11 research outputs found
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Measurement of Outlet Pressures Favors Rib Resection for Decompression of Thoracic Outlet Syndrome
Background. When conservative therapy for thoracic outlet syndrome fails, scalenectomy with or without first-rib resection (FRR) is the treatment of choice. We measured pressure in the costoclavicular space before and after FRR at time of neurogenic thoracic outlet syndrome release to evaluate whether FRR is required to completely decompress the costoclavicular space.
Methods. Using a supraclavicular exposure for anterior-middle scalenectomy with FRR, costoclavicular space pressures were measured using a balloon catheter with the patient's arm in neutral anatomic position, secondarily, the arm abducted and externally rotated. Pressures were recorded in both arm positions before scalenectomy, after scalenectomy, and after FRR. Paired Student's t test was used to compare differences in group means for paired samples. Patient-reported outcomes were reported using the Derkash classification and quick disabilities of the arm, shoulder, and hand (qDASH) questionnaire.
Results. Fifteen patients (16 cases) surgically treated for neurogenic thoracic outlet syndrome were included in this retrospective study. There was no significant difference in pressure change between arm positions before scalenectomy (161.56 +/- 71.65 mm Hg difference) or after scalenectomy (148.5 +/- 80.24 mm Hg difference). There was a significant difference in pressure change between post-scalenectomy and post-FRR arm positions; mean pressure change between arm positions after FRR was 50.56 +/- 40.28 mm Hg. Mean postoperative qDASH score was 20 +/- 23.2. All patients reported improvement in symptoms and functional status.
Conclusions. Supraclavicular first rib resection for management of neurogenic thoracic outlet syndrome can be safely performed with favorable outcomes. The pressure increase in the costoclavicular space caused by arm abduction and external rotation was significantly reduced only after FRR, raising concerns about potential incomplete costoclavicular space decompression with scalenectomy alone for neurogenic thoracic outlet syndrome management. (C) 2020 by The Society of Thoracic Surgeons
Morphology and Thermodynamic Properties of a Copolymer with an Electronically Conducting Block: Poly(3-ethylhexylthiophene)-<i>block</i>-poly(ethylene oxide)
We report on the synthesis and morphology of a block
copolymer,
poly(3-(2′-ethylhexyl)thiophene)-<i>b</i>-poly(ethylene
oxide) (P3EHT-<i>b</i>-PEO), that conducts both electrons
and ions. We show that in the melt state the P3EHT-<i>b</i>-PEO chains self-assemble to produce traditional nanoscale morphologies
such as lamellae and gyroid. This is in contrast to a majority of
previous studies on copolymers with electronically conducting blocks
wherein a nanofibrillar morphology is obtained. Our approach enables
estimation of the Flory–Huggins interaction parameter, χ.
The segregation strength between the two blocks is controlled through
the addition of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI).
For the salt-free sample, the gyroid morphology, obtained in the melt
state, is transformed into lamellae below the melting temperature
of the P3EHT block. This is due to the “breaking out”
of the crystalline phase. For the salt-containing sample, P3EHT-<i>b</i>-PEO has a lamellar morphology in both melt and crystalline
states (confined crystallization)
Glass Transition Temperature and Ion Binding Determine Conductivity and LithiumIon Transport in Polymer Electrolytes
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Glass Transition Temperature and Ion Binding Determine Conductivity and Lithium-Ion Transport in Polymer Electrolytes
Measurement of Outlet Pressures Favors Rib Resection for Decompression of Thoracic Outlet Syndrome
Morphology and Thermodynamic Properties of a Copolymer with an Electronically Conducting Block: Poly(3-ethylhexylthiophene)- block
Training improves interobserver reliability for the diagnosis of scaphoid fracture displacement
Background The diagnosis of displacement in scaphoid fractures is notorious for poor interobserver reliability.Questions/purposes We tested whether training can improve interobserver reliability and sensitivity, specificity, and accuracy for the diagnosis of scaphoid fracture displacement on radiographs and CT scans.Methods Sixty-four orthopaedic surgeons rated a set of radiographs and CT scans of 10 displaced and 10 nondisplaced scaphoid fractures for the presence of displacement, using a web-based rating application. Before rating, observers were randomized to a training group (34 observers) and a nontraining group (30 observers). The training group received an online training module before the rating session, and the nontraining group did not. Interobserver reliability for training and nontraining was assessed by Siegel’s multirater kappa and the Z-test was used to test for significance.Results There was a small, but significant difference in the interobserver reliability for displacement ratings in favor of the training group compared with the nontraining group. Ratings of radiographs and CT scans combined resulted in moderate agreement for both groups. The average sensitivity, specificity, and accuracy of diagnosing displacement of scaphoid fractures were, respectively, 83%, 85%, and 84% for the nontraining group and 87%, 86%, and 87% for the training group. Assuming a 5% prevalence of fracture displacement, the positive predictive value was 0.23 in the nontraining group and 0.25 in the training group. The negative predictive value was 0.99 in both groups.Conclusions Our results suggest training can improve interobserver reliability and sensitivity, specificity and accuracy for the diagnosis of scaphoid fracture displacement, but the improvements are slight. These findings are encouraging for future research regarding interobserver variation and how to reduce it further.<br /
Diagnosis of elbow fracture patterns on radiographs: interobserver reliability and diagnostic accuracy
Item does not contain fulltextBACKGROUND: Studies of traumatic elbow instability suggest that recognition of a pattern in the combination and character of the fractures and joint displacements helps predict soft tissue injury and guide the treatment of traumatic elbow instability, but there is no evidence that patterns can be identified reliably. QUESTIONS/PURPOSES: We therefore determined (1) the interobserver reliability of identifying specific patterns of traumatic elbow instability on radiographs for subgroups of orthopaedic surgeons; and (2) the diagnostic accuracy of radiographic diagnosis. METHODS: Seventy-three orthopaedic surgeons evaluated 53 sets of radiographs and diagnosed one of five common patterns of traumatic elbow instability by using a web-based survey. The interobserver reliability was analyzed using Cohen's multirater kappa. Intraoperative diagnosis was the reference for fracture pattern in calculations of the sensitivity, specificity, accuracy, and positive predictive and negative predictive values of radiographic diagnosis. RESULTS: The overall interobserver reliability for patterns of traumatic elbow instability on radiographs was kappa=0.41. Treatment of greater than five such injuries a year was associated with greater interobserver agreement, but years in practice were not. Diagnostic accuracy ranged from 76% to 93% and was lowest for the terrible triad pattern of injury. CONCLUSIONS: Specific patterns of traumatic elbow instability can be diagnosed with moderate interobserver reliability and reasonable accuracy on radiographs. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence