An In Vitro Evaluation of Periotest Implant Stability Measurements Taken on Implant Retained Crowns and Healing Abutments.

OBJECTIVE: To assess the reliability of implant stability measurements recorded with the Periotest device and to investigate the differences in values when these measurements were taken on implant retained crowns and healing abutments. MATERIALS AND METHODS: Fifty-six implants in eight synthetic bone blocks were used to carry out implant stability measurements using the Periotest device by two different operators. Each block constituted an example of bone of density D1, D2, D3, or D4, and two blocks of each density were used. The healing abutments placed were of a height to allow approximately 6 mm of the implant-abutment complex to be supracrestal and temporary crowns were made to match the dimensions of an average central incisor. Descriptive statistics were used to describe the perio test values (PTVs) at each of the different heights on the implant abutments and implant crowns. Means for each site were calculated and distribution of data assessed using the Kruskal Wallis test. The interclass correlation coefficient (ICC) was used to determine the relationship between the PTVs recorded on the implant abutments and implant crowns. RESULTS: The mean PTV (±standard devidation) recorded across all sites was 5.57 ± 11.643 on the implant abutments, and 12.27 ± 11.735 on the temporary crowns. Excellent/good inter-operator ICCs were recorded for the mid-abutment site in all bone blocks D1-D4 (ICC = 0.814, p < 0.001, ICC = 0.922, p < 0.001, ICC = 0.938, p < 0.001, ICC = 776, p < 0.001). For mid crown sites, ICC between operators was excellent/good only for recordings in D2 bone (ICC = 0.897, p < 0.001). CONCLUSIONS: Periotest device seems to be able to reliably measure implant stability across all types of bones when the implant stability is assessed at approximately 3 mm coronal to the implant platform for abutments and 4.5 mm for implant supported single crowns.

An in vitro study evaluating the efficacy of a novel mount with torque control designed to tighten Osstell® transducers.

OBJECTIVES: To evaluate the efficacy of a novel mount with torque control for tightening of Osstell® transducers and to determine the reliability of recorded ISQ measurements from implants placed in various bone densities. MATERIAL AND METHODS: Fifty-six implants, comprising seven different implant types, were placed in eight polyurethane blocks representing D1, D2, D3, and D4 bone densities. Resonance frequency analysis (RFA) transducers were attached to each implant in four different ways: (a) hand tightening, (b) hand tightening with a SmartPeg Mount™, (c) hand tightening using the novel mount with torque control (SafeMount) and (d) tightening to 6 Ncm with a calibrated torque device. ISQ measurements were taken and a second operator repeated the measurements. Intraclass correlation coefficient (ICC) was calculated to assess the reliability of the measurements and linear mixed effects regression was employed to determine the effect explanatory variables had on ISQ values. RESULTS: There was a statistically significant difference in ISQ values obtained by hand tightening transducers compared to the calibrated torque device p < .001, 95%(-2.89, -1.21) but not between any other tightening methods. There was excellent agreement between the two RFA devices (ICC 0.986) and between buccal and mesial measurements (ICC 0.977). For all transducer tightening methods there was excellent inter-operator agreement in D1 and D2 (ICC > 0.8) but very poor agreement in D4 (ICC < 0.24). Bone density accounted for 36% of the variation in ISQ values, the implant for 11% and the operator for 6%. CONCLUSIONS: SafeMount, did not significantly improve the reliability of the RFA measurements when compared to the standard mount, but calibrated torque devices seem to have benefits when compared to tightening the transducers by hand. Results also indicate that the ISQ values should be interpreted with caution when measuring implant stability in poor quality bone regardless of the implant geometry.

Improving the metric of surgical freedom in the laboratory based on a novel concept of volume.

BACKGROUND: In laboratory-based neuroanatomical studies, surgical freedom, the most important metric of instrument maneuverability, has been based on Heron's formula. Inaccuracies and limitations hinder this study design's applicability. A new methodology, volume of surgical freedom (VSF), may produce a more realistic qualitative and quantitative representation of a surgical corridor. METHODS: Overall, 297 data set measurements assessing surgical freedom were completed for cadaveric brain neurosurgical approach dissections. Heron's formula and VSF were calculated specifically to different surgical anatomical targets. Quantitative accuracy and the results of an analysis of human error were compared. RESULTS: Heron's formula for irregularly shaped surgical corridors resulted in overestimation of the respective areas (minimum overestimation 31.3%). In 92% (188/204) of data sets reviewed for influence of offset, areas calculated on the basis of measured data points were larger than areas calculated on the basis of the translated best-fit plane points (mean [SD] overestimation of 2.14% [2.62%]). Variability in the probe length attributable to human error was small (mean [SD] calculated probe length 190.26 mm [5.57 mm]). CONCLUSIONS: VSF is an innovative concept that can develop a model of a surgical corridor producing better assessment and prediction of the ability to maneuver and manipulate surgical instruments. VSF corrects for deficits in Heron's method by generating the correct area for an irregular shape using the shoelace formula, adjusting the data points to account for offset, and attempting to correct for human error. VSF produces 3-dimensional models and, therefore, is a preferable standard for assessing surgical freedom.

Toward "bigger" data for neurosurgical anatomical research: a single centralized quantitative neurosurgical anatomy platform.

Quantitative neurosurgical anatomy research aims to produce surgically applicable knowledge for improving operative decision-making using measurements from anatomical dissection and tools such as stereotaxis. Although such studies attempt to answer similar research questions, there is little standardization between them, offering minimal comparability. Modern technology has been incorporated into the research methodology, but many scientific principles are lacking, and results are not broadly applicable or suitable for evaluating big-data trends. Advances in information technology and the concept of big data permit more accessible and robust means of producing valuable, standardized, reliable research. A technology project, "Inchin," is presented to address these needs for neurosurgical anatomy research. This study applies the concept of big data to neurosurgical anatomy research, specifically in quantifying surgical metrics. A remote-hosted web application was developed for computing standard neurosurgical metrics and storing measurement data. An online portal (Inchin) was developed to produce a database to facilitate and promote neurosurgical anatomical research, applying optimal scientific methodology and big-data principles to this recent and evolving field of research. Individual data sets are not insignificant, but a collective of data sets present advantages. Large data sets allow confidence in data trends that are usually obscured in smaller numbers of samples. Inchin, a single centralized software platform, can act as a global database of results of neurosurgical anatomy studies. A calculation tool ensuring standardized peer-reviewed methodology, Inchin is applied to the analysis of neurosurgical metrics and may promote efficient study collaboration within and among neurosurgical laboratories.

Campaign Disaster Response - What Makes It Different.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has seen health systems adapt and change in response to local and international experiences. This study describes the experiences and learnings by the Central Adelaide Local Health Network (CALHN) in managing a campaign style, novel public health disaster response. METHODS: Disaster preparedness has focused on acute impact, mass casualty incidents. In early 2020, CALHNs largest hospital the Royal Adelaide Hospital (RAH) was appointed as the state primary COVID-19 adult receiving hospital. Between the period of February 1, 2020, when the first COVID-19 positive patient was admitted, through to December 31, 2020, the RAH had admitted 146 inpatients with COVID-19, 118 admitted to our hospital in the home service, 18 patients admitted to Intensive Care, and 4 patients died while inpatients. During this time CALHN has sustained an active (physical and virtual) Network Incident Command Centre (NICC) supported by a Network Incident Management Team (NIMT). RESULTS: This study describes our key lessons learnt in relation to the management of a campaign style disaster response including the importance of disaster preparedness, fatigue management, and communication. Also described, were the challenges of operating in a command model and the role of exercising and education and an overview of our operating rhythm, how we built capability, and lessons management. CONCLUSIONS: Undertaking a longer duration disaster response, relating to the COVID-19 pandemic has shown that, although traditional disaster principles still are important, there are many nuances that need to be considered to retain a proportionate response. Our key lessons have revolved around the key tenants of disaster management, communication, capability, and governance.

Volumetric 3-Dimensional Analysis of the Supraorbital vs Pterional Approach to Paramedian Vascular Structures: Comprehensive Assessment of Surgical Maneuverability.

BACKGROUND: Both the pterional and supraorbital approaches have been proposed as optimal access corridors to deep and paramedian anatomy. OBJECTIVE: To assess key intracranial structures accessed through the surgical approaches using the angle of attack (AOA) and the volume of surgical freedom (VSF) methodologies. METHODS: Ten pterional and 10 supraorbital craniotomies were completed. Data points were measured using a neuronavigation system. A comparative analysis of the craniocaudal AOA, mediolateral AOA, and VSF of the ipsilateral paraclinoid internal carotid artery (ICA), terminal ICA, and anterior communicating artery (ACoA) complex was completed. RESULTS: For the paraclinoid ICA, the pterional approach produced larger craniocaudal AOA, mediolateral AOA, and VSF than the supraorbital approach (28.06° vs 10.52°, 33.76° vs 23.95°, and 68.73 vs 22.59 mm3 normalized unit [NU], respectively; P < .001). The terminal ICA showed similar superiority of the pterional approach in all quantitative parameters (27.43° vs 11.65°, 30.62° vs 25.31°, and 57.41 vs 17.36 mm3 NU; P < .05). For the ACoA, there were statistically significant differences between the results obtained using the pterional and supraorbital approaches (18.45° vs 10.11°, 29.68° vs 21.01°, and 26.81 vs 16.53 mm3 NU; P < .005). CONCLUSION: The pterional craniotomy was significantly superior in all instrument maneuverability parameters for approaching the ipsilateral paraclinoid ICA, terminal ICA, and ACoA. This global evaluation of 2-dimensional and 3-dimensional surgical freedom and instrument maneuverability by amalgamating the craniocaudal AOA, mediolateral AOA, and VSF produces a comprehensive assessment while generating spatially and anatomically accurate corridor models that provide improved visual depiction for preoperative planning and surgical decision-making.

Volume of Surgical Freedom: The Most Applicable Anatomical Measurement for Surgical Assessment and 3-Dimensional Modeling.

Surgical freedom is the most important metric at the disposal of the surgeon. The volume of surgical freedom (VSF) is a new methodology that produces an optimal qualitative and quantitative representation of an access corridor and provides the surgeon with an anatomical, spatially accurate, and clinically applicable metric. In this study, illustrative dissection examples were completed using two of the most common surgical approaches, the pterional craniotomy and the supraorbital craniotomy. The VSF methodology models the surgical corridor as a cone with an irregular base. The measurement data are fitted to the cone model, and from these fitted data, the volume of the cone is calculated as a volumetric measurement of the surgical corridor. A normalized VSF compensates for inaccurate measurements that may occur as a result of dependence on probe length during data acquisition and provides a fixed reference metric that is applicable across studies. The VSF compensates for multiple inaccuracies in the practical and mathematical methods currently used for quantitative assessment, thereby enabling the production of 3-dimensional models of the surgical corridor. The VSF is therefore an improved standard for assessment of surgical freedom.