Cost analysis and clinical outcomes of anatomic pre-contoured locking versus conventional plates for distal fibula ankle fractures.

PURPOSE: To analyze differences in union, complication rates and cost from surgical fixation of distal fibula fractures with fibular plating implants. METHODS: In total, 380 adult patients from 2012 to 2015 treated with 12 fibular plates from 4 different manufacturers utilized by 9 surgeons were retrospectively reviewed. They were stratified into a conventional one-third tubular fibular plate group, pre-contoured anatomic locking plate group, or a heterogeneous group including 3.5-mm reconstruction, one-third tubular locking, composite, and limited compression plates. The outcomes included failure of fixation, deep infection requiring debridement, time to union, anatomic reduction, superficial infection, hardware removal, and post-traumatic arthritis. Plate and screw costs were calculated from hospital billing records. RESULTS: Pre-contoured locking plates were used in older, female patients with a greater number of comorbidities. Open injuries and OTA 44B fractures were more likely to be an indication for pre-contoured plates. There was no difference noted in time to union between the different plating groups. Risk factors for deep infection requiring debridement included a history of tobacco use, open fractures, and pre-contoured locking plates relative to the conventional plating group. The pre-contoured plating group was on average $586 more expensive compared to the conventional group. CONCLUSION: Pre-contoured locking plates achieved similar radiographic outcomes compared to conventional plates with an increased risk of complications and higher cost. Surgeons should consider their choice of implant based on the patient's fracture pattern, underlying comorbidities, and risk for infection.

Spin-Polarized Molecular Triplet States as Qubits: Phosphorus Hyperfine Coupling in the Triplet State of Benzoisophosphinoline.

Advances in quantum information science (QIS) require the development of new molecular materials to serve as microwave addressable qubits that can be read out optically. Laser photoexcitation of organic π-conjugated molecules often results in spin-polarized phosphorescent triplet states that can be readily observed and manipulated using time-resolved electron paramagnetic resonance (EPR) techniques. Photoexcitation of N-mesityl-1,8-naphthalimide (M-NMI) and its phosphorus analogues, 2-mesitylbenzoisophosphinoline (M-BIPD) and 2-mesitylbenzoisophosphinoline oxide (M-BIPDO) results in ultrafast spin-orbit charge-transfer intersystem crossing to form the corresponding phosphorescent triplet states M-3*NMI, M-3*BIPD and M-3*BIPDO. The ultrafast triplet formation dynamics, phosphorescence, and spin-polarized EPR spectra of these triplet states were examined. The most promising qubit candidate, M-3*BIPD, was examined using pulse-EPR to measure its spin relaxation times, and pulse electron-nuclear double resonance spectroscopy to perform a two-qubit CNOT gate using the phosphorus nuclear spin.

Ureteral Entrapment in an Associated Anterior Column and Posterior Hemitransverse Acetabular Fracture: A Case Report.

CASE: A 59-year-old man was struck by an automobile resulting in left anterior column posterior hemitransverse acetabular fracture with ureteral entrapment. Open reduction internal fixation was performed with removal of the ureter from the fracture. At follow-up 7 months post-op, the patient did not report significant hip or urinary symptoms, and implant position and fracture alignment remained intact. CONCLUSION: Surgeons should be mindful of possible ureteral injury associated with acetabular fractures. Awareness of this rare entrapment within medially displaced acetabular fractures may heighten clinical suspicion and improve management.

Iatrogenic Nerve Palsy Occurs With Anterior and Posterior Approaches for Humeral Shaft Fixation.

OBJECTIVE: To determine if surgical approach impacts the rate of nerve palsy after plate fixation of humerus shaft fractures and whether or not iatrogenic nerve palsy recovers in similar ways to preoperative palsy. DESIGN: Retrospective. SETTING: Two trauma centers. PATIENTS: Patients 18+ years of age with nonpathologic, extra-articular humerus shaft fractures (OTA/AO 12A/B/C and 13A2-3) treated with plate fixation. INTERVENTION: Plate fixation of humerus shaft fractures, from 2008 to 2016. MAIN OUTCOME MEASUREMENT: Rate of iatrogenic nerve palsy by a surgical approach and injury characteristics. RESULTS: Two hundred sixty-one humeral shaft fractures were included. The rate of preoperative palsy was 19%. Radial nerve palsy (RNP) was present in 18%. Iatrogenic RNP occurred in 12.2% and iatrogenic ulnar palsy in 1.2%. Iatrogenic palsy occurred in 15.6% of middle and 15% of distal fractures, with fracture location significantly different in those developing RNP (P = 0.009). Iatrogenic RNP occurred in 7.1% of anterolateral, 11.7% of posterior triceps-splitting, and 17.9% of posterior triceps-sparing approaches (P = 0.11). Follow-up data were available for 139 patients at an average of 12 months. Preoperative RNP resolved less often than iatrogenic RNP, in 74% versus 95% (P = 0.06). Time to resolution was longer for preoperative RNP, at 5.5 versus 4.1 months (P = 0.91). Twenty-two percent with preoperative RNP underwent tendon transfer or wrist fusion, versus 0% after iatrogenic RNP (P = 0.006). CONCLUSION: Iatrogenic RNP is not uncommon with humeral fracture fixation and occurs at similar rates in anterior and posterior approaches and with midshaft and distal fractures. Iatrogenic RNP had a high rate of recovery. Preoperative RNP more often requires surgery for unresolved palsy. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Spin-Selective Photoinduced Electron Transfer within Naphthalenediimide Diradicals.

There has been increasing interest in the excited states of stable diradicals as means of manipulating their spin states for potential applications in quantum information science (QIS). In this work, we examine a set of diradicals composed of two stable naphthalene-1,8:4,5-bis(dicarboximide) radical anions (NDI•-) bound either directly at their imide nitrogen atoms or through a series of benzene spacers resulting in diradicals with either singlet or triplet ground states. We use time-resolved near-UV, visible, near-IR, and mid-IR spectroscopy to show that the population in the singlet ground state can undergo photoinduced electron transfer upon excitation of one of the NDI•- radicals to produce the NDI0-NDI2- moiety, while the corresponding triplet population cannot. In particular, spectroscopy in the wavelength region 330-450 nm and in the energy range 1450-1750 cm-1 is critical to distinguishing the two populations. By varying the connectivity between the two radical anions, we vary both the sign and magnitude of the singlet-triplet energy splitting (2J) of the diradicals, thereby varying the proportion of singlet and triplet ground state populations that are detected optically. EPR spectroscopy provides corroborating evidence for the ground spin state of the diradicals. This result has implications for using photoexcitation to manipulate the spin states of diradicals for QIS applications.

Substituent effects on energetics and crystal morphology modulate singlet fission in 9,10-bis(phenylethynyl)anthracenes.

Singlet fission (SF) converts a singlet exciton into two triplet excitons in two or more electronically coupled organic chromophores, which may then be used to increase solar cell efficiency. Many known SF chromophores are unsuitable for device applications due to chemical instability or low triplet state energies. The results described here show that efficient SF occurs in derivatives of 9,10-bis(phenylethynyl)anthracene (BPEA), which is a highly robust and tunable chromophore. Fluoro and methoxy substituents at the 4- and 4'-positions of the BPEA phenyl groups control the intermolecular packing in the crystal structure, which alters the interchromophore electronic coupling, while also changing the SF energetics. The lowest excited singlet state (S1) energy of 4,4'-difluoro-BPEA is higher than that of BPEA so that the increased thermodynamic favorability of SF results in a (16 ± 2 ps)-1 SF rate and a 180% ± 16% triplet yield, which is about an order of magnitude faster than BPEA with a comparable triplet yield. By contrast, 4-fluoro-4'-methoxy-BPEA and 4,4'-dimethoxy-BPEA have slower SF rates, (90 ± 20 ps)-1 and (120 ± 10 ps)-1, and lower triplet yields, (110 ± 4)% and (168 ± 7)%, respectively, than 4,4'-difluoro-BPEA. These differences are attributed to changes in the crystal structure controlling interchromophore electronic coupling as well as SF energetics in these polycrystalline solids.

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles.

The 1-substituted-4-imino-1,2,3-triazole motif is an established component of coordination compounds and bioactive molecules, but depending on the substituent identity, it can be inherently unstable due to Dimroth rearrangements. This study examined parameters governing the ring-degenerate rearrangement reactions of 1-substituted-4-imino-1,2,3-triazoles, expanding on trends first observed by L'abbé et al. The efficiency of condensation between 4-formyltriazole and amine reactants as well as the propensity of imine products towards rearrangement was each strongly influenced by the substituent identity. It was observed that unsymmetrical condensation reactions conducted at 70 °C produced up to four imine products via a dynamic equilibrium of condensation, rearrangement and hydrolysis steps. Kinetic studies utilizing 1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carbaldehyde with varying amines showed rearrangement rates sensitive to both steric and electronic factors. Such measurements were facilitated by a high throughput colorimetric assay to directly monitor the generation of a 4-nitroaniline byproduct.

Phenothiazine Radical Cation Excited States as Super-oxidants for Energy-Demanding Reactions.

We demonstrate that the 10-phenyl-10 H-phenothiazine radical cation (PTZ+•) has a manifold of excited doublet states accessible using visible and near-infrared light that can serve as super-photooxidants with excited-state potentials is excess of +2.1 V vs SCE to power energy demanding oxidation reactions. Photoexcitation of PTZ+• in CH3CN with a 517 nm laser pulse populates a Dn electronically excited doublet state that decays first to the unrelaxed lowest electronic excited state, D1' (τ < 0.3 ps), followed by relaxation to D1 (τ = 10.9 ± 0.4 ps), which finally decays to D0 (τ = 32.3 ± 0.8 ps). D1' can also be populated directly using a lower energy 900 nm laser pulse, which results in a longer D1'→D1 relaxation time (τ = 19 ± 2 ps). To probe the oxidative power of PTZ+• photoexcited doublet states, PTZ+• was covalently linked to each of three hole acceptors, perylene (Per), 9,10-diphenylanthracene (DPA), and 10-phenyl-9-anthracenecarbonitrile (ACN), which have oxidation potentials of 1.04, 1.27, and 1.6 V vs SCE, respectively. In all three cases, photoexcitation wavelength dependent ultrafast hole transfer occurs from Dn, D1', or D1 of PTZ+• to Per, DPA, and ACN. The ability to take advantage of the additional oxidative power provided by the upper excited doublet states of PTZ+• will enable applications using this chromophore as a super-oxidant for energy-demanding reactions.

Orthopaedic Watercraft Injuries: Characterization of Mechanisms, Fractures, and Complications in 216 Injuries.

OBJECTIVE: To review the orthopaedic injuries from watercraft treated surgically at our institution and report the mechanisms, fractures, and complications encountered. DESIGN: Retrospective case series. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: There were 216 fractures from watercraft in 146 patients. Average age was 33 years (range 4-78 years), there were 68% males (99/146), and 16% of the injuries occurred in children. INTERVENTION: Operative fracture fixation. MAIN OUTCOME MEASUREMENTS: After IRB approval, data were collected from January 1, 1998, to December 31, 2015, for patients including demographics, watercraft type, mechanism of injury, fracture pattern, infection, organisms, union, and amputation. Descriptive statistics were used. RESULTS: There were 130 closed fractures (60%) and 86 open fractures (40%). There were 146 (67%) lower extremity injuries, 49 (23%) upper extremity injuries, and 21 (10%) pelvic injuries. The overall postoperative infection rate was 9% (20/216) and was commonly polymicrobial in nature. The postoperative infection rate in closed fractures was 4% (5/130) and the postoperative infection rate in open fractures was 17% (15/86). Open fractures also had a high proportion of nonunion (8%) and amputation (16%). CONCLUSIONS: This is the largest reported series of orthopaedic injuries from watercraft. These injuries can be devastating in nature and difficult to manage, particularly when they are open (40%). There is a high rate of postoperative infection (17%), nonunion (8%), and amputation (16%) associated with open orthopaedic watercraft fractures. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Tandem synthesis of 1-formyl-1,2,3-triazoles.

A tandem method for preparing 4-formyl-1,2,3-triazoles via a two-step one-pot acetal cleavage/CuAAC reaction was developed. Using this method, 4-formyl-1,2,3-triazole analogs with both electron-withdrawing and electron-donating substituents were prepared in good yield and purity. Expansion of this method to a three-step tandem reaction that incorporates an additional step of azide substitution was also successful, circumventing the need for organic azide isolation. This one-pot method, noteworthy in its simplicity and mild conditions, utilizes practical, readily available reactants and relies on protic solvent to promote acid-catalyzed acetal cleavage.

2-(1,2,3-Triazol-4-yl)pyridine-containing ethynylarenes as selective 'turn-on' fluorescent chemosensors for Ni(II).

A series of ethynylarene compounds containing 2-(1,2,3-triazol-4-yl)pyridine chelating units were studied as fluorescent chemosensors for metal cations in aqueous solution. Analogs possessing two chelating units bridged by either 1,4-diethynylphenyl or 2,7-diethynylnaphthyl subunits displayed large hypsochromic shifts coupled with signal intensification when exposed to increasing concentrations of Ni(II), a unique response among 22 metal cation analytes. This response was shown to be reversible, and is proposed to derive from disruption of aggregate formation upon Ni(II) binding at the peripheral chelating units.