We present an analytical model and measurements of the pump to signal relative intensity noise (RIN) transfer characteristics of copumped and counterpumped Raman amplifiers. We give a quantitative ...analysis of noise averaging from chromatic dispersion in copumped systems and from different propagation directions in counterpumped systems. It is shown that nondispersion-shifted fibers and other fibers with high dispersion between the signal and pump wavelengths give a greater potential for use in copumped Raman amplified systems.
IMPORTANCE: Postoperative delirium is the most common complication following major surgery in older patients. Intraoperative sedation levels are a possible modifiable risk factor for postoperative ...delirium. OBJECTIVE: To determine whether limiting sedation levels during spinal anesthesia reduces incident delirium overall. DESIGN, SETTING, AND PARTICIPANTS: This double-blind randomized clinical trial (A Strategy to Reduce the Incidence of Postoperative Delirum in Elderly Patients STRIDE) was conducted from November 18, 2011, to May 19, 2016, at a single academic medical center and included a consecutive sample of older patients (≥65 years) who were undergoing nonelective hip fracture repair with spinal anesthesia and propofol sedation. Patients were excluded for preoperative delirium or severe dementia. Of 538 hip fractures screened, 225 patients (41.8%) were eligible, 10 (1.9%) declined participation, 15 (2.8%) became ineligible between the time of consent and surgery, and 200 (37.2%) were randomized. The follow-up included postoperative days 1 to 5 or until hospital discharge. INTERVENTIONS: Heavier (modified observer’s assessment of sedation score of 0-2) or lighter (observer’s assessment of sedation score of 3-5) propofol sedation levels intraoperatively. MAIN OUTCOMES AND MEASURES: Delirium on postoperative days 1 to 5 or until hospital discharge determined via consensus panel using Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria. The incidence of delirium was compared between intervention groups with and without stratification by the Charlson comorbidity index (CCI). RESULTS: Of 200 participants, the mean (SD) age was 82 (8) years, 146 (73%) were women, 194 (97%) were white, and the mean (SD) CCI was 1.5 (1.8). One hundred participants each were randomized to receive lighter sedation levels or heavier sedation levels. A good separation of intraoperative sedation levels was confirmed by multiple indices. The overall incident delirium risk was 36.5% (n = 73) and 39% (n = 39) vs 34% (n = 34) in heavier and lighter sedation groups, respectively (P = .46). Intention-to-treat analyses indicated no statistically significant difference between groups in the risk of incident delirium (log-rank test χ2, 0.46; P = .46). However, in a prespecified subgroup analysis, when stratified by CCI, sedation levels did effect the delirium risk (P for interaction = .04); in low comorbid states (CCI = 0), heavier vs lighter sedation levels doubled the risk of delirium (hazard ratio, 2.3; 95% CI, 1.1- 4.9). The level of sedation did not affect delirium risk with a CCI of more than 0. CONCLUSIONS AND RELEVANCE: In the primary analysis, limiting the level of sedation provided no significant benefit in reducing incident delirium. However, in a prespecified subgroup analysis, lighter sedation levels benefitted reducing postoperative delirium for persons with a CCI of 0. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00590707
Patients with hip fractures are at very high risk for the development of venous thromboembolism (VTE). To provide an overview of cause, risk factors, current treatment strategies, and complications ...associated with VTE prophylaxis, we reviewed the most current, best available evidence on VTE prophylaxis for patients with hip fractures. We comprehensively reviewed the literature to assess the efficacy of VTE prophylaxis in patients with hip fractures, including the most recent published guidelines by national medical and surgical health organizations from the UK, USA, and Canada. Mechanical devices are effective in reducing the risk of VTE for hip fracture, but poor patient compliance is common and the devices are not recommended for sole VTE prophylaxis. Aspirin reduces the risk of VTE but does not provide optimal protection compared with other chemical agents; therefore, it is not recommended for sole VTE prophylaxis. Fondaparinux, warfarin, low-molecular-weight heparin, and unfractionated heparin reduce the risk of venographic deep vein thrombosis, but there is insufficient evidence that they reduce fatal pulmonary embolism or all-cause mortality. Fondaparinux is considered to be cost effective and more efficacious than low-molecular-weight heparin. At present, most major health organizations advocate at least 28 days of postoperative chemical prophylaxis. Chemical VTE prophylaxis should be administered to all patients with hip fractures unless contraindicated. Additional research is required to establish an agent that has a significant impact on fatal pulmonary embolism and all-cause mortality, without increasing bleeding complications, in this group of patients.
The use of narcotics has been found to be a modifiable risk factor for success of arthroplasty. We sought to determine the risk factors leading to increased narcotic use after total hip arthroplasty ...and total knee arthroplasty.
A retrospective chart review was performed on new patients presenting to an orthopedic reconstructive-service clinic. New patients aged 18 years or older with osteoarthritis of the hip or knee who presented over a 1-year period and underwent total knee arthroplasty or total hip arthroplasty were included. The Arkansas prescription monitoring program was then used to determine recent narcotic and benzodiazepine prescriptions filled within 3 months of surgery, and this was converted into morphine milligram equivalents (MME).
One hundred seventy-nine patients met the inclusion criteria. When compared with patients who did not take any preoperative opioids, narcotic- and tramadol-only users filled an average of 86% and 38% more MME, respectively. Benzodiazepine users required an average of 81% more MME postoperative than nonusers, and smokers required an average of 90% more MME postoperative than nonsmokers. Subjects with body mass index >40 kg/m2 had 82% higher average postoperative MME than subjects with body mass index <25 kg/m2. Age and sex had no significant correlation with postoperative narcotic use.
This study suggests that a patient's preoperative narcotic, tramadol, benzodiazepine, and tobacco use are correlated to the amount of postoperative narcotic prescriptions filled in the 3 months following surgery. Predisposition to substance abuse may be a characteristic which leads to increased postoperative narcotic use.
Update
This article was updated on September 4, 2020, because of a previous error. On page 1211, in the author affiliation section, “W.L. Walter, MBBS, PhD
3
” now reads “W.L. Walter, MBBS, PhD
3,4
...,” the affiliation for Dr. Van Onsem that had read “
3
Specialist Orthopedic Group, The Mater Clinic, North Sydney, New South Wales, Australia” now reads “
3
Royal North Shore Hospital, St. Leonards, New South Wales, Australia,” and the affiliation for Dr. Walter that had read “
3
Specialist Orthopedic Group, The Mater Clinic, North Sydney, New South Wales, Australia” now reads “
3
Royal North Shore Hospital, St. Leonards, New South Wales, Australia” and “
4
University of Sydney, Sydney, New South Wales, Australia.”
An erratum has been published: J Bone Joint Surg Am. 2020 Oct 7;102(19):e113
» As we resume elective surgical procedures, it is important to understand what practices and protocols should be altered or implemented in order to minimize the risk of pathogen transfer during the severe acute respiratory syndrome (SARS)-CoV-2 pandemic.
» Each hospital and health system should consider their unique situation in terms of SARS-CoV-2 prevalence, staffing capabilities, personal protection equipment supply, and so on when determining how and when to implement these recommendations.
» All patients should be screened for SARS-CoV-2 by means of a thorough history and physical examination, as well as reverse transcription-polymerase chain reaction (RT-PCR) testing whenever possible, prior to undergoing elective surgery.
» Patients who are currently infected with coronavirus disease 2019 (COVID-19) should not undergo elective surgery.
» These guidelines are based on the available scientific evidence, albeit scant. The recommendations have been reviewed and voted on by the expert delegates who produced this document.
Currently, the effect of the volume of cement used during sacroplasty on the restoration of pelvic strength and stiffness is unknown. The purpose of this study was to measure that effect in a sacral ...insufficiency fracture model.
Twenty-five osteoporotic cadaveric pelves were potted, and sacral fractures were produced. Specimens were divided into 4 groups: group 0 + 0 (control), no sacroplasty; group 3 + 0, sacroplasty (posterior approach), 3 mL of a bone cement injected bilaterally into the fracture site at S1; group 3 + 3, sacroplasty (posterior approach), 3 mL of the same cement injected bilaterally into the fracture site at S1 and S2; and group 6 + 3, sacroplasty (posterior approach), 6 mL of the same cement injected bilaterally at S1 and 3 mL injected bilaterally at S2. Cement position and extravasation were documented with CT. Specimens were tested to failure to assess the strength and stiffness after sacroplasty.
There were no significant differences in strength or stiffness restoration between control and treatment groups.
Sacroplasty does not restore the strength or stiffness of the sacrum in a cadaveric model regardless of the volume or location of cement.
Low-energy fragility fractures account for >80% of fractures in elderly patients, and with aging populations, geriatric fracture surgery makes up a substantial proportion of the orthopedic workload. ...Elderly patients have markedly less physiologic reserve than do younger patients, and comorbidity is common. Even with optimal care, the risk of mortality and morbidity remains high. Multidisciplinary care, including early orthogeriatric input, is recommended to anticipate and treat complications. This article explores modern treatment strategies for this challenging group of patients and provides guidance for systematically preparing and optimizing elderly patients before surgery, based on best available current evidence and recommendations by relevant health organizations.
Patients taking narcotics chronically are more likely to have worse outcomes after total joint arthroplasty. These negative outcomes may be avoided when modifiable risk factors such as narcotic use ...are identified and improved before elective joint replacement. An accurate assessment of narcotic use is needed to identify patients before surgery. This study examines the amount of reported narcotic use in patients with hip or knee osteoarthritis and compares this with the narcotic prescriptions recorded in our state’s drug prescription monitoring database.
All new patients seen during a 1-year period by our adult reconstruction practice were identified. Patients’ electronic health records were reviewed to determine whether narcotic use was reported. A subsequent search was performed using the Arkansas Prescription Drug Monitoring Program to determine if the patient had been previously prescribed a narcotic.
A total of 502 patients were included in the study. One hundred seventy patients (34%) were prescribed a narcotic within 3 months of the clinic visit according to the Arkansas Prescription Drug Monitoring Program, but only 111 (22%) reported narcotic use in their electronic health record (P < .0001). Moreover, only 92 patients (54% of 170) prescribed a narcotic within 3 months reported it. Narcotic recipients were more likely to be under the age of 65 years (P = .0081), smokers (P < .0001), and current benzodiazepine users (P < .0001).
This study demonstrates that patients significantly underreport their narcotic use to their physician. The availability of a state prescription drug monitoring program allows physicians to check the frequency of filled narcotic prescriptions by their patients.
This investigation sought to advance the work published in our prior biomechanical study (Journal of Orthopaedic Research, 2016). We specifically sought to determine whether there are additional ...easy-to-measure parameters on plain radiographs of the proximal humerus that correlate more strongly with ultimate fracture load, and whether a parameter resembling the Dorr strength/quality characterisation of proximal femurs can be applied to humeri.
A total of 33 adult humeri were used from a previous study where we quantified bone mineral density of the proximal humerus using radiographs and dual-energy x-ray absorptiometry (DEXA), and regional mean cortical thickness and cortical index using radiographs. The bones were fractured in a simulated backwards fall with the humeral head loaded at 2 mm/second via a frustum angled at 30° from the long axis of the bone. Correlations were assessed with ultimate fracture load and these new parameters: cortical index expressed in areas ("areal cortical index") of larger regions of the diaphysis; the canal-to-calcar ratio used analogous to its application in proximal femurs; and the recently described medial cortical ratio.
The three new parameters showed the following correlations with ultimate fracture load: areal cortical index (r = 0.56, p < 0.001); canal-to-calcar ratio (r = 0.38, p = 0.03); and medial cortical ratio (r = 0.49, p < 0.005). These correlations were weaker when compared with those that we previously reported: mean cortical thickness of the proximal diaphysis versus ultimate fracture load (r = 0.71; p < 0.001); and mean density in the central humeral head versus ultimate fracture load (r = 0.70; p < 0.001).
Simple-to-measure radiographic parameters of the proximal humerus reported previously are more useful in predicting ultimate fracture load than are areal cortical index, canal-to-calcar ratio, and medial cortical ratio.Cite this article: J. G. Skedros, C. S. Mears, W. Z. Burkhead. Ultimate fracture load of cadaver proximal humeri correlates more strongly with mean combined cortical thickness than with areal cortical index, DEXA density, or canal-to-calcar ratio. Bone Joint Res 2017;6:1-7. DOI: 10.1302/2046-3758.61.BJR-2016-0145.R1.
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