Objective:To evaluate the treatment of nonunion of lateral humeral condyle complicated with cubitus valgus with primary fixation in situ and secondary supracondylar varus osteotomy.Methods:A retrospective analysis was made of the 8 children who had been treated for nonunion of lateral humeral condyle complicated with cubitus valgus at Department of Pediatric Orthopedics, Honghui Hospital from January 2016 to March 2018. They were 5 boys and 3 girls with 5 left and 3 right sides involved. Their age at injury ranged from 6 to 14 years (average, 10 years) and the duration from injury to operation from 2 to 6 years (average, 4 years). At the primary stage, the fragments were fixated in situ with compressive cannulated screws after cleaning the nonunion ends, followed by iliac autograft. At the secondary stage, the humeral supracondylar varus osteotomy was performed after the nonunion was healed and the elbow range of motion recovered. The therapeutic effects were assessed by comparing the elbow range of motion, carrying angle and Mayo elbow performance score (MEPS) between preoperation and the final follow-up.Results:All the patients were followed up for an average of 44.5 months (range, from 27 to 64 months). The average healing time for obsolete nonunion of lateral humeral condyle was 81.3 days (range, from 55 to 120 days) after the primary operation and that for supracondylar varus osteotomy 51.1 days (range, from 45 to 60 days) after the secondary operation. The elbow range of motion was 129.0°±4.6° before operation and 138.0°±5.4° at the final follow-up, showing a significant difference ( P<0.001). The average carrying angle at the healthy side in 8 children was 5.4° (range, from 3° to 8°). The carrying angle at the affected side was 31.9°±4.7° (range, from 25° to 42°) before operation and 4.0°±2.2°(range, from 1° to 8°) at the final follow-up, showing a significant difference ( P<0.05). Their preoperative MEPS was 57.5 ± 6.5 (4 good cases and 4 poor ones) but 95.9±3.4 (6 excellent cases and 2 good ones) at the final follow-up, showing a significant difference ( P<0.05). Conclusions:Treatment of nonunion of lateral humeral condyle complicated with cubitus valgus can be effectively carried out by cleaning fibrous tissue in the nonunion gap, iliac autograft and fragments fixation in situ with compressive cannulated screws at the primary stage and supracondylar varus osteotomy at the secondary stage. Intraoperative preservation of the blood supply to the nonunited fragments is the key to successful management.

Research on application of ultrasound has made continuous progress in airway manage-ment,providing theoretical basis and new ideas for clinical use of ultrasound in airway management,and ex-panding the application range of ultrasound in airway management.Ultrasound can develop real-time imaging and measure almost all the tissue structures of the whole airway,ensuring the accurate locating and measure-ment of airway anatomical structure,which offers objective theoretical support for airway evaluation.Its char-acteristic of real-time imaging also helps to guide endotracheal intubation,determine the position of endotra-cheal tube and laryngeal mask airway,and assess gastric contents.Artificial intelligence improves the accu-racy and efficiency of ultrasonic identification of anatomical structure,which promotes the expanded applica-tion of ultrasound in airway management.This article briefly outlines the recent advance in the application of ultrasound in guiding endotracheal intubation,confirming endotracheal intubation,detecting laryngeal mask airway position,predicting successful tracheal extubation,predicting difficult airway,locating airway ana-tomical structure,and assessing the risk of gastric aspiration,and discusses the application of ultrasound combined with artificial intelligence in airway management.

Objective:To purify H5N1 influenza virus concentrate prepared by MDCK cells with a new mixed-mode chromatography medium Capto Core700 and the traditional medium Sepharose 4FF, and to compare the separation and purification efficacy of the two media.Methods:Capto Core700 and Sepharose 4FF were used to purify inactivated H5N1 influenza virus concentrate. The morphology of virus particles in different samples was then observed under a transmission electron microscope. Single radial immunodiffusion (SRID), Folin-Phenol (Lowry) method, double-antibody sandwich ELISA and qPCR were used to detect hemagglutinin, total protein, host cell protein (HCP) and host cell DNA (HCD) before and after purification. The recovery rate of virus antigen and the removal rate of impurities were calculated. The immunogenicity of the viruses purified with different media was analyzed using animal experiments. Difference in the purification efficacy of the two chromatography media was analyzed by t-test. Results:H5N1 influenza viruses purified by Capto Core700 or Sepharose 4FF showed the typical influenza virus morphology under transmission electron microscope. There was no significant difference in the recovery rate of hemagglutinin between the two chromatography media ( P>0.05), but compared with Sepharose 4FF, Capto Core700 had a higher removal rate of impurities (total protein, HCP, HCD) and the difference was statistically significant ( P<0.05). Animal experiments showed that the viruses purified by the two chromatography media had good immunogenicity. Conclusions:Compared with Sepharose 4FF chromatography medium, Capto Core700 could more effectively remove process-related impurities such as HCP, HCD and total protein without affecting the recovery rate of viral antigen. This study provided reference for the development of purification technology in the production of H5N1 influenza virus vaccine in MDCK cells.

Objective:To summarize and discuss the concept and clinical manifestations of complex fracture-dislocations of the elbow in children, and compare its injury characteristics, treatment and clinical effect with adults.Methods:From September 2015 to January 2020, 34 patients seen and treated at our institution for complex fracture-dislocations of the elbow were identified, and their medical records and radiographs were reviewed retrospectively. The inclusion criteria were elbow dislocation combined with one or more fractures at the proximal ulna and radius. There were 25 boys and 9 girls, with an average age of 8.3±3.2 years. The left arm was involved in 27 cases, and the right arm was involved in 7 cases. The causes of injury included falling from a scooter in 16 cases, falling from height in 10 cases, cycling in 5 cases and traffic accident in 3 cases. All patients were treated with closed reduction and the application of plaster under local anaesthesia in the emergency room. Then, X-ray, CT and MRI were performed to evaluate the fracture-dislocation and ligament injury. The following treatment plan was comprehensively evaluated according to the size and displacement of the combined fracture block and the stability of the elbow, for example, open reduction with K-wires and tension band or plate fixation for olecranon fracture, open reduction with loop plate fixation for coronal process fracture, closed reduction or open reduction with K-wires or elasticstable intramedullary nail for radial neck fracture.Results:Among the 34 patients, there were 16 cases of transolecranon fracture-dislocation, 1 case of varus posteromedial rotational instability, 4 cases of valgus posterolateral rotatory instability and 13 cases of divergent dislocation of elbow. All patients were followed up for 13(8, 15) months, and the average fracture healing time was 3.5±0.8 weeks, with no failure of internal fixation. In 2 cases of elbow dislocation combined radial neck fracture, one case had ischemic necrosis of the radial head and one case had early closure of epiphyseal plate of the proximal radius. At the last follow-up, all patients had no subluxation, dislocation or instability of the elbow. The therapeutic efficacy was evaluated at the final follow-up by the Mayo elbow performance score (MEPS) as excellent in 25 cases, good in 5 cases, fair in 3 cases, and poor in one case, with excellent and good rate 88%.Conclusion:The complex fracture-dislocations of the elbow is rare in children. We have the opinion that the clinical characteristics are dislocation combined with one or more fractures of the proximal ulna and radius. Compared with adults, its pathological characteristics and the scope of injury are similar, but most of the injuries are mild. The clinical manifestations are mainly transolecranon fracture-dislocation and divergent dislocation of elbow. Good results can be achieved in most cases through open reduction with internal fixation for fractures.

Objective:To explore the clinical characteristics and treatment of a head-neck separation type of Monteggia equivalent fractures in children.Methods:From March 2016 to February 2019, 12 children sought medical attention at Pediatric Orthopedic Hospital, Honghui Hospital Affiliated to Xi'an Jiaotong University for a head-neck separation type of Monteggia equivalent fractures. They were 8 boys and 4 girls, aged from 3 to 14 years (average, 8.3 years). All cases were treated with closed reduction, deformity correction and plaster fixation at emergency department after X-ray examination. In line with the treatment principles for Monteggia fractures, after the ulnar length was first restored and stabilized, a proper fixation method was chosen according to the location and type of the ulnar fracture, followed by treatment of the radial neck fracture. The fracture union and complications were evaluated according to the X-ray films after operation, and the therapeutic efficacy was evaluated according to the Mayo elbow performance score (MEPS) at the final follow-up.Results:The head-neck separation type of Monteggia equivalent fractures in children was characterized by a fracture of ulnar diaphysis or metaphysis and a fracture of the radial neck with complete separation of the head and neck, a longitudinal axis of the radius off the capitellum center at the distal fracture end but normal proximal humeroradial relationship. The fractures were classified into 2 types depending on the angulation direction of the ulnar fracture and the direction of distal displacement of the radial neck fracture: 7 cases belonged to the extension-valgus type and 5 cases to the flexion-varus type. The 12 patients were followed up for 8 to 38 months (average, 16.0 months). Of the ulnar fractures, one was treated with closed reduction and Kirschner wire fixation, 4 with elastic intramedullary nail fixation, 5 with plate fixation, one untreated, and one with manual reduction only. Of the radial neck fractures, 11 were treated with closed reduction and elastic intramedullary nail fixation, and one with open reduction and K-wires fixation. All fractures got united after 8 to 12 weeks (mean, 9.6 weeks). The time for removal of internal fixation ranged from 12 to 50 weeks (mean, 31.2 weeks). Avascular necrosis occurred in one case and bulk formation of proximal metaphysis in another. By the MEPS at the final follow-up, the therapeutic efficacy was excellent in 10 cases, good in one and fair in one.Conclusions:The head-neck separation type of Monteggia equivalent fractures in children is different from common Monteggia fractures or radial neck fractures, because its clinical manifestations are characterized by a fracture of ulnar diaphysis or metaphysis and a fracture of the radial neck with complete separation of the head and neck, a longitudinal axis of the radius off the capitellum center at the distal fracture end but normal proximal humeroradial relationship. The treatment options for ulnar fractures include closed reduction with Kirschner wire fixation, elastic intramedullary nailing, open reduction and bone plate fixation or no fixation, while radial neck fractures are mostly treated by closed reduction and elastic intramedullary nailing. Early functional exercise can lead to satisfactory clinical outcomes.