Learning curve associated with CT-based navigation assisted cup orientation for muscle-sparing total hip arthroplasty: a cumulative summation analysis

Hip arthroscopy is known to have a steep learning curve by measuring operation times or complication rates. However, these measures are arbitrary and are based on the number of procedures performed rather than clinical outcomes. Recently, Cumulative sum (CUSUM) analysis has been used to monitor the performance of a single surgeon by evaluating clinical outcomes. Our purpose was to determine the learning curve for basic hip arthroscopy technique using CUSUM technique. Forty consecutive patients who underwent hip arthroscopy were evaluated. Modified Harris Hip Score less than 80 at 6 months postoperatively was considered as treatment failure. Patients were chronologically stratified in two groups (the early group--cases 1-20, and the late group--cases 21-40), and age, gender, body mass index, and operation time were compared in both group. CUSUM analysis was then used to plot the learning curve. Eight patients (20 %) experienced treatment failure. Although there was no significant difference of treatment failure rate between the early and late groups (30 vs. 10 %, n.s.), the operation time was shorter in the late group (p = 0.014). In addition, CUSUM analysis showed that failure rates diminished rapidly after 21 cases and reached an acceptable rate after 30 cases. Surgeon's experience is an important predictor of failure after hip arthroscopy, and CUSUM analysis revealed that a learning period is required to become proficient at this procedure, and that experience of approximately 20 cases is required to achieve satisfactory outcomes in terms of clinical outcomes. Surgeon can use the present learning curve for self-monitoring and continuous quality improvement in hip arthroscopy. Retrospective case series, Level IV.

The term motor fitness is most often used synonymously with physical fitness by the coaches but it is very important for the physical education

Image-free navigation has been proven as reliable as that using computed tomography (CT) in positioning the acetabular cup in total hip arthroplasty (THA), but previous studies rarely included hip dysplasia cases. The purpose of the present study was to determine the accuracies of CT-based navigation and image-free navigation for acetabular cup insertion, including hip dysplasia cases. Sixty-three hips were studied, including 57 with hip dysplasia. The hips were divided into two groups based on the registration point of image-free navigation. In Group I, the ipsilateral anterior superior iliac spine (ASIS) and the L5 spinous process were registered in 31 hips. In Group II, bilateral ASIS points were registered in 32 hips. Final component orientation was measured from postoperative CT scans. The accuracy of cup orientation was compared between CT-based and image-free navigation. In Group I, the cup inclination was more accurate with CT-based navigation (1.9°) than with image-free navigation (4.4°, p=.009). Cup anteversion was also more accurate with CT-based navigation (2.9°) than with image-free navigation (7.1°, p<.001). In Group II, the accuracies of cup inclination and anteversion showed no differences between CT-based and image-free navigation. The accuracy of cup positioning was better with CT-based navigation than with image-free navigation when the ipsilateral ASIS and L5 spinous process were digitized. However, accuracy was similar when bilateral ASIS points were digitized.

Learning curve analyses in spine surgery: a systematic simulation-based critique of methodologies

Obesity is known to be associated with postoperative morbidity in gastric cancer surgery, but its impact on laparoscopy assisted gastrectomy (LAG) for gastric cancer has rarely been evaluated. The clinical data for 1,485 LAG procedures for gastric cancer in 10 institutions were reviewed. The patients were divided into high body mass index (BMI) (BMI > or = 25 kg/m(2); n = 432) and low BMI (BMI <25 kg/m(2); n = 1,053) groups, and their clinical outcomes were compared. The mean age and proportion of comorbid patients were higher in the high BMI group than in the low BMI group. Postoperative morbidity and mortality did not differ between the high BMI (15.7% and 0.9%) and low BMI (14% and 0.5%) groups (p = 0.37 and p = 0.29). Only the operation time and the number of retrieved lymph nodes were significantly different between the high BMI (242.5 min and 30.4) and low BMI (223.7 min and 32.6) groups (p < 0.001 and p = 0.005), especially for male patients undergoing surgery by surgeons who have performed 40 or fewer LAGs. High BMI itself may not increase operative morbidity after LAG for gastric cancer. However, when a surgeon is relatively inexperienced with LAG, a careful approach is required for male patients with a high BMI.

Low body mass index is a risk factor for increased post-operative mortality and poor functional improvement in distal femur fractures among patients aged over 65: A multicentre (TRON) study

Robotic-arm assisted surgery aims to reduce manual errors and improve the accuracy of implant positioning and orientation during total hip arthroplasty (THA). The objective of this study was to assess the surgical team's learning curve for robotic-arm assisted acetabular cup positioning during THA. This prospective cohort study included 100 patients with symptomatic hip osteoarthritis undergoing primary total THA performed by a single surgeon. This included 50 patients receiving conventional manual THA and 50 patients undergoing robotic-arm assisted acetabular cup positioning during THA. Independent observers recorded surrogate markers of the learning curve including operative times, confidence levels amongst the surgical team using the state-trait anxiety inventory (STAI) questionnaire, accuracy in restoring native hip biomechanics, acetabular cup positioning, leg-length discrepancy, and complications within 90 days of surgery. Cumulative summation (CUSUM) analysis revealed robotic-arm assisted acetabular cup positioning during THA was associated with a learning curve of 12 cases for achieving operative times (p < 0.001) and surgical team confidence levels (p < 0.001) comparable to conventional manual THA. There was no learning curve of robotic-arm assisted THA for accuracy of achieving the planned horizontal (p = 0.83) and vertical (p = 0.71) centres of rotation, combined offset (p = 0.67), cup inclination (p = 0.68), cup anteversion (p = 0.72), and correction of leg-length discrepancy (p = 0.61). There was no difference in postoperative complications between the two treatment groups. Integration of robotic-arm assisted acetabular cup positioning during THA was associated with a learning curve of 12 cases for operative times and surgical team confidence levels but there was no learning curve effect for accuracy in restoring native hip biomechanics or achieving planned acetabular cup positioning and orientation.

Retrospective review of prospectively collected data. To analyze the learning curves of three spine surgeons for robotic minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Although the learning curve for robotic MI-TLIF has been described, the current evidence is of low quality with most studies being single-surgeon series. Patients who underwent single-level MI-TLIF with three spine surgeons (years in practice: surgeon 1: 4, surgeon 2: 16, and surgeon 3: two) using a floor-mounted robot were included. Outcome measures were operative time, fluoroscopy time, intraoperative complications, screw revision, and patient-reported outcome measures. Each surgeon's cases were divided into successive groups of 10 patients and compared for differences. Linear regression and cumulative sum (CuSum) analyses were performed to analyze the trend and learning curve, respectively. A total of 187 patients were included (surgeon 1: 45, surgeon 2: 122, and surgeon 3: 20). For surgeon 1, CuSum analysis showed a learning curve of 21 cases with the attainment of mastery at case 31. Linear regression plots showed negative slopes for operative and fluoroscopy time. Both learning phase and postlearning phase groups showed significant improvement in patient-reported outcome measures. For surgeon 2, CuSum analysis demonstrated no discernible learning curve. There was no significant difference between successive patient groups in either operative time or fluoroscopy time. For surgeon 3, CuSum analysis demonstrated no discernible learning curve. Even though the difference between successive patient groups was not significant, cases 11 to 20 had an average operative time of 26 minutes less than cases 1-10), suggesting an ongoing learning curve. Surgeons who are well-experienced can be expected to have no or minimal learning curve for robotic MI-TLIF. Early attendings are likely to have a learning curve of around 21 cases with the attainment of mastery at case 31. Learning curve does not seem to impact clinical outcomes after surgery. Level 3.

ObjectiveWe aimed to explored the association between atherogenic index of plasma (AIP), body mass index (BMI) and stroke risk among people with abnormal glucose metabolism.MethodsThis study included participants with abnormal glucose metabolism from the China Health and Retirement Longitudinal Study (CHARLS). AIP was computed using the formula log (Triglyceride/High-density lipoprotein cholesterol). Participants were categorized into high and low levels based on median values for both AIP and BMI. Logistic regression models were employed to investigate the associations between AIP, BMI, and stroke.ResultsIn the longitudinal analysis, 195 out of 3,682 individuals (5.3%) experienced stroke. Joint effects of AIP and BMI on stroke risk indicated that odds ratios for stroke were 1.41 (0.86-2.31) for high AIP & low BMI group, 1.81 (1.14-2.89) for low AIP & high BMI group, and 2.15 (1.42-3.27) for high AIP & high BMI group when compared to low AIP & low BMI group. A significant interaction was observed between AIP and BMI regarding stroke risk. However, this association appeared diminished within cross-sectional evaluations.ConclusionElevated levels of both AIP and BMI are significantly correlated with an increased risk of stroke among individuals exhibiting abnormal glucose metabolism during longitudinal analysis.

Endoscopic spine surgery has been widely performed to treat degenerative spinal diseases to mitigate the risks and complications associated with traditional open surgery. However, endoscopic procedures pose challenges, including a limited field of view and a restricted operating space, which can affect the surgeon's learning curve. This study aimed to evaluate the learning curves for unilateral biportal endoscopic spinal surgery (UBESS) and percutaneous transforaminal endoscopic surgery (PTES) by performing cumulative sum (CUSUM) analysis and to assess their efficacies in managing degenerative spinal diseases. This retrospective cohort study included 100 consecutive patients who underwent PTES and 100 consecutive patients who received UBESS. CUSUM analysis was conducted to assess the learning curve, with cutoff points used to categorize the early and late phases. These two phases were analyzed in terms of differences in operative time, hospital stay, complications, and patient-reported outcome measures (PROMs). Additionally, PROMs between the PTES and UBESS groups, which were performed by the same surgeon, were compared. CUSUM analysis revealed that the operative time for PTES and UBESS decreased after 35 and 28 cases, respectively. Both early- and late-phase cases exhibited significant improvement in all PROMs postoperatively. Furthermore, PROMs did not differ between patients who underwent PTES and those who underwent UBESS. Both procedures achieved comparable clinical outcomes with low complication incidences. However, achieving proficiency in PTES required a learning curve of at least 35 cases, whereas that in UBESS required a minimum of 28 cases.

The aim of this study was to evaluate the impact of surgical experience on laparoscopic distal gastrectomy in high body mass index (BMI) patients. Retrospective data were collected on patients who underwent laparoscopic distal gastrectomy for early gastric cancer from July 2002 to December 2014. Patients were divided into a high BMI group (BMI≥25 kg/m) and a low BMI group (BMI<25 kg/m) and classified into subgroups by surgeon experience. Patient characteristics and surgical outcomes between groups were analyzed and compared. Mean operation time in the high BMI group was longer than the low BMI group (173.0±52.5 vs. 164.2±48.0 min; P=0.009). Subgroup analysis showed longer operation time in the high BMI group than the low BMI group (200.8±49.3 vs. 187.9±45.2 min; P<0.001) and fewer retrieved lymph nodes (36.3±11.7 vs. 33.0±13.1; P=0.004) in the early surgeon experience period. Patients in the late experience period showed no significant differences in surgical outcomes between the high BMI and low BMI group. High BMI did not influence surgical outcomes of laparoscopic distal gastrectomy after accumulation of surgical experience.

139 Background: Obesity is considered as a major perioperative risk factor in various cancer surgeries. We aimed to elucidate the effect of two different obesity index, such as VFA (visceral fat area) and BMI (body mass index), on gastrectomy. Methods: From Mar 2009 to July 2010, 632 patients with diagnosed gastric carcinoma underwent curative gastrecomy at Seoul St. Mary’s hospital. We reviewed patients’ clinicopatholic data and collected 187 patients who had data including BMI, VFA and SFA. Patients with body mass index (BMI) ≥ 25 kg/m 2 were defined as obese and visceral fat area (VFA) ≥ 100 were defined as centrally obese. Results: Out of a total 187 patients, eighty patients were in the high BMI group and 107 patients were in the low BMI group. We selected patients with high VFA and low BMI (group A) and compared to the patients with low VFA and low BMI (group B). Out of a total 107 patients in low BMI, seventy three patients were censored as high VFA, and age older than 60 and male patients were prevalent in this group (p=0.045 and 0.046). The operation time (OT) and estimated blood loss (EBL) were significantly higher in group A than group B (p=0.043 and p=0.05). Conclusions: VFA and BMI are correlated each other and successfully represent patients’ obesity. However in selected patients, such as male patients with age older than sixty, VFA more practically represent their obesity.

The objective of the study was to evaluate the contribution of insulin resistance and β cell dysfunction to gestational diabetes mellitus (GDM) in Chinese women stratified by pre-pregnant body mass index (BMI). A total of 847 pregnant women were enrolled. They were divided into low BMI and high BMI groups according to the median of pre-pregnancy BMI. The homeostasis model assessment of insulin resistance (HOMA-IR) and β cell function (HOMA-β), Matsuda index, and 60-min insulinogenic index (IGI60) were used to evaluate insulin resistance and β cell function. In all the participants, 150 (17.71%) were diagnosed with GDM. ROC analyses showed that in the low BMI group, the association of β cell dysfunction (IGI60 or HOMA-β) with GDM was stronger than that of insulin resistance (Matsuda index or HOMA-IR), while in the high BMI group, the association of β cell dysfunction with GDM was weaker than that of insulin resistance (all P < 0.05). Among all GDM patients, 47.33% demonstrated predominant insulin resistance (Matsuda index < 25th percentile), and 46% had predominant β cell defect (IGI60 < 25th percentile). In the low BMI group, 15.09% of GDM patients demonstrated predominant insulin resistance, and 62.26% of GDM patients had predominant β cell defect, whereas in the high BMI group, 64.95% of GDM patients demonstrated mainly insulin resistance and 36.08% of GDM patients had mainly β cell defect. In women with low BMI, β cell dysfunction is the major etiologic factor, whereas, in women with high BMI, insulin resistance is the predominant etiologic factor in the development of GDM.

Obesity increases the risk for many diseases, including some malignancies. We found that in diffuse large B-cell lymphoma, the most common form of non-Hodgkin's lymphoma, patients with higher body mass index had significantly longer overall survival. Patients with peripheral T-cell lymphoma usually have worse outcomes than those with diffuse large B-cell lymphoma. Nonetheless, the association between body mass index at diagnosis and survival in patients with peripheral T-cell lymphoma remains unclear. This retrospective study included 411 peripheral T-cell lymphoma patients from January 2010 to July 2017. Patients were stratified by body mass index into low body mass index (<24.0kg/m2) and high body mass index (≥24.0kg/m2) groups. We mainly used Cox modelling and the Kaplan-Meier method to evaluate survival and other variables. Multivariate analysis demonstrated that body mass index, international prognostic index and triglyceride level were independent prognostic factors of overall survival. Interestingly, patients with high body mass index had significantly longer overall survival (P<0.01), with 69% of patients alive at 3years versus 43% in the low body mass index group. Cox analysis showed reduced mortality in the high body mass index group compared with the low body mass index group (hazard ratio=0.511, 95% CI, 0.309-0.846, P=0.009). In addition, patients with high body mass index and low international prognostic index had the longest overall survival (P<0.001). High body mass index at the time of diagnosis was associated with improved overall survival in Chinese peripheral T-cell lymphoma patients.

Objective To investigate the learning curve of Da Vinci robot-assisted laparoscopic radical gastrectomy for gastric cancer. Methods The retrospective cohort study was conducted. The clinicopathological data of 42 patients who underwent Da Vinci robot-assisted radical gastrectomy for gastric cancer in the First Affiliated Hospital of Xi′an Jiaotong University from October 2017 to August 2018 were collected. There were 30 males and 12 females, aged from 36 to 84 years, with an average age of 59 years. The learning curve was evaluated using the cumulative sum (CUSUM) analysis and the best fitting curve method. According to the minimum number of surgeries required to cross the learning curve, the patients were divided into learning stage group and mastery stage group. Then general data and surgical efficacy of the two groups were compared. Observation indicators: (1) surgical situations; (2) results of CUSUM analysis; (3) comparison of general data between the two groups; (4) comparison of surgical efficacy between the two groups; (5) follow-up. Patients were followed up by outpatient examination or telephone interview to detect the postoperative complications, tumor recurrence and metastasis up to February 2019. Measurement data with normal distribution were presented as Mean±SD, and comparison between groups was done using the independent sample t test. Count data were represented as absolute number, and comparison between groups was analyzed using the chi-square test or Fisher exact propability. Comparison of ordinal data between groups was analyzed using the Mann-Whitney U test. Results (1) Surgical situations: all the 42 patients underwent Da Vinci robot-assisted radical gastrectomy for gastric cancer successfully, without conversion to open surgery or perioperative death. Fourteen out of 42 patients underwent Da Vinci robot-assisted total radical gastrectomy and 28 underwent Da Vinci robot-assisted distal radical gastrectomy. The operation time and docking time were (213±31)minutes and (26±11)minutes. The operation time and docking time had a tendency to decreasing as the surgical cases increasing. (2) Results of CUSUM analysis. The CUSUM learning curve were best modeled as a polynomial with equation: CUSUM (operation time)=0.016 9X3-1.913 3X2+ 50.985X-16.595, CUSUM(docking time)=0.012 8X3-1.070 7X2+ 22.189X-23.097 respectively (X means the surgical case). The P value of fitting test of models was 0.05). There was no significant difference in the previous abdominal surgery history between the two groups (P>0.05). (4) Comparison of surgical efficacy between the two groups: operation time, volume of intraoperative blood loss, number of lymph nodes harvested, time to first liquid food intake, cases with postoperative complications and duration of postoperative hospital stay were (230±25)minutes, (176±103)mL, 21±7, (5.1±2.0)days, 2, (9.3±2.5)days in the learning stage group, and (191±18)minutes, (95±41)mL, 21±6, (4.7±1.7)days, 3, (8.4±2.1)days in the mastery stage group, respectively. There were statistically significant differences in the operation time and volume of intraoperative blood loss between the two groups (t=5.951, -3.359, P 0.05). There was no significant difference in the cases with postoperative complications between the two groups (P>0.05). (5) Follow-up: all the 42 patients were followed up for 6-16 months, with a median time of 11 months. No serious long-term complications, tumor recurrence and metastasis or death occurred during the follow-up. Conclusions The CUSUM learning curve of Da Vinci robot-assisted radical gastrectomy for gastric cancer can be divided into the learning stage and the mastery stage. It is suggested that the surgeons need to finish 19 cases or more to master Da Vinci robot-assisted radical gastrectomy for gastric cancer. Key words: Gastric neoplasms; Gastric cancer; Cumulative sum analysis; Best fitting curve; Learning curve; Da Vinci robotic surgical system