Mortality following proximal femoral fractures in elderly patients: a large retrospective cohort study of incidence and risk factors.

BACKGROUND: Global prevalence of osteoporosis and fragility fractures is increasing due to the aging population. Proximal femoral fractures are among the most common orthopedic conditions in elderly that significantly cause health deterioration and mortality. Here, we aimed to evaluate the mortality rates and risk factors, besides the functional outcomes after these injuries. METHODS: In a retrospective cohort study, all patients admitted with a femoral neck or intertrochanteric fracture between 2016 and the end of 2018 were enrolled in this study. Medical records were reviewed to include patients over 60 years of age who had a proximal femoral fracture and had a complete medical record and radiographs. Exclusion criteria included patients with pathological fractures, cancer under active treatment, follow-up loss, and patient access loss. Demographic and clinical features of patients alongside the details of fracture and patient management were recorded and analyzed. In-hospital and post-discharge mortalities due to included types of fractures at one and 12 months were the primary outcome. Modified Harris Hip Scores (mHHS) was the measure of functional outcome. RESULTS: A total of 788 patients including 412 females (52.3%) and 376 males (47.7%) with a mean age of 76.05 ± 10.01 years were included in this study. Among patients, 573 (72.7%) had an intertrochanteric fracture, while 215 (27.3%) had a femoral neck fracture, and 97.1% of all received surgical treatment. With a mean follow-up of 33.31 months, overall mortality rate was 33.1%, and 5.7% one-month and 20.2% 12-months rates. Analysis of 1-month mortality showed a significant mortality difference in patients operated after 48 h of fracture (p = 0.01) and in patients with American Society of Anesthesiologists (ASA) scores of 3-4 compared to ASA scores of 1-2 (p = 0.001). One-year mortality data showed that the mortality rate in femoral neck fractures was lower compared to other types of fracture. Surgical delay of > 48 h, ASA scores of 3-4, and treatment by proximal femoral plate were associated with shorter survival. The overall mean mHHS score was 53.80 ± 20.78. CONCLUSION: We found several risk factors of mortality, including age ≥ 80 years, a > 48-hour delay to surgery, and pre-operative ASA scores of 3-4 in patients with proximal femoral fracture. Furthermore, the use of a proximal femoral plate was a significant risk factor for mortality and lower mHHS scores.

Room-Temperature Patterning of Nanoscale MoS2 under an Electron Beam.

Molybdenum disulfide (MoS2) is traditionally grown at a high temperature and subsequently patterned to study its electronic properties or make devices. This method imposes severe limitations on the shape and size of MoS2 crystals that can be patterned precisely at required positions. Here, we describe a method of direct nanoscale patterning of MoS2 at room temperature by exposing a molybdenum thiocubane single-source precursor to a beam of electrons. Molybdenum thiocubanes with various alkylxanthate moieties [Mo4S4(ROCS2)6, where R = alkyl] were prepared using a "self-assembly" approach. Micro-Raman and micro-FTIR spectroscopic studies suggest that exposure to a relatively smaller dose of electrons results in the breakdown of xanthate moieties, leading to the formation of MoS2. High-resolution transmission electron micrographs suggest that the growth of MoS2 most likely happens along (100) planes. An electron-beam-induced chemical transformation of a molybdenum thiocubane resist was exploited to fabricate sub-10 nm MoS2 lines and dense dots as small as 13 nm with a pitch of 33 nm. Since this technique does not require the liftoff and etching steps, patterning of MoS2 with interesting shapes, sizes, and thicknesses potentially leading to tunable band gap is possible.

Direct Patterning of Zinc Sulfide on a Sub-10 Nanometer Scale via Electron Beam Lithography.

Nanostructures of metal sulfides are conventionally prepared via chemical techniques and patterned using self-assembly. This poses a considerable amount of challenge when arbitrary shapes and sizes of nanostructures are desired to be placed at precise locations. Here, we describe an alternative approach of nanoscale patterning of zinc sulfide (ZnS) directly using a spin-coatable and electron beam sensitive zinc butylxanthate resist without the lift-off or etching step. Time-resolved electron beam damage studies using micro-Raman and micro-FTIR spectroscopies suggest that exposure to a beam of electrons leads to quick disappearance of xanthate moieties most likely via the Chugaev elimination, and further increase of electron dose results in the appearance of ZnS, thereby making the exposed resist insoluble in organic solvents. Formation of ZnS nanocrystals was confirmed by high-resolution transmission electron microscopy and selected area electron diffraction. This property was exploited for the fabrication of ZnS lines as small as 6 nm and also enabled patterning of 10 nm dots with pitches as close as 22 nm. The ZnS patterns fabricated by this technique showed defect-induced photoluminescence related to sub-band-gap optical transitions. This method offers an easy way to generate an ensemble of functional ZnS nanostructures that can be arbitrarily patterned and placed in a precise way. Such an approach may enable programmable design of functional chalcogenide nanostructures.