Trainee Operators Research Articles

Trauma and orthopaedic higher specialty trainee operating during the COVID-19 pandemic

Trauma and orthopaedic higher specialty trainee operating during the COVID-19 pandemic

Virtual reality-based bioreactor digital twin for operator training

The use of immersive technologies and digital twins can enhance training and learning outcomes in various domains. These technologies can reduce the cost and risk of training and improve the retention and transfer of knowledge by providing feedback in real-time. In this paper, a novel virtual reality (VR) based Bioreactor simulation is developed that covers the set-up and operation of the process. It allows the trainee operator to experience infrequent events, and reports on the effectiveness of their response. An embedded complex simulation of the bioreaction effectively replicates the impact of operator decisions to mimic the real-world experience. The need to train and assess the skills acquired aligns with the requirements of manufacturing in a validated environment, where proof of operator capability is a prerequisite. It has been deployed at UK’s National Horizons Center(NHC) to train the trainees in biosciences.

The Benefits of Promoting Junior Trainees in Vascular Surgery.

Introduction United Kingdom surgical training consists of a two-year core surgical training (CST) followed by a six-year higher speciality training (ST). There is a significant step up in responsibility and operative skills when transitioning from core to higher training. One-way trainees can bridge this gap is to "act up" to registrar level "CST-R."The CST "steps up" to the role of ST typically in the latter part of their core trainingand gains exposure at being the "reg of the week," primary assistant in theatre, managing MDTs, and taking speciality referrals. This can be an excellent training opportunity. This study aims to demonstrate a quantitative improvement in trainee operation as a result of stepping up. Methods This study compares the operative experience of one vascular surgery-themed trainee during six months as a CST and six months acting up as a CST-R.The trainee's eLogbook was searched for all operations between August 3, 2022, and January 31, 2023, and between February 1, 2023, and August1, 2023. The number of cases performed and the role played in each were analyzed.The number of low complexity cases conducted in each block was used as a baseline to ensure the progression seen was because of increasingly complex ST operating rather than the increase in CST level operating expected throughout CST. An abscess incision and drainage were used as the reference low-complexity case. Results The number of cases the trainee performed independently increased from 13% to 25%, while the number where they were simply assisting decreased from 43% to 35%. The number of cases where the trainer remained scrubbed decreased nonsignificantly from 43% to 39%. The number of low-complexity cases performed remained unchanged for each six-month block. Conclusion As a CST-R, the trainee played a more prominent operative role in a greater number of cases. The CST-R does require a supportive department and consultant body. It also enables other STs to gain more surgical exposure because of their reduced frequency of being the "reg of the week." If a trainee can remain in a post for two six-month blocks, then there is much to be gained from a formalised acting-up program, and consideration should be given to formally incorporating this into core surgical programs.

A Bilateral Teleoperation System With Learning-Based Cognitive Guiding Force

This article investigates the problem involving a fuzzy logic system-based bilateral teleoperation system with a unified impedance/admittance structure and learning-based assisted cognitive guiding force, enhancing a smooth transition between augmentation and autonomous motion on the master side. The impedance structure regulates the impedance and admittance via the parameters determined by the fuzzy logic system and, besides the variable impedance during interaction with the environment, the fuzzy Q-learning algorithm generates an assisted cognitive guiding force to guide the trainee operator in free space for reaching the interaction surface smoothly and steadily. The degeneration of tracking performance in the bilateral teleoperation system caused by time delay is analyzed and reduced via a mixed-type error. Experimental results verify the stability analyses, and under the proposed control scheme, the human-robot-environment interaction is smooth and stable.

Evaluation of the operator learning curve for radiofrequency ablation for atrioventricular nodal reentrant tachycardia

Aim The aim of this study was to determine the average minimum number of slow pathway ablation procedures required to reach a steady success rate among inexperienced operators.Material and Methods We analyzed the consecutive AVNRT ablation procedures of three inexperienced operators for the rate of operational success and complications.Results Operators performed a total of 156 AVNRT ablation procedures. There was no statistical significance between the three operators regarding the rate of success (p=0.69) and complications. There were significant differences between the operators in terms of procedure time, fluoroscopy time, and cumulative air kerma. The variability of procedure time and cumulative air kerma, both among three operators and within each operator, decreased significantly after the 25th case. Each operator was analyzed individually for the probability of success as related to the cumulative number of ablations. All trainee operators reached a success rate of 90 % at the 27th procedure.Conclusion An average of 27 slow pathway ablation procedures should be performed by a beginner operator to achieve proficiency.

The Design and Demonstrative Analysis of the Gas Turbine Operation’s Simulator

The Gas Turbine operation was investigated with a view to evolving a system designed to provide a realistic imitation of the controls and operation of a Gas Turbine, used for training purposes. Operator Training Simulator has been widely adopted by many industries being a computer simulation which attempts to model a real-life plant so that it can be studied. A well trained and skilled operator is key in increasing power plant safety and productivity. Therefore, enabling quality training for operators is becoming more important as they need to handle increased load of information and duties whereas the lack of training is a major reason for inadequate performance. By changing variables in the simulator, predictions are made about the behaviour of the engine. It is a tool to virtually investigate the behaviour of the system while in operation. This work becomes indispensable because it is prohibitively expensive or simply too dangerous to allow trainees use the real equipment in a power plant. The Gas Turbine operation’s simulator is born from Object Oriented Programming, employing key programming languages. The simulator design focused on specific tasks in the operation of the Gas Turbine which include; startup, synchronization and monitoring of vital parameters like vibration, temperature, pressure, and angle of the Inlet Guide Vane. The statuses of various valves, pumps and motors as well as the Performance of actuators and the response of concatenated components are also being tracked. The simulator was found to effectively mimic a real plant life. With this simulator, trainee operators in Gas Turbine can spend time learning valuable lessons in a "safe" virtual environment yet living a lifelike experience. This will go a long way in minimizing operators’ error in GT power plants, thereby curtailing power outages and conserving power plant components.

Orthodontic Rubber Band-Assisted Endoscopic Submucosal Dissection: An Efficient Method for Treating Superficial Colorectal Tumors.

Background Colorectal endoscopic submucosal dissection (ESD) is a complex operation. Effective traction is crucial. We have successfully used an orthodontic rubber band (ORB) combined with the clip traction method to assist ESD (ORB-ESD). The aim of this retrospective study is to describe the method and to compare the efficacy and safety of ORB-ESD versus conventional ESD in the treatment of superficial colorectal tumors. Methods We retrospectively analyzed the data of patients with superficial colorectal tumor (with diameter ≥ 20 mm) who received either ORB-ESD (n = 34) or conventional ESD (n = 90) between January 2019 and September 2020. Propensity score matching (PSM) was used to match the clinical data of 31 pairs of patients in each group. Results Operation time was significantly shorter for ORB-ESD than for conventional ESD (34.5 minutes vs. 56 minutes, P ≤ 0.001). In the propensity-matched cohorts, the operation time remained significantly shorter in the ORB-ESD patients (35 minutes vs. 50 minutes, P = 0.001). Postoperative adverse events, en bloc resection rate, and R0 resection rate were comparable between the two groups (P > 0.05), both before and after propensity score matching. In the ORB subgroup analysis, the trainee and expert ESD operation times were similar (37 (26–53) vs. 33.5 (26–37) minutes, respectively; P = 0.274). Conclusion ORB-ESD appears to be an effective technique for ESD of colorectal cancer. Our findings need to be confirmed in large prospective multicenter studies.

SP10.2.8 Trainee led Emergency Laparotomy operating; does it impact on outcomes?

Abstract Introduction To achieve completion of training in general surgery, trainees are required to demonstrate competency in common procedures performed at Emergency Laparotomy (Em Lap). We describe the patterns of trainee led emergency laparotomy operating and the association between post-operative outcomes. Methods All patients who had an Em Lap were extracted from the National Emergency Laparotomy Audit database from December 2013 to November 2017. Patients were grouped by grade of operative surgeon; trainee (speciality registrar) or Consultant (including Post Certificate of Completion (CCT) fellows). Trends in trainee operating by education deanery, hospital size and time of day of surgery were investigated. Adjusted regression analysis for the outcomes of 90-day mortality and return to theatre in operative subgroups of segmental colectomy, Hartmann's procedure, adhesiolysis and repair of perforated peptic ulcer disease were performed. Results The study cohort contained 95 520 patients. There were no increased odds of death by 90 days or of return to theatre across any of the operative groups when a trainee was listed as the most senior surgeon present in theatre. Trainees were more likely to operate independently in the Welsh deanery, high volume centres and at night (all P < 0.001). Conclusion There is significant variation in trainee led operating in Em Lap cases by deanery, hospital size and by time of day. However, this involvement in cases required for CCT in general surgery does not appear to impact on mortality or return to theatre in patients when adjusting for various pre-operative features.

Equilibrium radionuclide angiography: Intra- and inter-observer repeatability and reproducibility in the assessment of cardiac systolic and diastolic function

BackgroundThis study aimed to assess intra- and inter-observer agreement in assessing the systolic and diastolic function with equilibrium radionuclide angiography (ERNA). Materials and methodsThirty-two adults underwent baseline and repeat ERNA. An experienced and a trainee operator analyzed the data by assigning regions of interest manually, fully automatically, and semi-automatically. The Bland-Altman statistic (mean ± 1.96 standard deviations of the differences) was used to assess the repeatability (two different assessments of a single acquisition) and reproducibility (assessments of two different acquisitions). ResultsUsing the semi-automated technique the intraobserver repeatability and reproducibility of left ventricular ejection fraction for the experienced physician were − 0.1 ± 3.7 and 0.0 ± 3.8 and for the trainee 2.2 ± 10.6 and 1.9 ± 8.4, respectively. The inter-observer repeatability and reproducibility were − 1.8 ± 6.4 and 0.4 ± 9.0, respectively. Among the parameters of diastolic function, the intraobserver repeatability and reproducibility of the peak filling rate for the experienced physician were − 0.0 ± 1.1 and − 0.1 ± 1.1 and for the trainee 0.2 ± 3.5 and 0.4 ± 3.7, respectively. The inter-observer repeatability and reproducibility were 0.3 ± 1.5 and 0.5 ± 4.0, respectively. Similar was the pattern for the other diastolic indices. In all cases the limits of agreement varied according to the quantification approach. ConclusionA good repeatability but a moderate reproducibility was found in the assessment of the LVEF. Less good were the findings in the assessment of diastolic function.

Assistant skill in gastric endoscopic submucosal dissection using a clutch cutter.

BACKGROUNDA clutch cutter is a scissor-type knife used in endoscopic submucosal dissection (ESD) for gastrointestinal tract tumors. The assistant during the ESD using a clutch cutter (ESD-C) needs to rotate the device and grasp the target tissue appropriately; therefore, the assistant’s skill may affect the technical outcomes of ESD-C. AIMTo determine how assistant skill level affected the technical outcomes of gastric ESD-C using an ex vivo porcine training model.METHODSIn this pilot study, mock lesions of 15-30 mm in diameter were created in the middle or lower third of the porcine stomach. A total of 32 ESD-C procedures were performed by 16 trainees. Each trainee operator performed two ESD-C procedures; one ESD-C was assisted by an expert (ESD-C-E), and the other was assisted by a non-expert (ESD-C-NE). The total procedure time of the ESD was set as the primary outcome, and en bloc resection rate, complete procedure rate, perforation rate, and each procedure time/speed for mucosal incision or submucosal dissection were set as the secondary outcomes. In addition, we investigated factors associated with the difficulty of ESD including incompletion of ESD procedure, a long procedure time (≥ 20 min) or intraoperative perforation.RESULTSThe median total procedure time of the ESD-C-E was significantly shorter than that of the ESD-C-NE (12.9 min vs 21.9 min, P = 0.001). The en bloc resection rate was 100% in both groups. Complete resection rates of the ESD-C-E and ESD-C-NE groups were 100% and 93.8%, respectively. No intraoperative perforation was observed in both groups. In the multivariate analysis, assistant skill was significantly associated with the difficulty of ESD, with the highest odds ratio of 16.5.CONCLUSIONAssistance by an expert is an important factor when trainees perform ESD-C procedures.

Analysis of Kinematic Differences in Hand Motion between Novice and Experienced Operators in IR: A Pilot Study

PurposeTo prospectively validate electromagnetic hand motion tracking in interventional radiology to detect differences in operator experience using simulation. MethodsSheath task: Six attending interventional radiologists (experts) and 6 radiology trainees (trainees) placed a wire through a sheath and performed a “pin-pull” maneuver, while an electromagnetic motion detection system recorded the hand motion. Radial task: Eight experts and 12 trainees performed palpatory radial artery access task on a radial access simulator. The trainees repeated the task with the nondominant hand. The experts were classified by their most frequent radial artery access technique as having either palpatory, ultrasound, or overall limited experience. The time, path length, and number of movements were calculated. Mann-Whitney U tests were used to compare the groups, and P < .05 was considered significant. ResultsSheath task: The experts took less time, had shorter path lengths, and used fewer movements than the trainees (11.7 seconds ± 3.3 vs 19.7 seconds ± 6.5, P < .01; 1.1 m ± 0.3 vs 1.4 m ± 0.4, P < .01; and 19.5 movements ± 8.5 vs 31.0 movements ± 8.0, P < .01, respectively). Radial task: The experts took less time, had shorter path lengths, and used fewer movements than the trainees (24.2 seconds ± 10.6 vs 33.1 seconds ± 16.9, P < .01; 2.0 m ± 0.5 vs 3.0 m ± 1.9, P < .001; and 36.5 movements ± 15.0 vs 54.5 movements ± 28.0, P < .001, respectively). The trainees had a shorter path length for their dominant hand than their nondominant hand (3.0 m ± 1.9 vs 3.5 m ± 1.9, P < .05). The expert palpatory group had a shorter path length than the ultrasound and limited experience groups (1.8 m ± 0.4 vs 2.0 m ± 0.4 and 2.3 m ± 1.2, respectively, P < .05). ConclusionsElectromagnetic hand motion tracking can differentiate between the expert and trainee operators for simulated interventional tasks.

The tension‐free vaginal tape operation: Is the inexperienced surgeon a risk factor? Learning curve and Swedish quality reference

IntroductionTo reduce the risk of avoidable damage to the patient when training surgeons, one must predefine what standards to achieve, as well as supervise and monitor trainees' performance. The aim of this study is to establish a quality reference, to devise comprehensive tension‐free vaginal tape (TVT) learning curves and to compare trainees' results to our quality reference.Material and methodsUsing the Swedish National Quality Register for Gynecologic Surgery, we devised TVT learning curves for all Swedish TVT trainees from 2009 to 2017, covering their first 50 operations. These outcomes were compared with the results of Sweden's most experienced TVT surgeons for 14 quality variables.ResultsIn all, 163 trainees performed 2804 operations and 40 experienced surgeons performed 3482 operations. For our primary outcomes – perioperative bladder perforations and urinary continence after 1 year – as well as re‐admission, re‐operation and days to all daily living activities, there was no statistically significant difference between trainees and experienced surgeons at any time. For the first 10 trainee operations only, there were small differences in favor of the experienced surgeons: patient‐reported minor complications after discharge (14% vs 18.4%, P = .002), 1‐year patient‐reported improvement (95.9% vs 91.8%, P < .000), and patient satisfaction (90.9% vs 86.2%, P = .002). For both trainee operations 1‐10 and 11‐50, compared with experienced surgeons, operation time (33.8 vs 22.2 min, P < .000; 28.3 vs 22.2 min, P < .000) and hospital stay time (0.16 vs 0.06 days, P < .001; 0.1 vs 0.06 days, P < .001) were longer, perioperative blood loss was higher (27.7 vs 24.4 mL, P = .001; 26.5 vs 24.4 mL, P = .004), and patient‐reported catheterization within 8 weeks was higher (3.9% vs 1.8%, P < .000; 2.5% vs 1.8%, P = .001). One‐year voiding difficulties for trainee patients (operations 1‐10:14.2%, P = .260; operations 11‐50:14.5%, P = .126) were comparable to the experienced surgeons (12.4%).ConclusionsThere is a learning curve for several secondary outcomes but the small effect size makes it improbable that the difference has clinical significance. Our national Swedish results show that it is possible to train new TVT surgeons without exposing patients to noteworthy extra risk and achieve results which are equivalent to the most experienced Swedish surgeons.

Repair of oesophageal atresia by consultants and supervised trainees results in similar outcomes.

Consultants and trainees require exposure to complex cases for maintaining and gaining operative experience. Oesophageal atresia (OA) repair is a neonatal surgical procedure with indicative numbers for completion of training. A conflict of interest may exist between adequate training, maintaining consultant experience and achieving good outcomes. We aimed to review outcomes of procedures performed primarily by trainees and those performed by consultants. We carried out a retrospective case note review of all consecutive infants who underwent surgical repair of OA with distal tracheooesophageal fistula (TOF) between January 1994 and December 2014 at our institution. Only cases that underwent primary oesophageal anastomosis were included. Surgical outcomes were compared between cases that had a trainee and those that had a consultant listed as the primary operator. One hundred and twenty-two cases were included. A total of 52 procedures were performed by trainees, and 68 by consultants. Two cases were undeterminable and excluded. Infant demographics, clinical characteristics and duration of follow-up were similar between groups. All infants survived to discharge. Procedures performed by trainees and those performed by consultants as primary operators had a similar incidence of postoperative pneumothorax (trainees 4, consultants 3; p=0.46), anastomotic leak (trainees 5, consultants 3; p=0.29) and recurrent TOF (trainees 0, consultants 2; p=0.5). Overall 52% of cases had an anastomotic dilatation during follow-up, with no difference between the trainee and consultant groups (50% vs 53%; p=0.85). Surgical outcomes for repair of OA/TOF are not adversely affected by trainee operating. Trainees with appropriate skills should perform supervised OA/TOF repair. These data are important for understanding the interrelationship between provision of training and surgical outcomes.

Trainee-led emergency laparotomy operating.

To achieve completion of training in general surgery, trainees are required to demonstrate competency in common procedures performed at emergency laparotomy. The aim of this study was to describe the patterns of trainee-led emergency laparotomy operating and the association between postoperative outcomes. Data on all patients who had an emergency laparotomy between December 2013 and November 2017 were extracted from the National Emergency Laparotomy Audit database. Patients were grouped by grade of operating surgeon: trainee (specialty registrar) or consultant (including post-Certificate of Completion of Training fellows). Trends in trainee operating by deanery, hospital size and time of day of surgery were investigated. Univariable and adjusted regression analyses were performed for the outcomes 90-day mortality and return to theatre, with analysis of patients in operative subgroups segmental colectomy, Hartmann's procedure, adhesiolysis and repair of perforated peptic ulcer disease. The study cohort included 87 367 patients. The 90-day mortality rate was 15·1 per cent in the consultant group compared with 11·0 per cent in the trainee group. There were no increased odds of death by 90 days or of return to theatre across any of the operative groups when the operation was performed with a trainee listed as the most senior surgeon in theatre. Trainees were more likely to operate independently in high-volume centres (highest- versus lowest-volume centres: odds ratio (OR) 2·11, 95 per cent c.i. 1·91 to 2·33) and at night (00.00 to 07.59 versus 08.00 to 11.59hours; OR 3·20, 2·95 to 3·48). There is significant variation in trainee-led operating in emergency laparotomy by geographical area, hospital size and by time of day. However, this does not appear to influence mortality or return to theatre.

Trainee Operative Autonomy in Plastic Surgery.

Appropriate, progressive trainee autonomy is critical for training competent plastic surgeons who are adequately prepared to enter independent practice. Evaluation and reporting of meaningful operative autonomy among trainees in plastic surgery are understudied. Parallel survey instruments were developed using the Zwisch metric for progressive operative autonomy and distributed electronically to trainees and faculties in all accredited training programs. Trainees were queried about their operative autonomy in 17 core plastic surgery procedures, associated approach to logging cases, and perceived readiness to enter practice. Faculties provided assessment of their final-year trainees using the same metrics. Trainees in 28 programs and faculties in 35 programs participated. Final-year trainees reported the most operative independence with breast tissue expander reconstruction and carpal tunnel release and the least with facelift and rhinoplasty. A mean of 40% of final-year trainees reached supervision only autonomy in the procedures queried; none achieved this with rhinoplasty. Faculties identified the highest final-year trainee operative autonomy with botulinum toxin injection and burn excision and grafting; the least trainee independence was reported with rhinoplasty, cleft lip repair, and facelift. Faculty perception of final-year trainee autonomy was higher than that of trainees for 82% of procedures queried. Although plastic surgery trainees endorse gradual operative autonomy overall, a majority of final-year trainees do not perceive supervision only independence in the majority of core procedures queried. Faculties perceive higher trainee operative autonomy than trainees for most procedures. Discordant approaches to case logging were identified both among trainees and between trainees and faculties. Standardization may improve both progression and assessment of operative autonomy in plastic surgery training.

Innovative Approach to Evaluating Trainee Operative Skills: Electronic Health Record-Mediated Real-Time Resident Assessment

Fisher, Jason C. MD, FACS, FAAP; Lee, Sabrina MPA; Savadamuthu, Vikashini MPA; Garcia, Julio MS; Stellakis, Vivian MA, C-TAGME; Ude-Welcome, Akuezunkpa MD, FACS; Berman, Russell S. MD, FACS; Pachter, Leon H MD, FACS Author Information

Retinal detachment following cataract phacoemulsification-a review of the literature.

A link between cataract surgery and rhegmatogenous retinal detachment (RRD) has long been considered. Indeed, pseudophakic retinal detachment (PPRD) forms a substantial and increasing proportion of RRD. We reviewed the literature to answer the following questions: what is the incidence of PPRD in eyes following phacoemulsification cataract surgery and how does its risk change over time following surgery? We also sought to assess how the risk is modified by intraoperative factors (operative complications, surgeon grade, subsequent laser capsulotomy), intrinsic eye-related factors (laterality, myopia, previous RRD, previous trauma, previous PVD) and patient factors (sex, age, ethnicity, affluence, systemic comorbidities). Secondarily we asked how the incidence of PPRD after phacoemulsification compares with the RRD incidence in the general population and how identified risk factors contribute to the pathophysiology of PPRD. A search of the Medline and Ovid databases was conducted for relevant publications from 1990 onwards using defined search terms with pre planned inclusion and exclusion criteria. The 10-year PPRD incidence after phacoemulsification was identified as being between 0.36 and 2.9%. This decreases over time to 0.1-0.2% annually but remains above the general population. The PPRD risk is further elevated by (in order of decreasing effect) intraoperative vitreous loss, increasing axial length, younger age, male sex and trainee operating surgeons. The PPRD risk after phacoemulsification is approximately ten times the general population's RRD risk. This risk is modified by the interplay of a hierarchy of risk factors, of which intraoperative vitreous loss, myopia, age and sex have the biggest effect.

Skills development of mechanized softwood sawtimber cut-to-length harvester operators on the Highveld of South Africa

ABSTRACTIn this study, a South African pine sawtimber mechanized cut-to-length harvesting operation was analyzed with the objective of modelling productivity development learning curves of beginner operators in both clear-felling and thinning operations. Trainee operators were selected based on the results of an assortment of psychometric testing and subsequently completed several harvester simulator tests. On average, a trainee operator would start at aperformance level (PL) of 60% lower than the population’s mean test time per test (PTmean) and end with a PL of 22% higher than the PTmean. Furthermore, when the PL of an average simulator trainee was measured over a period of 8.4 days or 25.2 tests (three tests per day), the operator’s PL was improved by 200%. Following sufficient simulator training, the operators began working in-field. Thinning operators worked with an average tree size of 0.18 m3, starting at a productivity of 13.71 m3 per productive machine hour excluding delays longer than 5 minutes (PMH5) at month one and increasing their productivity to 38.96 m3·PMH5−1 by the end of month 12. Clear-felling operators worked with an average tree size of 0.54 m3, starting at a productivity of 27.56 m3·PMH5−1 at month one and increased their productivity to 43.75 m3·PMH5−1 by the end of month 12. Ultimately, the thinning and clear-fell operators reached the end of their learning curves after an average of 9 and 6.5 months, and increased their productivity performances by 218% and 104%, respectively. These findings suggest acceptable learning periods and performance increases for beginner harvester operators.

The Impact of Patient and Surgical Factors on the Rate of Postoperative Infection After Total Hip Arthroplasty—A New Zealand Joint Registry Study

BackgroundPeriprosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty (THA). The potential to define and modify risk factors for infection represents an important opportunity to reduce the incidence of PJI. This study uses New Zealand Joint Registry data to identify independent risk factors associated with PJI after primary THA. MethodsData on 91,585 THAs performed between 2000 and 2014 were analyzed. Factors associated with revision for PJI within 12 months were identified using univariate and multivariate analyses. ResultsRevision rates for PJI were 0.15% and 0.21% at 6 and 12 months, respectively. Multivariate analysis showed significant associations with the American Society of Anesthesiologists grade (odds ratio [OR] 6.13, 95% confidence interval [CI] 1.28-29.39), severe or morbid obesity (OR 2.15, CI 1.01-4.60 and OR 3.73, CI 1.49-9.39), laminar flow ventilation (OR 1.98, CI 1.38-2.85), consultant-supervised trainee operations (OR 1.94, CI 1.22-3.08), male gender (OR 1.68, CI 1.23-2.30) and anterolateral approach (OR 1.62, CI 1.11-2.37). Procedures performed in the private sector were protective for revision for infection (OR 0.68, CI 0.48-0.96). ConclusionsThe PJI risk profile for patients undergoing THA is constituted of a complex of patient and surgical factors. Several patient factors had strong independent associations with revision rates for PJI. Although surgical factors were less important, these may be more readily modifiable in practice.

腹腔鏡下手術トレーニングシステムの構築

Laparoscopic surgery is a difficult surgical procedure as compared with open operation. Therefore, training is necessary for surgeons to perform laparoscopic surgery. In this paper, a training system in which trainees can train a process by themselves that makes a forceps arrive at the target position during ligation based on the evaluation results of hands movement and an operation time, is proposed. First, an acceleration of the forceps is measured by 9-axis sensors attached to the forceps and frequency analysis is performed to the measured acceleration. When the spectrum of the trainee's acceleration in low frequency band is larger than the threshold value determined from pre-measured spectrum of the skilled surgeon's acceleration, the hands movement is regarded as superfluous. Second, an operation time of the trainee's forceps operation which makes the forceps arrive at the target position during ligation is compared with that of the skilled surgeon. Finally, the evaluation results of trainee's hands movement and operation time in comparison with those of the skilled surgeon are displayed on the monitor screen.