True Failure Rate Research Articles

Determining the Failure Rate of Direct Restorations-Chart Review versus Electronic Health Record Reports.

Amalgam and composite restorations are used to treat minor dental issues. University of Michigan, School of Dentistry Electronic Health Record (EHR) reports show a 2.31% failure rate for amalgam and 1.14% for composite. Our study aims to determine the true failure rates through manual EHR chart reviews. Patient data from the University of Michigan School of Dentistry were utilized-216 amalgam restorations from 2020 to 2022 and 350 composite restorations in 2021 were searched. We defined failure and retreatment as replacing a restoration with the same material and failure and alternate treatment as replacing restoration with an alternative treatment within one year. The failure rate refers to a combination of replacement with the same and alternative treatment material within one year. For Amalgam: 1.85% failed and were retreated; 7.87% failed and were received an alternate treatment. Composite: 9.71% failed and retreated; 2.86% failed and received alternate treatment. In total anterior composite: 10.5% retreated, 2.6% failed; posterior composite: 9.1% retreated, 3.0% failed. Our study revealed higher restoration failure rates than the reports extracted in the EHR. This highlights the need to foster a culture of precise documentation to align EHR reports with hand-search findings.

THE SURVIVAL OF TOTAL ANKLE ARTHROPLASTIES: A DATA LINKAGE STUDY FROM THE NATIONAL JOINT REGISTRY

IntroductionDespite the increasing numbers of ankle replacements that are being performed there are still limited studies on the survival of ankle replacements and comparisons between different implants. The primary aim of this study is to link NJR data with NHS digital data to determine the true failure rates of ankle replacements. Secondary outcomes include analysis risk factors for failure, patient demographics and outcomes of individual prosthesis.MethodsA data linkage study combined National Joint Registry Data and NHS Digital data. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device inserted during ankle replacement surgery. Life tables and Kaplan Meier survival charts demonstrated survivorship. Cox proportional hazards regression models with the Breslow method used for ties were fitted to compare failure rates.Results5,562 primary ankle replacement were recorded on the NJR. The 1-year survivorship was 98.8% (95% CI 98.4%–99.0%), 5-year survival in 2725 patients was 90.2% (95% CI 89.2%–91.1%), and 10-year survival in 199 patients was 86.2% (95% CI 84.6%–87.6%).When using a Cox regression model for all implants with over 100 implantations using the Infinity as the reference, only the Star (Hazard ratio 1.60 95% CI 0.87–2.96) and Inbone (HR 0.38 95% CI 0.05–2.84) did not produce significantly worse survivorship.ConclusionAnkle replacements have increased in numbers over the past decade, and the currently used implants have lower failure rates than older prosthesis. It is expected that in the future the outcomes of ankle replacements will continue to improve.

Gross failure rates and failure modes for a commercial AI-based auto-segmentation algorithm in head and neck cancer patients.

Artificial intelligence (AI) based commercial software can be used to automatically delineate organs at risk (OAR), with potential for efficiency savings in the radiotherapy treatment planning pathway, and reduction of inter- and intra-observer variability. There has been little research investigating gross failure rates and failure modes of such systems. 50 head and neck (H&N) patient data sets with "gold standard" contours were compared to AI-generated contours to produce expected mean and standard deviation values for the Dice Similarity Coefficient (DSC), for four common H&N OARs (brainstem, mandible, left and right parotid). An AI-based commercial system was applied to 500 H&N patients. AI-generated contours were compared to manual contours, outlined by an expert human, and a gross failure was set at three standard deviations below the expected mean DSC. Failures were inspected to assess reason for failure of the AI-based system with failures relating to suboptimal manual contouring censored. True failures were classified into 4 sub-types (setup position, anatomy, image artefacts and unknown). There were 24 true failures of the AI-based commercial software, a gross failure rate of 1.2%. Fifteen failures were due to patient anatomy, four were due to dental image artefacts, three were due to patient position and two were unknown. True failure rates by OAR were 0.4% (brainstem), 2.2% (mandible), 1.4% (left parotid) and 0.8% (right parotid). True failures of the AI-based system were predominantly associated with a non-standard element within the CT scan. It is likely that these non-standard elements were the reason for the gross failure, and suggests that patient datasets used to train the AI model did not contain sufficient heterogeneity of data. Regardless of the reasons for failure, the true failure rate for the AI-based system in the H&N region for the OARs investigated was low (∼1%).

Proof testing to improve the reliability and lifetime of ceramic dental prostheses.

Ceramic dental prostheses exhibit increasing failure rates with service time. In particular, veneered crowns and bridges are susceptible to chipping and other fracture modes of failure. The purpose of this manuscript is to introduce a computational methodology and associated software that can predict the time-dependent probability of failure for ceramic prostheses and subsequently design proof test protocols to significantly enhance their reliabilities and lifetimes. Transient reliability and corresponding proof testing theories are introduced. These theories are coded in the Ceramic Analysis and Reliability Evaluation of Structures (CARES/Life) code. This software will be used to demonstrate the predictive capability of the theory as well as its use in designing proof test protocols to significantly improve the reliability (survival probability) and lifetime for dental prostheses. A three-unit fixed dental prosthesis (FDP) with zirconia core (ZirCAD) and veneering ceramic (ZirPress) are used to compare the predicted probabilities of failure to general clinical results. In addition, the capability to use proof testing to significantly improve the performance (reliability and lifetime) for this restoration is demonstrated. The probability of failure, Pf, after five years without proof testing is predicted to be 0.337. This compares to clinical studies showing the failure rate to be between 0.2 and 0.23 after 5 years. After 10 years, reference 18 found the clinical failure rate for similar bridges (but not the same) to be up to 0.28 compared to the predicted Pf of 0.38. The difference may be due to the analysis applying the load at an inclination of 75° which is more critical than vertical loading. In addition, clinical studies often report a simple survival rate instead of using Kaplan-Meier analysis to properly account for late enrollees. Therefore, true clinical failure rates may be higher than reported and may more closely match the predictions of this manuscript. The effectiveness of proof testing increases with selecting materials less susceptible to slow crack growth (higher SCG exponent, N). For example, proof testing the ZirPress glass-veneered bridges with N=43.4 analyzed in this manuscript at 400N bite force for 1s which induces a failure rate during proof testing of 0.31, reduces the Pf of bridges not proof tested from 0.45 to an attenuated-proof-tested probability of failure Pfa of 0.21 after 20 years of usage. If another material is selected with improved resistance to SCG of N=60 and the same loading conditions, the failure rate for the proof tested bridges after 20 years of service drops to 2 in 10,000 from 2.4 in 100 had they been not proof tested. The failure rate during proof testing for this material would be 5.1 in 100. Proof testing a material with absolutely no susceptibility to SCG at the same service load (in this case 285N, not even the 400N load used above) results in 0 % failure rate and is of course independent of time. The transient reliability and proof test theory presented in this paper and associated computational software CARES/Life were successful in predicting the performance of ceramic dental restorations when compared to clinical data. Well-designed proof test protocols combined with proper material selection can significantly enhance the reliabilities and lifetimes of ceramic prostheses. This proof test capability can be a translational technology if properly applied to dental restorations.

P056Oral contraceptive adherence and pregnancy rates in estetrol/drospirenone pooled phase 3 trials

<h3>Objectives</h3> To assess the relationship of adherence and pregnancy in participants using an estetrol and drospirenone combined oral contraceptive. <h3>Methods</h3> We pooled data from two parallel, multicenter, open-label, phase 3 trials (US/Canada and Europe/Russia) that enrolled healthy participants aged 16–50 to receive estetrol 15 mg/drospirenone 3 mg in a 24/4 regimen for up to 13 cycles. We limited this efficacy analysis to participants aged 16–35 at screening. Participants reported adherence using paper diaries. We assessed the relationship between number of missed pills and pregnancies in at-risk cycles (≥1 confirmed intercourse and no other contraceptive use) and when pregnancies occurred during product use with test for trend and chi-square analyses as appropriate. <h3>Results</h3> Among 3,027 participants in this analysis, 31 on-treatment pregnancies occurred during 26,455 at-risk cycles of use for an overall Pearl Index of 1.52 (95% CI, 1.04–2.16). Pregnancies occurred in 0.09%, 0.25%, 0.83%, and 1.6% of cycles in which participants reported missing 0 (n=25,613 cycles), 1 (n=405 cycles), 2 (n=121 cycles) and >2 (n=314 cycles) active pills, respectively (p<0.0001). Pregnancy rates ranged from 0-0.21% per cycle with no significant trend by cycle (p=0.45). About half (48.4%) of all pregnancies occurred in the first four cycles, with pregnancies occurring in 0.17% of cycles vs. 0.08% during cycles 5–8 and 0.10% in cycles 9–13 (p=0.07). <h3>Conclusions</h3> Pregnancy occurs more frequently when combined oral contraceptive users report missing pills and exceeds 1% only when >2 pills are missed. A 0.09% pregnancy risk among users reporting no missed pills likely approximates a true method failure rate.

A Cohort Study of Risk Factors for Failure of Total Ankle Replacements: A Data Linkage Study using the National Joint Registry and NHS Digital

Category: Ankle Arthritis Introduction/Purpose: Despite the increasing numbers of ankle replacements that are being performed there are still limited studies on the survival of ankle replacements and which factors influence survivorship comparisons between different implants. The primary aim of this study is to link NJR data with NHS digital data to determine the true failure rates of ankle replacements and to determine the risk factors for failure of total ankle replacements Methods: A data linkage study combined National Joint Registry Data and NHS Digital data. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device inserted during ankle replacement surgery. Life tables and Kaplan Meier survival charts demonstrated survivorship. Cox proportional hazards regression models with the Breslow method used for ties were fitted to compare failure rates. Results: 5,562 primary ankle replacement were recorded on the NJR between 1st April 2010 and 31st December 2018. The unadjusted 1-year survivorship of ankle replacements was 98.8% (95% CI 98.4%-99.0the 5-year survival in 2725 patients was 90.2% (95% CI 89.2%-91.1) and the 10-year survival in 199 patients was 86.2% (95% CI 84.6%-87.6%). In univariate cox regression models age, BMI, ASA, Charlson co-morbidity score, indication for surgery were significantly associated with an increased risk of failure. In multivariate cox regression models only age (HR 0.956, 95% CI 0.942-0.970), BMI (HR 1.032, 95% CI 1.006-1.059) and indication (HR 0.880, 95% CI 0.799-0.968) were associated with an increased risk of failure. Conclusion: Ankle replacements have been demonstrated to have higher failure rates in younger patients, those with an increased BMI, and those with osteoarthritis. These findings should be taken into account when deciding which patients should undergo an ankle replacement and in counselling them on the likely survivorship of their ankle replacement

Meniscal Repair Outcomes at &gt;5 Years: A Systematic Review and Meta-Analysis

Introduction:Meniscal repair techniques (inside-out, all-inside, outside-in) continue to evolve. Assessment of meniscus repair outcomes at a minimum of 5 years postoperatively appears to best represent the true failure rates compared to 1 and 2-year timepoints. In the last decade, the literature on outcomes of meniscus repair has grown significantly.Purpose:To conduct a systematic review and meta-analysis to assess the rate of failure after meniscal repair at a minimum 5 years postoperatively.Methods:We performed a systematic review of studies reporting the outcomes of meniscal repair at a minimum of 5 years postoperatively. A standardized search strategy was utilized with the assistance of a medical librarian. s and full-text articles were reviewed by two reviewers to identify studies assessing the clinical outcome of meniscus repair, which was most uniformly assessed by reoperation. Outcomes were assessed (when reported) relative to anterior cruciate ligament (ACL) status, sex, age, and postoperative rehabilitation protocol. Pooling of data and meta-analysis with a random-effects model were performed.Results:A total of 28 studies of 1712 patients were included. In the last decade, 15 studies of 1168 patients have been reported, compared to 566 patients in 13 studies in the previous decade. The pooled failure rate of all devices was 22.2% (365/1712) and the failure rates of modern repairs was 17.5% (194/1128). Medial repairs were significantly more likely to fail compared to lateral repairs (26.4% [178/745] v. 13.0% [55/365], p=0.01). Failure rates varied from 16.9% for inside-out (78/501), 16.2% modern all-inside (66/396), 20.2% for outside-in (34/153), and 19.8% for open (22/109). First generation all-inside devices had a significantly higher failure rate (30.3%) compared to modern all-inside devices (16.2%) (p=0.01). There was no significant difference in failure rates between meniscal repair with concomitant ACL reconstruction (19.0%) and isolated meniscal repairs (19.6%, p=0.780). There was also no difference between post-operative rehabilitation protocols, sex, or age (all p>0.05).Conclusions:The outcomes of meniscal repair at a minimum 5 years postoperatively had an overall failure rate of 21.8%. Modern all-inside meniscus repair techniques appear to have improved the success rates compared to first-generation all-inside devices, and now appear similar to those of inside-out meniscus repair. Lateral repairs were significantly more likely to be successful compared to medial repairs. Finally, despite traditional teaching that ACL reconstruction improves rates of meniscus healing, across ˜700 patients, no difference in rates of healing were seen in ACL reconstruction compared to isolated meniscus repair.Figure 1.Scatter Plot of the failure rate reported by the study compared time of follow up completed. Each study is represented by a dot, the size of which represents the indivudual study’s sample size. A simple linear regression line of best fit is shown (R2=0.02).Figure 2.Forest plot demonstrating failure rates sorted by the technique of repair used. All inside divices were subdivided into first generation (meniscal arrows) and modern (defined as 2nd generation and newer). Other techniques include inside out, outside in, and open.Es=Estimated significance; 95% CI-95% Confidence interval.

Meniscal Repair Outcomes at Greater Than 5 Years: A Systematic Review and Meta-Analysis.

The utilization of meniscal repair techniques continues to evolve in an effort to maximize the rate of healing. Meniscal repair outcomes at a minimum of 5 years postoperatively appear to better represent the true failure rates. Thus, a systematic review and meta-analysis of the current literature was conducted to assess the rate of failure at a minimum of 5 years after meniscal repair. We performed a systematic review of studies reporting the outcomes of meniscal repair at a minimum of 5 years postoperatively. A standardized search and review strategy was utilized. Failure was defined as recurrent clinical symptoms or a meniscal reintervention to repair or resect the meniscus in any capacity, as defined by the study. When reported, outcomes were assessed relative to anterior cruciate ligament (ACL) status, sex, age, and postoperative rehabilitation protocol. Meta-analyses were performed with a random-effects model. A total of 27 studies of 1,612 patients and 1,630 meniscal repairs were included in this review and meta-analysis. The pooled overall failure rate was 22.6%, while the failure rate of modern repairs (excluding early-generation all-inside devices) was 19.5%. Medial repairs were significantly more likely to fail compared with lateral repairs (23.9% versus 12.6%, p = 0.04). Failure rates were similar for inside-out (14.2%) and modern all-inside repairs (15.8%). Early-generation all-inside devices had a significantly higher failure rate (30.2%) compared with modern all-inside devices (15.8%, p = 0.01). There was no significant difference in meniscal failure rate between repairs with concomitant ACL reconstruction (21.2%) and repairs in ACL-intact knees (23.3%, p = 0.54). Modern meniscal repair had an overall failure rate of 19.5% at a minimum of 5 years postoperatively. Modern all-inside techniques appear to have improved the success rate of meniscal repair compared with use of early-generation all-inside devices. Lateral repairs were significantly more likely to be successful compared with medial repairs, while no difference was seen between patients undergoing meniscal repair with and without concomitant ACL reconstruction. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Ultra-short versus standard-length dental implants in conjunction with osteotome-mediated sinus floor elevation: A randomized controlled clinical trial.

The ability to restore missing teeth with dental implants is dictated by the available bone and by the presence of anatomical structures. The potential to insert ultrashort implants avoids additional surgical procedures and its inherent complications. The last European Association of Dental Implantologists consensus in 2016 defined ultrashort implants and standard-length dental implants as <6 and >8 mm, respectively. The present study aimed to investigate whether single standing ultrashort dental implants (US) could provide a viable therapeutic alternative to osteotome mediated sinus floor elevation in combination with standard-length dental implants (SL) 10 mm in posterior maxillary rehabilitation with reduced bone height. The study was conducted as a prospective parallel group controlled clinical trial with a 12 month follow-up, where 48 implants were randomized into two groups; US-group (5.5 mm) and SL-group (10 mm) implants placed with osteotome-mediated sinus floor elevation. Crestal bone loss (CBL) was defined as the study's primary outcome, while implant survival, buccal bone thickness, implant stability, probing depth, gingival recession, and adverse effects were assessed as secondary outcomes. Mesial CBL was 1.13 ± 0.52 mm in SL- and 0.72 ± 0.52 mm in US-group (P=.021), while distal CBL was 1.44 ± 0.72 mm in SL- and 0.91 ± 0.69 mm in US-group at 12 months (P=.0179). Regarding implant stability, probing depth, and gingival recession there was no statistically significant difference between the two groups. Regarding implants' survival, three implants were lost in the US-while only one implant was lost in the SL-group (P=.6085; Fisher's exact test). Nevertheless, the ultrashort implants were associated with a tripling of the failure rate and uncertainty where the true failure rate is uncertain (relative risk 3.0; confidence interval 0.3-26.8). Within the current trial's limitations, US-appear appear promising as they are associated less postoperative discomfort, minimal invasiveness and less CBL. However, larger sample size is required to determine whether the ultrashort have an acceptable survival rate.

Opioid Free Ureteroscopy: What is the True Failure Rate?

ObjectiveTo determine the true failure rate of opioid free ureteroscopy (OF-URS) and rates of new-persistent opioid use utilizing a national prescription drug monitoring program. Material and MethodsWe identified 239 patients utilizing our retrospective stone database who underwent OF-URS from Februrary 2018-March 2020. In Feb 2018, we initiated a OF-URS pathway (diclofenac, tamsulosin, acetaminophen, pyridium and oxybutynin). Patients who had a contraindication to NSAIDs were excluded from primary analyses. A prescription drug monitoring program was then utilized to determine the number of patients who failed OF-URS (defined as receipt of an opioid within 31 days of surgery) as well as rates of new-persistent opioid use (defined as receipt of opioid 91-180 days after surgery).All statistical analyses were performed using SAS 9.4. Tests were 2-sided and statistical significance was set at P<0.05. ResultsWe found a OF-URS failure rate of 16.6% and 14.0% in the total and opioid naïve cohorts, respectively. Rates of new-persistent opioid use were 0.9% and 1.2%, respectively (lower than published expected rate of ~6% after URS with postoperative opioids). 91% of patients obtained opioid from alternative sources. Uni/multivariate analyses were performed for both cohorts. In the total cohort, benzodiazepine users had a higher risk of OF-URS failure on multivariate analysis. No variables were associated with OF-URS failure in the opioid naïve cohort. ConclusionThe true failure rate of OF-URS is higher than previously thought at 16.6% and 14.0%. However, efforts to reduce opioid prescriptions with OF-URS pathways have successfully reduced new-persistent opioid use.

Abstract P297: The Accuracy of the Comprehensive Stroke Performance CSTK-5b Measure Rates

Introduction: Symptomatic intracerebral hemorrhage (ICH) is a feared complication of reperfusion therapy in acute ischemic stroke. The Joint Commission (JC) national quality measure Comprehensive Stroke (CSTK-5b) reflects the rate of symptomatic ICH after mechanical thrombectomy (MT) and is used as a marker of comprehensive stroke center (CSC) performance. We sought to determine the accuracy of the CSKT-5b as determined by vascular neurologists. Methods: We reviewed the CSTK-5b failures in our JC certified CSC program for the years 2018 and 2019. Our CSC abstractors follow the instructions from the Joint Commission National Quality Measures manual without deviation and do not allow for clinician over-ride or adjudication (consistent with manual instructions). All CSKT-5b failures were reviewed by study neurologists to determine the true CSTK-5b rate. Data was collected on National Institute of Health Stroke Scale (NIHSS), symptomatic ICH, and neuroimaging results. European Cooperative Acute Stroke Study (ECASS) definitions were used and included hemorrhagic infarction (HI) (grade 1 or 2) and parenchymal hematoma (PH) (grade 1 or 2). Results: Among 361 MT patients for the 2 year period, the CSTK-5b failure rate reported to JC was 34/250 (13.6%), whereas the true rate was 21/250 (8.4%). Among the 13 cases that were miscoded, the ECASS grading included 1 HI-1, 7 HI-2, 1 PH-1, and 4 subarachnoid hemorrhage, and all had a 4 point change in NIHSS that was determined to be clinically unrelated to ICH. Comparing annual data, the 2018 CSTK-5b failure rate was 14/111 (12.6%) whereas the true CSTK-5b failure rate was 7/111 (6.3%). In 2019, the CSTK 5b failure rate was 20/139 (14.4%), whereas the true CSTK-5b failure rate was 14/139 (10.1%). Conclusions: Non-physician abstractors relying on instructions from the JC manual over-estimate the rate of CSKT-5b measure failure. The determination of symptomatic ICH after MT is complex and requires clinical knowledge for accuracy.

Success and failure are dynamic, recurrent event states after surgical treatment for pelvic organ prolapse

The ideal measure of success after surgery for pelvic organ prolapse has long been debated. Historically, strict definitions based on anatomic perfection have dominated the literature. However, the importance of patient-centered perception of outcomes is equally or more important when comparing the success of various prolapse surgeries. Understanding the limitations of existing outcome definitions will guide surgical outcome reporting and comparisons of pelvic organ prolapse surgeries. This study aimed to describe the relationships and overlap among the participants who met the anatomic, subjective, and retreatment definitions of success or failure after pelvic organ prolapse surgery; demonstrate rates of transition between success and failure over time; and compare scores from the Pelvic Organ Prolapse Distress Inventory, Short-Form Six-Dimension health index, and quality-adjusted life years among these definitions. Definitions of surgical success were evaluated at 3 or 6, 12, 24, 36, 48, and 60 months after surgery for ≥stage II pelvic organ prolapse in a cohort of women (N=1250) from 4 randomized clinical trials conducted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Pelvic Floor Disorders Network. Surgical failure was defined by a composite measure requiring 1 or more of (1) anatomic failure (Pelvic Organ Prolapse Quantification point Ba, Bp, or C of >0), (2) subjective failure (presence of bothersome vaginal bulge symptoms), or (3) pessary or surgical retreatment for pelvic organ prolapse. Pelvic Organ Prolapse Distress Inventory, Short-Form Six-Dimension health index, and quality-adjusted life years were compared among participants who met a variety of definitions of success and failure including novel "intermittent" success and failure over time. Among the 433 of 1250 women (34.6%) who had surgical failure outcomes at ≥1 time point, 85.5% (370 of 433) met only 1 component of the composite outcome at the assessment of initial failure (anatomic failure, 46.7% [202 of 433]; subjective failure, 36.7% [159 of 433]; retreatment, 2.1% [9 of 433]). Only 12.9% (56 of 433) met the criteria for both for anatomic and subjective failure. Despite meeting the criteria for failure in primary study reporting, 24.2% of these (105 of 433) transitioned between success and failure during follow-up, of whom 83.8% (88 of 105) met the criteria for success at their last follow-up. There were associations between success or failure classification and the 1- and 2-year quality-adjusted life years and a time-varying group effect on Pelvic Organ Prolapse Distress Inventory and Short-Form Six-Dimension health index scores. True failure rates after prolapse surgery may be overestimated in the current literature. Only 13% of clinical trial subjects initially met both subjective and objective criteria for failure. Approximately one-quarter of failures were intermittent and transitioned between success and failure over time, with most intermittent failures being in a state of "surgical success" at their last follow-up. Current composite definitions of success or failure may result in the overestimation of surgical failure rates, potentially explaining, in part, the discordance with low retreatment rates after pelvic organ prolapse surgery.

Arthroscopic Superior Capsular Reconstruction of the Shoulder Using Dermal Allograft

Irreparable massive cuff tears in young patients pose a difficult problem for shoulder surgeons. Arthroscopic superior capsular reconstruction has shown promise in recent years in the treatment of this challenging patient population. The majority of the literature is limited to surgical techniques. The authors present the 2-year clinical outcomes of 25 patients undergoing arthroscopic superior capsular reconstruction with dermal allograft from a single center. The Oxford Shoulder Score and range of motion were assessed preoperatively and then at 3 to 6 months, 1 year, and 2 years following surgery. Patient satisfaction was recorded at final follow-up. Magnetic resonance imaging was performed at 3 months postoperatively to assess graft integrity. All patients were available at 1-year follow-up, and 23 were available at 2 years. The mean Oxford Shoulder Score improved by a minimum of 10 points at all time points compared with preoperatively. The mean forward flexion and abduction improved by 20° and external rotation by 7°. Revision to reverse shoulder arthroplasty was seen in 3 patients (12%). Graft failure was seen in 4 patients (16%). Overall, 20 patients had successful outcomes at 1 year (80%) and 18 patients had successful outcomes at 2 years (72%). Superior capsular reconstruction offers a safe and effective short-term bridging option for young patients with irreparable supraspinatus tears in the absence of glenohumeral arthritis. However, long-term outcome studies are required to evaluate the true clinical effectiveness and failure rates. [Orthopedics. 2020;43(4):215-220.].

Repair of Ventral Abdominal Wall Hernias

The repair of noninguinal abdominal wall defects is one of the most common procedures general surgeons perform. Despite this, there is little agreement or consensus in the literature as to the ideal approach for this difficult problem. In recent years, population-based studies have provided better data on the true failure rates associated with the various herniorrhaphies. Wound morbidity has also emerged as an important outcome measure, and definitions by the Ventral Hernia Working Group (VHWG) have begun to standardize such benchmarks. Future evidence will come from the large multi-institutional collaborations currently forming. This topic review discusses the classification of ventral hernias, abdominal wall anatomy, and choices of prosthetic materials. Incisional hernia repair is discussed, as are the operative steps and techniques for both an open and a laparoscopic ventral hernia repair. Special circumstances, including loss of abdominal domain and contaminated surgical fields, periumbilical hernia repair, and atypical ventral hernias are also described. This review contains 10 figures, 18 tables, and 71 references. Keywords: Hernia, incisional hernia, mesh, laparotomy, laparoscopy, incarceration, surgical site infection, hernia repair

Abstract WP269: Direct Oral Anticoagulant “Pseudo-Failure” vs. “True Failure” to Prevent Ischemic Stroke in Nonvalvular Atrial Fibrillation

Background: Despite the efficacy of Direct Oral Anticoagulants (DOACs) in Nonvalvular Atrial Fibrillation (NVAF), some patients may still develop an ischemic stroke while taking this medication. This can be from a primary efficacy problem, called DOAC “True failure” (due to drug absorption, metabolism, or clearance), or DOAC “Pseudo-failure” (due to alternate causes of stroke, not the NVAF). We aim to study the factors contributing to DOAC Pseudo-failures and isolate DOAC True Failure rates. Methods: IRB-approved, retrospective study of NVAF patients on DOAC who developed ischemic stroke between Jan 2012 and Dec 2017. Variables reviewed include DOAC Pseudo-failure causes listed in the mnemonic CHAMP: C for Compliance concerns (adherence [held for procedure, ran out, or discontinued], incorrect dose, or incorrect frequency [QD vs BID]); H for Hypertensive lacunar disease; A for Arterial diseases (such as Atherosclerosis [intra- or extra-cranial, carotid or vertebral arterial stenosis or dissection]); M for Malignant cancer or other hypercoagulable states; and P for Patent Foramen Ovale (PFO). Results: We identified 87 NVAF patients on DOAC who presented with ischemic stroke: 18 on Dabigatran, 37 on Apixaban and 32 on Rivaroxaban. Of those, 67 patients (77%) had at least one of the CHAMP variables (DOAC Pseudo-failure) while 20 (23%) were DOAC True failures. Compliance concerns were responsible for nearly half (49%) of the Pseudo-failures, followed by Malignancy/hypercoagulability (26%), Arterial disease (17%), HTN (5.7%) and PFO (2.3%). True Failure was lowest for Dabigatran (5.6%) followed by Apixaban (16%) and highest with Rivoraxaban (41%) despite its high compliance rate of 66%. Compliance for the BID DOACs (Dabigatran and Apixaban) were similar at 39 % and 43%, respectively. Conclusion: Patients on DOAC for NVAF who develop ischemic stroke are three times more likely to have another identifiable etiology. Compliance concerns, Cancer/Hypercoagulability, and arterial disease represent over 90% of DOAC Pseudo-failures. Thus, providers should educate patients on correct DOAC doses and frequencies, and screen presumed DOAC failures with scans of the chest, abdomen and pelvis in addition to intracranial and extracranial vessel imaging.

Warranty pricing with consumer learning

We consider a problem in which a firm dynamically prices a product and its warranty service over time. Consumers can learn about the reliability of products based on warranty prices. A firm’s optimal product and warranty pricing policies are characterized. We find that a warranty should be priced lower than the marginal warranty service cost, which implies that warranty sales will not generate profits directly. However, offering a modest warranty still benefits the firm’s overall profits. We also show that consumers’ beliefs and the firm’s warranty policy converge in the long run. In a steady state, either a fraction of consumers will purchase a warranty or no consumer will purchase a warranty. Comparative statics analysis is conducted to show how factors such as a firm’s warranty service cost, consumers’ learning speed, and the heterogeneity of consumers’ handling costs determine consumers’ beliefs, the firm’s warranty policy and profitability in a steady state. Lastly, we note that a firm benefits from consumer learning by hiding the information about the true product reliability only when the true product failure rate is relatively high.

Outcome of mitral valve plasty or replacement: atrial fibrillation an effect modifier.

BackgroundAdvances in the understanding of mitral valve pathology have laid to mitral valve plasty (MPL) as the procedure of choice of all the mitral intervention as compared to mitral valve replacement (MVR).This study is aimed to compare the outcome mortality and reoperation and to estimate failure of repair between the two procedures during the follow up time.Material and methodsA cohort of 355 patients with mitral valve disease operated between January 1993 to January 2007 with closing date first of mars 2011. There were 214 MPL and 141 MVR at the Hospital discharge. This retrospective cohort had the design of exposed (MPL) versus non-exposed (MVR) with outcome total mortality and reoperation during follow up. Also echocardiography follow-up was undertaken to estimate the true long-term failure rate of repair.ResultsThe mean follow up was 5.3 years SE (3.82) maximum follow up was 14.1 years. Considering the patient time model the association between repair/replacement and total mortality RR = 0.43 95% (0.28-074) p = 0.002 controlling for the confounding effect of 3-vessels disease. Those results were confirmed by propensity score analysis.As far as outcome re-operation, presence of atrial fibrillation AF was an effect modifier indicating lower reoperation rate for MPL compared to MVR for patients without AF, RR = 0.32 95% CL (0.13-0.81) p = 0.017 while no difference in reoperation rates between MPL/MVR for patients with AF RR = 1.82 95% CL (0.52-6.4) p = 0.344.Echocardiography follows up showed incidence of moderate and severe recurrent mitral regurgitation was 1.34 per 100 patients years and 0.27 per 100 patients years during the follow-up time.ConclusionIn a cohort of patient with mitral valve disease undergoing MPL/MVR was examined. MPL was associated with better survival, and lower reoperation rate for patients without AF but same rate for patients with AF. We advocate more attention in controlling risk factors of AF in the clinical management of mitral disease. Long-term failure rate of MPL was low during follow up time. A replication of our results by a randomized clinical trial is mandatory.

Abstract OT2-1-02: Clinical node negative breast cancer patients undergoing breast conserving therapy: follow-up versus sentinel lymph node biopsy

Abstract Background: The ACOSOG-Z0011 study demonstrated no additional value of complementary axillary lymph node dissection in case of limited axillary sentinel lymph node (SLN) metastases in breast cancer patients undergoing breast conserving therapy1. Since axillary ultrasound can exclude advanced axillary metastatic disease pre-operative2, there is ample opportunity to evaluate whether SLN biopsies are still indicated in a selected group of breast cancer patients. Trial design: A prospective non-inferiority randomized multicenter trial was designed. Breast cancer patients with cT1-2N0 disease, with no evidence for axillary metastases on ultrasound, treated with breast conserving therapy (lumpectomy + whole breast radiotherapy), will be randomized between follow-up and SLN biopsy. If adjuvant systemic therapy is not indicated by tumor or patient characteristics, gene expression profiling may be used for evaluation. To assess Quality of Life, 3 validated questionnaires will be used: QLQ-C30, QLQ-BR 23 and Lymph-ICF3-5. Eligibility criteria: – Women with histological confirmed cT1-2 invasive unilateral breast carcinoma– Clinical node negative: no palpable nodes at physical examination and an axillary ultrasound without signs of lymph node metastases (cyto-/histology if indicated)– Neoadjuvant systemic therapy is allowed. Specific aims: Primary endpoint is the axillary recurrence rate. The number of delayed axillary dissections will be registered. Secondary endpoints are distant-disease free survival, overall survival, local recurrence, morbidity and Quality of Life. Statistical methods: Based on a 5-year axillary recurrence free survival rate: failure rate of 0.99 for controls and a true failure rate of 0.96 (as considered acceptable) for study subjects. Overall, 2086 patients will be included to be able to reject the null hypothesis that the failure rate for experimental and control subjects is inferior by at least 5% (D = −5%) with probability of 0.8 and alpha of 5%. Present accrual and target accrual: This study is expected to start in late 2012 after approval by the Ethical Medical Committee.

Abstract OT2-1-03: The Z11 design for breast cancer patients undergoing a mastectomy

Abstract Background: The diagnostic work-up and treatment of axillary lymph nodes in breast cancer patients is an ongoing topic of research. The ACOSOG-Z0011 study demonstrated no additional value of complementary axillary lymph node dissection (cALND) in case of limited axillary sentinel lymph node (SLN) metastases in breast cancer patients undergoing breast conserving therapy1. It is questionable whether these results can be applied to patients undergoing a mastectomy2. Trial design: A prospective non-inferiority randomized multicenter trial was designed. Breast cancer patients with cT1-2N0 disease treated with mastectomy and limited axillary SLN metastases will be randomized for follow-up versus complementary axillary treatment. To assess the Quality of Life and morbidity benefits of this experimental treatment, 3 validated questionnaires will be used: QLQ-C30, QLQ-BR 23 and Lymph-ICF3-5. Eligibility criteria: – Women with histological confirmed cT1-2 invasive unilateral breast carcinoma– Clinical node negative: no palpable nodes in physical examination and the axillary ultrasound without signs of lymph node metastases (cyto-/histology if indicated)– Sentinel lymph node biopsy must contain at least one and a maximum of 3 (micro)metastases– Neoadjuvant systemic therapy is allowed Specific aims: Primary endpoint is the axillary recurrence rate. The number of delayed axillary dissections will be registered. Secondary endpoints are distant-disease free survival, overall survival, local recurrence, morbidity and Quality of Life. Statistical methods: Based on 5-year axillary recurrence free survival rate, a failure rate of 0.98 among controls and a true failure rate of 0.96 for study subjects are considered acceptable. Overall, 1114 patients will be included to be able to reject the null hypothesis that the failure rate for experimental and control subjects is inferior by at least 5% (D = −5%) with probability of 0.8 and alpha of 5%. Present accrual and target accrual: This study is expected to start in late 2012 after approval by the Ethical Medical Committee.

Instrument Failures for the da Vinci Surgical System: a Food and Drug Administration MAUDE Database Study

Our goal was to analyze reported instances of the da Vinci robotic surgical system instrument failures using the FDA's MAUDE (Manufacturer and User Facility Device Experience) database. From these data we identified some root causes of failures as well as trends that may assist surgeons and users of the robotic technology. We conducted a survey of the MAUDE database and tallied robotic instrument failures that occurred between January 2009 and December 2010. We categorized failures into five main groups (cautery, shaft, wrist or tool tip, cable, and control housing) based on technical differences in instrument design and function. A total of 565 instrument failures were documented through 528 reports. The majority of failures (285) were of the instrument's wrist or tool tip. Cautery problems comprised 174 failures, 76 were shaft failures, 29 were cable failures, and 7 were control housing failures. Of the reports, 10 had no discernible failure mode and 49 exhibited multiple failures. The data show that a number of robotic instrument failures occurred in a short period of time. In reality, many instrument failures may go unreported, thus a true failure rate cannot be determined from these data. However, education of hospital administrators, operating room staff, surgeons, and patients should be incorporated into discussions regarding the introduction and utilization of robotic technology. We recommend institutions incorporate standard failure reporting policies so that the community of robotic surgery companies and surgeons can improve on existing technologies for optimal patient safety and outcomes.