Synthesis and application of manganese-doped zinc oxide as a potential adsorbent for removal of Congo red dye from wastewater.

Synthetic dyes are considered toxic compounds and as such are not easily removed by conventional water treatment processes. This study demonstrated the synthesis of pure and manganese- (Mn), silver- (Ag), and iron- (Fe) doped zinc oxide (ZnO) nanoparticles via the wet chemical route. In particular, it investigated the batch adsorption studies and physiochemical properties of synthesized pure and doped ZnO materials for removing toxic congo red (CR) dye. X-ray diffraction (XRD), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDS) confirmed the synthesis of the pure and doped ZnO materials. The batch adsorption investigation revealed adsorption efficiencies of 99.4% for CR dye at an optimal dose of 0.03 g/30 ml for Mn-doped ZnO at a solution pH of 2. The adsorption capacity of each of the synthesized materials was found to be in order Mn-doped ZnO (232.5 mg/g) > Ag-doped ZnO (222.2 mg/g) > pure ZnO (212.7 mg/g) > Fe-doped ZnO (208.3 mg/g). Both pseudo-second-order kinetics model and the Langmuir isotherm model accurately explained the adsorption behaviors of CR dye. As such, Van der Waal interactions, H-bonding, and electrostatic interaction were found to be the adsorption mechanisms responsible for dye removal. In addition, the desorption-regeneration investigation indicated the successful reuse of the exhausted Mn-doped ZnO material for five cycles of CR dye adsorption with an efficiency of 83.1%. Overall, this study has demonstrated that Mn-doped ZnO could be considered a viable adsorbent for the cleanup of dye-contaminated water.

A study of biochar physiochemistry and particle size distribution influencing the properties of water-based slurry fuels.

Biochar-based slurry is a fossil-free-liquid fuel derived from a renewable source, biomass. This study aims to examine the properties of this fuel as an alternative to coal-water slurries. The slurries were produced by suspending 40 wt% biochar in a solution made of water and a surfactant. Two biochar types from chemically treated and untreated rice straw (RS) were utilized to assess the impact of particle-particle interactions and biochar physicochemical composition on slurry properties, including stability, rheology, and heating value. Additionally, three particle size distributions (PSD), two unimodal and a bimodal, were used to analyze the effect of PSD on the abovementioned properties. All slurries had an average energy content of 7.32 ± 0.27 MJ/kg. The stability of the slurry was higher for fine particles from treated RS with unimodal PSD (Dv50 8.8 ± 0.68 µm). However, slurries containing fine and coarse particles with bimodal PSD (Dv50 15.8 ± 0.64 µm) had relatively lower apparent viscosities of 342.1 and 336.55 mPa.s at a shear rate of 100 s-1 for slurries made of biochar from treated and untreated RS, respectively. Slurries containing coarse particles from treated and untreated RS with unimodal PSD (Dv50 18.6 ± 0.32 µm) led to higher viscosities and particle settling rates. Biochar morphology and chemical surface constitution significantly influenced slurry stability, while PSD greatly impacted rheological results.

Helping Surgeons' Hands: A Biomechanical Evaluation of Ergonomic Instruments.

PURPOSE: "Ergonomic" is a common descriptor for a desk or computer workspace but is a term rarely used to describe a surgical instrument. Instead, surgeons spend many hours in inconvenient positions, often using instruments that are not ergonomic. Improving the ergonomics of surgical instruments may decrease the required force for simple tasks and allow for more efficient surgery. METHODS: To evaluate the impact of ergonomic surgical instruments, the authors developed ergonomic screwdriver handles. The shape and size of these handles were engineered using previous dental studies and 3-dimensional modeling to create an ideal handle for specific glove sizes. Participants were recruited to test 3 different ergonomic handle sizes against a standard screwdriver while assessing digital peak force, digital contact area, and participant preference. Ten participants (3 women) with glove sizes ranging from 6 to 8 were evaluated. RESULTS: Ergonomic screwdriver handles sized for glove sizes 6 and 7 required significantly less thumb peak force than the standard screwdriver for all participants (702 N for glove size 6 and 567 N for glove size 7 ergonomic screwdrivers, vs 1780 N for "one size fits all" standard screwdriver). Participants consistently preferred screwdrivers that required lower thumb and index finger forces. All ergonomic handles required lower thumb and index finger force. Eighty percent of participants preferred a screwdriver modeled within 1 glove size of their own. CONCLUSIONS: Improved ergonomic handles require less force and are preferred by surgeons. CLINICAL RELEVANCE: The significant decrease in thumb peak force for glove sizes 6 and 7 suggests that there is room for ergonomic improvement in instruments, especially for surgeons with smaller hands. Manufacturing ergonomic screwdriver handles and using the evolving convenience of 3-dimensional printing may help to develop a more comfortable work environment for surgeons.

Is Hand Surgery in the Procedure Room Setting Associated With Increased Surgical Site Infection? A Cohort Study of 2,717 Patients in the Veterans Affairs Population.

PURPOSE: Procedure rooms (PRs) are increasingly used for hand surgeries, but few studies have directly compared surgical site infection (SSI) rates between the PR and operating room. We tested the hypothesis that procedure setting is not associated with an increased SSI incidence in the VA population. METHODS: We identified carpal tunnel, trigger finger, and first dorsal compartment releases performed at our VA institution from 1999 to 2021 of which 717 were performed in the main operating room and 2,000 were performed in the PR. The incidence of SSI, defined as signs of wound infection within 60 days of the index procedure, which was treated with oral antibiotics, intravenous antibiotics, and/or operating room irrigation and debridement, was compared. We constructed a multivariable logistic regression analysis to assess the association between procedure setting and SSI incidence, adjusting for age, sex, procedure type, and comorbidities. RESULTS: Surgical site infection incidence was 55/2,000 (2.8%) in the PR cohort and 20/717 (2.8%) in the operating room cohort. In the PR cohort, five (0.3%) cases required hospitalization for intravenous antibiotics of which two (0.1%) cases required operating room irrigation and debridement. In the operating room cohort, two (0.3%) cases required hospitalization for intravenous antibiotics of which one (0.1%) case required operating room irrigation and debridement. All other SSIs were treated with oral antibiotics alone. The procedure setting was not independently associated with SSI (adjusted odds ratio, 0.84 [95% confidence interval, 0.49, 1.48]). The only risk factor for SSI was trigger finger release (odds ratio, 2.13 [95% confidence interval, 1.32, 3.48] compared with carpal tunnel release), which was independent of setting. CONCLUSIONS: Minor hand surgeries can be performed safely in the PR without an increased rate of SSI. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Is There a Critical Dorsal Lunate Facet Size in Distal Radius Fractures That Leads to Dorsal Carpal Subluxation? A Biomechanical Study of the Dorsal Critical Corner.

PURPOSE: Intra-articular distal radius fractures are common and can be associated with carpal instability. Failure to address articular fragments linked to maintaining carpal stability can lead to radiocarpal subluxation or dislocation. The purpose of this study was to evaluate the size of a dorsal osteotomy in the dorsal/volar plane of the lunate facet that leads to dorsal carpal subluxation. METHODS: Dorsal lunate facet fractures were simulated twice in each of nine fresh-frozen cadavers. After completing a partial dorsal osteotomy in the radial/ulnar plane between the scaphoid and lunate facets, an osteotomy in the dorsal/volar plane was completed. Using a cutting jig, first an estimated 5-mm osteotomy, and then a 10-mm osteotomy (from the dorsal rim of the distal radius) were completed. The wrist was mounted in a custom jig and loaded with 100 N. Displacement of the lunate in the dorsal/volar plane compared with displacement in an intact specimen was evaluated and used to assess carpal subluxation. RESULTS: Lunate translation was 0 mm ± 0 mm in the intact state. The 5-mm osteotomy averaged 29% of the distal radius dorsal lunate facet in the dorsal/volar plane, and lunate translation was 0.7 mm ± 1.7 mm. The 10-mm osteotomy averaged 54% of the dorsal lunate facet in the dorsal/volar plane, and lunate translation was 2.8 mm ± 2.6 mm. Assuming a linear relationship from the osteotomies created, an osteotomy of an estimated ≥40% of the distal radius in the dorsal to volar plane resulted in substantial dorsal subluxation, although this specific osteotomy was not assessed in our study. CONCLUSIONS: Sequentially increased dorsal osteotomies of the dorsal lunate facet result in increased dorsal carpal subluxation. CLINICAL RELEVANCE: Distal radius fractures that include >40% of the "dorsal critical corner" are at risk for dorsal carpal subluxation and may require supplementary fixation.

Distal Metaphyseal Ulnar Shortening Osteotomy Fixation: A Biomechanical Analysis.

PURPOSE: Ulnar shortening osteotomy can be used to treat ulnar impaction syndrome and other causes of ulnar wrist pain. Distal metaphyseal ulnar shortening osteotomy (DMUSO) is one technique that has been proposed to reduce the complications seen with a diaphyseal USO or a wafer resection. However, to our knowledge, the optimal fixation construct for DMUSO has not been studied. We sought to characterize the biomechanical stiffness and rotational stability of different DMUSO constructs. METHODS: A DMUSO was performed on 40 human cadaveric ulnas using 4 different fixation constructs (10 specimens per group): one 3.0 mm antegrade screw; two 2.2 mm antegrade screws; one 3.0 mm retrograde screw; and two 2.2 mm retrograde screws. Biaxial testing using axial load and cyclical axial torque was performed until failure, defined as 10° of rotation or 2 mm displacement. Specimens were assessed for stiffness at failure. Bone density was assessed using the second metacarpal cortical percentage. RESULTS: Bone density was similar between all 4 testing groups. Of the 4 groups, the 2 antegrade screw group exhibited the highest rotational stiffness of 232 ± 102 Nm/deg. In paired analysis, this was significantly greater than 1 retrograde screw constructs. In multivariable analysis, 2-screw constructs were significantly stiffer than 1 screw and antegrade constructs were significantly stiffer than retrograde. Maximum failure torque did not differ with orientation, but 2 screws failed at significantly higher torques. CONCLUSION: Using 2 screws for DMUSO fixation constructs may provide higher stiffness and maximum failure torque, and antegrade screw constructs may provide more stiffness than retrograde constructs. CLINICAL RELEVANCE: Antegrade screw fixation using 2 screws may provide the strongest construct for DMUSO. Antegrade fixation may be preferred because it avoids violating the distal radioulnar joint capsule and articular surface of the ulna.

Failure of humeral shaft fixation: construct characteristics.

PURPOSE: Fixation failure following open reduction and internal fixation (ORIF) of humeral shaft fractures can be a challenging complication. We aimed to identify the modes of failure and characteristics of failed fixation constructs. METHODS: We queried our institutional database for patients > 18 years old with fixation failure after ORIF with single plate and screw constructs of humeral shaft fractures from 2006 to 2017. Demographics, fracture characteristics, fixation construct design and mode of failure were recorded. RESULTS: Twenty-three failures were identified. Mean age was 55.9 years (SD 19.2 years) with 15 (65%) women. Twelve patients (52%) had midshaft fractures; the remainder had distal-third shaft (8 pts, 35%) or proximal-third shaft (3 pts, 13%) fractures. Midshaft fractures were most commonly fixed through an anterolateral approach with plates and all non-locking screws (83%), while distal-third shaft fractures were fixed with a combination of locking and non-locking screws from a posterior approach. Distal-third shaft fractures failed by plate breakage (63%) or screw pullout (38%) and all midshaft failures occurred by screw pullout proximal (92%) or distal (8%) to the fracture. Resultant varus deformity occurred in 20 (87%) fractures. CONCLUSION: Screw pullout in midshaft fractures suggests that fixation to bone was insufficient or biomechanically disadvantageous. Varus moments contribute significantly to the failure of humeral shaft fracture ORIF. Plate breakage in distal fractures suggests high concentrations of stress over a narrow working length of constructs with inadequate plate strength. Recognizing how these constructs fail can aid proper implant selection and application for humeral shaft fracture. LEVEL OF EVIDENCE: Treatment level IV.

Radiocarpal Fusion: Indications, Technique, and Modifications.

Degenerative disorders of the wrist may affect isolated joints and inhibit normal functions of the wrist secondary to pain and stiffness. These processes that affect only the radiocarpal joint may be secondary to posttraumatic osteoarthritis, primary osteoarthritis, or rheumatoid arthritis. Radiocarpal wrist arthrodesis may help preserve some of the native wrist kinematics while alleviating pain and improving the range of motion. However, the surgeon must ensure that the patient's pathologic process primarily affects the radiocarpal articulations while relatively sparing the midcarpal articulations. Depending on the location of the pathology, isolated radiolunate or radioscapholunate arthrodesis have been described to preserve some motion in the midcarpal joint. To maximize motion in the midcarpal joint after radiocarpal arthrodesis, techniques for distal scaphoid and triquetrum excision have been described. We report patient outcomes for various techniques and describe our preferred technique for radioscapholunate arthrodesis using distal scaphoid excision.

Conversion of pyrolytic non-condensable gases from polypropylene co-polymer into bamboo-type carbon nanotubes and high-quality oil using biochar as catalyst.

The conversion of low-value plastic waste into high-value products such as carbon nanomaterial is of recent interest. In the current study, the non-condensable pyrolysis gases, produced from Polypropylene Copolymer (PPC) feedstock, was converted into bamboo-type carbon nanotubes (BCNTs) through catalytic chemical vapour deposition using biochar. Experiments were conducted in a three-zone furnace fixed bed reactor, where PPC was pyrolysed in the second zone and carbon nanotubes (CNTs) growth was eventuated in the third zone. The effects of different growth temperatures (500, 700, 900 °C) and biochar particle sizes (nanoparticle as well as 0-100 and 100-300 µm) were investigated to optimise the production of hydrogen and the yield of carbon nanotubes on the biochar surface. Biochar samples used in the synthesis of CNTs were obtained from the pyrolysis of saw dust at 700 °C in a muffle furnace. Analyses performed by using Scanning electron microscopy, Transmission electron microscopy, X-ray diffraction, and Raman spectroscopy techniques suggested that the best crystalline structure of CNTs were obtained at 900 °C with nano-sized biochar as a catalyst. The strong gas-solid contact and void fraction of nano-sized particles enhances the diffusion-precipitation mechanism, leading to the growth of CNTs. The nano-sized biochar increased hydrogen production at 900 °C and reduced the polycyclic aromatic hydrocarbons content in oil to only 1%, which is advantageous for further utilisation. Therefore, the production of high-value CNTs from waste plastic using low-cost biochar catalyst can be a sustainable approach in the management of waste plastic while participating in the circular economy.

Gorham Disease Limited to the Left Upper Extremity Without Hand Involvement.

In this case report, we present a young female patient with a history of Gorham disease, who sustained pathologic fractures of the left radius and ulna after a low-impact fall. Massive osteolysis of the left forearm and wrist was noted on plain radiographs. The patient had had 8 previous left upper-extremity fractures without evidence of disease in any other area of the body.

Measurement of the coracohumeral distance on magnetic resonance imaging in a large patient cohort.

BACKGROUND: Coracoid impingement syndrome is an increasingly recognized etiology of anterior shoulder pain. Numerus studies have documented the coracohumeral distance (CHD) as a primary or secondary measurement in symptomatic individuals, but there lacks an evaluation of CHD in a large cohort of asymptomatic individuals. The purpose of this study was to quantify a normative distribution of the CHD in a large cohort of healthy, asymptomatic subjects with no history of impingement or shoulder instability. METHODS: Incoming first-year students in the United States Military Academy were offered enrollment in this study as part of a prospective cohort to assess the normal anatomic relationships of the shoulder girdle. Magnetic resonance images were obtained, and a board-certified, fellowship-trained musculoskeletal radiologist performed measurements of the smallest distance from the coracoid to the humeral head on axial images. RESULTS: Magnetic resonance images of 714 subjects were available for analysis, including 630 males and 84 females, with a total of 1120 individual shoulders with images of adequate quality. The mean CHD for all shoulders imaged was 13.7 mm. The mean CHD in male shoulders was 13.8 mm, and in female subjects the average was 12.4 mm. CONCLUSIONS: This study is the largest of its kind to evaluate the CHD in asymptomatic, healthy shoulders to date and demonstrates a mean CHD of 13.7 mm for all subjects. This information can help to standardize "normal" ranges and act as a comparison for future work, when taken in the context of age and imaging in neutral rotation.

Has a Prescription-limiting Law in Rhode Island Helped to Reduce Opioid Use After Total Joint Arthroplasty?

BACKGROUND: In the United States, since 2016, at least 28 of 50 state legislatures have passed laws regarding mandatory prescribing limits for opioid medications. One of the earliest state laws (which was passed in Rhode Island in 2016) restricted the maximum morphine milligram equivalents provided in the first postoperative prescription for patients defined as opioid-naïve to 30 morphine milligram equivalents per day, 150 total morphine milligram equivalents, or 20 total doses. While such regulations are increasingly common in the United States, their effects on opioid use after total joint arthroplasty are unclear. QUESTIONS/PURPOSES: (1) Are legislative limitations to opioid prescriptions in Rhode Island associated with decreased opioid use in the immediate (first outpatient prescription postoperatively), 30-day, and 90-day periods after THA and TKA? (2) Is this law associated with similar changes in postoperative opioid use among patients who are opioid-naïve and those who are opioid-tolerant preoperatively? METHODS: Patients undergoing primary THA or TKA between January 1, 2016 and June 28, 2016 (before the law was passed on June 28, 2016) were retrospectively compared with patients undergoing surgery between June 1, 2017 and December 31, 2017 (after the law's implementation on April 17, 2017). The lapse between the pre-law and post-law periods was designed to avoid confounding from potential voluntary practice changes by physicians after the law was passed but before its mandatory implementation. Demographic and surgical details were extracted from a large multi-specialty orthopaedic group's surgical billing database using Current Procedural Terminology codes 27130 and 27447. Any patients undergoing revision procedures, same-day bilateral arthroplasties, or a second primary THA or TKA in the 3-month followup period were excluded. Secondary data were confirmed by reviewing individual electronic medical records in the associated hospital system which included three major hospital sites. We evaluated 1125 patients. In accordance with the state's department of health guidelines, patients were defined as opioid-tolerant if they had filled any prescription for an opioid medication in the 30-day preoperative period. Data on age, gender, and the proportion of patients who were defined as opioid tolerant preoperatively were collected and found to be no different between the pre-law and post-law groups. The state's prescription drug monitoring program database was used to collect data on prescriptions for all controlled substances filled between 30 days preoperatively and 90 days postoperatively. The primary outcomes were the mean morphine milligram equivalents of the initial outpatient postoperative opioid prescription after discharge and the mean cumulative morphine milligram equivalents at the 30- and 90-day postoperative intervals. Secondary analyses included subgroup analyses by procedure and by preoperative opioid tolerance. RESULTS: After the law was implemented, the first opioid prescriptions were smaller for patients who were opioid-naïve (mean 156 ± 106 morphine milligram equivalents after the law's passage versus 451 ± 296 before, mean difference 294 morphine milligram equivalents; p < 0.001) and those who were opioid-tolerant (263 ± 265 morphine milligram equivalents after the law's passage versus 534 ± 427 before, mean difference 271 morphine milligram equivalents; p < 0.001); however, for cumulative prescriptions in the first 30 days postoperatively, this was only true among patients who were previously opioid-naïve (501 ± 416 morphine milligram equivalents after the law's passage versus 796 ± 597 before, mean difference 295 morphine milligram equivalents; p < 0.001). Those who were opioid-tolerant did not have a decrease in the cumulative number of 30-day morphine milligram equivalents (1288 ± 1632 morphine milligram equivalents after the law's passage versus 1398 ± 1274 before, mean difference 110 morphine milligram equivalents; p = 0.066). CONCLUSIONS: The prescription-limiting law was associated with a decline in cumulative opioid prescriptions at 30 days postoperatively filled by patients who were opioid-naïve before total joint arthroplasty. This may substantially impact public health, and these policies should be considered an important tool for healthcare providers, communities, and policymakers who wish to combat the current opioid epidemic. However, given the lack of a discernible effect on cumulative opioids filled from 30 to 90 days postoperatively, further investigations are needed to evaluate more effective policies to prevent prolonged opioid use after total joint arthroplasty, particularly in patients who are opioid-tolerant preoperatively. LEVEL OF EVIDENCE: Level III, therapeutic study.

Opioid-Limiting Regulation: Effect on Patients Undergoing Knee and Shoulder Arthroscopy.

PURPOSE: To determine the effect prescription-limiting legislation passed in Rhode Island has had on opioids prescribed following arthroscopic knee and shoulder surgery at various time points, up to 90 days postoperatively. METHODS: All patients undergoing the 3 most common arthroscopic procedures at our institution (anterior cruciate ligament reconstruction, partial meniscectomy, and rotator cuff repair) were included. Patients were selected from 2 6-month study periods (prepassage and postimplementation of the law). The state's Prescription Drug Monitoring Program database was queried for controlled substances filled in the perioperative period (from 30 days preoperatively to 90 days postoperatively). Multiple logistic regressions were used to identify predictors of chronic (>30 days) opioid use. RESULTS: The morphine milligram equivalents (MMEs) prescribed in the initial postoperative script decreased from 319.04 (∼43 5-mg oxycodone tablets) in the prepassage to 152.45 MMEs (∼20 5-mg oxycodone tablets) in the postimplementation group (P < .001). The total MMEs filled in the first 30 days decreased from 520.93 to 299.94 MMEs (∼70 to ∼40 5-mg oxycodone tablets) (P < .001). MMEs filled between 30 and 90 days fell by 22.5% for all patients in this study; however, this change was not statistically significant (P = .263). Preoperative opioid use (odds ratio, 10.85; P < .001) and preoperative benzodiazepine use (odds ratio, 2.13; P = .005) predicted chronic opioid use postoperatively. CONCLUSIONS: State opioid-limiting legislation reduced cumulative MMEs following arthroscopic knee and shoulder surgery in the first 30 days. Further research assessing the impact of this legislation on postoperative pain control, patient satisfaction, and functional outcomes following surgery is warranted. LEVEL OF EVIDENCE: Level III, case-control study.

Suture Suspension Arthroplasty for the Treatment of Thumb Carpometacarpal Arthritis.

PURPOSE: Most studies have demonstrated little difference in the outcome of the various techniques proposed for the surgical treatment of thumb carpometacarpal (CMC) arthritis. However, the difficulty and time required to perform each technique vary widely. In addition, the introduction of recent implants has increased the cost of the overall procedure. We hypothesize that using a simple, yet stable, suture suspension technique without tendon interposition or ligament reconstruction yields similar results to conventional approaches with less operative time. METHODS: Three hundred twenty consecutive patients underwent thumb CMC arthroplasty by trapezial excision and metacarpal suspension using #2 high-strength orthopedic suture locked weave alone passed from the distal most abductor pollicis longus and flexor carpi radialis insertions without K-wire fixation or tendon transfer. Average duration of preoperative symptoms was 17.8 months. Patient radiographs were graded for arthritis severity and a visual analog scale (VAS) pain score (scale 0-10) obtained. Postoperative clinical and radiological follow-up averaged 5.4 years (minimum, 24 months). RESULTS: The average age at surgery was 57.3 years and there were 221 women (243 procedures) and 65 men (77 procedures). Average total operative time was 23.4 minutes. The dominant hand was involved in 52% of patients. All had prior treatment including orthoses and nonsteroidal anti-inflammatory drugs with 312 having had at least 1 steroid injection. Five patients had stage 1, 134 had stage 2, 164 had stage 3, and 17 had stage 4 disease on radiographs. Average trapezial space height on final follow-up radiographs was 0.8 cm. Two patients had complete trapezial space collapse and required a revision procedure. The average VAS score was 0.6 with pain eliminated in 269 thumbs, minimal in 49, and unchanged/worse in 2. All patients that were employed at the time of surgery returned to work at an average of 2.3 months (range, 3-16 weeks). CONCLUSIONS: Suture suspension thumb CMC arthroplasty provides comparable clinical results and several advantages over many current techniques that are described in the literature. The advantages include shortened operative time, inherent stability of the thumb metacarpal height, and no necessity for K-wire fixation, tendon transfers, or implants. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Medical Malpractice Litigation Following Arthroscopic Surgery.

PURPOSE: Our study aims to analyze a variety of factors involving malpractice lawsuits following arthroscopy, focusing on reasons for lawsuit and establishing predictors for the outcome of the lawsuit. METHODS: Two legal databases, VerdictSearch and Westlaw, were queried for arthroscopic cases in adult patients. For all included cases, clinical and demographic data were recorded. The effects of plaintiff demographics, joint involved, lawsuit allegation, case ruling, and size of indemnity payments were assessed. RESULTS: Of the 240 included cases, 62 (26%) resulted in plaintiff verdict, 160 (67%) resulted in defense verdict, and 18 (8%) were settled without trial. Plaintiff demographics (age and sex) had no effect on the case ruling. There was no statistical difference between indemnity awards for plaintiff verdicts ($1,013,494) and settled cases ($848,331; P = .13). Patient death was noted in 20 cases (8.3%); a significantly higher proportion of these cases were settled versus went to trial (P = .0022), including 19 patients (95%) who had knee arthroscopy and 16 deaths (80%) resulting from a pulmonary embolus. Plaintiff verdict or settlement were seen significantly more frequently for vascular complications and wrong-sided surgery. Alternatively, defense verdicts followed lawsuits alleging surgeon technical error. Wrong-sided surgery, retained instruments, deep venous thrombosis, and postoperative infections were seen at a significantly higher proportion after knee arthroscopy than after arthroscopy of other joints. Similarly, neurological injury was significantly associated with elbow and hip arthroscopy, while allegations of technical error by the surgeon and block-related complications were associated with shoulder arthroscopy. CONCLUSIONS: Plaintiff verdict or settlement were seen for vascular complications and wrong-sided surgery, while defense verdicts followed lawsuits alleging surgeon technical error and block-related complications. We also identified types of allegations that were associated with arthroscopy of different joints. All but one case of patient death (20 cases) were noted to involve knee arthroscopy, and an overwhelming majority resulted due to a pulmonary embolism. This information helps the arthroscopic surgeon better counsel patients and employ strategies to mitigate preventable complications. LEVEL OF EVIDENCE: Level IV, case series.

Evidence against resveratrol as a viable therapy for the rescue of defective ΔF508 CFTR.

BACKGROUND: Resveratrol, a natural phenolic compound, has been reported to rescue mutant ΔF508 CFTR in expression systems and primary epithelial cells. Although this implies a therapeutic benefit to patients with CF, investigations were performed using resveratrol concentrations greatly in excess of those achievable in plasma. We evaluated the efficacy of resveratrol as a CFTR corrector in relevant primary airway cells, using physiologically achievable resveratrol concentrations. METHODS: Cells expressing wt or ΔF508 CFTR were exposed to chronic or acute resveratrol. CFTR mRNA and protein expression were monitored. The effects of resveratrol on primary ΔF508 human airway cells were evaluated by equivalent current analysis using modified Ussing chambers. RESULTS: Consistent with previously published data in heterologous expression systems, high doses of resveratrol increased CFTR expression; however physiologically relevant concentrations were without effect. In contrast to heterologous expression systems, resveratrol was unable to increase mutant CFTR channel activity in primary airway cells. Elevated amiloride-sensitive currents, indicative of sodium transport and characteristically elevated in CF airway cells, were also unaffected by resveratrol. CONCLUSIONS: High concentrations of resveratrol can increase CFTR mRNA and protein in some cell types. In addition, acute resveratrol exposure can stimulate CFTR mediated chloride secretion, probably by increasing cellular cAMP levels. Resveratrol at physiologically achievable levels yielded no benefit in primary ΔF508 airway cells, either in terms of amiloride-sensitive currents of CFTR currents. GENERAL SIGNIFICANCE: Taken together, our results do not support the use of resveratrol supplements as a therapy for patients with cystic fibrosis. It is possible that further modifications of the resveratrol backbone would yield a more efficacious compound.

Quantum Chemical Molecular Dynamics Simulations of 1,3-Dichloropropene Combustion.

Oxidative decomposition of 1,3-dichloropropene was investigated using quantum chemical molecular dynamics (QM/MD) at 1500 and 3000 K. Thermal oxidation of 1,3-dichloropropene was initiated by (1) abstraction of allylic H/Cl by O2 and (2) intra-annular C-Cl bond scission and elimination of allylic Cl. A kinetic analysis shows that (2) is the more dominant initiation pathway, in agreement with QM/MD results. These QM/MD simulations reveal new routes to the formation of major products (H2O, CO, HCl, CO2), which are propagated primarily by the chloroperoxy (ClO2), OH, and 1,3-dichloropropene derived radicals. In particular, intra-annular C-C/C-H bond dissociation reactions of intermediate aldehydes/ketones are shown to play a dominant role in the formation of CO and CO2. Our simulations demonstrate that both combustion temperature and radical concentration can influence the product yield, however not the combustion mechanism.

Quantitative Assessment of Scalene Muscle Block for the Diagnosis of Suspected Thoracic Outlet Syndrome.

PURPOSE: To measure changes in upper limb work and power capacity before and after anterior scalene muscle block (ASMB) to suggest thoracic outlet syndrome caused by costoclavicular space compression. METHODS: We evaluated 34 patients disabled by symptoms suggesting thoracic outlet syndrome. An ASMB was performed via a supraclavicular injection. The sternocleidomastoid muscle was injected as a control. We captured data obtained from work simulator measurements before and after ASMB. Each patient performed a push-pull test with the forearm at waist level (test 1), an overhead bar push-pull test with the arm elevated (test 2), and the extremity abduction stress test with repetitive hand gripping during static arm elevation (test 3). We measured the work product, time to fatigue, and power generation. Sensory testing was performed after ASMB to rule out improved performance associated with possible sensory nerve block. RESULTS: In contrast to sternocleidomastoid injection controls, symptomatic and functional improvement was noted in all patients (n = 34) after ASMB. Work product measurement improved 93%, 108%, and 104% for tests 1, 2, and 3, respectively. Time to fatigue and power output also increased after the block. CONCLUSIONS: Temporary symptomatic improvement after ASMB may be anticipated in patients with TOS. This study documents a significant concurrent increase in upper limb motor function after the block. Increased work and power measurements after ASMB may draw diagnostic inference regarding a dynamic change in the scalene muscle and the costoclavicular space associated with symptomatic thoracic outlet syndrome. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.