Biomechanical Comparison of Impaction Techniques and Cross-Sectional Femoral Stem Shapes for Cementless Total Hip Arthroplasty.

Introduction: Traditional mallet broaching and stem seating in cementless total hip arthroplasty (THA) can result in femoral stem misalignment, potentially reducing implant longevity. This study aimed to compare the pullout strength of cementless THA femoral stems with different cross-sectional designs achieved through the powered impactor method versus the traditional mallet method. Methods: The authors utilized 24 polyurethane foam femurs and two femoral bone preservation stems with different proximal cross-sectional shapes (double taper: ACTIS®, size 5; flat taper: TRI-LOCK®, size 5). A single orthopedic surgeon broached each femur from size 0 to size 5 using either the powered impactor or mallet impaction methods. Broaching time and component implantation times were recorded. A load-to-failure pullout strength test was conducted, and the ultimate pullout load was recorded. Results: The broaching time for the TRI-LOCK® stem showed a statistically significant difference between the two impaction methods (powered: 37±7 seconds, mallet: 75±29 seconds, F[3, 20] = 4.56, p = 0.002), but no statistically significant difference was detected for the ACTIS® stem between the two impaction methods (powered: 47±22 seconds, mallet: 59±9 seconds, F[3, 20] = 4.56, p = 0.304). There was a statistically significant difference in pullout strength between the two impaction groups, and this strength was influenced by the implant cross-sectional shape (ACTIS®: 774±75N versus 679±22N, F(3,20) = 16.38, p = 0.018; TRI-LOCK®: 616±57N versus 859±85N, F(3, 20) = 16.38, p <0.001). Conclusions: The technique used for femoral bone preparation (powered impactor versus mallet) and the cross-sectional design of the cementless femoral stem are crucial factors that affect initial stem stability and operation time.

Center-Center Surgical Technique With Dynamic Syndesmosis Fixation: A Cadaveric Pilot Study.

The objective of this cadaveric biomechanical study was to evaluate if the center-center surgical technique is a reliable and repeatable method of achieving proper syndesmotic reduction when using dynamic syndesmotic fixation. Nine fresh frozen above-knee cadaveric lower extremities were used. Computerized tomography (CT) scans were first obtained for each intact specimen as the baseline for comparison. A simulated complete syndesmotic disruption was created by transection of all deltoid and syndesmotic ligaments. Instability of the ankle was confirmed with stress imaging using fluoroscopy. Each unstable specimen was repaired using the center-center surgical technique with dynamic syndesmosis fixation. A series of measurements from the axial CT images of intact and repaired specimens were used to determine the anatomic distal tibiofibular relationships for comparison of changes from intact to postfixation. All radiographic measurements were performed by 4 independent foot and ankle surgeons. The level of inter-rater reliability for all the measurements was found to be "moderate" to "excellent" agreement (ICC value: 0.865-0.983, 95% confidence interval: 0.634-0.996). There was no statistical difference found between rotational alignment of native and postfixation (a/b: p = .843; b-a: p = .125; θ: p = .062). There was a statistical difference detected for lateral alignment at the center of fibularis incisura between native and postfixation (average: -0.6 ± 0.8 mm, range: -2.3 to 1.2 mm, p < .001). There was no statistical difference found for the anteroposterior translation alignment between native and postfixation (d/e: p = .251; f: p = .377). This study demonstrated the use of the center-center surgical technique as a viable and repeatable method for achieving anatomical reduction of the tibiofibular syndesmosis when used with dynamic fixation modalities.

The Effect of Bone Quality on Treatment of Intertrochanteric Fractures with Helical Blade Versus Lag Screw Fixation in Cephalomedulary Nails.

Introduction: The specific aim of this retrospective study was to determine whether bone quality has any effect on the complication rates or overall survivorship between helical blades and lag screws in cephalomedullary nails used for intertrochanteric hip fractures. Methods: The authors reviewed clinical charts and radiographic studies of patients between January 2012 and August 2019. We reviewed radiographic images (pre-, intra-, and post-operative) to evaluate fracture fixation type, fracture reduction grade, and post-operative complications. We collected dual energy x-ray absorptiometry scan results (T-score) and serum alkaline phosphatase (ALP) isoenzyme activity values to evaluate patient bone quality. Results: We included 303 cases (helical: 197, screw: 106) in the study. Complications were found in 31 (16%) helical blade cases and 23 (22%) lag screw cases. No statistically significant difference was detected when comparing complication rates with patient bone quality between the two groups. These two groups had similar one-year implant survivorship with respect to T-score, the low ALP level group, and normal ALP level group. The helical blade had higher implant survivorship compared to lag screw in five-year survival rate with respect to osteoporotic group, high ALP level group, and normal ALP level group (osteoporotic: 77% vs 69%, high ALP: 73% vs 67%, normal ALP: 70% vs 64%). Conclusions: Similar complication rates were observed between helical blade and lag screw constructs in cephalomedullary femoral nails when accounting for patient bone quality. However, the helical blade design had a higher five-year survival rate.

A Biomechanical Evaluation of Casting Technique and Cast Core Size Effect.

BACKGROUNDS: The goals of this study were to (1) compare the effect of casting technique on biomechanical function with different casting materials and different cast core diameters, and (2) compare the strength of a cast based on the number of layers in relation to the core diameter. METHODS: Two standardized cylindrical cast model sizes were used to simulate forearm and short leg casts (core diameter: 60 mm, 100 mm) with 2 different casting techniques (non-smoothing vs. smoothing with lamination), utilizing 2 casting materials [fiberglass and Plaster of Paris (POP)]. Each cast was created using 3 different layers (Fiberglass: 2 to 4 layers; POP: 3 to 5 layers). Ultimate load-to-failure and flexural rigidity were analyzed through cyclic 4-point bend testing. RESULTS: The biomechanical comparison between forearm and short leg casts were significantly different regardless of the same number of layers for both casting materials and between 2 casting techniques. Increased cast thickness significantly increased the ultimate load-to-failure and bending strength. An increased core diameter size significantly decreased the cast's ultimate load-to-failure (fiberglass: 50% to 108%; POP: 10% to 93%) and bending strength (fiberglass: 17% to 35%; POP: 37% to 49%). Casting technique with smoothing with lamination technique had a negative biomechanical effect on POP and a minimal effect on fiberglass. CONCLUSION: The number of layers to apply for a cast should be based on the size of the extremity. Smoothing and lamination technique did not significantly improve the cast mechanical behavior. CLINICAL RELEVANCE: The findings of this study provide valuable evidence, analysis, and supplementary knowledge that helps guide physicians in proper casting technique.

Evaluation of Intramedullary Olecranon Screw Fixation for Simple Olecranon Fractures: A Biomechanical Study.

PURPOSE: The purpose of this study was to biomechanically evaluate the stability of the 6.5 mm intramedullary (IM) olecranon screw compared to locking compression plate fixation for Orthopedic Trauma Association/AO Foundation (OTA/AO) 2U1B1 olecranon fractures under cyclic range of motion of the elbow. METHODS: Twenty paired elbows were randomized to either IM olecranon screw or locking compression plate fixation of a simulated OTA/AO 2U1B1 fracture. Pullout strength was tested by increasing force applied to the triceps and proximal fragment. Fracture gap displacement was measured using differential variable reluctance transducers as the elbow was cycled through a 135° arc of motion using a servohydraulic testing system. RESULTS: Analysis of variance revealed significant interaction between group and load on fracture distraction after the 500th cycle in three settings: between the plate at 5-pound load and screw at 35-pound load, the screw at 5-pound load and screw at 35-pound load, and between the plate at 15-pound load and screw at 35-pound load. The difference in the rate of failure between plate (2 of 80 samples) and screw (4 of 80 samples) was not statistically significant. CONCLUSIONS: For OTA/AO 2U1B1 olecranon fractures, a single 6.5 mm IM olecranon screw demonstrated similar stability when compared to the locking compression plates throughout range of motion testing. CLINICAL RELEVANCE: From a biomechanical perspective, 6.5 mm IM screws and locking compression plates have similar ability to maintain fracture reduction following simulated elbow range of motion exercises in OTA/AO 2U1B1 fractures, giving surgeons another option in the management of these fractures.

Symptomatic Hammertoes Treatment Comparison: Peg-in-Hole Arthrodesis Versus End-to-End Screw Fixation.

Proximal interphalangeal (PIP) arthrodesis technique utilizing the peg-in-hole arthrodesis was founded to avoid the use of retained internal fixation implants and thereby potentially decrease the concern of hardware complication. The specific aim of this study was to report the complication rates of the modified peg-in-hole arthrodesis technique and the end-to-end arthrodesis with single screw fixation technique for correcting symptomatic hammertoe deformities in lesser digits. This retrospective chart review included patients who underwent surgical hammertoe correction of lesser digits between the dates of January 2012 and December 2019. Patient demographic data and charts were reviewed to evaluate need for revision including screw/pin removal and complications related to corrective surgery. Five hundred ninety-three symptomatic hammertoe deformity cases (443 female, 150 male) were identified, with 113 cases (88 female, 25 male) treated with peg-in-hole arthrodesis technique and 480 cases (355 female, 125 male) treated with end-to-end arthrodesis with a single screw technique. The deformity recurrence rate was not significantly different between the two techniques (peg-in-hole: 10%, end-to-end: 13%, p = .428). There were 97 cases with postoperative complications that required re-operation (peg-in-hole: 7 cases, end-to-end: 90 cases) with the majority detected at <6 months. There was no statistically significant difference in reoperation rate between the peg-in-hole technique and the end-to-end arthrodesis technique reoperated with reasons excluding simple screw removal (p = .068). This study tended to show these two arthrodesis techniques have equivalent risks and similar success in bone healing; however, the peg-in-hole arthrodesis technique offers an advantage that does not result in retained hardware.

Use of electrocautery devices for suture passage through the greater tuberosity: a biomechanical study.

BACKGROUND: The use of electrocautery to facilitate passage of a suture needle through bone without the aid of a drill or burr is a novel technique that has potential utility in orthopedic procedures, but there is a scarcity of research to support its utility. The specific aims of this cadaveric biomechanical study were to evaluate (1) the axial force reduction during suture passage using electrocautery when applied to rotator cuff repair, (2) the temperature change caused while using electrocautery, and (3) the failure loads and failure modes of this technique. METHODS: Five matched pairs of fresh frozen humeri were used, classified into 2 groups: with electrocautery on needle (study group) and without electrocautery on needle (control group). Four individual osseous tunnels were made on the greater tuberosity around the insertion of the supraspinatus tendon. Each specimen was sequentially tested in 2 parts: a needle penetration test (part I) to measure the peak axial force and temperature change and a single load-to-failure test (part II) to measure the maximum load to failure as well as the mechanism of failure. A No. 2 FiberWire suture with a straight needle was used. RESULTS: In part I, the mean peak axial force was lower in the study group compared with the control group for all osseous tunnels but was not statistically significant for individual tunnels. However, there was a significant decrease in peak axial force in the study group of 36% compared with the control group overall (P = .033). There was no significant change in temperature of the tunnel site with the use of electrocautery (mean: 0.2 ± 0.3°C, P = .435). In part II, 100% of the samples from each study group experienced bone tunnel failure. Forty percent of the trials in the study group found lower ultimate failure loads compared with the control group (reduction range: 7%-38%). There was no statistically significant difference in the ultimate failure load between either the loop tested or between the 2 study groups (loop 1: P = .352; loop 2: P = .270). CONCLUSION: Suture passage using electrocautery does significantly decrease the peak force needed to pass a needle directly through the greater tuberosity. This technique does not appear to burn the bone or weaken the bone tunnels. This technique may be useful during open rotator cuff repair or shoulder arthroplasty, although clinicians should be cautious when using this technique as its utility depends on bone quality and cortical thickness, and in vivo results may differ.

Can a Blade-Stopping Mechanism on Circular Table Saws Reduce the Severity of Hand Injuries in Contact Scenarios? A Cadaveric Study.

PURPOSE: Table saws are commonly used woodworking tools that carry a substantial risk of injury. Blade-stopping technology has been developed and has the potential to reduce the frequency and severity of injury. This study aimed to evaluate this technology on human tissue and characterize the resulting injuries. METHODS: Twenty-seven fresh, frozen cadaveric specimen hands were used. Three scenarios were tested, with the specimen (1) moving forward ("forward"); (2) moving backward, such as in a kickback scenario ("reverse"); and (3) dropped from above the saw blade ("top"). Each scenario was tested at both slow (0.001 m/sec) and fast (forward: 0.6 m/sec; reverse: 0.5 m/sec; top: 2.4 m/sec) approach speeds. The severity of the injuries was characterized by anatomic evaluation and confirmed with radiographic evaluation. Injuries were classified as no laceration, superficial soft tissue injury, deep soft tissue injury, and bony injury. RESULTS: For the slow approach speed, the brake cartridge engaged in 100% of the trials for all 3 scenarios, and 100% of the specimens sustained no injuries. Forward testing at a fast approach speed revealed the brake cartridge engaged in 89% of the trials (injuries: 4 superficial, 2 deep, 3 bony). Reverse testing at a fast approach speed revealed the brake cartridge engaged in 11% of trials (injuries: 1 superficial, 8 bony). Top testing at a fast approach speed revealed the brake cartridge engaged in 89% of the trials (injuries: 9 bony). CONCLUSIONS: Modern blade-stopping technology did not prevent all traumatic hand injuries in fast approach speed scenarios, but it reduced the incidence and severity of injuries. The technology was more effective at low approach speed scenarios. CLINICAL RELEVANCE: The findings of this study provide information to help understand the factors that can prevent or reduce the severity of contact injuries (hand, finger, or thumb) for operators of table saws.

Biomechanical Comparison of Knotless Suture Anchor Versus Percutaneous End-to-End Technique for Mid-Substance Achilles Tendon Rupture Repair.

Percutaneous Achilles tendon repairs can be performed with 2 distal fixation techniques: knotless suture anchor repair (KL) or percutaneous end-to-end repair (ETE). There is a paucity of literature comparing the biomechanical strength of these 2 distal fixation techniques. The aim of this study was to compare the strength of KL and ETE repairs using flat-braided suture for mid-substance Achilles tendon rupture during simulated progressive rehabilitation. Nine matched pairs of fresh-frozen below-knee cadaveric extremities were randomly assigned into these 2 repair groups. Each specimen was tested in 2 parts sequentially; Part I simulating passive ankle range of motion (cyclic: 20N-100N), and Part II simulating ambulation in a walking boot (cyclic: 20N-190N). The number of cycles, gap displacement, and the mode of failure were recorded for each repair. Achilles tendon repairs using the percutaneous methods of ETE and KL techniques showed no significant difference in the number of cycles to clinical failure, mean gap displacement, or overall failure rate. During Part I, the survival rate in terms of clinical failure for KL and ETE groups was 8 of 9 repairs and 7 of 9 repairs, respectively. During Part II, all repairs experienced clinical failure in both groups. Five repairs in the KL group experienced suture anchor pull out from the calcaneus, and 3 repairs failed at suture-tendon interface. Four repairs in the ETE group failed due to knot slippage and 5 repairs failed at suture-tendon interface. Both techniques are viable options in treating acute mid-substance Achilles tendon ruptures.

Computed Tomography Derived Patient-specific Instrumentation Total Ankle Arthroplasty Survivorship Outcomes.

Computed tomography (CT) derived patient-specific total ankle arthroplasty (TAA) systems have been utilized for improved accuracy and reproducible implant alignment. The purpose of the present study was to report the overall implant survivorship as well as radiographic analysis of patients who underwent primary TAA utilizing CT-derived patient-specific instrumentation. A retrospective review of medical charts and radiographs were performed on patients who had undergone primary TAA at a single institution in the Midwest region from March 2013 to October 2020. Radiographic analysis included preoperative, initial postoperative, and final follow-up coronal and sagittal tibiotalar alignment as well as periprosthetic radiolucency. A total of 96 patients with a mean follow-up of 3 years (range, 0.3-7.3 years) were included. Implant survivorship was found to be 92% at median follow-up of 3 years. A total of 8 cases (8.3%) required revision/reoperation, with 6 (6.3%) of these reoperations directly related for failure of one of the metallic implant components. There was significant improvement in both coronal and sagittal tibiotalar alignment from preoperative to initial postoperative follow-up (p < .001). At latest postoperative follow-up, there were 88% of TAAs that remained in a neutral alignment following surgery. A total of 10 cases were found to have radiolucency at latest follow-up. In conclusion, the use of CT derived patient-specific TAA showed high implant survivorship with significant improvement of sagittal and coronal tibiotalar alignment. With better implant alignment and position, it potentially reduces the risk of early implant failure or implant loosening in long-term follow-up.

Use of Electrocautery to Facilitate Suture Passage Through the Greater Trochanter of the Femur: A Biomechanical Study.

Introduction: The specific aims of this study were to evaluate (1) the axial force reduction of suture passage utilizing electrocautery when applied to the greater trochanter of the femur, (2) the temperature change caused while using electrocautery for suture passage, and (3) the failure loads and failure modes utilizing this technique. Methods: Five matched pairs of fresh-frozen femurs were used and classified into two groups: with electrocautery on needle (study group) and without electrocautery on needle (control group). Two bicortical, osseous tunnels were made around the insertion of the gluteus medius tendon. Each specimen was sequentially tested in a needle penetration test and a single load-to-failure test. A #5 Ethibond suture with a straight needle was used. Results: Electrocautery reduced the peak axial force for bone penetration in 40% (near cortex) and 70% (far cortex) of the trials, and no significant difference was detected between groups or between two osseous tunnels. The average peak force was significantly higher for the far cortex for both groups and for both osseous tunnels compared to the near cortex. There was no significant change in temperature of the tunnel site with electrocautery. Ninety percent of the samples experienced bone tunnel failure for the study group compared to 70% in the control group. The average ultimate failure load for the study group was lower compared with the control group, but this finding was not statistically significant (range: 6%-15%). Conclusions: Suture passage using electrocautery may not significantly decrease the peak force needed to pass a needle directly through the greater trochanter.

A microtubule-connexin-43 regulatory link suppresses arrhythmias and cardiac fibrosis in Duchenne muscular dystrophy mice.

Dilated cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD), an inherited degenerative disease of the cardiac and skeletal muscle caused by absence of the protein dystrophin. We showed one hallmark of DMD cardiomyopathy is the dysregulation of cardiac gap junction channel protein connexin-43 (Cx43). Proper Cx43 localization and function at the cardiac intercalated disc (ID) is regulated by post-translational phosphorylation of Cx43-carboxy-terminus residues S325/S328/S330 (pS-Cx43). Concurrently, Cx43 traffics along microtubules (MTs) for targeted delivery to the ID. In DMD hearts, absence of dystrophin results in a hyperdensified and disorganized MT cytoskeleton, yet the link with pS-Cx43 remains unaddressed. To gain insight into the relationship between MTs and pS-Cx43, DMD mice (mdx) and pS-Cx43-deficient (mdxS3A) mice were treated with an inhibitor of MT polymerization, colchicine (Colch). Colch treatment protected mdx, not mdxS3A mice, against Cx43 remodeling, improved MT directionality, and enhanced pS-Cx43/tubulin interaction. Likewise, severe arrhythmias were prevented in isoproterenol-stressed mdx, not mdxS3A mice. Furthermore, MT directionality was improved in pS-Cx43-mimicking mdx (mdxS3E). Mdxutr+/- and mdxutr+/-S3A mice, lacking one copy of dystrophin homolog utrophin, displayed enhanced cardiac fibrosis and reduced lifespan compared with mdxutr+/-S3E; and Colch treatment corrected cardiac fibrosis in mdxutr+/- but not mdxutr+/-S3A. Collectively, the data suggest that improved MT directionality reduces Cx43 remodeling and that pS-Cx43 is necessary and sufficient to regulate MT organization, which plays crucial role in correcting cardiac dysfunction in DMD mice. Thus, identification of novel organizational mechanisms acting on pS-Cx43-MT will help develop novel cardioprotective therapies for DMD cardiomyopathy.NEW & NOTEWORTHY We found that colchicine administration to Cx43-phospho-deficient dystrophic mice fails to protect against Cx43 remodeling. Conversely, Cx43-phospho-mimic dystrophic mice display a normalized MT network. We envision a bidirectional regulation whereby correction of the dystrophic MTs leads to correction of Cx43 remodeling, which in turn leads to further correction of the MTs. Our findings suggest a link between phospho-Cx43 and MTs that provides strong foundations for novel therapeutics in DMD cardiomyopathy.

Completion of Social Drivers of Health Screenings in Pediatric Practices Participating in a Quality Improvement Initiative.

OBJECTIVES: The Indiana Chapter of the American Academy of Pediatrics (INAAP) participated in a national quality improvement project led by the AAP called Addressing Social Health and Early Childhood Wellness, which sought to screen for and address social drivers of health (SDoH), socioemotional development, and perinatal depression in pediatric practices through practice and system improvement. This project aims to evaluate positive SDoH screenings and subsequent referrals from participating Indiana practices. METHODS: Ten pediatric practices in mid-central Indiana participated in this collaboration between July 2020 and July 2021 and submitted information about clinic resources, patient demographics, and process measures. Monthly chart reviews of well-child visits assessed completion of SDoH screenings, discussion of screening results with families, and referrals for positive screens. Composite measures of performance were developed from chart review. RESULTS: Measures showed significant improvements in SDoH screening and identified opportunities for improvement in the care continuum. SDoH screenings of eligible patients significantly increased from 21% to 62% on average ( p = 0.0002). Needed referrals fulfilled increased from 37% to 57% ( p = 0.003) on average. Interestingly, no significant improvement was seen in referring patients who screened positive (81% vs 89%, p = 0.0949). CONCLUSION: This project provided a framework for successful development and efficient integration of screening and referral processes into clinic workflow. Implementing Plan-Do-Study-Act cycles, monthly chart reviews, and collaborative meetings facilitated increased documentation of screening, counseling, and referral for positive SDoH screens in participating practices. Future analysis should measure health outcomes and social and community capital derived by health systems and patients from such interventions.

Clinical Outcome of Different Postoperative Prophylactic Strategies on Symptomatic Venous Thromboembolism after Total Knee Arthroplasty.

Introduction: The objective of this study was to evaluate the use of different post-operative prophylactic strategies on the rates of symptomatic venous thromboembolic events (VTE) incidence after primary total knee arthroplasty (TKA). Methods: A retrospective study of patients who underwent primary TKA procedure was performed from January 2015 through July 2020. Outcomes examined prophylaxis medication used during inpatient and outpatient care, amount of medication, length of medication, complications occurring within 90 days post-operatively, including symptomatic VTE (deep venous thrombosis (DVT), and pulmonary embolism (PE)), gastrointestinal (GI) bleeding requiring medical attention, change in management protocols after post-operative complications, and mortality. Results: In total, 5,663 cases were included (mean age 66 ± 10 years, mean BMI 34.1 ± 7.1kg/m2). The overall post-operative complication rate was 0.9% (DVT: 0.5%, PE: 0.3%, VTE: 0.04%, and GI bleeding: 0.09%). Enoxaparin use as inpatient anticoagulation medication was reduced significantly (67% vs. 13%, p < 0.001), and apixaban was increased significantly (6% vs. 49%, p < 0.001). Average hospital stays were reduced significantly among the years (3 ± 2 days vs. 2 ± 1 days, p < 0.001), and complication rates were not significantly different between the five years (~1%, p < 0.001). Most post-operative complications occurred on either aspirin 325 mg (36%) or apixaban (26%). However, the relative risk ratio results indicating that utilization of warfarin, rivaroxaban, and aspirin 81 mg as outpatient anticoagulation medication were more likely to increase the risk of symptomatic VTE incidence compared to other anticoagulants. The average time of complication detected was 21 ± 21 days (range: 1 - 87 days). More than 54% of complication events occurred after the patient had completed their medication (enoxaparin, rivaroxaban, and apixaban). Conclusions: The observed incidence of symptomatic VTE in this study was similar to previous studies regardless of the type of post-operative inpatient or outpatient prophylaxis prescribed. The ultimate choice of prophylaxis should remain with the treating physician and their knowledge of a particular patient's medical history.

Laparoscopic-Assisted Transversus Abdominis Plane Block Is Superior to Port Site Infiltration in Reducing Post-Operative Opioid Use in Laparoscopic Surgery.

BACKGROUND: The ultrasound-guided transversus abdominis plane (TAP) block can be time-consuming, costly, and technically challenging in the bariatric patient population. Laparoscopic-assisted TAP (L-TAP) block was developed and has been shown to be non-inferior to ultrasound-guided blocks. Postoperative pain can be significant, and pain control in the morbidly obese patients can be challenging. This study's aim was to compare L-TAP block to traditional port site infiltration in terms of postoperative opioid requirement for morbidly obese patients after laparoscopic Roux-en-Y gastric bypass (RYGB) surgery. METHODS: A retrospective chart review was performed from February 2019 through February 2020. Two study groups: L-TAP block and port site infiltration. Outcomes examined the amount of opioid used at different time segments relative to the operation. All intravenous (IV) and oral opioids used were converted into IV morphine milligram equivalents (MME) for standardization. RESULTS: 150 patients were included. The patient characteristics were not statistically significant between the two groups. Post-operative opioid use trended lower in the L-TAP block group in all time segments. A significant difference was detected in IV opioid use during post-operative day 0 with the mean MME for the L-TAP block group being 1.1±3.8 and port site infiltration group being 2.8±4.5 (P = .02). CONCLUSIONS: The L-TAP block more effectively reduces postoperative opioid use in comparison to port site infiltration in laparoscopic Roux-en-Y gastric bypass (RYGB) surgery. Based on these findings, as well as the efficiency and cost-effectiveness of L-TAP blocks, its routine use in laparoscopy should be considered.

SARS-CoV-2 RNA Shedding in Semen and Oligozoospermia of Patient with Severe Coronavirus Disease 11 Weeks after Infection.

We report severe acute respiratory syndrome coronavirus 2 in semen by using quantitative reverse transcription PCR during the late convalescent phase. Virus was associated with adequate humoral and cell-mediated responses, suggesting possible seeding of the immune-privileged testes. We provide longitudinal semen quality data for 6 other men, including 3 who had oligozoospermia.

Clinico-histopathologic and single-nuclei RNA-sequencing insights into cardiac injury and microthrombi in critical COVID-19.

Acute cardiac injury is prevalent in critical COVID-19 and associated with increased mortality. Its etiology remains debated, as initially presumed causes - myocarditis and cardiac necrosis - have proved uncommon. To elucidate the pathophysiology of COVID-19-associated cardiac injury, we conducted a prospective study of the first 69 consecutive COVID-19 decedents at CUIMC in New York City. Of 6 acute cardiac histopathologic features, presence of microthrombi was the most commonly detected among our cohort. We tested associations of cardiac microthrombi with biomarkers of inflammation, cardiac injury, and fibrinolysis and with in-hospital antiplatelet therapy, therapeutic anticoagulation, and corticosteroid treatment, while adjusting for multiple clinical factors, including COVID-19 therapies. Higher peak erythrocyte sedimentation rate and C-reactive protein were independently associated with increased odds of microthrombi, supporting an immunothrombotic etiology. Using single-nuclei RNA-sequencing analysis on 3 patients with and 4 patients without cardiac microthrombi, we discovered an enrichment of prothrombotic/antifibrinolytic, extracellular matrix remodeling, and immune-potentiating signaling among cardiac fibroblasts in microthrombi-positive, relative to microthrombi-negative, COVID-19 hearts. Non-COVID-19, nonfailing hearts were used as reference controls. Our study identifies a specific transcriptomic signature in cardiac fibroblasts as a salient feature of microthrombi-positive COVID-19 hearts. Our findings warrant further mechanistic study as cardiac fibroblasts may represent a potential therapeutic target for COVID-19-associated cardiac microthrombi.

Intrathymic differentiation of natural antibody-producing plasma cells in human neonates.

The thymus is a central lymphoid organ primarily responsible for the development of T cells. A small proportion of B cells, however, also reside in the thymus to assist negative selection of self-reactive T cells. Here we show that the thymus of human neonates contains a consistent contingent of CD138+ plasma cells, producing all classes and subclasses of immunoglobulins with the exception of IgD. These antibody-secreting cells are part of a larger subset of B cells that share the expression of signature genes defining mouse B1 cells, yet lack the expression of complement receptors CD21 and CD35. Data from single-cell transcriptomic, clonal correspondence and in vitro differentiation assays support the notion of intrathymic CD138+ plasma cell differentiation, alongside other B cell subsets with distinctive molecular phenotypes. Lastly, neonatal thymic plasma cells also include clones reactive to commensal and pathogenic bacteria that commonly infect children born with antibody deficiency. Thus, our findings point to the thymus as a source of innate humoral immunity in human neonates.

Oral Microbiome Alterations and SARS-CoV-2 Saliva Viral Load in Patients with COVID-19.

Bacterial-viral interactions in saliva have been associated with morbidity and mortality for respiratory viruses such as influenza and SARS-CoV. However, such transkingdom relationships during SARS-CoV-2 infection are currently unknown. Here, we aimed to elucidate the relationship between saliva microbiota and SARS-CoV-2 in a cohort of newly hospitalized COVID-19 patients and controls. We used 16S rRNA sequencing to compare microbiome diversity and taxonomic composition between COVID-19 patients (n = 53) and controls (n = 59) and based on saliva SARS-CoV-2 viral load as measured using reverse transcription PCR (RT-PCR). The saliva microbiome did not differ markedly between COVID-19 patients and controls. However, we identified significant differential abundance of numerous taxa based on saliva SARS-CoV-2 viral load, including multiple species within Streptococcus and Prevotella. IMPORTANCE Alterations to the saliva microbiome based on SARS-CoV-2 viral load indicate potential biologically relevant bacterial-viral relationships which may affect clinical outcomes in COVID-19 disease.