Accuracy of pelvic bone segmentation for 3d printing: a study of segmentation accuracy based on anatomic landmarks to evaluate the influence of the observer.

BACKGROUND: 3D printing has a wide range of applications and has brought significant change to many medical fields. However, ensuring quality assurance (QA) is essential for patient safety and requires a QA program that encompasses the entire production process. This process begins with imaging and continues on with segmentation, which is the conversion of Digital Imaging and Communications in Medicine (DICOM) data into virtual 3D-models. Since segmentation is highly influenced by manual intervention the influence of the users background on segmentation accuracy should be thoroughly investigated. METHODS: Seventeen computed tomography (CT) scans of the pelvis with physiological bony structures were identified, anonymized, exported as DICOM data sets, and pelvic bones were segmented by four observers with different backgrounds. Landmarks were measured on DICOM images and in the segmentations. Intraclass correlation coefficients (ICCs) were calculated to assess inter-observer agreement, and the trueness of the segmentation results was analyzed by comparing the DICOM landmark measurements with the measurements of the segmentation results. The correlation between segmentation trueness and segmentation time was analyzed. RESULTS: The lower limits of the 95% confidence intervals of the ICCs for the seven landmarks analyzed ranged from 0.511 to 0.986. The distance between the iliac crests showed the highest agreement between observers, while the distance between the ischial tuberosities showed the lowest. The distance between the upper edge of the symphysis and the promontory showed the lowest deviation between DICOM measurements and segmentation measurements (mean deviations < 1 mm), while the intertuberous distance showed the highest deviation (mean deviations 14.5-18.2 mm). CONCLUSIONS: Investigators with diverse backgrounds in segmentation and varying experience with slice images achieved pelvic bone segmentations with landmark measurements of mostly high agreement in a setup with high realism. In contrast, high variability was observed in the segmentation of the coccyx. In general, interobserver agreement was high, but due to measurement inaccuracies, landmark-based approaches cannot conclusively show that segmentation accuracy is within a clinically tolerable range of 2 mm for the pelvis. If the segmentation is performed by a very inexperienced user, the result should be reviewed critically by the clinician in charge.

Quality assurance of 3D-printed patient specific anatomical models: a systematic review.

BACKGROUND: The responsible use of 3D-printing in medicine includes a context-based quality assurance. Considerable literature has been published in this field, yet the quality of assessment varies widely. The limited discriminatory power of some assessment methods challenges the comparison of results. The total error for patient specific anatomical models comprises relevant partial errors of the production process: segmentation error (SegE), digital editing error (DEE), printing error (PrE). The present review provides an overview to improve the general understanding of the process specific errors, quantitative analysis, and standardized terminology. METHODS: This review focuses on literature on quality assurance of patient-specific anatomical models in terms of geometric accuracy published before December 4th, 2022 (n = 139). In an attempt to organize the literature, the publications are assigned to comparable categories and the absolute values of the maximum mean deviation (AMMD) per publication are determined therein. RESULTS: The three major examined types of original structures are teeth or jaw (n = 52), skull bones without jaw (n = 17) and heart with coronary arteries (n = 16). VPP (vat photopolymerization) is the most frequently employed basic 3D-printing technology (n = 112 experiments). The median values of AMMD (AMMD: The metric AMMD is defined as the largest linear deviation, based on an average value from at least two individual measurements.) are 0.8 mm for the SegE, 0.26 mm for the PrE and 0.825 mm for the total error. No average values are found for the DEE. CONCLUSION: The total error is not significantly higher than the partial errors which may compensate each other. Consequently SegE, DEE and PrE should be analyzed individually to describe the result quality as their sum according to rules of error propagation. Current methods for quality assurance of the segmentation are often either realistic and accurate or resource efficient. Future research should focus on implementing models for cost effective evaluations with high accuracy and realism. Our system of categorization may be enhancing the understanding of the overall process and a valuable contribution to the structural design and reporting of future experiments. It can be used to educate specialists for risk assessment and process validation within the additive manufacturing industry.

[Patient-centered vs. employee-centered radiology : Does this pose a conflict?] / Patienten- vs. mitarbeiterzentrierte Radiologie : Birgt dies einen Konflikt?

BACKGROUND: Patient-centered radiology and employee-centered radiology are being increasingly discussed as an extension of the established structure- and process-oriented management perspective. Concerning potential conflicts, it is unclear if and how these approaches should best be implemented in a radiology department. OBJECTIVE: The aim of this narrative review is to identify and critically correlate underlying characteristics of patient-centered and employee-centered approaches including their similarities, conflicts, and synergies as applicable to the radiological work environment. MATERIALS AND METHODS: Based on a literature search using PubMed, Scopus, Web of Science, and Google Scholar, the current body of knowledge regarding patient- and employee-centered radiology is presented. RESULTS: Patient- and employee-centered radiology focus on the individual needs of patients and employees, respectively, and promise to improve patient satisfaction, healthcare outcomes, and organizational performance. Conflicts result from an increased organizational complexity and the concurrent utilization of limited resources, such as time, money, and staff. Overall, however, synergies outweigh the potential conflicts. CONCLUSIONS: Successful implementation of patient- and employee-centered approaches in radiology requires a human-centered leadership approach and an overarching strategy with the execution of specific interventions in the processes. We provide specific recommendations to this effect.

[Sustainability and climate protection : Implications on patient-centered care in radiology]. / Nachhaltigkeit und Klimaschutz : Auswirkungen auf die patientenzentrierte Versorgung in der Radiologie.

BACKGROUND: Sustainability and patient-centered radiology (PCR) include a multivariant, complex network of synergic and opportunistic elements. PCR is a subfactor of the social element, climate protection is part of the ecological element, and sustainable economics are part of the financial element. OBJECTIVES: We aimed to identify PCR-symbiotic and PCR-opposed elements of sustainability using literature research. This article will provide an overview of the core sustainability elements and innovative concepts for supporting PCR. MATERIALS AND METHODS: A digital literature search was carried out to identify scientific publications about sustainability and PCR via Medline. Results are provided as a narrative summary. RESULTS: In particular, the social component and parts of the ecological element of sustainability support PCR. Climate protection and a natural environment show a positive correlation with health and patient satisfaction. Patient contact improves the quality of the diagnostic report and promotes satisfaction of patients and radiologists. However, increasing economization is often conditionally compatible with the social core element of sustainability and especially with PCR. Digital tools can ease communication and improve reports in times of increasing workload. CONCLUSION: Socially and environmentally sustainable radiology supports the well-being of both employees and patients. Innovative concepts are necessary to balance the ecological elements of sustainability with employees' and patients' interests.

Effects of anti-osteoporosis therapy on the risk of secondary fractures and surgical complications following surgical fixation of proximal humerus fracture in older people.

BACKGROUND: age-related fragility fractures cause significant burden of disease. Within an ageing society, fracture and complication prevention will be essential to balance health expenditure growth. OBJECTIVE: to assess the effect of anti-osteoporotic therapy on surgical complications and secondary fractures after treatment of fragility fractures. PATIENTS AND METHODS: retrospective health insurance data from January 2008 to December 2019 of patients ≥65 years with proximal humeral fracture (PHF) treated using locked plate fixation (LPF) or reverse total shoulder arthroplasty were analysed. Cumulative incidences were calculated by Aalen-Johansen estimates. The influence of osteoporosis and pharmaceutical therapy on secondary fractures and surgical complications were analysed using multivariable Fine and Gray Cox regression models. RESULTS: a total of 43,310 patients (median age 79 years, 84.4% female) with a median follow-up of 40.9 months were included. Five years after PHF, 33.4% of the patients were newly diagnosed with osteoporosis and only 19.8% received anti-osteoporotic therapy. A total of 20.6% (20.1-21.1%) of the patients had at least one secondary fracture with a significant reduction of secondary fracture risk by anti-osteoporotic therapy (P < 0.001). An increased risk for surgical complications (hazard ratio: 1.35, 95% confidence interval: 1.25-1.47, P < 0.001) after LPF could be reversed by anti-osteoporotic therapy. While anti-osteoporotic therapy was more often used in female patients (35.3 vs 19.1%), male patients showed significantly stronger effects reducing the secondary fracture and surgical complication risk. CONCLUSIONS: a significant number of secondary fractures and surgical complications could be prevented by consequent osteoporosis diagnosis and treatment particularly in male patients. Health-politics and legislation must enforce guideline-based anti-osteoporotic therapy to mitigate burden of disease.

Medical imaging training with eye movement modeling examples: A randomized controlled study.

PURPOSE: To determine whether ultrasound training in which the expert's eye movements are superimposed to the underlying ultrasound video (eye movement modeling examples; EMMEs) leads to better learner outcomes than traditional eye movement-free instructions. MATERIALS AND METHODS: 106 undergraduate medical students were randomized in two groups; 51 students in the EMME group watched 5-min ultrasound examination videos combined with the eye movements of an expert performing the task. The identical videos without the eye movements were shown to 55 students in the control group. Performance and behavioral parameters were compared prepost interventional using ANOVAs. Additionally, cognitive load, and prior knowledge in anatomy were surveyed. RESULTS: After training, the EMME group identified more sonoanatomical structures correctly, and completed the tasks faster than the control group. This effect was partly mediated by a reduction of extraneous cognitive load. Participants with greater prior anatomical knowledge benefited the most from the EMME training. CONCLUSION: Displaying experts' eye movements in medical imaging training appears to be an effective way to foster medical interpretation skills of undergraduate medical students. One underlying mechanism might be that practicing with eye movements reduces cognitive load and helps learners activate their prior knowledge.

Treatment Reality of Proximal Humeral Fractures in the Elderly-Trending Variants of Locking Plate Fixation in Germany.

BACKGROUND: The surgical treatment of proximal humeral fractures (PHFs) with locking plate fixation (LPF) in the elderly is associated with high complication rates, especially in osteoporotic bone. Variants of LPF such as additional cerclages, double plating, bone grafting and cement augmentation can be applied. The objective of the study was to describe the extent of their actual use and how this changed over time. METHODS: Retrospective analysis of health claims data of the Federal Association of the Local Health Insurance Funds was performed, covering all patients aged 65 years and older, who had a coded diagnosis of PHF and were treated with LPF between 2010 and 2018. Differences between treatment variants were analyzed (explorative) via chi-squared or Kruskal-Wallis tests. RESULTS: Of the 41,216 treated patients, 32,952 (80%) were treated with LPF only, 5572 (14%) received additional screws or plates, 1983 (5%) received additional augmentations and 709 (2%) received a combination of both. During the study period, relative changes were observed as follows: -35% for LPF only, +58% for LPF with additional fracture fixation and +25% for LPF with additional augmentation. Overall, the intra-hospital complication rate was 15% with differences between the treatment variants (LPF only 15%, LPF with additional fracture fixation 14%, LPF with additional augmentation 19%; p < 0.001), and a 30-day mortality of 2%. CONCLUSIONS: Within an overall decrease of LPF by approximately one-third, there is both an absolute and relative increase of treatment variants. Collectively, they account for 20% of all coded LPFs, which might indicate more personalized treatment pathways. The leading variant was additional fracture fixation using cerclages.

Increased complication rates of salvage reverse total shoulder arthroplasty (RTSA) after failed locked plate fixation compared with primary RTSA in the treatment of proximal humeral fractures in elderly patients.

HYPOTHESIS: Common surgical treatment options for proximal humeral fractures in elderly patients include locked plate fixation (LPF) and reverse total shoulder arthroplasty (RTSA). It was hypothesized that secondary RTSA after LPF would be associated with higher complication rates and costs compared with primary RTSA. METHODS: We analyzed the health insurance data of patients aged ≥65 years who received RTSA for the treatment of a proximal humeral fracture between January 2013 and September 2019 with a pre-study phase of 5 years. Multivariable Cox, logistic, and linear regression models were used to evaluate the association between treatment group and complications, hospital length of stay, charges, and mortality rate during a 34-month follow-up period. RESULTS: A total of 14,220 patients underwent primary RTSA and 1282 patients underwent secondary RTSA after prior surgery using LPF for the treatment of proximal humeral fractures. After adjustment for patient characteristics, more surgical complications were observed after secondary RTSA during index hospitalization (odds ratio, 4.62; 95% confidence interval [CI], 4.00-5.34; P < .001) and long-term follow-up (hazard ratio, 1.52; 95% CI, 1.27-1.81; P < .001). Moreover, secondary RTSA was associated with an increased cumulative total cost of €6638.1 (95% CI, €6229.9-€7046.5; P < .001). If conversion from LPF to secondary RTSA occurred during index hospitalization, more major adverse events, more thromboembolic events, and a higher mortality rate were found in the short and long term (all P < .05). CONCLUSION: Secondary RTSA is associated with higher total costs and more complications. Hence, if surgical treatment of a proximal humeral fracture in an elderly patient is needed, prognostic factors for LPF need to be evaluated carefully. If in doubt, the surgeon should opt to perform primary RTSA as patients will benefit in the long term.

Respiratory motion correction in F-18-FDG PET/CT impacts lymph node assessment in lung cancer patients.

BACKGROUNDS: Elastic motion correction in PET has been shown to increase image quality and quantitative measurements of PET datasets affected by respiratory motion. However, little is known on the impact of respiratory motion correction on clinical image evaluation in oncologic PET. This study evaluated the impact of motion correction on expert readers' lymph node assessment of lung cancer patients. METHODS: Forty-three patients undergoing F-18-FDG PET/CT for the staging of suspected lung cancer were included. Three different PET reconstructions were investigated: non-motion-corrected ("static"), belt gating-based motion-corrected ("BG-MC") and data-driven gating-based motion-corrected ("DDG-MC"). Assessment was conducted independently by two nuclear medicine specialists blinded to the reconstruction method on a six-point scale [Formula: see text] ranging from "certainly negative" (1) to "certainly positive" (6). Differences in [Formula: see text] between reconstruction methods, accounting for variation caused by readers, were assessed by nonparametric regression analysis of longitudinal data. From [Formula: see text], a dichotomous score for N1, N2, and N3 ("negative," "positive") and a subjective certainty score were derived. SUV and metabolic tumor volumes (MTV) were compared between reconstruction methods. RESULTS: BG-MC resulted in higher scores for N1 compared to static (p = 0.001), whereas DDG-MC resulted in higher scores for N2 compared to static (p = 0.016). Motion correction resulted in the migration of N1 from tumor free to metastatic on the dichotomized score, consensually for both readers, in 3/43 cases and in 2 cases for N2. SUV was significantly higher for motion-corrected PET, while MTV was significantly lower (all p < 0.003). No significant differences in the certainty scores were noted. CONCLUSIONS: PET motion correction resulted in significantly higher lymph node assessment scores of expert readers. Significant effects on quantitative PET parameters were seen; however, subjective reader certainty was not improved.

The Surgical Treatment of Proximal Humeral Fractures in Elderly Patients.

BACKGROUND: The goal of this study is to compare mortality, major adverse events, and complication rates after the surgical treatment of proximal humeral fractures with locked plate fixation (LPF) versus reverse total shoulder arthroplasty (RTSA) in elderly patients. METHODS: Health insurance data from patients aged 65 and above for the period January 2010 to September 2018 were retrospectively evaluated. The median follow-up duration after LPF (40 419 patients) or RTSA (13 552 patients) was 52 months. Hazard ratios adapted to the patients' risk profiles were determined with the aid of multivariable Cox regression models. The p-values were adjusted using the Bonferroni-Holm method. RESULTS: After adaptation to the patients' risk profiles, reverse shoulder replacement showed statistically significantly lower mortality (HR 0.92, 95% confidence interval [0.88; 0.95]; p <0.001) and fewer major adverse events (HR 0.92 [0.89; 0.95]; p<0.001). Eight years after surgery, the risk of surgical complications was twice as high for LPF (12.2% [11.9; 12.7]; HR for RTSA versus LPF 0.5 [0.46; 0.55]; p<0.001 for both), with 3.8% [3.6; 4.0] of the patients receiving a secondary RTSA. Surgical complications were more common (p<0.05) in patients with a diagnosis of osteo - porosis, obesity, alcohol abuse, chronic polyarthritis, or frozen shoulder. CONCLUSION: The long-term findings are in agreement with clinical short-term findings from other studies and support the current trend toward more liberal use of reverse shoulder replacements in elderly patients.

[Influence of complications and comorbidities on length of hospital stay and costs for surgical treatment of proximal humeral fractures]. / Einfluss von Komplikationen und Komorbiditäten auf Liegedauer und Kosten bei der operativen Behandlung der proximalen Humerusfraktur.

After a proximal humeral fracture in older patients, locked plate fixation and reverse total shoulder arthroplasty are two competing surgical procedures. Even if recent clinical studies indicate a functional superiority of reverse shoulder arthroplasty over locked plate fixation, health-economic comparative data are lacking in the literature. Health claims data of 55,070 patients aged 65 years or older who were treated with reverse total shoulder arthroplasty or locked plate fixation after proximal humeral fractures, were analyzed regarding length of hospital stay and costs. Multivariable linear regression models were used to analyze the influence of comorbidities and complications on the length of hospital stay and costs. The length of hospital stay after reverse total shoulder arthroplasty with 20.0 days (±13.5 days) was statistically noticeable longer compared to locked plate fixation with 14.6 days (±11.4 days, p < 0.001). The costs per case showed a clear difference with 11,165.70€ (±5884.36€) for reverse total shoulder arthroplasty and 7030.11€ (±5532.02€) for locked plate fixation (p < 0.001). Statistically noticeable cost increases due to comorbidities and complications underline the urgent need for specialized geriatric trauma centers.

Male Sex Is Associated with Higher Mortality and Increased Risk for Complications after Surgical Treatment of Proximal Humeral Fractures.

AIMS: The best surgical treatment of multi-fragmentary proximal humeral fractures in the elderly is a highly controversial topic. The aim of this study is to assess for sex-related differences regarding mortality and complications after reverse total shoulder arthroplasty (RTSA) and locking plate fixation (LPF). PATIENTS AND METHODS: All patients from the largest German healthcare insurance (26.5 million policy holders) above the age of 65 years that were treated with LPF or RTSA after a multi-fragmentary proximal humerus fracture between January 2010 and September 2018 were included. Multivariable Cox regression models were used to assess the association of sex with overall survival, major adverse events and surgical complications. RESULTS: A total of 8264 (15%) men and 45,707 (85%) women were followed up for a median time of 52 months. After 8 years, male patients showed significantly higher rates for death (65.8%; 95% CI 63.9-67.5% vs. 51.1%; 95% CI 50.3-51.9%; p < 0.001) and major adverse events (75.5%; 95% CI 73.8-77.1% vs. 61.7%; 95% CI 60.9-62.5%; p < 0.001). With regard to surgical complications, after adjustment of patient risk profiles, there were no differences between females and males after LPF (p > 0.05), whereas men showed a significantly increased risk after RTSA (HR 1.86; 95% CI 1.56-2.22; p < 0.001) with more revision surgeries performed (HR 1.76, 95% CI 1.46-2.12; p < 0.001) compared to women. CONCLUSION: The male sex is an independent risk factor for death and major adverse events after both LPF and RTSA. An increased risk for surgical complications after RTSA suggests that male patients benefit more from LPF. Sex should be considered before making treatment decisions.

Complex Bone Tumors of the Trunk-The Role of 3D Printing and Navigation in Tumor Orthopedics: A Case Series and Review of the Literature.

The combination of 3D printing and navigation promises improvements in surgical procedures and outcomes for complex bone tumor resection of the trunk, but its features have rarely been described in the literature. Five patients with trunk tumors were surgically treated in our institution using a combination of 3D printing and navigation. The main process includes segmentation, virtual modeling and build preparation, as well as quality assessment. Tumor resection was performed with navigated instruments. Preoperative planning supported clear margin multiplanar resections with intraoperatively adaptable real-time visualization of navigated instruments. The follow-up ranged from 2-15 months with a good functional result. The present results and the review of the current literature reflect the trend and the diverse applications of 3D printing in the medical field. 3D printing at hospital sites is often not standardized, but regulatory aspects may serve as disincentives. However, 3D printing has an increasing impact on precision medicine, and we are convinced that our process represents a valuable contribution in the context of patient-centered individual care.

In-hospital Complications Are More Likely to Occur After Reverse Shoulder Arthroplasty Than After Locked Plating for Proximal Humeral Fractures.

BACKGROUND: Currently, there seems to be a paradigm change in the surgical treatment of proximal humeral fractures in patients aged 65 years and older, with a considerable increase in the use of reverse total shoulder arthroplasty (RTSA) compared with angular stable internal fixation (locking plate fixation). However, even among shoulder specialists there is controversy regarding the best treatment strategy. QUESTIONS/PURPOSES: To evaluate for (1) a greater risk of in-hospital major adverse events, (2) a greater risk for in-hospital surgical complications, and (3) a greater risk of 30-day mortality, locking plate fixation and RTSA were compared for the treatment of proximal humerus fractures of patients aged 65 years and older after controlling for potentially confounding variables in a large-database analysis. METHODS: Health claims data of the largest German insurance company including approximately one-third of the population (26.5 million policyholders) between 2010 and 2018 were analyzed. This database was chosen because of its size, nationwide distribution, and high quality/completeness. In total, 55,070 patients (≥ 65 years of age) treated with locking plate fixation (75% [41,216]) or RTSA (25% [13,854]) for proximal humeral fracture were compared. As primary endpoints, major adverse events (including acute myocardial infarction, stroke, organ failure, resuscitation, and death) and surgical complications (infection, hematoma, loss of reduction, dislocation, and revision surgery) were analyzed. The risk of all endpoints was analyzed with multivariable logistic regression models in the context of comorbidities to address existing group differences. RESULTS: After controlling for potentially confounding variables such as age, sex, and risk profile, RTSA was associated with a higher risk for major adverse events (OR 1.40 [95% CI 1.29 to 1.53]; p < 0.001) and surgical complications (OR 1.13 [95% CI 1.05 to 1.21]; p < 0.01) compared with locking plate fixation. There was no evidence for an increase in mortality (OR 0.98 [95% CI 0.86 to 1.12]; p = 0.81). CONCLUSION: The increased in-hospital risk for major adverse events and surgical complications may moderate the enthusiasm associated with RTSA for proximal humeral fractures in patients 65 years and older. Treatment decisions should be based on individual risk estimation to avoid potential harmful events. Future studies must include long-term outcomes and quality of life to enlighten these findings in a broader context. LEVEL OF EVIDENCE: Level III, therapeutic study.