses the economic cost of polysomnography or overnight oximetry as part of pre-operative risk stratification in paediatric AT, supplementing previously published research demonstrating the efficacy of this protocol in predicting respiratory complications.

METHODS

This cost-minimisation analysis examines costs associated with pre-operative overnight oximetry and polysomnography in triaging paediatric patients older than 2 years old, with no major comorbidities except for OSA, undergoing AT for OSA (n = 1801) to either a secondary or quaternary Australian hospital. Decision analysis modelling via probability trees were utilized to estimate pre- and peri-operative costs. A third hypothetical 'no investigation' model based upon conducting all AT at a secondary hospital was performed. Costs are derived from the financial year 2020-2021, censored at discharge.

RESULTS

The total cost per patient of AT including pre-operative investigations of oximetry and polysomnography, and associated inpatient costs, were AUD4181.34 and 5013.99 respectively. This is more expensive compared to a hypothetical no-investigation model (AUD3958.98).

CONCLUSION

Within the scope of this partial economic evaluation, this study finds a small additional cost for a model of care involving overnight oximetry as a pre-operative triage tool, balanced by the reduced cost of care in a lower acuity centre for low-risk patients and potential high cost of complications if all children are treated in a low acuity centre. This supports oximetry in peri-operative risk stratification for paediatric AT from a financial perspective.

Paediatric tonsillectomy and adenotonsillectomy in a rural setting: a retrospective study over a period of 6-years

BACKGROUND

Swan Hill District Health (SHDH) provides Otolaryngological services to outer regional Victoria. A preoperative checklist determines eligibility for tonsillectomy, and the role of preoperative investigations such as oximetry. Visiting specialists who provide T&A also remain on-site for 24 h post-surgery. Management of post-discharge complications is supported by SHDH's Emergency Department. Unstable patients are transferred to tertiary care hospitals. This study examines the safety outcomes associated with rural Tonsillectomy and adenotonsillectomy (T&A) and the impact of peri-operative protocols on these outcomes.

METHODS

This is a retrospective cohort study of all paediatric (2-18 years old) patients undergoing T&A from August 2014 to June 2020 at SHDH. Four external hospital databases which accept patient transfers from SHDH were searched for T&A-related complications. The primary outcome was complication incidence. Secondary outcomes were length of stay, and rates of hospital readmissions, return to theatre and inter-hospital transfer.

RESULTS

Two hundred and four patients were included, with median age 6 years old; 68.1% (n = 139/204) had obstructive sleep apnoea, or sleep disordered breathing, wherein 36.0% (n = 50/139) had documented evidence of normal/inconclusive oximetry. The complication rate is 6.9% (n = 14/204), with two intraoperative, five perioperative and seven post-discharge complications. All intra- and peri-operative complications were managed locally. All post-discharge complications presented to outer regional EDs. Two patients required inter-hospital transfer for monitoring of post-tonsillectomy bleeds in a specialist unit.

CONCLUSIONS

Patients who pass a preoperative risk checklist can safely undergo T&A in selected rural settings which adhere to strict patient selection criteria and implement safety measures to address complications.

Systematic review and meta-analysis of cervical metastases in oral maxillary squamous cell carcinoma

Background

Management of the node‐negative neck in oral maxillary squamous cell carcinoma (SCC), encompassing the hard palate and upper alveolar subsites of the oral cavity, is controversial, with no clear international consensus or recommendation regarding elective neck dissection in the absence of cervical metastases.

Aim

To assess the occult metastatic rate in patients with clinically node negative oral maxillary SCC; both as an overall metastatic rate, and a comparison of patients managed with an elective neck dissection at index surgery, compared to excision of the primary with clinical observation of the neck.

Methods and results

A systematic review was performed by two independent investigators for studies relating to oral maxillary SCC and analysed according to PRISMA criteria. Data were extracted from Pubmed, Ovid MEDLINE, EMBASE, and SCOPUS via relevant MeSH terms. Grey literature was searched through Google Scholar and OpenGrey. Five hundred and fifty‐three articles were identified on the initial search, 483 unique articles underwent screening against eligibility criteria, and 29 studies were identified for final data extraction. Incidence of occult metastases in patients with clinically node negative oral maxillary SCC was identified either on primary elective neck dissection or on routine follow up. Meta‐analyses were performed. Of 553 relevant articles identified on initial search, 29 were included for analysis. The pooled overall rate of occult metastases in patients initially presenting with clinically node‐negative disease was 22.2%. There is a statistically significant effect of END on decreasing regional recurrence demonstrated in this study (RR 0.36, 95% CI 0.24, 0.59).

Conclusion

The results of this systematic review and meta‐analysis suggest elective neck dissection for patients presenting with hard palate or upper alveolar SCC, even in a clinically node negative neck.

The role of methadone in cancer-induced bone pain: a retrospective cohort study

PURPOSE

Cancer-induced bone pain (CIBP) can be challenging to manage in advanced cancer. The unique properties of methadone may have a role in refractory CIBP. We aimed to evaluate the analgesic effects of methadone for CIBP when other opioids are ineffective or intolerable.

METHODS

A retrospective study of palliative care inpatients rotated to methadone from another opioid for CIBP over a 4-year period. Primary outcome was ≥ 30% reduction in pain intensity (11-point numeric rating scale) from baseline to completion of methadone rotation (MR). Secondary outcomes were ≥ 50% reduction in pain intensity and changes in long-acting and breakthrough opioid requirements.

RESULTS

Ninety-four eligible patients completed MR for the following reasons: poor pain control (72.3%), opioid toxicities (4.3%) or both (23.4%). On completion of MR, 70.2% and 53.2% achieved a ≥ 30% and ≥ 50% reduction in pain respectively, with mean pain intensity score reduced from 5.6 (SD = 2.1) at baseline to 2.6 (SD = 2.5) (p < 0.001). Mean calculated daily methadone dose pre-MR was 25.7 mg (SD = 10.9), with 72.3% of patients requiring a lower dose on completion of MR (mean 17.0 mg, SD = 8.5). The mean number of breakthrough opioid analgesia used a day reduced from 3.4 (SD = 2.3) to 1.8 (SD = 1.7) (p < 0.001).

CONCLUSIONS

MR for CIBP may result in reduction in pain intensity, when other opioids are ineffective or intolerable, with patients requiring reduced overall dosing of their long-acting opioid and frequency of breakthrough opioid use.

Pulmonary adverse events of small molecule JAK inhibitors in autoimmune disease: systematic review and meta-analysis

Objectives

Small molecule tyrosine kinase inhibitors [smTKI, comprising mostly of Janus kinase (JAK) and to a lesser extent, spleen tyrosine kinase (SyK) inhibitors] modulate the cytokine receptor-mediated intracellular signal cascade, and are an effective treatment for autoimmune diseases and malignancies. As smTKI are novel, long-term safety is uncertain. Due to increasing use, characterization of their true adverse event profile is critical.

Methods

We performed a systematic review and meta-analysis of all published trial data on the pulmonary and serious adverse effects of smTKIs in autoimmune disease. EMBASE, MEDLINE, CENTRAL and Pneumotox databases were searched up to April 2019 for randomized controlled trials, observational studies and post marketing surveillance, comparing any smTKI with placebo or another therapy, or as monotherapy at different doses. Primary outcomes comprised of any respiratory complications including upper and lower respiratory tract infections (URTI, LRTI), influenza, pneumonia, opportunistic respiratory infections, drug-induced interstitial lung disease, pulmonary embolism and lung neoplasm.

Results

We identified 4667 citations for screening, and selected 319 studies for full text review. Seventy-nine studies were analysed, including 47 randomized controlled trials, 25 observational studies and seven post-marketing surveillance studies, comprising 159 652 participants. There were significantly increased risks of URTI [risk difference (RD) 0.03; 95% CI: 0.01, 0.05; P = 0.00; 36 studies, 14 724 participants], LRTI (RD 0.01; 95% CI: 0.00, 0.02; P = 0.02; 24 studies, 12 302 participants), influenza (RD 0.01; 95% CI: 0.00, 0.01; P = 0.04; 22 studies, 10 684 participants), and pneumonia (RD 0.00; 95% CI: 0.00, 0.01; P = 0.02; 33 studies, 15 511 participants). No increased risk was found for other respiratory complications, including pulmonary embolism.

Conclusion

SmTKI increases the risk of non-opportunistic respiratory infections compared with placebo. The risk of any serious pulmonary adverse events is low.

Salvage reirradiation for local prostate cancer recurrence after radiation therapy. For who? When? How?

PURPOSE

Literature review reporting results of salvage brachytherapy and stereotactic body radiotherapy for prostate recurrence only after radiotherapy for prostate cancer.

MATERIALS AND METHODS

A total of 38 studies (including at least 15 patients per study) were analysed: 19 using low-dose-rate brachytherapy, nine high-dose-rate brachytherapy and ten stereotactic body radiotherapy. Only five studies were prospective. The median numbers of patients were 30 for low-dose-rate brachytherapy, 34 for high-dose-rate brachytherapy, and 30 for stereotactic body radiotherapy. The median follow-up were 47months for low-dose-rate brachytherapy, 36months for high-dose-rate brachytherapy and 21months for stereotactic body radiotherapy.

RESULTS

Late genitourinary toxicity rates ranged, for grade 2: from 4 to 42% for low-dose-rate brachytherapy, from 7 to 54% for high-dose-rate brachytherapy and from 3 to 20% for stereotactic body radiotherapy, and for grade 3 or above: from 0 to 24% for low-dose-rate brachytherapy, from 0 to 13% for high-dose-rate brachytherapy and from 0 to 3% for grade 3 or above (except 12% in one study) for stereotactic body radiotherapy. Late gastrointestinal toxicity rates ranged, for grade 2: from 0 to 6% for low-dose-rate brachytherapy, from 0 to 14% for high-dose-rate brachytherapy and from 0 to 11% for stereotactic body radiotherapy, and for grade 3 or above: from 0 to 6% for low-dose-rate brachytherapy, and from 0 to 1% for high-dose-rate brachytherapy and stereotactic body radiotherapy. The 5-year biochemical disease-free survival rates ranged from 20 to 77% for low-dose-rate brachytherapy and from 51 to 68% for high-dose-rate brachytherapy. The 2- and 3-year disease-free survival rates ranged from 40 to 82% for stereotactic body radiotherapy. Prognostic factors of biochemical recurrence have been identified.

CONCLUSION

Despite a lack of prospective data, salvage reirradiation for prostate cancer recurrence can be proposed to highly selected patients and tumours. Prospective comparative studies are needed.

Does lateral lift-off occur in static and dynamic activity in a medially spherical total knee arthroplasty? A pulsed-fluoroscopic investigation

Objectives

The medially spherical GMK Sphere (Medacta International AG, Castel San Pietro, Switzerland) total knee arthroplasty (TKA) was previously shown to accommodate lateral rollback while pivoting around a stable medial compartment, aiming to replicate native knee kinematics in which some coronal laxity, especially laterally, is also present. We assess coronal plane kinematics of the GMK Sphere and explore the occurrence and pattern of articular separation during static and dynamic activities.

Methods

Using pulsed fluoroscopy and image matching, the coronal kinematics and articular surface separation of 16 well-functioning TKAs were studied during weight-bearing and non-weight-bearing, static, and dynamic activities. The closest distances between the modelled articular surfaces were examined with respect to knee position, and proportions of joint poses exhibiting separation were computed.

Results

Overall, 1717 joint poses were analyzed. At a 1.0 mm detection threshold, 37 instances of surface separation were observed in the lateral compartment and four medially (p < 0.001). Separation was activity-dependent, both laterally and medially (p < 0.001), occurring more commonly during static deep flexion in the lateral compartment, and during static rotation in the medial compartment. Lateral separation occurred more frequently than medial during kneeling (7/14 lateral vs 1/14 medial; p = 0.031) and stepping (20/1022 lateral vs 0/1022 medial; p < 0.001). Separation varied significantly between individuals during dynamic activities.

Conclusion

No consistent association between closest distances of the articular surfaces and knee position was found during any activity. Lift-off was infrequent and depended on the activity performed and the individual knee. Lateral separation was consistent with the design rationale. Medial lift-off was rare and mostly in non-weight-bearing activities.

Cite this article: S. Key, G. Scott, J.G. Stammers, M. A. R. Freeman†, V. Pinskerova, R. E. Field, J. Skinner, S. A. Banks. Does lateral lift-off occur in static and dynamic activity in a medially spherical total knee arthroplasty? A pulsed-fluoroscopic investigation. Bone Joint Res 2019;8:207–215. DOI: 10.1302/2046-3758.85.BJR-2018-0237.R1.

Outcomes after early return to theatre following hip hemiarthroplasty for intracapsular fracture of the femoral neck

AIMS

Hip hemiarthroplasty is a standard treatment for intracapsular proximal femoral fractures in the frail elderly. In this study we have explored the implications of early return to theatre, within 30 days, on patient outcome following hip hemiarthroplasty.

PATIENTS AND METHODS

We retrospectively reviewed the hospital records of all hip hemiarthroplasties performed in our unit between January 2010 and January 2015. Demographic details, medical backround, details of the primary procedure, complications, subsequent procedures requiring return to theatre, re-admissions, discharge destination and death were collected.

RESULTS

A total of 705 procedures were included; 428 Austin Moore and 277 Exeter Trauma Stems were used. A total of 34 fractures (in 33 patients) required early return to theatre within 30 days. Age, gender, laterality, time from admission to primary procedure, American Society of Anesthesiologists grade, and implant type were similar for those requiring early return to theatre and those who did not. Early return to theatre was associated with a significantly higher length of stay (mean 33.6 days (7 to 107) versus 18.6 days (0 to 152), p < 0.001), re-admission rate (38.2% versus 8.6%, p < 0.001), and subsequent revision rate (17.6% versus 1.3%, p < 0.001). We found no difference in level of care required on discharge or mortality.

CONCLUSION

Proximal femoral fractures are common in the elderly population, with far-reaching medical and economic implications. Factors such as infection or dislocation may require early return to theatre, and this is associated with outcomes which may be both medically and economically detrimental. This illustrates the importance of avoiding early complications to improve longer term outcome. Return to theatre within 30 days is associated with longer length of stay, higher re-admission rate, and higher subsequent revision rate. It may be a useful short-term quality indicator for longer term outcome measures following hip hemiarthroplasty for intracapsular fractures of the proximal femur. Cite this article: Bone Joint J 2017;99-B:958-63.

Dispersed donor salivary gland cells are widely distributed in the recipient gland when infused up the ductal tree

The salivary glands often are severely and permanently damaged by therapeutic irradiation for cancer of the head and neck. The markedly reduced quantity and quality of saliva results in greatly increased susceptibility to dental caries and infection of the oral mucosa and alveolar bone. Recently, subcapsular injection of cultured mouse salivary gland cells has achieved a significant degree of regeneration in a previously irradiated mouse salivary gland; however, the recovery was limited to one lobule. We describe here a method for delivering donor rat salivary gland cells via the main duct that distributes several thousand cells throughout the recipient rat's salivary gland. The donated cells exhibited the cytodifferentiation of the structures in which they lodged, i.e., acini, granular convoluted tubules, and the several types of ducts. This method may facilitate the simultaneous functional recovery of almost all of the lobules of irradiated rat salivary glands.

Microbicides for HIV/AIDS. 3. Observation of apparent dynamic protonation and deprotonization in CD4+ T-cell model systems

New measurements of the electrophoretic mobility of T-cell model systems have been carried out and analyzed to obtain the dynamic variation in mobility in small titration increments during separate upscale and downscale sweeps in pH. We demonstrate that a plot of plambda vs p[NaCl] has been found essential in evaluating the consistency of electrophoretic mobility measurements at different (1:1) electrolyte concentrations and show, for the first time, that electrophoretic mobility measurements as a function of pH can reflect different rates of the respective ionization and association that occur in the surface functional groups as a consequence of the different changes in the hydration-dehydration reactions involved. Differences found between the upscale and downscale sweeps suggest that it is easier to protonate a protein cell surface than to deprotonate it. The effect is most pronounced at the highest salt concentration (similar to that which exists for the cells in their native state) and becomes less pronounced as the salt concentration is lowered. The effect is interpreted as a result of the different changes in the state of hydration as a proton moves from the bulk through the double layer to a surface group and the reverse. The effect occurs with both replicating and activated T-cells. This latter result may be of biological significance and particularly relevant to HIV-1 infection, since during male-to-female transmission, the environment where most infections occur supports this protonation effect.

Glucocorticoid modulation of tryptophan hydroxylase-2 protein in raphe nuclei and 5-hydroxytryptophan concentrations in frontal cortex of C57/Bl6 mice

Considerable attention has focused on regulation of central tryptophan hydroxylase (TPH) activity and protein expression. At the time of these earlier studies, it was thought that there was a single central TPH isoform. However, with the recent identification of TPH2, it becomes important to distinguish between regulatory effects on the protein expression and activity of the two isoforms. We have generated a TPH2-specific polyclonal antiserum (TPH2-6361) to study regulation of TPH2 at the protein level and to examine the distribution of TPH2 expression in rodent and human brain. TPH2 immunoreactivity (IR) was detected throughout the raphe nuclei, in lateral hypothalamic nuclei and in the pineal body of rodent and human brain. In addition, a prominent TPH2-IR fiber network was found in the human median eminence. We recently reported that glucocorticoid treatment of C57/Bl6 mice for 4 days markedly decreased TPH2 messenger RNA levels in the raphe nuclei, whereas TPH1 mRNA was unaffected. The glucocorticoid-elicited inhibition of TPH2 gene expression was blocked by co-administration of the glucocorticoid receptor antagonist mifepristone (RU-486). Using TPH2-6361, we have extended these findings to show a dose-dependent decrease in raphe TPH2 protein levels in response to 4 days of treatment with dexamethasone; this effect was blocked by co-administration of mifepristone. Moreover, the glucocorticoid-elicited inhibition of TPH2 was functionally significant: serotonin synthesis was significantly reduced in the frontal cortex of glucocorticoid-treated mice, an effect that was blocked by mifepristone co-administration. This study provides further evidence for the glucocorticoid regulation of serotonin biosynthesis via inhibition of TPH2 expression, and suggest that elevated glucocorticoid levels may be relevant to the etiology of psychiatric diseases, such as depression, where hypothalamic-pituitary-adrenal axis dysregulation has been documented.

Wedding rings are not a significant source of bacterial contamination following surgical scrubbing

INTRODUCTION

Despite some evidence that the wearing of rings may increase the microbial load, there is currently nothing to suggest that viable bacteria remain following a standard surgical scrub. The aim of the study was to examine the distribution and type of microbial flora seen on the hands of doctors following a standard surgical scrub.

MATERIALS AND METHODS

Ten surgeons and 10 anaesthetists, all of whom wore wedding rings on the fourth finger of their left hand, participated in the study. Each individual was asked to 'scrub-up' as for their normal first scrub of the day. Following completion of washing, the wedding ring was removed, its internal circumference swabbed and the swab placed in a culture medium. Volunteers placed each hand palm-down on separate agar plates. The plates were incubated and the number of colonies counted and classified.

RESULTS

The culture plates of one of the anaesthetists were damaged in transit leaving a total of 19 subjects for analysis. In all the palm imprint plates, coagulase-negative staphylococci were grown. One surgeon grew coagulase-negative staphylococci from the ring swab. A Candida spp. from the right hand of one surgeon was grown. There was no statistically significant difference between the number of colony-forming units (CFUs) cultured from the right and left (ring-wearing) hands of the surgeons (P = 0.260) and anaesthetists ( P = 0.345). There was no statistical difference in CFUs when surgeons were compared with anaesthetists (P = 0.383 for right hand and P = 0.234 for left).

CONCLUSIONS

This preliminary study would suggest that a traditional band wedding ring is not a source of a bacterial load following a standard surgical scrub procedure and, as such, there is no requirement for their removal pre-operatively.

Microbicides for HIV/AIDS. 2. Electrophoretic fingerprinting of CD4+ T-cell model systems

New measurements of the dependence of the surface charge on the pH and electrolyte concentration for three living human white blood cell lines that are the principal targets of the HIV-1 virus are reported. Comparison of the electrophoretic fingerprint (EF) pattern, especially the line of zero mobility, with that of reference colloids establishes the separate individual identities and shows that all three exhibit a zwitterionic surface. With the EF results as a guide, preliminary biological infectivity measurements showed that small polyvalent cations modulate the negative charge on the T-cell surface in a way that strongly affects the infection kinetics. H9 cells were exposed to an infectious virus (X4), and the data showed that HIV interaction with target cells is enhanced by physiological fluids. The nondestructive methodology described is generally applicable to characterization of the surface charge and determination of the colloidal stability of any aqueous charged colloidal system without reference to any model of the double layer.

Microbicides for HIV/AIDS. 1. Electrophoretic fingerprinting the H9 cell model system

An electrophoretic fingerprint of a CD4+ T-cell (H9) has been produced for the first time. Samples were taken from three separate cultures prepared at different times to obtain a general characterization of the cells. The availability of commercial instrumentation equipped with an auto-titrator has made possible the application of both the 2-dimensional and 3-dimensional representation of electrophoretic fingerprinting. The 2-dimensional treatment has been used to assess the reliability of the data and has detected hysteresis as a possible second-order effect. The 3-dimensional representation has been used to explore the data needed for a reliable overall pattern that characterizes the conditions of pH and conductivity required for an effective microbicide. The dome negative maximum in the electrophoretic fingerprint at high pH, along with the line of zero mobility (LZM) and a dome positive maximum at low pH, are interpreted as evidence for surface carboxyl groups prominent in the alkaline regime and surface amino groups prominent in the acid regime, suggesting that the H9 cell surface is zwitterionic. This has important implications as to the choice and design of microbicide actives.

Susceptibility of dopamine D5 receptor targeted mice to cysteamine

BACKGROUND

Recently we demonstrated that gastric mucosa of rats can synthesize, store and release dopamine. Out of five different subtypes, mRNA of D5 (=D1b) dopamine receptor is very abundant in the gastric epithelium. D1 receptor selective dopamine agonists have been shown to protect against experimental gastro-duodenal lesions.

AIMS

To test the hypothesis that protective effects of dopamine involve D5 receptors, mucosal lesions were induced in D5 receptor deficient (KO) and wild-type (WT) mice using cysteamine. Morphology and gastric acid secretion of D5 KO mice were also studied.

METHODS

Single doses of 600 mg/kg, 300 mg/kg cysteamine or vehicle were administered subcutaneously to fasted animals. After 24 h, number and severity of gastro-duodenal lesions were analyzed. Basal and histamine-induced maximal gastric acid output were measured by a stomach-sac wash-through method.

RESULTS

All the KOs in the 600 mg/kg cysteamine group died within 4 h showing symptoms of toxicity while three out of four WTs survived (P<0.05). Mortality after 300 mg/kg cysteamine was significantly higher in KOs versus the WTs: 6/14 versus 2/11, P<0.05. Gastric lesion-index was also significantly higher in KOs (median, middle quartile): four (3-9) versus 0 (0-0), P<0.05. Duodenal lesions did not develop from this single dose of cysteamine in either genotype. Basal and histamine-induced maximal gastric acid output were comparable in the two genotypes.

CONCLUSIONS

This study demonstrates that loss of D5 receptor causes mucosal vulnerability and increased toxicity of cysteamine in genetically manipulated mice. Thus, D5 receptor subtype is indeed likely to be involved in protective effects of dopamine in the stomach.

Two olfactory placode derived galanin subpopulations: luteinizing hormone-releasing hormone neurones and vomeronasal cells

In adult rodents, the peptide galanin is expressed in a subpopulation of hypothalamic luteinizing hormone-releasing hormone (LHRH) neurones in an activity-dependent manner. In this investigation, we examined whether galanin mRNA expression in mice was activated coincident with LHRH mRNA expression, as LHRH neurones differentiate from the olfactory placode. Using in situ hybridization, we show (i) that galanin mRNA is coexpressed in LHRH neurones prenatally, (ii) that there is a decrease in galanin mRNA expression relative to LHRH mRNA expression once LHRH mRNA positive/galanin mRNA positive neurones migrate out of the olfactory pit and into the nasal septum, and (iii) the presence of a novel population of galanin mRNA positive/LHRH mRNA negative expressing neurones in the olfactory pit/vomeronasal organ which do not migrate into the central nervous systenm (CNS). This study demonstrates that there are at least two populations of galanin mRNA expressing neurones arising from the olfactory placode; one that remains in nasal regions, is LHRH mRNA negative and whose function is unknown, and one which is coexpressed with LHRH. In addition, the temporal expression of galanin mRNA in LHRH cells indicates that initial activation and subsequent inactivation of galanin mRNA expression is independent of synaptic CNS connections.

Limited role of rodents as reservoirs of Borrelia burgdorferi sensu lato in Ireland

Despite the presence of Borrelia burgdorferi s.l.-infected Ixodes ricinus ticks in a west of Ireland location, very few small rodents from the same habitats were infected. Most of the infected ticks contained B. garinii or B. valaisiana, which implicates birds as the important reservoir hosts in this location.