Intramedullary nailing for irreducible spiral subtrochanteric fractures: A comparison of cerclage and non-cerclage wiring.

PURPOSE: Intramedullary nailing is the preferred internal fixation technique for the treatment of subtrochanteric fractures because of its biomechanical advantages. However, no definitive conclusion has been reached regarding whether combined cable cerclage is required during intramedullary nailing treatment. This study was performed to compare the clinical effects of intramedullary nailing with cerclage and non-cerclage wiring in the treatment of irreducible spiral subtrochanteric fractures. METHODS: Patients with subtrochanteric fractures admitted to our center from January 2013 to December 2021 were retrospectively analyzed. The patients were enrolled in the case-control study according to the inclusion and exclusion criteria and divided into the non-cerclage group and the cerclage group. The patients' clinical data, including the operative time, intraoperative blood loss, hospital stay, reoperation rate, fracture union time, and Harris hip score, were compared between these 2 groups. Categorical variables were compared using Chi-square or Fisher's exact test. Continuous variables with normal distribution were presented as mean ± standard deviation and analyzed with Student's t-test. Non-normally distributed variables were expressed as median (Q1, Q3) and assessed using the Mann-Whitney test. A p value < 0.05 was considered significant. RESULTS: In total, 69 patients were included in the study (35 patients in the non-cerclage group and 34 patients in the cerclage group). The baseline data of the 2 groups were comparable. There were no significant difference in the length of hospital stay (z = -0.391, p = 0.696), operative time (z = -1.289, p = 0.197), or intraoperative blood loss (z = -1.321, p = 0.186). However, compared with non-cerclage group, the fracture union time was shorter (z = -5.587, p < 0.001), the rate of nonunion was lower (χ2 = 6.030, p = 0.03), the anatomical reduction rate was higher (χ2 = 5.449, p = 0.03), and the Harris hip score was higher (z = -2.99, p = 0.003) in the cerclage group, all with statistically significant differences. CONCLUSIONS: Intramedullary nailing combined with cable cerclage wiring is a safe and reliable technique for the treatment of irreducible subtrochanteric fractures. This technique can improve the reduction effect, increase the stability of fracture fixation, shorten the fracture union time, reduce the occurrence of nonunion, and contribute to the recovery of hip joint function.

Formation of o-Allyl- and Allenyl-Modified Amides via Intermolecular Claisen Rearrangement.

We developed a new transition-metal-free intermolecular Claisen rearrangement process to introduce allyl and allenyl groups into the α position of tertiary amides. In this transformation, amides were activated by trifluoromethanesulfonic anhydride to produce the keteniminium ion intermediates that exhibit strong electrophilic activity. This atom-economical process delivers α position-modified amides under mild conditions in moderate to good yields and showcases a broad substrate compatibility.

[Curative effect of anterolateral spinal canal decompression combined with short segment screw fixation with posterior approach for severe thoracolumbar burst fractures with spinal cord injury].

OBJECTIVE: To explore the effect of anterolateral spinal canal decompression combined with short segment screw fixation with posterior approach for severe thoracolumbar burst fractures with spinal cord injury. METHODS: From January 2016 to June 2018, 16 patients with severe thoracolumbar burst fractures (more than 50% of ratio of spinal canal encroachment, reverse fragment at the posterior edge of the vertebral body) with spinal cord injury were retrospectively analyzed, including 10 males and 6 females, ranging in age from 19 to 57 years old. Causes of injury:8 cases of fall injury, 6 cases of traffic accident injury and 2 cases of other injuries. Fracture site:T11 in 4 cases, T12 in 5 cases, L1 in 5 cases, L2 in 2 cases. All the patients underwent anterolateral spinal canal decompression combined with short segment screw fixation with posterior approach. The curative imaging effects were evaluated by measuring the loss height of the anterior edge of the injured vertebra, Cobb angle of the adjacent segment of the injured vertebra, and ratio of spinal canal encroachment. The clinical effects were evaluated by Frankel spinal cord injury rating and visual analogue scale (VAS). RESULTS: All 16 patients were followed up, and the average follow up time was (15.9±5.4) months. The average operation time was (234±41) minutes and the average amount of bleeding was (431±93) ml. The loss of anterior height of injured vertebrae was (52.25±10.10)% before operation, (8.93± 3.61)% at 3 days after operation, and (9.25±2.88)% at the latest follow up. The results of 3 days after operation and the latest follow up were better than that before operation, and there was no significant differencesbetween results at the latest follow up and 3 days after operation (P<0.01). Cobb angle of adjacent segment of injured vertebrae was (28.19±10.89)°before operation, (5.31±5.14)° 3 days after operation, and (6.81±4.59)°at the latest follow-up. The ratio of spinal canal encroachment was (67.68±12.45)% before operation, (7.69±4.46)% at 3 days after operation, and (4.75±1.63)% at the latest follow-up. At 3 days and the latest follow-up, the rate recovered to a certain extent (P<0.05). At the latest follow up, spinal nerve function was improved in 12 patients, no improvement in 4 patients and no deterioration in nerve function. VSA score was improved from preoperative 7.8±0.9 to final follow-up 1.8±0.7. CONCLUSION: For severe thoracolumbar burst fracture and spinal cord injury, with more than 50% of ratio of spinal canal encroachment and reverse fragment at the posterior edge of the vertebral body, the anterolateral spinal canal decompression combined with short segment screw fixation with posterior approach has the characteristics of accurate reduction, complete decompression and firm fixation, and the clinical effect is satisfactory.

Organocatalyzed Synthesis of Functionalized Quinolines.

As one of the most widely investigated compound skeleton, quinolines possess important medicinal and biological activities. As such, a great number of literatures, including reviews, have reported various methodologies to construct quinolines. Recently, organocatalyzed reactions have attracted the attention of organic chemists due to its being "green" because the reactions avoid the use of toxic metals. In this review, various distinctive contributions are surveyed with specific emphasis on organocatalyzed reactions for quinoline core constructions.

New Friedel-Crafts strategy for preparing 3-acylindoles.

A selective Friedel-Crafts acylation of indoles via an unusual cleavage of the amide C-N bond was achieved by triflic anhydride activation. This method offers rapid efficient access to high-biological-value 3-acylindoles, performs a series of scrupulous mechanistic studies and offers a strong courage that amide synthons can form new C-C bonds under transition-metal-free conditions.

Transition-metal-free multinitrogenation of amides by C-C bond cleavage: a new approach to tetrazoles.

A metal-free brand-new one-pot multinitrogenation of amides for the chemo- and regioselective synthesis of 1,5-disubstituted tetrazoles has been developed. By means of electrophilic amide activation, and further C-C bond cleavage and rearrangement, a diverse set of functionalized 1,5-DST derivatives were selectively constructed under mild conditions. As showcased in the mechanisms, the chemoselectivity is easily switched by the selection of the starting materials in the reaction.

Synthesis of Functionalized Quinolines through a Reaction of Amides and Alkynes Promoted by Triflic Anhydride/Pyridine.

A concise, novel and flexible metal-free single step to synthesize functionalized quinolines is reported. Triflic anhydride-mediated (Tf2 O) activation of amides is discussed in the presence of pyridine to offer strong electrophiles, thereby showcasing excellent productivity, high regio- and chemoselectivity, and widely tolerable substrates. This approach provides a straightforward and efficient way to construct azaheterocycle structures.

[Effect of the Food to Mass Ratio and Hydraulic Retention Time on Hydrogen Production from Fruit and Vegetable Waste].

Semi-continuous biogas production from fruit and vegetable waste by medium temperature anaerobic fermentation was conducted. Hydrogen production under different food-microorganism ratios (F/M 0.5, 0.75, 1.0, 1.5) and hydraulic retention times (HRT) (2, 3, 4 d) were investigated. The results show that in the case of a smaller F/M values (0.5 and 0.75), not all HRT stages were conducive to the continuous production of hydrogen, however, they were conducive to producing methane, especially when HRT was 3 or 4 d. Continuous hydrogen production was viable when the F/M ration was relatively higher (1.0 and 1.5), however, this was not conducive to the production of methane, with almost no methane production detected in this process. A F/M of 1.0 and a HRT of 3 d provided the best conditions for continuous hydrogen production from fruit and vegetable waste. Meanwhile, the highest and average daily volume of hydrogen production were 451.2 mL·(L·d)-1 and (186±29) mL·(L·d)-1 respectively, whereas the highest and average hydrogen production rate of volatile solids were 133 mL·g-1 and (27±5) mL·g-1 respectively. The hydrogen content was 20%-30%.

Synthesis of ß-Difluoroalkylated Acrylonitriles in the Presence of Copper Powder.

A highly regio- and stereoselective copper-mediated cyanodifluoroalkylation of alkynes with ethyl difluoroiodoacetate and trimethylsilyl cyanide (TMSCN) is described. The three-component coupling reaction provides straightforward access to a variety of useful difluoroalkyl-substituted acrylonitriles. The introduction of the nitrile unit is of great importance in drug discovery for the modification of this fragment. Preliminary mechanistic investigations indicate that a vinyl iodide intermediate and a difluoroalkyl radical might be involved in this transformation.

Less wound complications of a sinus tarsi approach compared to an extended lateral approach for the treatment of displaced intraarticular calcaneal fracture: A randomized clinical trial in 64 patients.

BACKGROUND: We conducted a prospective randomized clinical trial to compare the clinical and radiological outcomes of the sinus tarsi and extended lateral approaches for the surgical treatment of displaced intraarticular calcaneal fractures. METHODS: Between January 2009 and January 2014, patients with displaced intraarticular calcaneal fracture were randomly assigned to receive surgical treatment by the sinus tarsi approach or the extended lateral approach using block randomization. We recorded and analyzed data on demographics, time to surgery, wound complications, Böhler angles pre- and postoperatively, and American Orthopedic Foot & Ankle Society score. RESULTS: Sixty-four patients met the inclusion criteria and were randomly assigned to the 2 groups: 32 patients underwent sinus tarsi approach, and 32 patients the extended lateral approach. Baseline characteristics of both groups were similar. The time to surgery in the sinus tarsi approach group was significantly shorter than in the extended lateral approach group (P = 0.04). The wound complication rates were 6.3% and 31.2% in the sinus tarsi approach and extended lateral approach groups, respectively, which was significantly different (P = 0.01). Regarding the clinical outcomes, the groups did not differ significantly on walking visual analogue scale or American Orthopedic Foot & Ankle Society scores at 6 months and 1 year postoperatively. No significant differences existed between groups regarding the Böhler angle at different times and reduction quality of the articular surface and the medial wall. CONCLUSION: Compared with the extended lateral approach, the sinus tarsi approach decreased wound complications and preoperative waiting time, and achieved similar functional and radiological outcomes for displaced intraarticular calcaneal fractures.

Lewis Acid Catalyzed [4 + 3] Cycloaddition of Propargylic Alcohols with Azides.

An unprecedented Lewis acid catalyzed [4 + 3] cycloaddition reaction is described that provides a straightforward route to polycyclic products containing an imine-based indole azepine scaffold, starting from readily available internal tertiary alkynols and azides. This cycloaddition protocol provides efficient and atom-economical access to a new class of fascinating imine-containing products in satisfactory yields, which has shown good application in the construction of seven-membered N-heterocycles.

Iodine-Promoted Radical Cyclization in Water: A Selective Reaction of 1,6-Enynes with Sulfonyl Hydrazides.

An iodine-promoted one-pot radical cyclization reaction of 1,6-enynes with sulfonyl hydrazides to provide five-membered and hexatomic ring sulfonylated products under the same conditions is established. This reaction proceeded smoothly in water and gave the corresponding products by using I2/TBHP instead of expensive and toxic catalysts with C-S and C-I bond formed in one step. This method also allowed easy access to significant functional sulfones for potential applications in medicinal and organic chemistry.

[Reconstruction intramedullary nailing for treatment of ispsilateral femoral neck and shaft fractures].

OBJECTIVE: To evaluate the curative effect and surigical skills of reconstruction intramedullary nailing in the treatment of ipsilateral femoral neck and shaft fractures. METHODS: From January 2007 to January 2013, 13 patients with ipsilateral femoral neck and shaft fractures were treated by reconstruction intramedullary nailing including 11 males and 2 females with an average age of 38.9 yeas old ranging from 25 to 53 years old. For femoral neck fractures,10 cases were basilar neck fracture, 3 were transcervical fractures and according to Garden classification,10 were type II, 2 were type III and 1 was type IV. For feormal shaft fracture, 5 were type I, 4 were type II, 3 were type III and 1 was type IV according to Winquist classification. The location of all 13 feormal shaft fractures were all in the uper 3/4 of the feormal shaft. Complications and postoperative function were recorded and evaluated. RESULTS: Eleven patients were followed up for 23.45 months (12 to 36 months). Time from injury to operation was 5.9 days in average. Malunion of femoral neck fracture happened in 1 patient, nonunion of femoral shaft fracture happened in 2 patients. NO femoral head osteonecrosis, infection and malunion of femoral shaft fracture happened. According to Friedman-Wyman classification, 8 cases get good result, 2 get faii and 1 get poor. CONCLUSION: Reconstruction intramedullary nailing is a good choice for the ipsilateral femoral neck and shaft fractures with the advantages of less soft-tissue trauma and complications.

Palladium-Catalyzed Intermolecular Aryldifluoroalkylation of Alkynes.

A palladium-catalyzed aryldifluoroalkylation of alkynes with ethyl difluoroiodoacetate and arylboronic acids as reaction partners is described. The alkyne difunctionalization process provides various aryldifluoroalkylated products in one pot under mild reaction conditions. A wide range of alkynes and diverse arylboronic acids are compatible with these reaction conditions. High reaction efficiency and broad substrate scope are the notable features of this transformation. Preliminary mechanistic investigations indicate that a difluoroalkyl radical addition pathway is involved in this transformation.

Silver-promoted oxidative cyclization of 1,6-enynes: highly regioselective synthesis of phosphorated fluorene derivatives.

A silver-promoted oxidative cyclization of 1,6-enynes with disubstituted phosphine oxides is developed for the synthesis of fluorene derivatives. The reaction proceeds with high regioselectivity by constructing one C-P bond and two C-C bonds in one step. Moreover, reduction of the pentavalent phosphine enlarges the application scope of the product.

Direct oxidative nitration of aromatic sulfonamides under mild conditions.

A direct nitration of aromatic sulfonamides using sodium nitrite as the nitrating agent has been developed. The reaction shows typically mono-substitution selectivity and can be enlarged to the gram scale with good yield.

Copper-catalyzed three-component cyanotrifluoromethylation/azidotrifluoromethylation and carbocyclization of 1,6-enynes.

A novel three-component strategy for the cyanotrifluoromethylation/azidotrifluoromethylation and carbocyclization of 1,6-enynes is developed. The reaction proceeds smoothly under a moderate temperature by using a copper catalyst, which provides a rapid and concise access to addition-carbocyclization products. Furthermore, the products obtained can be useful building blocks in discoveries of lead compounds and other biologically active CF3-containing heterocycles.

Zinc-catalyzed [4+3] cycloaddition with concomitant furan annulation: formation of cyclohepta[b]furans.

A convenient zinc-promoted [4+3] cycloaddition of a carbonyl ene-yne with simple dienes was first achieved. This reaction provided an efficient strategy to prepare various cyclohepta[b]furan rings by cascade cycloadditions. Additionally, a multicomponent reaction of dione, alkynal, and diene was also reported, which exhibited a novel strategy for selective creations of C-O bonds and C-C bonds.

Copper-catalyzed intermolecular cyanotrifluoromethylation of alkenes.

A novel and highly practical reaction for the copper-catalyzed intermolecular cyanotrifluoromethylation of alkenes is presented here. This methodology provides a general and straightforward way to synthesize a variety of useful CF3-containing nitriles, which can be used for further preparation of pharmaceutically and agrochemically important compounds in synthetic organic chemistry.