Theoretical study on multi-perspective interaction analysis of ADN and ADN-H2O-CH3OH solutions.

CONTEXT: Revealing the mechanism of intermolecular interactions in dinitroamine ammonium (ADN)-based liquid propellants and exploring the reasons for their performance changes, multi-perspective interaction analyses of ADN and ADN-water (H2O)-methanol (CH3OH) solutions have been conducted via theoretical methods. The band structure, density of states (DOS), surface electrostatic potential (ESP), Hirshfeld surface, reduced density gradient (RDG), AIM topological analysis, and detonation performance were studied and the results showed that both the ADN and ADN-H2O-CH3OH solutions had hydrogen bonds and van der Waals interactions. By introducing the small molecules H2O and CH3OH, the detonation performance of the ADN-H2O-CH3OH solution slightly decreased, but its sensitivity also decreased. Overall, the comprehensive performance of the ADN-H2O-CH3OH solution has improved, and the application range has expanded. These results are helpful for obtaining a deeper understanding of ADN-based liquid propellants at the atomic level and contribute to the development of new liquid propellants. METHODS: The ADN and ADN-H2O-CH3OH solutions were constructed by Amorphous cell module and optimized via GGA with PBE methods in the Dmol3 module of the Materials Studio, and their electronic properties were calculated. Hirshfeld surfaces were generated with CrystalExplorer 3.0. A topological analysis of a variety of molecular clusters was performed via QTAIM. The QTAIM and RDG analyses in this work were generated by Multiwfn 3.0.

[F-type forceps for assisted reduction in femoral shaft fractures surgery].

OBJECTIVE: To explore clinical efficacy of F-type forceps for assisted reduction in femoral shaft fracture reduction. METHODS: Forty-five patients with femoral shaft fracture treated with intramedullary nail and internal fixation from January 2019 to December 2021 were retrospectively analyzed and divided into two groups according to different reduction methods. In observation group, there were 21 patients, included 15 males and 6 females, aged from 27 to 92 years old with an average of (53.38±18.81) years old;9 patients on the left side, 12 patients on the right side;7 patients were type A, 8 patients were type B and 6 patients were type C according to AO fracture classification;the time from injury to operation ranged from 7 to 13 days with an average of (4.62±3.34) days;reduction was assisted by F-shaped forceps. In control group, there were 24 patients, including 17 males and 7 females, aged from 20 to 92 years old with an average of (51.96±20.43) years old;12 patients on the left side, 12 patients on the right side;11 patients were type A, 8 patients were type B and 5 patients were type C according to AO fracture classification;the time from injury to operation ranged from 2 to 13 days with an average of (6.29±3.04) days;traditional reset mode was adopted. Operative time, intraoperative blood loss, intraoperative fluoroscopy times, intraoperative open reduction ratio, clinical healing time of fracture, postoperative complications, hospital stay, hospital cost and Lysholm score of knee joint at 6 and 12 months after surgery were compared between two groups to evaluate clinical effect. RESULTS: All patients were followed up for 12 to 24 months with an average of (16.60±3.45) months. In observation group, operative time, intraoperative blood loss, intraoperative fluoroscopy times, open reduction cases, and clinical healing time of fractures were (58.19±7.93) min, (88.10±44.45) ml, (25.29±5.54) times, 0 case, (4.76±0.77) months, respectively;while in control group was (79.33±22.94) min, (222.92±144.45) ml, (47.46±26.25) times, 5 cases, (7.13±1.80) months, and the difference between two groups were statistically significant (P<0.05). There were no significant difference in postoperative complications, length of stay and hospitalization cost between two groups (P>0.05). At 6 months after surgery, Lysholm score of knee joint in observation group (88.62±4.48) was better than that in control group (79.21±8.91) (F=21.948, P=0.000). There were no significant difference in support use, pain and squat score between two groups (P>0.05). At 12 months after surgery, Lysholm scores of stair climbing and pain in observation group were (9.62±1.20) and (19.76±1.92), which were better than those in control group (7.83±2.04) and (21.88±2.88) (P<0.05). There were no significant difference in scores and total scores of other items between two groups (P>0.05). CONCLUSION: Compared with traditional reduction method, F-type forceps instrument could shorten operation time, reduce intraoperative blood loss, reduce intraoperative fluoroscopy times, accelerate clinical healing of fracture, and promote earlier functional recovery of knee joint.

[Comparison of clinical efficacy of subchondral blocking technique combined with plate-screw biplanar fixation and simple plate-screw support peripheral block fixation in the treatment of complex posterior wall acetabular fracture].

OBJECTIVE: To investigate the clinical effect of subchondral blocking technique combined with plate and screw biplane fixation in the treatment of complex acetabular posterior wall fractures. METHODS: From July 2015 to December 2019, a total of 47 cases of acetabular posterior wall fractures were treated. According to the different internal fixation techniques, they were divided into the external blocking fixation group supported by lateral plate and screw(control group of 23 cases) and the subchondral blocking technique combined with lateral plate and screw support biplane fixation group(study group of 24 cases). In the control group, there were 15 males and 8 females, aged 18 to 68 years old with an average of (40.9±7.2) years;preoperative preparation was 4 to 13 days with an average of (7.9±1.5) days. In the study group, there were 14 males and 10 females, aged 20 to 71 years old with an average of (41.7±7.9) years;preoperative preparation was 4 to 12 days with an average of (7.5±1.9) days. Kocher-Langenbeck approach was used in both groups and all patients were followed up for at least 1 year. The operation time, intraoperative blood loss, hospitalization time, quality of fracture reduction after operation, modified Merle D'Aubigne Postel score of hip joint one year after operation and postoperative complication rate of two groups were statistically analyzed and compared. RESULTS: The patients in both groups were followed up for at least 1 year. One year after operation, the Merled'Aubigne Postel score(16.042±1.517) of hip function improvement in the study group was significantly higher than that in the control group (14.696±1.222)(P<0.05). There was no significant difference in operation time and intraoperative bleeding between the two groups(P>0.05). One year after operation, there was a significant difference between two groups in the evaluation results of Matta fracture reduction quality(P<0.05). There was no significant difference in postoperative complications between two groups(P>0.05). CONCLUSION: The treatment of complex acetabular posterior wall fracture with subchondral blocking technique combined with plate and screw biplane fixation technique has lower postoperative complication rate, better functional recovery of hip joint and satisfactory clinical effect.

[Effect analysis of trajectory screw technique in fragility fracture of pelvic ring].

OBJECTIVE: To assess the clinical efficacy of minimally invasive technology with trajectory screw fixation for fragility fractures of pelvic(FFP). METHODS: A retrospective case control study was performed to analyze the clinical data of 35 patients with FFP who were treated and followed up between January 2016 and December 2019. There were 12 males and 23 females, aged from 65 to 99 years with an average of(75.4±7.8) years old. There were 13 cases of type Ⅱb, 7 cases of type Ⅱc, 8 cases of type Ⅲa, 2 cases of type Ⅲb, 2 cases of type Ⅲc, 1 case of type Ⅳb, and 2 cases of type Ⅳc according to Rommens FFP comprehensive classification. All patients received the treatment of minimally invasive technology with trajectory screws fixation. According to the different methods of anterior pelvic ring fixation, FFP patients were divided into two groups:12 cases were fixed with the pedicle screw rod system in the anterior pelvic subcutaneous internal fixator (INFIX) group;23 cases were fixed with hollow screws of the pubic symphysis, superior ramus of pubis or acetabular anterior column in the screw group. The operation time, intraoperative blood loss, intraoperative fluoroscopy times, length of hospital stay, cost of internal fixation, pre- and post-operative visual analogue scale(VAS) were compared between the two groups. The fracture reduction quality was evaluated according to the Matta criteria, and the clinical function was evaluated by the Majeed functional scoring system respectively. RESULTS: All patients were followed up for 12 to 39(16.5±5.4) months after surgery. There was no statistically significant difference in the operation time, intraoperative blood loss, intraoperative fluoroscopy time, and length of hospital stay between the two groups(P>0.05). As for the cost of internal fixation, the cost of internal fixation in the screw group [2 914 (2 914, 4 371) yuan] was significantly lower than that of the INFIX group [6 205 (6 205, 6 205) yuan] (P<0.05). No significant difference was observed in the incidence of postoperative complications between the two groups (P>0.05). There was no significant difference in VAS assessment at admission, 1 week, and 3 months after surgery between the two groups(P>0.05). However, the VAS assessment at 1 week and 3 months after surgery of the two groups were significantly better than those at admission(P<0.05). There was no significant difference in the quality of fracture reduction after the operation and the efficacy evaluation at the last follow-up between the two groups(P>0.05). CONCLUSION: For the treatment of fragility fractures, minimally invasive technology with trajectory screw fixation can achieve good clinical efficacy. It has the advantages of being relatively minimally invasive, less bleeding, relieving the pain. It deserves clinical application.

[Analysis of clinical effects of iliolumbar fixation in treating U-shaped sacral fractures].

OBJECTIVE: To evaluate the efficacy of iliolumbar fixation in the treatment of U-shaped sacral fractures. METHODS: A retrospective study was conducted on the 14 complex U-shaped sacral fractures which had been treated from January 2014 to December 2019, involved 10 males and 4 females, aged 24 to 48 (35.4±6.5) years. Fracture healing time, nerve function, clinical function and complications were observed in the patients. RESULTS: All patients were followed up for 9 to 16(26.0±5.9) months. The complete weight-bearing time for bone healing was(12.4±2.0) weeks. One case of surgical incision infection occurred after operation, and one case of sacrum nailspenetrated to the outer plate of sacrum. No complications such as pressure ulcers, loosening or rupture of internal fixation occurred. According to Gibbons scoring, the neurological function recovered from preoperative 2.9±0.9 to postoperative 2.1±1.1, there were statistically significant differences between preoperative and postoperative (t=6.9, P=0.00). There was significant difference between preoperative malformation angle (41.4±11.2)° and postoperative value (28.3±7.5)° (t=4.70, P=0.00). According to Majeed scoring to evaluate the clinical function, postoperative pain, standing, sitting, sexual life, work ability, total score respectively were 23.21±3.17, 25.57± 3.94, 7.71±1.54, 2.64±0.92, 16.14±2.41, 75.30±8.10, 2 cases got excellent results, 10 good, 2 fair. CONCLUSION: Sacral lumbar fixation is an effective method for the treatment of U-shaped sacrum fractures. It has the advantages of strong internal fixation and satisfactory functional recovery.

[Comparison of different minimally invasive internal fixation in the treatment of pelvic anterior ring fracture].

OBJECTIVE: To compare the clinical efficacy of three minimally invasive methods of anterior column screw, plate and screw rod system in the treatment of anterior pelvic ring fracture. METHODS: From December 2015 to September 2018, 77 patients with pelvic anterior ring fracture were treated and followed up, including 45 males and 32 females, aged 19 to 73 years. According to AO / OTA classification, there were 26 cases of type B1, 20 cases of type B2, 17 cases of type B3 and 14 cases of type C. According to the different internal fixation methods, they were divided into three groups:anterior column screw group(35 cases), plate group(20 cases), and screw rod system group(22 cases). The operation time, intraoperative fluoroscopy times, blood loss, fracture reduction quality, complications and curative effect of the three groups were compared. RESULTS: All 77 patients were followed up for 12 to 33 (16.5±5.7) months. The operation time, intraoperative blood loss and incision length of anterior column screw group were significantly shorter than those of plate group and screw rod system group, and intraoperative fluoroscopy times of plate group were significantly less than those of anterior column screw group and screw rod system group (P<0.05). There was no significant difference in the quality of fracture reduction and curative effect among the three groups(P>0.05). The incidence of complications was significant different among three group(P<0.05). CONCLUSION: Minimally invasive internal fixation with anterior column screw, plate and screw rod system can obtain good clinical effect, but anterior column screw fixation has less trauma and lower incidence of surgicalcomplications.

[Progress on diagnosis and treatment of cartilage injury of the talus].

The diagnosis of osteochondral lesions of the talus can be based on the patients' symptoms, medical history, MRI, detailed physical examination and arthroscopy. Its treatment includes conservative treatment and surgical treatment. Conservative treatment includes rest, partial-weight bearing, plaster immobilization, wear the orthopedic support, take the non-steroidal anti-inflammatory drugs and so on. Conservative treatment is less risky and effective for mild injuries. Surgical treatment includes debridement, marrow stimulation, internal fixation and cartilage transplantation, autologous chondrocyte transplantation, articular cavity injection biological additions, ultrasonic and electromagnetic stimulation technology, tissue engineering technology, etc. Currently, there are various treatment methods, each with indications and advantages and disadvantages. Among these methods, the most commonly used ones are debridement, marrow stimulation, cartilage transplantation and autologous chondrocyte transplantation, and they deserve extensive promotion. Debridement and marrow stimulation are performed minimally traumatically under arthroscopy. The operation is simple and inexpensive with positive effects and mild pain. There is a higher rate of success for small-scale injuries, but if the operation fails, it will result in a wider range of defects, because of the fibrous cartilages formed after the operation. The cartilage transplantation can be performed in an one-stage operation. After the operation, the hyaline cartilage can be restored, but there are different levels of pathological changes in the donor sites. Chondrocytes transplantation can solve the problem of larger osteochondral defects left after the initial treatment failure, and the donor cartilage can be repaired without affecting the donor sites. But the disadvantages are its long time treatment, staged operations and higher cost. As far as all these treatments are concerned, recent treatment effects are satisfactory, but the long-term efficacy is still questionable. For the autologous chondrocyte transplantation and emerging tissue engineering treatment technology, there is still broad research prospect.

[Surgical treatment of acetabular type C1 acetabular fracture by posteroproximal-posteroanterior sequential reduction and internal fixation].

OBJECTIVE: To investigate the operative reduction techniques and clinical results of surgical treatment of type C1 (AO/ASIF) acetabular fracture by posteroproximal-posteroanterior sequential reduction and internal fixation. METHODS: From August 2004 to January 2012, 13 patients with type C1 (AO/ASIF) acetabular fracture were treated by posteroproximal-posteroanterior sequential reduction and internal fixation. Of them, 8 cases were male and 5 cases were female with an average age of 42 years years old (ranged, 18 to 64). Pelvis 3-dimentional CT reconstruction were used to confirmed the classification of fracture, and the operation were performed during from 5 to 20 days with an average of 9.5 days. Operation time, blood loss, complications and reduction were recorded and evaluated. The function of hip joint were accessed at the final follow-up. RESULTS: The operation time ranged from 190 to 290 min with an average of 240 min. The mean blood loss was 1 800 ml (ranged, 1 300 to 3 000 ml). One case had superficial infection and healed after 3 weeks. According to Matta reduction criteria, 8 cases obtained anatomical reduction, 4 cases got satisfied results and 1 cases got unsatisfied results. Eleven cases were followed up with an average of (24.0 +/- 8.0) months, and 2 cases were lost to follow-up. According to revised Mede d'Aubingne and Postel evaluation system, 7 cases got excellent results, 2 good, 1 moderate and 1 poor. CONCLUSION: Posteroproximal-posteroanterior sequential reduction and internal fixation for the treatment of type C1 (AO/ASIF) acetabular fracture can achieve satisfied surgical proces and operation quality.