BACKGROUND The management of hepatoblastoma(HB)becomes challenging when the tumor remains in close proximity to the major liver vasculature(PMV)even after a full course of neoadjuvant chemotherapy(NAC).In such cases,e...BACKGROUND The management of hepatoblastoma(HB)becomes challenging when the tumor remains in close proximity to the major liver vasculature(PMV)even after a full course of neoadjuvant chemotherapy(NAC).In such cases,extreme liver resection can be considered a potential option.AIM To explore whether computer-assisted three-dimensional individualized extreme liver resection is safe and feasible for children with HB who still have PMV after a full course of NAC.METHODS We retrospectively collected data from children with HB who underwent surgical resection at our center from June 2013 to June 2023.We then analyzed the detailed clinical and three-dimensional characteristics of children with HB who still had PMV after a full course of NAC.RESULTS Sixty-seven children diagnosed with HB underwent surgical resection.The age at diagnosis was 21.4±18.8 months,and 40 boys and 27 girls were included.Fifty-nine(88.1%)patients had a single tumor,39(58.2%)of which was located in the right lobe of the liver.A total of 47 patients(70.1%)had PRE-TEXT III or IV.Thirty-nine patients(58.2%)underwent delayed resection.After a full course of NAC,16 patients still had close PMV(within 1 cm in two patients,touching in 11 patients,compressing in four patients,and showing tumor thrombus in three patients).There were 6 patients of tumors in the middle lobe of the liver,and four of those patients exhibited liver anatomy variations.These 16 children underwent extreme liver resection after comprehensive preoperative evaluation.Intraoperative procedures were performed according to the preoperative plan,and the operations were successfully performed.Currently,the 3-year event-free survival of 67 children with HB is 88%.Among the 16 children who underwent extreme liver resection,three experienced recurrence,and one died due to multiple metastases.CONCLUSION Extreme liver resection for HB that is still in close PMV after a full course of NAC is both safe and feasible.This approach not only reduces the necessity for liver transplantation but also results in a favorable prognosis.Individualized three-dimensional surgical planning is beneficial for accurate and complete resection of HB,particularly for assessing vascular involvement,remnant liver volume and anatomical variations.展开更多
The main aim of this opinion review is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023;29:4593–4603.The authors in the published article developed a new scoring ...The main aim of this opinion review is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023;29:4593–4603.The authors in the published article developed a new scoring system,Garg incon-tinence scores(GIS),for fecal incontinence(FI).FI is a chronic debilitating disease that has a severe negative impact on the quality of life of the patients.Rome IV criteria define FI as multiple episodes of solid or liquid stool passed into the clothes at least twice a month.The associated social stigmatization often leads to significant under-reporting of the condition,which further impairs management.An important point is that the complexity and vagueness of the disease make it difficult for the patients to properly define and report the magnitude of the problem to their physicians.Due to this,the management becomes even more difficult.This issue is resolved up to a considerable extent by a scoring ques-tionnaire.There were several scoring systems in use for the last three decades.The prominent of them were the Cleveland Clinic scoring system or the Wexner scoring system,St.Marks Hospital or Vaizey’s scores,and the FI severity index.However,there were several shortcomings in these scoring systems.In the opinion review,we tried to analyze the strength of GIS and compare it to the existing scoring systems.The main pitfalls in the existing scoring systems were that most of them gave equal weightage to different types of FI(solid,liquid,flatus,etc.),were not comprehensive,and took only the surgeon’s perception of FI into view.In GIS,almost all shortcomings of previous scoring systems had been addressed:different weights were assigned to different types of FI by a robust statistical methodology;the scoring system was made comprehensive by including all types of FI that were previously omitted(urge,stress and mucus FI)and gave priority to patients’rather than the physicians’perceptions while developing the scoring system.Due to this,GIS indeed looked like a paradigm shift in the evaluation of FI.However,it is too early to conclude this,as GIS needs to be validated for accuracy and simplicity in future studies.展开更多
BACKGROUND Subchorionic hematoma(SCH)is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane.SCH can lead to adverse pregnancy outcome...BACKGROUND Subchorionic hematoma(SCH)is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane.SCH can lead to adverse pregnancy outcomes such as miscarriage,preterm birth,and other complications.Early detection and accurate assessment of SCH are crucial for appropriate management and improved pregnancy outcomes.AIM To evaluate the diagnostic efficacy of virtual organ computer-assisted analysis(VOCAL)in measuring the volume ratio of SCH to gestational sac(GS)combined with serum progesterone on early pregnancy outcomes in patients with SCH.METHODS A total of 153 patients with SCH in their first-trimester pregnancies between 6 and 11 wk were enrolled.All patients were followed up until a gestational age of 20 wk.The parameters of transvaginal two-dimensional ultrasound,including the circumference of SCH(Cs),surface area of SCH(Ss),circumference of GS(Cg),and surface area of GS(Sg),and the parameters of VOCAL with transvaginal three-dimensional ultrasound,including the three-dimensional volume of SCH(3DVs)and GS(3DVg),were recorded.The size of the SCH and its ratio to the GS size(Cs/Cg,Ss/Sg,3DVs/3DVg)were recorded and compared.RESULTS Compared with those in the normal pregnancy group,the adverse pregnancy group had higher Cs/Cg,Ss/Sg,and 3DVs/3DVg ratios(P<0.05).When 3DVs/3DVg was 0.220,the highest predictive performance predicted adverse pregnancy outcomes,resulting in an AUC of 0.767,and the sensitivity,specificity were 70.2%,75%respectively.VOCAL measuring 3DVs/3DVg combined with serum progesterone gave a diagnostic AUC of 0.824 for early pregnancy outcome in SCH patients,with a high sensitivity of 82.1%and a specificity of 72.1%,which showed a significant difference between AUC.CONCLUSION VOCAL-measured 3DVs/3DVg effectively quantifies the severity of SCH,while combined serum progesterone better predicts adverse pregnancy outcomes.展开更多
Objective: To develop and validate a radiomics-based predictive risk score(RPRS) for preoperative prediction of lymph node(LN) metastasis in patients with resectable non-small cell lung cancer(NSCLC).Methods: We retro...Objective: To develop and validate a radiomics-based predictive risk score(RPRS) for preoperative prediction of lymph node(LN) metastasis in patients with resectable non-small cell lung cancer(NSCLC).Methods: We retrospectively analyzed 717 who underwent surgical resection for primary NSCLC with systematic mediastinal lymphadenectomy from October 2007 to July 2016. By using the method of radiomics analysis, 591 computed tomography(CT)-based radiomics features were extracted, and the radiomics-based classifier was constructed. Then, using multivariable logistic regression analysis, a weighted score RPRS was derived to identify LN metastasis. Apparent prediction performance of RPRS was assessed with its calibration,discrimination, and clinical usefulness.Results: The radiomics-based classifier was constructed, which consisted of 13 selected radiomics features.Multivariate models demonstrated that radiomics-based classifier, age group, tumor diameter, tumor location, and CT-based LN status were independent predictors. When we assigned the corresponding score to each variable,patients with RPRSs of 0-3, 4-5, 6, 7-8, and 9 had distinctly very low(0%-20%), low(21%-40%), intermediate(41%-60%), high(61%-80%), and very high(81%-100%) risks of LN involvement, respectively. The developed RPRS showed good discrimination and satisfactory calibration (C-index: 0.785, 95% confidence interval(95% CI):0.780-0.790)Additionally, RPRS outperformed the clinicopathologic-based characteristics model with net reclassification index(NRI) of 0.711(95% CI: 0.555-0.867).Conclusions: The novel clinical scoring system developed as RPRS can serve as an easy-to-use tool to facilitate the preoperatively individualized prediction of LN metastasis in patients with resectable NSCLC. This stratification of patients according to their LN status may provide a basis for individualized treatment.展开更多
AIM: To implement a quick and simple test- rapid assessment faecal incontinence score(RAFIS) and show its reliability and validity.METHODS: From March 2008 through March 2010, we evaluated a total of 261 consecutive p...AIM: To implement a quick and simple test- rapid assessment faecal incontinence score(RAFIS) and show its reliability and validity.METHODS: From March 2008 through March 2010, we evaluated a total of 261 consecutive patients, including 53 patients with faecal incontinence. Demographic and comorbidity information was collected. In a single visit, patients were administered the RAFIS. The results obtained with the new score were compared with those of both Wexner score and faecal incontinence quality of life scale(FIQL) questionnaire. The patient withoutinfluence of the surgeon completed the test. The role of surgeon was explaining the meaning of each section and how he had to fill. Reliability of the RAFIS score was measured using intra-observer agreement and Cronbach's alpha(internal consistency) coefficient. Multivariate analysis of the main components within the different scores was performed in order to determine whether all the scores measured the same factor and to conclude whether the information could be encompassed in a single factor. A sample size of 50 patients with faecal incontinence was estimated to be enough to detect a correlation of 0.55 or better at 5% level of significance with 80% power.RESULTS: We analysed the results obtained by 53 consecutive patients with faecal incontinence(median age 61.55 ± 12.49 years) in the three scoring systems. A total of 208 healthy volunteers(median age 58.41 ± 18.41 years) without faecal incontinence were included in the study as negative controls. Pearson's correlation coefficient between "state" and "leaks" was excellent(r = 0.92, P < 0.005). Internal consistency in the comparison of "state" and "leaks" yielded also excellent correlation(Cronbach's α = 0.93). Results in each score were compared using regression analysis and a correlation value of r = 0.98 was obtained with Wexner score. As regards FIQL questionnaire, the values of "r " for the different subscales of the questionnaire were: "lifestyle" r =-0.87, "coping/behaviour" r =-0.91, "depression" r =-0.36 and "embarrassment" r =-0.90,(P < 0.01). A multivariate analysis showed that all the scoring systems measured the same factor. A single factor may explain 80.84% of the variability of FI, so all the scoring systems measure the same factor. Patient's continence improves when RAFIS and Jorge-Wexner scores show low values and when the values obtained in the FIQL questionnaire are high.CONCLUSION: RAFIS is a valid and reliable tool to assess Faecal Incontinence.展开更多
The computer-assisted surgery (CAS)has significantly improved the accuracy, reliability and outcomes of traumatic,spinal,nerve surgery and many other operations with a less invasive way.The application of CAS for scap...The computer-assisted surgery (CAS)has significantly improved the accuracy, reliability and outcomes of traumatic,spinal,nerve surgery and many other operations with a less invasive way.The application of CAS for scaphoid fractures remains experimental.The related studies are scanty and most of them are cadaver researches.Some intrinsic defects from the registration procedure,scan and immobilization of limbs may inevitably result in deviations. Some deviations become more obvious with operations of small bones (such as scaphoid)although they are acceptable for spine and other orthopedic surgeries.We reviewed the current literatures on the applications of CAS for scaphoid operation and summarized technical principles,scan and registration methods,immobilization of limbs and their outcomes.On the basis of the data,we analyzed the limitations of this technique and envisioned its future development.展开更多
BACKGROUND Artificial intelligence in colonoscopy is an emerging field,and its application may help colonoscopists improve inspection quality and reduce the rate of missed polyps and adenomas.Several deep learning-bas...BACKGROUND Artificial intelligence in colonoscopy is an emerging field,and its application may help colonoscopists improve inspection quality and reduce the rate of missed polyps and adenomas.Several deep learning-based computer-assisted detection(CADe)techniques were established from small single-center datasets,and unrepresentative learning materials might confine their application and generalization in wide practice.Although CADes have been reported to identify polyps in colonoscopic images and videos in real time,their diagnostic performance deserves to be further validated in clinical practice.AIM To train and test a CADe based on multicenter high-quality images of polyps and preliminarily validate it in clinical colonoscopies.METHODS With high-quality screening and labeling from 55 qualified colonoscopists,a dataset consisting of over 71000 images from 20 centers was used to train and test a deep learning-based CADe.In addition,the real-time diagnostic performance of CADe was tested frame by frame in 47 unaltered full-ranged videos that contained 86 histologically confirmed polyps.Finally,we conducted a selfcontrolled observational study to validate the diagnostic performance of CADe in real-world colonoscopy with the main outcome measure of polyps per colonoscopy in Changhai Hospital.RESULTS The CADe was able to identify polyps in the test dataset with 95.0%sensitivity and 99.1%specificity.For colonoscopy videos,all 86 polyps were detected with 92.2%sensitivity and 93.6%specificity in frame-by-frame analysis.In the prospective validation,the sensitivity of CAD in identifying polyps was 98.4%(185/188).Folds,reflections of light and fecal fluid were the main causes of false positives in both the test dataset and clinical colonoscopies.Colonoscopists can detect more polyps(0.90 vs 0.82,P<0.001)and adenomas(0.32 vs 0.30,P=0.045)with the aid of CADe,particularly polyps<5 mm and flat polyps(0.65 vs 0.57,P<0.001;0.74 vs 0.67,P=0.001,respectively).However,high efficacy is not realized in colonoscopies with inadequate bowel preparation and withdrawal time(P=0.32;P=0.16,respectively).CONCLUSION CADe is feasible in the clinical setting and might help endoscopists detect more polyps and adenomas,and further confirmation is warranted.展开更多
The aim of the present study was to compare assessments of sperm concentration and sperm motility analysed by conventional semen analysis with those obtained by computer-assisted semen analysis (CASA) (Copenhagen R...The aim of the present study was to compare assessments of sperm concentration and sperm motility analysed by conventional semen analysis with those obtained by computer-assisted semen analysis (CASA) (Copenhagen Rigshospitalet Image House Sperm Motility Analysis System (CRISMAS) 4.6 software) using semen samples from 166 young Danish men. The CRISMAS software identifies sperm concentration and classifies spermatozoa into three motility categories. To enable comparison of the two methods, the four motility stages obtained by conventional semen analysis were, based on their velocity classifications, divided into three stages, comparable to the three CRISMAS motility categories: rapidly progressive (A), slowly progressive (B) and non-progressive (C+ D). Differences between the two methods were large for all investigated parameters (P〈0.001). CRISMAS overestimated sperm concentration and the proportion of rapidly progressive spermatozoa and, consequently, underestimated the percentages of slowly progressive and non-progressive spermatozoa, compared to the conventional method. To investigate whether results drifted according to time of semen analysis, results were pooled into quarters according to date of semen analysis. CRISMAS motility results appeared more stable over time compared to the conventional analysis; however, neither method showed any trends. Apparently, CRISMAS CASA results and results from the conventional method were not comparable with respect to sperm concentration and motility analysis. This needs to be accounted for in clinics using this software and in studies of determinants of these semen characteristics.展开更多
Glutathione peroxidase, the first example of selenoproteins identified in mammals, was subjected to force field calculations and molecular dynamics in order to enable a clearer comprehension of enzymatic selenium cata...Glutathione peroxidase, the first example of selenoproteins identified in mammals, was subjected to force field calculations and molecular dynamics in order to enable a clearer comprehension of enzymatic selenium catalysis. Starting from the established X-ray structure of bovine GPX, all kinetically defined intermediates and enzyme substrate complexes were modelled. The models thus obtained support the hypothesis that the essential steps of the catalysis are three distinct redox changes of the active site selenium which, in the ground state, presents itself at the surface of selenoperoxidases as the center of a characteristic triad built by selenocysteine, glutarnine and tryptophan. In GPX, four arginine residues and a lysine residue provide an electrostatic architecture which, in each reductive step, directs the donor substrate GSH towards the catalytic center in such a way that 1ts sulfhydryl group must react with the selenium moiety. To this end, different equally efficient modes of substrate binding appear possible. The models are consistent with substrate specificity data, kinetic pattern and other functional characteristics of the enzyme. Comparison of molecular models of GPX with those of other members of the GPX superfamily reveals that the cosubstrate binding mechanisrns are unique for the classical type of cytosolic glutathione peroxidases but cannot operate e. g. in plasma GPX and phospholipid hydroperoxide GPX. The structural differences between the selenoperoxidases, shown to be relevant to their specificities, are discussed in terms of functional diversification within the GPX superfamily展开更多
BACKGROUND Most complex renal stones are managed primarily with percutaneous nephrolithotomy(PCNL).However,PCNL is still a great challenge for surgeons because of poor comprehension on complex adjacent structures.Nove...BACKGROUND Most complex renal stones are managed primarily with percutaneous nephrolithotomy(PCNL).However,PCNL is still a great challenge for surgeons because of poor comprehension on complex adjacent structures.Novel techniques are required to assist in planning and navigation.AIM To apply and evaluate the Hisense computer-assisted surgery(CAS)system in PCNL.METHODS A total of 60 patients with complex renal stones were included.Thirty patients in the CAS group had three-dimensional(3 D)virtual models constructed with the CAS system.The model assisted in planning and navigating in the CAS system.Thirty patients in the control group planned and navigated as standard PCNL,without the application of the CAS system.Success rate of one attempt,operation time,initial stone-free rate,decrease in hemoglobin,and complications were collected and analyzed.RESULTS There were no statistically significant differences in the baseline characteristics or planning characteristics.The success rate of one puncturing attempt(90%vs 67%,P=0.028)and the initial stone-free rate(87%vs 63%,P=0.037)were significantly higher in the CAS group.However,there were no statistically significant differences in the operation time(89.20±29.60 min vs 92.33±33.08 min,P=0.859)or in the decrease in hemoglobin(11.07±8.32 g/L vs 9.03±11.72 g/L,P=0.300)between the CAS group and the control group.No statistically significant differences in the incidence of complications(Clavien-Dindo grade≥2)were found.CONCLUSION Compared with standard PCNL,CAS-assisted PCNL had advantages in terms of the puncturing success rate and stone-free rate.The Hisense CAS System was recommended to assist in preoperative planning and intraoperative navigation for an intuitive,precise and convenient PCNL.展开更多
Background: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia. The symptoms of hyperglycemia include polyuria, polydypsia, polyphagia, blurred vision and weight loss. Various diagnostic tes...Background: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia. The symptoms of hyperglycemia include polyuria, polydypsia, polyphagia, blurred vision and weight loss. Various diagnostic tests are used for the diagnosis of DM in patients, but the findings of these tests cannot be assumed to be completely valid. This study aimed at developing a novel scoring system to assess the patients suffering from DM. Method: We assessed the patients based on various diagnostic tests available for DM and prepared a single list of these tests. The tests were categorized and graded based on the World Health Organization (WHO) criteria. Further, we coverted the grades into numeric values for easy use. Results: NFS for diabetes is an 11-point scoring system that assesses the patient’s condition before and after therapy. To facilitate the conduct of probability based studies, we have converted the scores into numeric values in the range of (0, 1). Each symptom is graded as (1, 2, 3, 4, 5) that runs in BAD → GOOD direction. Conclusion: NFS is a beneficial scoring system that can be used worldwide to assess the patients with DM.展开更多
The albumin-bilirubin(ALBI)score,which was proposed to assess the prognosis of patients with hepatocellular carcinoma,has gradually been extended to other liver diseases in recent years,including primary biliary chola...The albumin-bilirubin(ALBI)score,which was proposed to assess the prognosis of patients with hepatocellular carcinoma,has gradually been extended to other liver diseases in recent years,including primary biliary cholangitis,liver cirrhosis,hepatitis,liver transplantation,and liver injury.The ALBI score is often compared with classical scores such as the Child-Pugh and model for end-stage liver disease scores or other noninvasive prediction models.It is widely employed because of its immunity to subjective evaluation indicators and ease of obtaining detection indicators.An increasing number of studies have confirmed that it is highly accurate for assessing the prognosis of patients with chronic liver disease;additionally,it has demonstrated good predictive performance for outcomes beyond survival in patients with liver diseases,such as decompensation events.This article presents a review of the application of ALBI scores in various non-malignant liver diseases.展开更多
BACKGROUND Radiomics is a promising tool that may increase the value of magnetic resonance imaging(MRI)for different tasks related to the management of patients with hepatocellular carcinoma(HCC).However,its implement...BACKGROUND Radiomics is a promising tool that may increase the value of magnetic resonance imaging(MRI)for different tasks related to the management of patients with hepatocellular carcinoma(HCC).However,its implementation in clinical practice is still far,with many issues related to the methodological quality of radiomic studies.AIM To systematically review the current status of MRI radiomic studies concerning HCC using the Radiomics Quality Score(RQS).METHODS A systematic literature search of PubMed,Google Scholar,and Web of Science databases was performed to identify original articles focusing on the use of MRI radiomics for HCC management published between 2017 and 2023.The methodological quality of radiomic studies was assessed using the RQS tool.Spearman’s correlation(ρ)analysis was performed to explore if RQS was correlated with journal metrics and characteristics of the studies.The level of statistical significance was set at P<0.05.RESULTS One hundred and twenty-seven articles were included,of which 43 focused on HCC prognosis,39 on prediction of pathological findings,16 on prediction of the expression of molecular markers outcomes,18 had a diagnostic purpose,and 11 had multiple purposes.The mean RQS was 8±6.22,and the corresponding percentage was 24.15%±15.25%(ranging from 0.0% to 58.33%).RQS was positively correlated with journal impact factor(IF;ρ=0.36,P=2.98×10^(-5)),5-years IF(ρ=0.33,P=1.56×10^(-4)),number of patients included in the study(ρ=0.51,P<9.37×10^(-10))and number of radiomics features extracted in the study(ρ=0.59,P<4.59×10^(-13)),and time of publication(ρ=-0.23,P<0.0072).CONCLUSION Although MRI radiomics in HCC represents a promising tool to develop adequate personalized treatment as a noninvasive approach in HCC patients,our study revealed that studies in this field still lack the quality required to allow its introduction into clinical practice.展开更多
BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing...BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing, and breathing as well as temporomandibular joint ankylosis. The main goal of the surgery is to release the ankylosis, establish functioning mandible, and prevent re-fusion.However, surgical procedures for this disease are rarely reported.CASE SUMMARY Here, we report a 7-mo-old girl with bilateral maxillomandibular syngnathia. The patient presented with difficulty in feeding, breathing, sounding, and swallowing and had developmental dysplasia. For treatment, we performed bone isolation by computer-assisted navigation and used silicone to fix the wound surface to prevent refusion of bone. To our knowledge, this is the only syngnathia case in the literature treated using computer-assisted navigation. With the guidance of precise navigation, we were able to minimize operation time by at least one hour,the patient's blood vessels, nerves, and tooth germs were well protected, and excessive bleeding was avoided. After six weeks, the patient showed improvement in mouth opening and no major issues of feeding.CONCLUSION Application of computer-assisted navigation can significantly improve accuracy,effectiveness, and surgical safety in correcting congenital maxillomandibular syngnathia.展开更多
The main aim of this editorial is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023;29:4593-4603.This original research presents a new scoring system for fecal inco...The main aim of this editorial is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023;29:4593-4603.This original research presents a new scoring system for fecal incontinence.Fecal incontinence is a chronic disease with a severe impact on the quality of life of the patients.Substantial social stigmatization often leads to significant underreporting of the condition even during visits to a specialist and could lead to further misman-agement or non-existent management of the disease.An important fact is that patients are often unable to describe their condition when not asked precisely defined questions.This problem is partially resolved by scoring questionnaires.Several scoring systems are commonly used;however,each of them has their shortcomings.For example,the absence of different kinds of leakage besides flatus and stool could further lead to underscoring the incontinence severity.Therefore,there has long been a call for a more precise scoring system.The correct identification of the presence and severity of fecal incontinence is paramount for further diagnostic approach and for choosing the appropriate therapy option.This editorial describes fecal incontinence,its effect on quality of life in general and further evaluates the diagnostic approach with a particular focus on symptom scoring systems and their implications for clinical practice.展开更多
AIM: To introduce the navigation system of software and instruments designed specifically for revision total knee arthroplasty(TKA).METHODS: We present an imageless navigation system for revision TKA,with optical poin...AIM: To introduce the navigation system of software and instruments designed specifically for revision total knee arthroplasty(TKA).METHODS: We present an imageless navigation system for revision TKA,with optical point and tracker identification to assess kinematic and anatomical landmarks.The system automatically positions the cutting guides with a motorized cutting unit.The cutting unit is placed on the distal femur with a femoral clamp and acts as a rigid body and the base for all femoral cuts.The surgical technique for using the navigation system for revision TKA is based on the technique used in primary TKA.However,there are some important differences.The most notable are:(1) differences in estimation of the position of the primary implant relative to the bone and the mechanical axes;(2) the specific possibilities the revision navigation software offers in terms of optimal joint level positioning; and(3) the suggested "best fit" position,in which the clock position,stem position and offset,femoral component size,and mediolateral position of the femoral component are taken into account to find the optimal femoral component position.We assessed the surgical technique,and accompanying software procedural steps,of the system,identifying any advantages or disadvantages that they present.RESULTS: The system aims to visualize critical steps of the procedure and is intended as a tool to support the surgeon in surgical decision-making.Combining a computer-assisted cutting device with navigation makes it possible to carry out precise cuts without pinning.Furthermore,the femoral clamp provides a stable fixation mechanism for the motorized cutting unit.A stable clamp is paramount in the presence of periarticular bony defects.The system allows the position of the primary implant relative to the bone and mechanical axes to be estimated,at which point any malalignments can be corrected.It also offers an optimal joint level position for implantation,and suggests a "best fit" position,in which the clock position,stem position and offset,femoral component size,and mediolateral position of the femoral component are considered.The surgeon can therefore make decisions intraoperatively to maximise alignment and,hence,outcomes.Based on the intraoperative findings of joint stability,the surgeon can modify the preoperative plan and switch from a constrained condylar system to a hinged version,or vice versa.CONCLUSION: The system is flexible and easy to learn and allows improvements in workflow during TKA.展开更多
基金Supported by National Natural Science Foundation of China,No.82293665Anhui Provincial Department of Education University Research Project,No.2023AH051763.
文摘BACKGROUND The management of hepatoblastoma(HB)becomes challenging when the tumor remains in close proximity to the major liver vasculature(PMV)even after a full course of neoadjuvant chemotherapy(NAC).In such cases,extreme liver resection can be considered a potential option.AIM To explore whether computer-assisted three-dimensional individualized extreme liver resection is safe and feasible for children with HB who still have PMV after a full course of NAC.METHODS We retrospectively collected data from children with HB who underwent surgical resection at our center from June 2013 to June 2023.We then analyzed the detailed clinical and three-dimensional characteristics of children with HB who still had PMV after a full course of NAC.RESULTS Sixty-seven children diagnosed with HB underwent surgical resection.The age at diagnosis was 21.4±18.8 months,and 40 boys and 27 girls were included.Fifty-nine(88.1%)patients had a single tumor,39(58.2%)of which was located in the right lobe of the liver.A total of 47 patients(70.1%)had PRE-TEXT III or IV.Thirty-nine patients(58.2%)underwent delayed resection.After a full course of NAC,16 patients still had close PMV(within 1 cm in two patients,touching in 11 patients,compressing in four patients,and showing tumor thrombus in three patients).There were 6 patients of tumors in the middle lobe of the liver,and four of those patients exhibited liver anatomy variations.These 16 children underwent extreme liver resection after comprehensive preoperative evaluation.Intraoperative procedures were performed according to the preoperative plan,and the operations were successfully performed.Currently,the 3-year event-free survival of 67 children with HB is 88%.Among the 16 children who underwent extreme liver resection,three experienced recurrence,and one died due to multiple metastases.CONCLUSION Extreme liver resection for HB that is still in close PMV after a full course of NAC is both safe and feasible.This approach not only reduces the necessity for liver transplantation but also results in a favorable prognosis.Individualized three-dimensional surgical planning is beneficial for accurate and complete resection of HB,particularly for assessing vascular involvement,remnant liver volume and anatomical variations.
文摘The main aim of this opinion review is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023;29:4593–4603.The authors in the published article developed a new scoring system,Garg incon-tinence scores(GIS),for fecal incontinence(FI).FI is a chronic debilitating disease that has a severe negative impact on the quality of life of the patients.Rome IV criteria define FI as multiple episodes of solid or liquid stool passed into the clothes at least twice a month.The associated social stigmatization often leads to significant under-reporting of the condition,which further impairs management.An important point is that the complexity and vagueness of the disease make it difficult for the patients to properly define and report the magnitude of the problem to their physicians.Due to this,the management becomes even more difficult.This issue is resolved up to a considerable extent by a scoring ques-tionnaire.There were several scoring systems in use for the last three decades.The prominent of them were the Cleveland Clinic scoring system or the Wexner scoring system,St.Marks Hospital or Vaizey’s scores,and the FI severity index.However,there were several shortcomings in these scoring systems.In the opinion review,we tried to analyze the strength of GIS and compare it to the existing scoring systems.The main pitfalls in the existing scoring systems were that most of them gave equal weightage to different types of FI(solid,liquid,flatus,etc.),were not comprehensive,and took only the surgeon’s perception of FI into view.In GIS,almost all shortcomings of previous scoring systems had been addressed:different weights were assigned to different types of FI by a robust statistical methodology;the scoring system was made comprehensive by including all types of FI that were previously omitted(urge,stress and mucus FI)and gave priority to patients’rather than the physicians’perceptions while developing the scoring system.Due to this,GIS indeed looked like a paradigm shift in the evaluation of FI.However,it is too early to conclude this,as GIS needs to be validated for accuracy and simplicity in future studies.
文摘BACKGROUND Subchorionic hematoma(SCH)is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane.SCH can lead to adverse pregnancy outcomes such as miscarriage,preterm birth,and other complications.Early detection and accurate assessment of SCH are crucial for appropriate management and improved pregnancy outcomes.AIM To evaluate the diagnostic efficacy of virtual organ computer-assisted analysis(VOCAL)in measuring the volume ratio of SCH to gestational sac(GS)combined with serum progesterone on early pregnancy outcomes in patients with SCH.METHODS A total of 153 patients with SCH in their first-trimester pregnancies between 6 and 11 wk were enrolled.All patients were followed up until a gestational age of 20 wk.The parameters of transvaginal two-dimensional ultrasound,including the circumference of SCH(Cs),surface area of SCH(Ss),circumference of GS(Cg),and surface area of GS(Sg),and the parameters of VOCAL with transvaginal three-dimensional ultrasound,including the three-dimensional volume of SCH(3DVs)and GS(3DVg),were recorded.The size of the SCH and its ratio to the GS size(Cs/Cg,Ss/Sg,3DVs/3DVg)were recorded and compared.RESULTS Compared with those in the normal pregnancy group,the adverse pregnancy group had higher Cs/Cg,Ss/Sg,and 3DVs/3DVg ratios(P<0.05).When 3DVs/3DVg was 0.220,the highest predictive performance predicted adverse pregnancy outcomes,resulting in an AUC of 0.767,and the sensitivity,specificity were 70.2%,75%respectively.VOCAL measuring 3DVs/3DVg combined with serum progesterone gave a diagnostic AUC of 0.824 for early pregnancy outcome in SCH patients,with a high sensitivity of 82.1%and a specificity of 72.1%,which showed a significant difference between AUC.CONCLUSION VOCAL-measured 3DVs/3DVg effectively quantifies the severity of SCH,while combined serum progesterone better predicts adverse pregnancy outcomes.
基金supported by the National Key Research and Development Plan of China (No. 2017YFC1309100)the National Natural Scientific Foundation of China (No. 81771912, 81901910, and 81701782)the Provincial Science and Technology Plan Project of Guangdong Province (No. 2017B020227012)
文摘Objective: To develop and validate a radiomics-based predictive risk score(RPRS) for preoperative prediction of lymph node(LN) metastasis in patients with resectable non-small cell lung cancer(NSCLC).Methods: We retrospectively analyzed 717 who underwent surgical resection for primary NSCLC with systematic mediastinal lymphadenectomy from October 2007 to July 2016. By using the method of radiomics analysis, 591 computed tomography(CT)-based radiomics features were extracted, and the radiomics-based classifier was constructed. Then, using multivariable logistic regression analysis, a weighted score RPRS was derived to identify LN metastasis. Apparent prediction performance of RPRS was assessed with its calibration,discrimination, and clinical usefulness.Results: The radiomics-based classifier was constructed, which consisted of 13 selected radiomics features.Multivariate models demonstrated that radiomics-based classifier, age group, tumor diameter, tumor location, and CT-based LN status were independent predictors. When we assigned the corresponding score to each variable,patients with RPRSs of 0-3, 4-5, 6, 7-8, and 9 had distinctly very low(0%-20%), low(21%-40%), intermediate(41%-60%), high(61%-80%), and very high(81%-100%) risks of LN involvement, respectively. The developed RPRS showed good discrimination and satisfactory calibration (C-index: 0.785, 95% confidence interval(95% CI):0.780-0.790)Additionally, RPRS outperformed the clinicopathologic-based characteristics model with net reclassification index(NRI) of 0.711(95% CI: 0.555-0.867).Conclusions: The novel clinical scoring system developed as RPRS can serve as an easy-to-use tool to facilitate the preoperatively individualized prediction of LN metastasis in patients with resectable NSCLC. This stratification of patients according to their LN status may provide a basis for individualized treatment.
基金CIBERehd was funded by the Instituto de Salud CarloⅢ
文摘AIM: To implement a quick and simple test- rapid assessment faecal incontinence score(RAFIS) and show its reliability and validity.METHODS: From March 2008 through March 2010, we evaluated a total of 261 consecutive patients, including 53 patients with faecal incontinence. Demographic and comorbidity information was collected. In a single visit, patients were administered the RAFIS. The results obtained with the new score were compared with those of both Wexner score and faecal incontinence quality of life scale(FIQL) questionnaire. The patient withoutinfluence of the surgeon completed the test. The role of surgeon was explaining the meaning of each section and how he had to fill. Reliability of the RAFIS score was measured using intra-observer agreement and Cronbach's alpha(internal consistency) coefficient. Multivariate analysis of the main components within the different scores was performed in order to determine whether all the scores measured the same factor and to conclude whether the information could be encompassed in a single factor. A sample size of 50 patients with faecal incontinence was estimated to be enough to detect a correlation of 0.55 or better at 5% level of significance with 80% power.RESULTS: We analysed the results obtained by 53 consecutive patients with faecal incontinence(median age 61.55 ± 12.49 years) in the three scoring systems. A total of 208 healthy volunteers(median age 58.41 ± 18.41 years) without faecal incontinence were included in the study as negative controls. Pearson's correlation coefficient between "state" and "leaks" was excellent(r = 0.92, P < 0.005). Internal consistency in the comparison of "state" and "leaks" yielded also excellent correlation(Cronbach's α = 0.93). Results in each score were compared using regression analysis and a correlation value of r = 0.98 was obtained with Wexner score. As regards FIQL questionnaire, the values of "r " for the different subscales of the questionnaire were: "lifestyle" r =-0.87, "coping/behaviour" r =-0.91, "depression" r =-0.36 and "embarrassment" r =-0.90,(P < 0.01). A multivariate analysis showed that all the scoring systems measured the same factor. A single factor may explain 80.84% of the variability of FI, so all the scoring systems measure the same factor. Patient's continence improves when RAFIS and Jorge-Wexner scores show low values and when the values obtained in the FIQL questionnaire are high.CONCLUSION: RAFIS is a valid and reliable tool to assess Faecal Incontinence.
基金the National Natural Science Foundation of China(No.51675036)the Innovation and Development Project of Intelligent Manufacturing Technique from Beijing Municipal Science and Technology Commission(No.Z161100001516012).
文摘The computer-assisted surgery (CAS)has significantly improved the accuracy, reliability and outcomes of traumatic,spinal,nerve surgery and many other operations with a less invasive way.The application of CAS for scaphoid fractures remains experimental.The related studies are scanty and most of them are cadaver researches.Some intrinsic defects from the registration procedure,scan and immobilization of limbs may inevitably result in deviations. Some deviations become more obvious with operations of small bones (such as scaphoid)although they are acceptable for spine and other orthopedic surgeries.We reviewed the current literatures on the applications of CAS for scaphoid operation and summarized technical principles,scan and registration methods,immobilization of limbs and their outcomes.On the basis of the data,we analyzed the limitations of this technique and envisioned its future development.
基金the National Key R&D Program of China,No.2018YFC1313103the National Natural Science Foundation of China,No.81670473 and No.81873546+1 种基金the“Shu Guang”Project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation,No.19SG30the Key Area Research and Development Program of Guangdong Province,China,No.2018B010111001.
文摘BACKGROUND Artificial intelligence in colonoscopy is an emerging field,and its application may help colonoscopists improve inspection quality and reduce the rate of missed polyps and adenomas.Several deep learning-based computer-assisted detection(CADe)techniques were established from small single-center datasets,and unrepresentative learning materials might confine their application and generalization in wide practice.Although CADes have been reported to identify polyps in colonoscopic images and videos in real time,their diagnostic performance deserves to be further validated in clinical practice.AIM To train and test a CADe based on multicenter high-quality images of polyps and preliminarily validate it in clinical colonoscopies.METHODS With high-quality screening and labeling from 55 qualified colonoscopists,a dataset consisting of over 71000 images from 20 centers was used to train and test a deep learning-based CADe.In addition,the real-time diagnostic performance of CADe was tested frame by frame in 47 unaltered full-ranged videos that contained 86 histologically confirmed polyps.Finally,we conducted a selfcontrolled observational study to validate the diagnostic performance of CADe in real-world colonoscopy with the main outcome measure of polyps per colonoscopy in Changhai Hospital.RESULTS The CADe was able to identify polyps in the test dataset with 95.0%sensitivity and 99.1%specificity.For colonoscopy videos,all 86 polyps were detected with 92.2%sensitivity and 93.6%specificity in frame-by-frame analysis.In the prospective validation,the sensitivity of CAD in identifying polyps was 98.4%(185/188).Folds,reflections of light and fecal fluid were the main causes of false positives in both the test dataset and clinical colonoscopies.Colonoscopists can detect more polyps(0.90 vs 0.82,P<0.001)and adenomas(0.32 vs 0.30,P=0.045)with the aid of CADe,particularly polyps<5 mm and flat polyps(0.65 vs 0.57,P<0.001;0.74 vs 0.67,P=0.001,respectively).However,high efficacy is not realized in colonoscopies with inadequate bowel preparation and withdrawal time(P=0.32;P=0.16,respectively).CONCLUSION CADe is feasible in the clinical setting and might help endoscopists detect more polyps and adenomas,and further confirmation is warranted.
文摘The aim of the present study was to compare assessments of sperm concentration and sperm motility analysed by conventional semen analysis with those obtained by computer-assisted semen analysis (CASA) (Copenhagen Rigshospitalet Image House Sperm Motility Analysis System (CRISMAS) 4.6 software) using semen samples from 166 young Danish men. The CRISMAS software identifies sperm concentration and classifies spermatozoa into three motility categories. To enable comparison of the two methods, the four motility stages obtained by conventional semen analysis were, based on their velocity classifications, divided into three stages, comparable to the three CRISMAS motility categories: rapidly progressive (A), slowly progressive (B) and non-progressive (C+ D). Differences between the two methods were large for all investigated parameters (P〈0.001). CRISMAS overestimated sperm concentration and the proportion of rapidly progressive spermatozoa and, consequently, underestimated the percentages of slowly progressive and non-progressive spermatozoa, compared to the conventional method. To investigate whether results drifted according to time of semen analysis, results were pooled into quarters according to date of semen analysis. CRISMAS motility results appeared more stable over time compared to the conventional analysis; however, neither method showed any trends. Apparently, CRISMAS CASA results and results from the conventional method were not comparable with respect to sperm concentration and motility analysis. This needs to be accounted for in clinics using this software and in studies of determinants of these semen characteristics.
文摘Glutathione peroxidase, the first example of selenoproteins identified in mammals, was subjected to force field calculations and molecular dynamics in order to enable a clearer comprehension of enzymatic selenium catalysis. Starting from the established X-ray structure of bovine GPX, all kinetically defined intermediates and enzyme substrate complexes were modelled. The models thus obtained support the hypothesis that the essential steps of the catalysis are three distinct redox changes of the active site selenium which, in the ground state, presents itself at the surface of selenoperoxidases as the center of a characteristic triad built by selenocysteine, glutarnine and tryptophan. In GPX, four arginine residues and a lysine residue provide an electrostatic architecture which, in each reductive step, directs the donor substrate GSH towards the catalytic center in such a way that 1ts sulfhydryl group must react with the selenium moiety. To this end, different equally efficient modes of substrate binding appear possible. The models are consistent with substrate specificity data, kinetic pattern and other functional characteristics of the enzyme. Comparison of molecular models of GPX with those of other members of the GPX superfamily reveals that the cosubstrate binding mechanisrns are unique for the classical type of cytosolic glutathione peroxidases but cannot operate e. g. in plasma GPX and phospholipid hydroperoxide GPX. The structural differences between the selenoperoxidases, shown to be relevant to their specificities, are discussed in terms of functional diversification within the GPX superfamily
基金Supported by the Science and Technology Program in Chinese Medicine of Shandong Province,No.2020M074。
文摘BACKGROUND Most complex renal stones are managed primarily with percutaneous nephrolithotomy(PCNL).However,PCNL is still a great challenge for surgeons because of poor comprehension on complex adjacent structures.Novel techniques are required to assist in planning and navigation.AIM To apply and evaluate the Hisense computer-assisted surgery(CAS)system in PCNL.METHODS A total of 60 patients with complex renal stones were included.Thirty patients in the CAS group had three-dimensional(3 D)virtual models constructed with the CAS system.The model assisted in planning and navigating in the CAS system.Thirty patients in the control group planned and navigated as standard PCNL,without the application of the CAS system.Success rate of one attempt,operation time,initial stone-free rate,decrease in hemoglobin,and complications were collected and analyzed.RESULTS There were no statistically significant differences in the baseline characteristics or planning characteristics.The success rate of one puncturing attempt(90%vs 67%,P=0.028)and the initial stone-free rate(87%vs 63%,P=0.037)were significantly higher in the CAS group.However,there were no statistically significant differences in the operation time(89.20±29.60 min vs 92.33±33.08 min,P=0.859)or in the decrease in hemoglobin(11.07±8.32 g/L vs 9.03±11.72 g/L,P=0.300)between the CAS group and the control group.No statistically significant differences in the incidence of complications(Clavien-Dindo grade≥2)were found.CONCLUSION Compared with standard PCNL,CAS-assisted PCNL had advantages in terms of the puncturing success rate and stone-free rate.The Hisense CAS System was recommended to assist in preoperative planning and intraoperative navigation for an intuitive,precise and convenient PCNL.
文摘Background: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia. The symptoms of hyperglycemia include polyuria, polydypsia, polyphagia, blurred vision and weight loss. Various diagnostic tests are used for the diagnosis of DM in patients, but the findings of these tests cannot be assumed to be completely valid. This study aimed at developing a novel scoring system to assess the patients suffering from DM. Method: We assessed the patients based on various diagnostic tests available for DM and prepared a single list of these tests. The tests were categorized and graded based on the World Health Organization (WHO) criteria. Further, we coverted the grades into numeric values for easy use. Results: NFS for diabetes is an 11-point scoring system that assesses the patient’s condition before and after therapy. To facilitate the conduct of probability based studies, we have converted the scores into numeric values in the range of (0, 1). Each symptom is graded as (1, 2, 3, 4, 5) that runs in BAD → GOOD direction. Conclusion: NFS is a beneficial scoring system that can be used worldwide to assess the patients with DM.
文摘The albumin-bilirubin(ALBI)score,which was proposed to assess the prognosis of patients with hepatocellular carcinoma,has gradually been extended to other liver diseases in recent years,including primary biliary cholangitis,liver cirrhosis,hepatitis,liver transplantation,and liver injury.The ALBI score is often compared with classical scores such as the Child-Pugh and model for end-stage liver disease scores or other noninvasive prediction models.It is widely employed because of its immunity to subjective evaluation indicators and ease of obtaining detection indicators.An increasing number of studies have confirmed that it is highly accurate for assessing the prognosis of patients with chronic liver disease;additionally,it has demonstrated good predictive performance for outcomes beyond survival in patients with liver diseases,such as decompensation events.This article presents a review of the application of ALBI scores in various non-malignant liver diseases.
基金Supported by the“Ricerca Corrente”Grant from Italian Ministry of Health,No.IRCCS SYNLAB SDN.
文摘BACKGROUND Radiomics is a promising tool that may increase the value of magnetic resonance imaging(MRI)for different tasks related to the management of patients with hepatocellular carcinoma(HCC).However,its implementation in clinical practice is still far,with many issues related to the methodological quality of radiomic studies.AIM To systematically review the current status of MRI radiomic studies concerning HCC using the Radiomics Quality Score(RQS).METHODS A systematic literature search of PubMed,Google Scholar,and Web of Science databases was performed to identify original articles focusing on the use of MRI radiomics for HCC management published between 2017 and 2023.The methodological quality of radiomic studies was assessed using the RQS tool.Spearman’s correlation(ρ)analysis was performed to explore if RQS was correlated with journal metrics and characteristics of the studies.The level of statistical significance was set at P<0.05.RESULTS One hundred and twenty-seven articles were included,of which 43 focused on HCC prognosis,39 on prediction of pathological findings,16 on prediction of the expression of molecular markers outcomes,18 had a diagnostic purpose,and 11 had multiple purposes.The mean RQS was 8±6.22,and the corresponding percentage was 24.15%±15.25%(ranging from 0.0% to 58.33%).RQS was positively correlated with journal impact factor(IF;ρ=0.36,P=2.98×10^(-5)),5-years IF(ρ=0.33,P=1.56×10^(-4)),number of patients included in the study(ρ=0.51,P<9.37×10^(-10))and number of radiomics features extracted in the study(ρ=0.59,P<4.59×10^(-13)),and time of publication(ρ=-0.23,P<0.0072).CONCLUSION Although MRI radiomics in HCC represents a promising tool to develop adequate personalized treatment as a noninvasive approach in HCC patients,our study revealed that studies in this field still lack the quality required to allow its introduction into clinical practice.
基金Supported by Ninth People's Hospital affiliated to Shanghai Jiao Tong University,School of Medicine "Multi-Disciplinary Team" Clinical Research Project,No.201701011
文摘BACKGROUND Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing, and breathing as well as temporomandibular joint ankylosis. The main goal of the surgery is to release the ankylosis, establish functioning mandible, and prevent re-fusion.However, surgical procedures for this disease are rarely reported.CASE SUMMARY Here, we report a 7-mo-old girl with bilateral maxillomandibular syngnathia. The patient presented with difficulty in feeding, breathing, sounding, and swallowing and had developmental dysplasia. For treatment, we performed bone isolation by computer-assisted navigation and used silicone to fix the wound surface to prevent refusion of bone. To our knowledge, this is the only syngnathia case in the literature treated using computer-assisted navigation. With the guidance of precise navigation, we were able to minimize operation time by at least one hour,the patient's blood vessels, nerves, and tooth germs were well protected, and excessive bleeding was avoided. After six weeks, the patient showed improvement in mouth opening and no major issues of feeding.CONCLUSION Application of computer-assisted navigation can significantly improve accuracy,effectiveness, and surgical safety in correcting congenital maxillomandibular syngnathia.
文摘The main aim of this editorial is to comment on the recent article published by Garg et al in the World Journal of Gastroenterology 2023;29:4593-4603.This original research presents a new scoring system for fecal incontinence.Fecal incontinence is a chronic disease with a severe impact on the quality of life of the patients.Substantial social stigmatization often leads to significant underreporting of the condition even during visits to a specialist and could lead to further misman-agement or non-existent management of the disease.An important fact is that patients are often unable to describe their condition when not asked precisely defined questions.This problem is partially resolved by scoring questionnaires.Several scoring systems are commonly used;however,each of them has their shortcomings.For example,the absence of different kinds of leakage besides flatus and stool could further lead to underscoring the incontinence severity.Therefore,there has long been a call for a more precise scoring system.The correct identification of the presence and severity of fecal incontinence is paramount for further diagnostic approach and for choosing the appropriate therapy option.This editorial describes fecal incontinence,its effect on quality of life in general and further evaluates the diagnostic approach with a particular focus on symptom scoring systems and their implications for clinical practice.
基金Supported by Smith and Nephew Gmb H,Marl,Germany
文摘AIM: To introduce the navigation system of software and instruments designed specifically for revision total knee arthroplasty(TKA).METHODS: We present an imageless navigation system for revision TKA,with optical point and tracker identification to assess kinematic and anatomical landmarks.The system automatically positions the cutting guides with a motorized cutting unit.The cutting unit is placed on the distal femur with a femoral clamp and acts as a rigid body and the base for all femoral cuts.The surgical technique for using the navigation system for revision TKA is based on the technique used in primary TKA.However,there are some important differences.The most notable are:(1) differences in estimation of the position of the primary implant relative to the bone and the mechanical axes;(2) the specific possibilities the revision navigation software offers in terms of optimal joint level positioning; and(3) the suggested "best fit" position,in which the clock position,stem position and offset,femoral component size,and mediolateral position of the femoral component are taken into account to find the optimal femoral component position.We assessed the surgical technique,and accompanying software procedural steps,of the system,identifying any advantages or disadvantages that they present.RESULTS: The system aims to visualize critical steps of the procedure and is intended as a tool to support the surgeon in surgical decision-making.Combining a computer-assisted cutting device with navigation makes it possible to carry out precise cuts without pinning.Furthermore,the femoral clamp provides a stable fixation mechanism for the motorized cutting unit.A stable clamp is paramount in the presence of periarticular bony defects.The system allows the position of the primary implant relative to the bone and mechanical axes to be estimated,at which point any malalignments can be corrected.It also offers an optimal joint level position for implantation,and suggests a "best fit" position,in which the clock position,stem position and offset,femoral component size,and mediolateral position of the femoral component are considered.The surgeon can therefore make decisions intraoperatively to maximise alignment and,hence,outcomes.Based on the intraoperative findings of joint stability,the surgeon can modify the preoperative plan and switch from a constrained condylar system to a hinged version,or vice versa.CONCLUSION: The system is flexible and easy to learn and allows improvements in workflow during TKA.