Reverse total shoulder arthroplasty with proximal bone loss: a biomechanical comparison of partially vs. fully cemented humeral stems.

BACKGROUND: The appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis. METHODS: A total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples. RESULTS: Fully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P < .001 and P < .01, respectively). Removal torque between fully cemented stems was 45.22 Nm (95% CI 21.86-68.57 Nm), vs. 9.26 Nm (95% CI 2.59-15.93 Nm) for partially cemented samples (P = .021). Every fully cemented humerus fractured during implant removal vs. only 1 in the reduced-cementation group. The mean donor age in our study was 76 years (range, 65-80 years). Only 1 matched pair of humeri belonged to a female donor with comorbid osteoporosis. The fractured humerus in the partially cemented group belonged to that donor. CONCLUSION: Partially and fully cemented humeral prostheses had subsidence that was significantly less than 5 mm. Partially cemented stems required less removal torque for debonding of the component from the cement mantle. In all cases, removal of fully cemented stems resulted in humeral fracture. Reduced cementation of humeral prostheses may provide both sufficient biomechanical stability and ease of future component removal.

Frequency and Predictors of Preoperative Cardiac Testing Overuse in Low-Risk Patients Before Laparoscopic Bariatric Surgery.

Adverse cardiac events after laparoscopic bariatric surgery are rare, yet preoperative cardiology evaluation and testing remain common, resulting in the overuse of cardiac testing in low-risk patients. Our objective was to assess the frequency of, and factors associated with, overuse of preoperative cardiac testing in patients at low cardiac risk before laparoscopic bariatric surgery. We retrospectively reviewed data from 1,094 adult patients who underwent laparoscopic bariatric surgery at our institution from January 1, 2015, through December 31, 2019. The cardiac risk was determined using the Revised Cardiac Risk Index (RCRI) and the National Surgical Quality Improvement Program Myocardial Infarction and Cardiac Arrest (NSQIP MICA) risk model. Multivariate logistic regression was used to evaluate risk factors associated with the overuse of cardiac testing in low-risk patients. Overall, 1,059 patients (96.8%) were estimated to be at low cardiac risk by the RCRI, and 1,094 (100%) were at low cardiac risk by NSQIP MICA. A total of 587 patients (51.8%) were referred to cardiology for preoperative evaluation, and 643 patients (56.7%) underwent one or more preoperative cardiac tests. Factors associated with overuse of preoperative cardiac testing in low-risk patients included preoperative cardiology referral (adjusted odds ratio 37.2, 95% confidence interval 25.3 to 54.7) and patient age (adjusted odds ratio 1.05, 95% confidence interval 1.03 to 1.07). Overuse of preoperative cardiac testing was common in patients at low cardiac risk before laparoscopic bariatric surgery. Preoperative referral to cardiology was the most significant risk factor associated with the overuse of preoperative cardiac testing. Application of risk models such as the RCRI or NSQIP MICA at the time of bariatric program enrollment may reduce unnecessary preoperative cardiac testing in low-risk patients.

Reevaluating the Cardiac Risk of Noncardiac Surgery Using the National Surgical Quality Improvement Program.

BACKGROUND: As surgical techniques evolve and patient outcomes improve over time, a renewed analysis of the cardiac risk of noncardiac surgeries is needed. The goal of this study was to investigate and categorize the cardiac risk of elective noncardiac surgeries. METHODS: This was a cohort study of surgical data and outcomes from the 2018 National Surgical Quality Improvement Program Participant Use Data File; 807,413 cases were analyzed after excluding non-elective, emergent, and cardiac surgeries. Postoperative major adverse cardiac events (MACE) were defined as 30-day all-cause mortality, myocardial infarction, or cardiac arrest. According to their 95% confidence intervals (CI) for postoperative MACE, surgeries were categorized as low risk (95% CI <1%), intermediate risk (95% CI above and below 1%), or elevated risk (95% CI ≥1%). Multivariable logistic regression analyses were performed to determine differences in the odds for postoperative MACE for the intermediate- and elevated-risk categories relative to the low-risk category while controlling for several risk factors of prognostic importance. RESULTS: Postoperative MACE occurred in 4047/807,413 cases (0.50%), including in 1708/667,735 (0.26%) of the low-risk category, in 516/53,499 (0.96%) of the intermediate-risk category, and in 1823/86,179 (2.12%) of the elevated-risk category. The elevated-risk category accounted for 10.7% of total procedures and 45.1% of total postoperative MACE. Compared with the low-risk category, the multivariable adjusted risk of postoperative MACE was increased in the intermediate-risk category (adjusted odds ratio 2.35; 95% CI, 2.12-2.62) and the elevated-risk category (adjusted odds ratio 3.15; 95% CI, 2.92-3.39). CONCLUSION: Categorization of noncardiac surgeries according to cardiac risk may help to identify populations who are most likely to benefit from preoperative cardiac evaluation when indicated.

Safety of bariatric surgery in patients with coronary artery disease.

BACKGROUND: Patients with obesity and established coronary artery disease (CAD) may benefit from surgical weight loss; however, its safety is unknown in this population. OBJECTIVE: To assess the association between CAD and the incidence of 30-day postoperative mortality and major adverse cardiac events (MACEs) in patients undergoing bariatric surgery. SETTINGS: Multicenter cohort study. METHODS: We used the 2017 MBSAQIP database to study patients undergoing bariatric surgery from accredited centers in the United States and Canada between Jan 1, 2017, and Dec 31, 2017. Multivariate logistic regression was used to determine whether established CAD was independently associated with 30-day mortality and MACE, a composite endpoint that included myocardial infarction and/or cardiac arrest. RESULTS: We reviewed data from 167,819 patients from 832 centers. There were 4172 patients with diagnosed CAD, and 163,647 without it. At 30-day follow-up, the endpoints of mortality, cardiac arrest, myocardial infarction, and MACE occurred in 172 (.10%), 82 (.05%), 57 (.03%), and 135 (.08%) patients, respectively. The endpoints occurred more significantly in patients with CAD compared with patients without CAD; 22 (.53%) versus 150 (.09%) for mortality, 13 (.31%) versus 69 (.04%) for cardiac arrest, 17 (.41%) versus 40 (.02%) for myocardial infarction, and 28 (.67%) versus 107 (.07%) for MACE (P < .001 for all comparisons). CONCLUSIONS: Postoperative mortality and MACE following bariatric surgery are higher in patients with CAD than those without; however, the absolute incidence is low (<1%). The decision to pursue bariatric surgery and/or preoperative cardiac testing in patients with CAD should include consideration of the overall incidence of adverse cardiac outcomes and the stability of CAD.

Development and Validation of a Deep Learning Algorithm for Gleason Grading of Prostate Cancer From Biopsy Specimens.

Importance: For prostate cancer, Gleason grading of the biopsy specimen plays a pivotal role in determining case management. However, Gleason grading is associated with substantial interobserver variability, resulting in a need for decision support tools to improve the reproducibility of Gleason grading in routine clinical practice. Objective: To evaluate the ability of a deep learning system (DLS) to grade diagnostic prostate biopsy specimens. Design, Setting, and Participants: The DLS was evaluated using 752 deidentified digitized images of formalin-fixed paraffin-embedded prostate needle core biopsy specimens obtained from 3 institutions in the United States, including 1 institution not used for DLS development. To obtain the Gleason grade group (GG), each specimen was first reviewed by 2 expert urologic subspecialists from a multi-institutional panel of 6 individuals (years of experience: mean, 25 years; range, 18-34 years). A third subspecialist reviewed discordant cases to arrive at a majority opinion. To reduce diagnostic uncertainty, all subspecialists had access to an immunohistochemical-stained section and 3 histologic sections for every biopsied specimen. Their review was conducted from December 2018 to June 2019. Main Outcomes and Measures: The frequency of the exact agreement of the DLS with the majority opinion of the subspecialists in categorizing each tumor-containing specimen as 1 of 5 categories: nontumor, GG1, GG2, GG3, or GG4-5. For comparison, the rate of agreement of 19 general pathologists' opinions with the subspecialists' majority opinions was also evaluated. Results: For grading tumor-containing biopsy specimens in the validation set (n = 498), the rate of agreement with subspecialists was significantly higher for the DLS (71.7%; 95% CI, 67.9%-75.3%) than for general pathologists (58.0%; 95% CI, 54.5%-61.4%) (P < .001). In subanalyses of biopsy specimens from an external validation set (n = 322), the Gleason grading performance of the DLS remained similar. For distinguishing nontumor from tumor-containing biopsy specimens (n = 752), the rate of agreement with subspecialists was 94.3% (95% CI, 92.4%-95.9%) for the DLS and similar at 94.7% (95% CI, 92.8%-96.3%) for general pathologists (P = .58). Conclusions and Relevance: In this study, the DLS showed higher proficiency than general pathologists at Gleason grading prostate needle core biopsy specimens and generalized to an independent institution. Future research is necessary to evaluate the potential utility of using the DLS as a decision support tool in clinical workflows and to improve the quality of prostate cancer grading for therapy decisions.

Eradicating Infecting Bacteria while Maintaining Tissue Integration on Photothermal Nanoparticle-Coated Titanium Surfaces.

Photothermal nanoparticles locally release heat when irradiated by near-infrared (NIR). Clinical applications initially involved tumor treatment, but currently extend toward bacterial infection control. Applications toward much smaller, micrometer-sized bacterial infections, however, bear the risk of collateral damage by dissipating heat into tissues surrounding an infection site. This can become a complication when photothermal nanoparticle coatings are clinically applied on biomaterial surfaces requiring tissue integration, such as titanium-made, bone-anchored dental implants. Dental implants can fail due to infection in the pocket formed between the implant screw and the surrounding soft tissue ("peri-implantitis"). We address the hitherto neglected potential complication of collateral tissue damage by evaluating photothermal, polydopamine nanoparticle (PDA-NP) coatings on titanium surfaces in different coculture models. NIR irradiation of PDA-NP-coated (200 µg/cm2) titanium surfaces with adhering Staphylococcus aureus killed staphylococci within an irradiation time window of around 3 min. Alternatively, when covered with human gingival fibroblasts, this irradiation time window maintained surface coverage by fibroblasts. Contaminating staphylococci on PDA-NP-coated titanium surfaces, as can be per-operatively introduced, reduced surface coverage by fibroblasts, and this could be prevented by NIR irradiation for 5 min or longer prior to allowing fibroblasts to adhere and grow. Negative impacts of early postoperative staphylococcal challenges to an existing fibroblast layer covering a coated surface were maximally prevented by 3 min NIR irradiation. Longer irradiation times caused collateral fibroblast damage. Late postoperative staphylococcal challenges to a protective keratinocyte layer covering a fibroblast layer required 10 min NIR irradiation for adverting a staphylococcal challenge. This is longer than foreseen from monoculture studies because of additional heat uptake by the keratinocyte layer. Summarizing, photothermal treatment of biomaterial-associated infection requires precise timing of NIR irradiation to prevent collateral damage to tissues surrounding the infection site.

Frequency of Appropriate and Low-Risk Noncardiac Preoperative Stress Testing Across Medical Specialties.

Preoperative stress testing in asymptomatic patients is considered rarely appropriate in patients with: (1) moderate to good functional capacity (≥4 metabolic equivalent (METs)), (2) no clinical risk factors, or who are (3) asymptomatic after revascularization, normal stress test, or normal coronary angiography within 1 year. Preoperative stress testing is also not recommended in patients at low risk (<1%) for adverse cardiac events. We investigated the frequency of rarely appropriate and low-risk preoperative stress testing across medical specialties at our institution in asymptomatic patients when applying appropriate use criteria and two different perioperative risk models. We reviewed preoperative stress tests for noncardiac surgeries performed at Hershey Medical Center from January 1, 2012 to December 31, 2014. Perioperative cardiac risk was estimated using the National Surgical Quality Improvement Program Myocardial Infarction and Cardiac Arrest risk calculator and the Revised Cardiac Risk Index (RCRI) score. We analyzed 501 preoperative stress tests meeting the study criteria. When applying appropriate use criteria, we found that 336 of 501 studies (67%) were rarely appropriate. When applying the risk score models, 369 of 501 studies (74%) were determined to be low risk by the RCRI (RCRI score ≤1), and 248 of 361 stress tests (69%) were determined to be low risk by the National Surgical Quality Improvement Program Myocardial Infarction and Cardiac Arrest risk calculator. Low risk and rarely appropriate preoperative stress testing was common across all ordering specialties reviewed. In conclusion, these findings suggest that preoperative stress testing is broadly overused in asymptomatic patients and that interventions to reduce rarely appropriate and low-risk preoperative stress testing require a multispecialty approach.

Enlarging nodule under the toenail · no history of trauma · unremarkable medical history · Dx?

A 28-year-old woman with an unremarkable medical history presented with an enlarging nodule that had been growing under her left great toenail for 6 months. The patient monitored the nodule, hoping that it would resolve on its own, but found that it steadily increased in size and began to displace the nail, causing pain. At the time of presentation, the nodule measured approximately 10 mm in diameter, and there was significant (~80°) superior displacement of the nail.

Structural changes in S. epidermidis biofilms after transmission between stainless steel surfaces.

Transmission is a main route for bacterial contamination, involving bacterial detachment from a donor and adhesion to receiver surfaces. This work aimed to compare transmission of an extracellular polymeric substance (EPS) producing and a non-EPS producing Staphylococcus epidermidis strain from biofilms on stainless steel. After transmission, donor surfaces remained fully covered with biofilm, indicating transmission through cohesive failure in the biofilm. Counter to the numbers of biofilm bacteria, the donor and receiver biofilm thicknesses did not add up to the pre-transmission donor biofilm thickness, suggesting more compact biofilms after transmission, especially for non-EPS producing staphylococci. Accordingly, staphylococcal density per unit biofilm volume had increased from 0.20 to 0.52 µm-3 for transmission of the non-EPS producing strain under high contact pressure. The EPS producing strain had similar densities before and after transmission (0.17 µm-3). This suggests three phases in biofilm transmission: (1) compression, (2) separation and (3) relaxation of biofilm structure to its pre-transmission density in EPS-rich biofilms.

Usefulness of the Myocardial Infarction and Cardiac Arrest Calculator as a Discriminator of Adverse Cardiac Events After Elective Hip and Knee Surgery.

The 2014 American College of Cardiology and American Heart Association guidelines on perioperative evaluation recommend differentiating patients at low risk (<1%) versus elevated risk (≥1%) for cardiac complications to guide appropriate preoperative testing. Among the tools recommended for estimating perioperative risk is the National Surgical Quality Improvement Program (NSQIP) Myocardial Infarction and Cardiac Arrest (MICA) risk calculator. We investigated whether the NSQIP MICA risk calculator would accurately discriminate adverse cardiac events in a cohort of adult patients undergoing elective orthopedic surgery. We retrospectively reviewed 1,098 consecutive, elective orthopedic surgeries performed at Hershey Medical Center from January 1, 2013, to December 31, 2014. Adverse cardiac events were defined as myocardial infarction or cardiac arrest within 30 days of surgery. The mean estimated risk for adverse cardiac events using the NSQIP MICA risk calculator was 0.54%, which was not significantly different (p = 1) compared with the observed incidence of 0.64% (7 of 1,098 procedures). The c-statistic for discriminating adverse cardiac events was 0.85 (95% CI 0.67 to 1) for the NSQIP MICA risk calculator and 0.9 (95% CI 0.75 to 1) for the Revised Cardiac Risk Index. In conclusion, the NSQIP MICA risk calculator is a good discriminator of adverse cardiac events in patients undergoing elective hip and knee surgery, performing comparably to the Revised Cardiac Risk Index.

Richter transformation with c-MYC overexpression: report of three cases.

Pathogenesis of Richter transformation (RT) or Richter syndrome (RS) of chronic lymphocytic leukemia (CLL) is still largely unknown. Increasing evidences show that c-MYC may play a role in the development of RS. Here we report three cases of RS with overexpression of c-MYC. The first case was a 78-year-old male who initially presented with CLL and then developed diffuse lymphadenopathy and ascites shortly after. Ascites cytology showed a population of large lymphoid cells positive for MYC (8q24) rearrangement by fluorescence in situ hybridization (FISH) and overexpression of c-MYC by immunohistochemistry (IHC). The second case was a 66-year-old male presented with rapidly enlarging lymph nodes and pleural effusion after a long history of CLL. Biopsy showed large B-cells positive for c-MYC overexpression and high Ki-67 proliferation index (80-90%). The third case was a 62-year-old female with CLL who presented for lobectomy for lung adenocarcinoma. Interestingly, along with the carcinoma, large B-cell lymphoma was incidentally found which had the same immunophenotype as the CLL. FISH analysis revealed gain of c-MYC at 8q and IHC showed increased c-MYC expression. This study supports that c-MYC plays a critical role in RS.

Juvenile Active Ossifying Fibroma.

A case of juvenile active ossifying fibroma affecting a 27 year-old man will be discussed. The characteristic radiologic and histologic features of the entity will be described.