Objective:To explore the biomechanical stability of a novel anchor-loop internal fixation system in the treatment of acromioclavicular joint dislocation using cadaveric specimens.Methods:The acromioclavicular ligaments were severed in 12 complete shoulder joint specimens, in which the quasi-static non-destructive cycle experiment was performed until the coracoclavicular ligaments failed. The failure intensities of the coracoclavicular ligaments were recorded. Next, the 12 specimens were randomly divided into groups A, B, C and D ( n=3), in which 4 different internal fixation materials were used respectively to reduce and fix the acromioclavicular joint. Group A was subjected to 3.5 mm clavicular hook locking compression plate, group B to 5 mm soft tissue with wire anchor, group C to 10 mm Endobutton steel plate, and group D to the novel anchor-loop internal fixation system (5 mm soft tissue with wire anchor + 10 mm Endobutton steel plate). An X-ray machine was used to evaluate the reduction and internal fixation of the acromioclavicular joint. After the shoulder specimens were securely fastened by a homemade fixation jig to a 100 KN electronic universal mechanical testing machine, each experimental specimen was subjected to a destructive static tensile mechanic determination in the vertical direction at a loading speed of 100 mm/min. The load-displacement curves were recorded and drawn by a computer connected with the biomechanical testing machine. The failure strength and failure causes were recorded for each internal fixation. Results:The fracture strength of the coracoclavicular ligament in 12 cadaver specimens was (374.6±0.8) N. The mechanical load of internal fixation failure was (409.5±2.6) N in group A, (297.8±3.4) N in group B, (375.2±3.1) N in group C and (376.2±3.1) N in group D. The internal fixation failure was due to clavicular fracture in 2 specimens and to acromial fracture in 1 specimen in group A, to anchor protrusion in all the 3 specimens in group B, to coracoid base fracture in all the 3 specimens in group C, and to anchor protrusion in all the 3 specimens in group D. The mechanical loads of internal fixation failure were significantly different among the 4 experimental groups ( P<0.05). The mechanical load of internal fixation failure in group D was significantly different from that in groups A and B ( P<0.05). Conclusions:Our self-developed novel anchor-loop internal fixation system can effectively reposit the acromioclavicular joint to treat acromioclavicular joint dislocation, because it conforms to the biomechanical characteristics of the acromioclavicular joint, and is easy to handle. Therefore, its feasibility is high.

Objective:To investigate the influence factors of poor efficacy after flap repair operation in patients with pressure ulcers.Methods:The retrospective case series study was conducted. From January 2011 to June 2021, 125 patients with stage Ⅲ and Ⅳ pressure ulcers treated in Hainan General Hospital met the inclusion criteria. There were 82 males and 43 females, aged 15-90 (57±20) years. According to the postoperative effects, the patients were divided into poor efficacy group (47 cases) and good efficacy group (78 cases). The clinical data of patients in the two groups were collected, including the age, gender, location, stage, size, and bone exposure of pressure ulcers, preoperative microorganism culture results of wound exudate sample, whether combined with osteomyelitis, diabetes, lower limb paroxysmal myospasm, and gatism or not, the number of surgical debridement combined with negative-pressure wound therapy, type of surgical flap, postoperative position, and preoperative albumin, leukocyte, C-reactive protein (CRP), and hemoglobin. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The binary multivariate logistic regression analysis was conducted to screen the independent risk factors influencing the poor efficacy after flap repair operation in 125 patients with stage Ⅲ and Ⅳ pressure ulcers. Results:The ratio of patients with lower limb paroxysmal myospasm in poor efficacy group was 22/47, which was significantly higher than 3/78 in good efficacy group ( χ2=33.83, P<0.01). The preoperative hemoglobin level of patients in poor efficacy group was (102±17) g/L, which was significantly lower than (113±20) g/L in good efficacy group ( t=-3.24, P<0.01). The preoperative CRP level of patients was 39.1 (14.1, 91.6) mg/L in poor efficacy group, which was significantly higher than 15.3 (6.6, 42.0) mg/L in good efficacy group ( Z=-3.04, P<0.01). There were no statistically significant differences in other indexes between patients in the two groups ( P>0.05). Multivariate logistic regression analysis showed that age, lower limb paroxysmal myospasm, and preoperative hemoglobin level were the independent risk factors for poor efficacy after flap repair operation in patients with pressure ulcers (with odds ratios of 1.03, 40.69, and 0.97, 95% confidence intervals of 1.00-1.06, 9.18-180.39, and 0.95-1.00, respectively, P<0.05 or P<0.01). Conclusions:Poor efficacy after flap repair operation in patients with pressure ulcers is affected by many factors, among which the age, lower limb paroxysmal myospasm, and preoperative hemoglobin level are the independent risk factors.

Objective:To compare the clinical effect of combined anterior and posterior approach and posterior median approach to treat O'Driscoll type III b fracture of ulnar coronoid process.Methods:A retrospective case control study was made on 67 patients with O'Driscoll type III b fracture of ulnar coronoid process treated in Honghui Hospital, Xi'an Jiaotong University from January 2015 to January 2019, including 35 males and 32 females, aged from 21 to 61 years [(38.0±9.4)years]. Among them, 31 patients were treated with combined anterior and posterior approach for reduction and internal fixation (combined approach group), and 36 patients with median posterior elbow approach group for reduction and internal fixation (posterior elbow approach group). The operation time, amount of intraoperative blood loss and fracture healing time were compared between groups. The visual analogue score (VAS), elbow joint range of motion and Mayo elbow performance score (MEPS) were assessed for pain and function evaluation at postoperative 1, 3, 6 months and at the last follow-up. The occurrence of complications were observed as well.Results:All patients were followed up for 12 to 28 months [(20.1±4.2)months]. There was no significant difference in operation time and VAS between the two groups ( P>0.05). The intraoperative blood loss [(133.6±20.3)ml] and fracture healing time [(12.3±1.7)months] in combined approach group were less or shorter than those in posterior elbow approach group [(144.4±22.1)ml, (13.2±2.0)months] ( P<0.05). The range of flexion and extension of elbow joint in combined approach group [(88.7±10.8)°, (111.1±13.9)°, (121.3±14.1)°, (127.1±13.3)°] was higher than that in posterior elbow approach group [(74.5±11.8)°, (97.6±12.6)°, (111.3±13.0)°, (115.2±12.7)°] at postoperative 1, 3, 6 months and at the last follow-up ( P<0.05). The MEPS in combined approach group [(31.7±8.6)points, (55.6±9.3)points, (84.6±10.5)points, (85.0±10.3)points] was higher than that in posterior elbow approach group [(27.2±8.2)points, (50.7±8.7)points, (77.4±11.2)points, (80.1±9.4)points] at postoperative 1, 3, 6 months and last follow-up ( P<0.05). The incidence of complications in combined approach group [10%(3/31)] was lower than that in posterior elbow approach group [31%(11/36)]( P<0.05). Conclusion:Compared with the simple posterior elbow median approach, the combined anterior and posterior elbow approach for treatment of O'Driscoll type IIIb fracture of ulnar coronoid process has lower intraoperative blood loss, faster fracture healing, lower incidence of complications and better elbow function.

Objective:To compare the efficacy of metaphyseal expansion and non-expansion when using proximal femoral nail antirotation（PFNA）in the treatment of severe osteoporotic intertrochanteric fracture in the elderly.Methods:A retrospective case-control study was conducted to analyze the clinical data of 66 elderly patients with severe osteoporotic intertrochanteric fracture admitted to Honghui Hospital, Xi'an Jiaotong University from January 2019 to January 2020, including 49 males and 17 females. The age ranged from 75 to 89 years［（80.9±3.3）years］. The AO types of fractures were 31-A1 in 23 patients, 31-A2 in 22 and 31-A3 in 21. A total of 34 patients were stabilized by the PFNA technique with metaphyseal expansion（metaphyseal expansion group）and 32 patients received PFNA fixation without metaphyseal expansion（metaphyseal non-expansion group）. The total blood loss, hidden blood loss, intraoperative blood loss, dominant blood loss, postoperative drainage, transfusion volume, transfusion rate, operation time, hospital stay and fracture healing time were compared between the two groups. The hip functional recovery was assessed by Harris hip score at 1, 3, 6 months postoperatively and at the last follow-up. The incidence of complications was observed.Results:All patients were followed up for 12-17 months［（13.5±1.1）months］. The total blood loss, hidden blood loss, intraoperative blood loss, dominant blood loss, postoperative drainage in metaphyseal expansion group were（976.3±210.1）ml,（712.4±224.4）ml,（139.4±21.0）ml,（263.8±36.3）ml,（124.4±29.5）ml respectively, significantly higher than those in metaphyseal non-expansion group［（799.0±119.5）ml,（603.0±136.4）ml,（94.1±18.8）ml,（195.9±35.4）ml,（101.9±27.5）ml］（ P<0.05）. The transfusion volume［2（0, 2）U］and transfusion rate［53%（18/34）］in metaphyseal expansion group ware increased compared to metaphyseal non-expansion group［0（0, 1.5）U, 25%（8/32）］（ P<0.05）. There were no significant differences in operation time, hospital stay, fracture healing time or hip Harris score at 1, 3, 6 months after surgery and the last follow-up between the two groups（ P>0.05）. No wedge-shaped distraction deformity, fracture nonunion, femoral head necrosis, wound infection, pulmonary embolism or fat embolism occurred in both groups. There was no significant difference in the incidence of iatrogenic lateral wall fracture, lower limb venous thrombosis or postoperative medical complications between the two groups（ P>0.05）. Conclusion:For elderly patients with severe osteoporotic intertrochanteric fracture, both PFNA with metaphyseal expansion and non-expansion can achieve satisfactory results, while the metaphyseal non-expansion is superior in perioperative blood loss and transfusion rate.

Objective:To compare the minimally invasive plate osteosynthesis (MIPPO) with versus without B-ultrasound surface localization of the upper arm nerves in the treatment of fractures of the middle and upper humeral shaft.Methods:A retrospective analysis was conducted of the 105 patients who had been admitted to Department of Orthopaedic Trauma, Honghui Hospital for fractures of the middle and upper humeral shaft from August 2015 to May 2017. They were divided into 2 groups according to whether or not B-ultrasound surface localization of the upper arm nerves had been used in MIPPO. There were 52 cases in the B-ultrasound localization group and 53 cases in the simple MIPPO group. The 2 groups were compared in terms of operation time, intraoperative blood loss, fracture union time and complications. The shoulder joint functions were assessed at the last follow-up using the Neer shoulder joint function scoring.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability between groups ( P>0.05). There were significant differences between the B-ultrasound localization group and the simple MIPPO group in operation time [(62.8±8.6) min versus (96.8±7.5) min], or intraoperative blood loss [(107.4±5.6) mL versus (215.4±7.2) mL]. Neer shoulder function scoring showed that the excellent and good rate in the B-ultrasound localization group [94.2% (49/52)] was significantly higher than that in the simple MIPPO group [81.1% (43/53)] ( P<0.05). Conclusions:In the MIPPO of fractures of the upper and middle humeral shaft, B-ultrasound surface localization of the upper arm nerves should be used as preoperative routines to reduce operation time and intraoperative blood loss to improve prognostic functions of the shoulder.

Objective:To study the association between preoperative hemoglobin amount and incidence of lower limb deep vein thrombosis (DVT) in patients with lower limb fracture.Methods:A retrospective study was performed of the 2, 482 patients with lower limb fracture who had been treated at Department of Orthopaedics Trauma, Honghui Hospital Affiliated to Xi'an Jiaotong University from July 2014 to August 2019. They were 1, 174 males and 1, 308 females with an age of (60.6±19.3) years. Recorded were the patients' age, gender, injury time, hemoglobin amount, D-dimer measurement, combined medical conditions, time and results of ultrasound vein examination on both lower extremities. According to the ultrasound results, the patients were divided into a thrombosis group and a thrombosis-free group. The 2 groups were compared in hemoglobin amount. Logistic regression was used to analyze the relationship between preoperative hemoglobin amount and incidence of lower limb DVT. The patients were divided into 5 groups according to the quintile of hemoglobin amount; the incidences of thrombosis were compared between the 5 groups.Results:The total incidence of DVT in this cohort was 29.53%(733/2, 482). The hemoglobin amount in the thrombosis group was (116.57±19.24) g/L, significantly lower than that in the thrombosis-free group (124.76±19.79) g/L ( P<0.05). The preoperative hemoglobin amount was a risk factor for incidence of DVT after a lower limb fracture ( OR=0.985, 95% CI: 0.980 to 0.990, P<0.001). As the quintile level of hemoglobin increased, the incidence of DVT showed a downward trend. In comparison of the group with the highest DVT incidence (40.58%) and the group with the lowest DVT incidence (17.27%), the risk increased by 2.386 times (95% CI: 1.718 to 3.315). Conclusions:The preoperative hemoglobin amount can affect the DVT incidence after a lower limb fracture, and a low hemoglobin amount may more likely lead to lower limb DVT.

Objective:To investigate the differences in incidence of deep vein thrombosis (DVT) after closed fracture of lower extremity between patients with different blood types ABO.Methods:A retrospective study was conducted in the 1, 951 patients who had been admitted to Department of Orthopaedics Trauma, Honghui Hospital Affiliated to Xi'an Jiaotong University for lower extremity fractures from August 2014 to June 2018. They were 924 males and 1,027 females with a mean age of 63 (46, 78) years (range, from 16 to 102 years). Of them, 572 were type O, 564 type A, 609 type B and 206 type AB. Venous ultrasonography was performed on both lower extremities within 12 hours after admission. The incidences of DVT after fracture were compared between different blood types in all the patients, patients with proximal fracture of the knee, peri-knee fracture and distal fracture of the knee, and patients<60 years old and ≥60 years old.Results:The incidences of DVT were, respectively, 26.75% (153/572), 28.72% (162/564), 34.32% (209/609) and 29.61% (61/206) for patients with blood type O, type A, type B and type AB. The DVT incidence for type B was significantly higher than that for type O ( P< 0.008). The incidences of DVT were, respectively, 28.74% (98/341), 28.99% (100/345), 39.45% (144/365) and 30.97% (35/113) for blood type O, type A, type B and type AB in the patients with proximal fracture of the knee. The DVT incidence for blood type B was significantly higher than those for blood type O and blood type A ( P< 0.008). There were no significant differences in the DVT incidence between different blood types ABO in the patients with peri-knee fracture, distal fracture of the knee,<60 years old or ≥60 years old( P>0.05). The incidences of DVT were, respectively, 30.99% (97/313), 33.33% (108/324), 45.22% (156/345), 34.74% (33/95) for blood type O, type A, type B and type AB in the patients ≥60 years old. The DVT incidence for blood type B was significantly higher than those for blood type O and blood type A ( P< 0.008). Conclusions:The incidence of DVT varied with different blood types ABO after lower extremity fracture. The highest DVT incidence was found in patients with blood type B. The impact of blood type on the DVT incidence after lower extremity fracture was mainly observed in the patients with proximal fracture of the knee or an age of ≥ 60 years old.

The coronavirus disease 2019 (COVID-19) was confirmed by nucleic acid test in 15 juvenile patients aged 4-17 years in Hangzhou Xixi Hospital from January 24 to February 10, 2020. The clinical data and the initial chest high resolution CT (HRCT) findings were retrospectively analyzed.Among 15 cases, 8 patients with a mean age of (6.5±2.3) years (4-11 year) had normal HRCT manifestations (mild disease), while 7 patients with a mean age of (11.9±3.0) years (7-17 years) showed abnormal manifestations (moderate disease). In the 7 moderate cases the CT findings included local thickening of bronchial wall in 2 cases, single lesion in 1 case, bilateral pulmonary lesions in 4 cases. There were total 11 lesions, 6 of which were ground glass and slightly high-density nodules, 5 of which were speckled ground glass and 2 with a little consolidation. There were 10 subpleural lesions, including 7 in the lower lobe of the two lungs, and 1 non-subpleural lesion; the thickened local bronchioles were observed in 3 cases. None of them had hilum and mediastinal lymph node enlargement or pleural effusion.

The coronal process of ulna is an important stable structure in front of the elbow joint, which is composed of the tip of the coronal process, towering tubercle and anterior medial face. The fracture of the coronal process is often accompanied by the fracture and dislocation of the elbow joint, which leads to the instability of the elbow joint. The coronoid process has the advantages of small size, special shape, complex surrounding soft tissue structure, and plays an important role in the stability of the elbow joint. The selection of safe, minimally invasive and well exposed surgical approach is a necessary condition for safe and effective internal fixation. The choice of surgical approach must comprehensively consider the concomitant injury and choose the best surgical approach. This article mainly describes the normal anatomical structure of the coronal process and around the elbow joint, analyzes the biomechanics and stability of the coronal process in the elbow joint, and reviews the latest progress in surgical treatment.

Objective:To investigate the risk factors of deep venous thrombosis in patients before hip arthroplasty, and to explore the possible causes of postoperative thrombosis.Methods:The clinical data of 361 patients with hip arthroplasty treated in the Department of Orthopaedic Trauma of Xi′an Honghui Hospital from September 2015 to December 2019 were studied retrospectively, including 102 males and 259 females, aged 65 to 94 years, and the average age was 72.25 years old. All fracture patients were given subcutaneous injection of low molecular weight heparin calcium to prevent lower extremity thrombosis. The deep veins of both lower extremities were examined before and after operation. The general data of the two groups of patients were collected and recorded, including age, sex, whether complicated with medical diseases (essential hypertension, type 2 diabetes, coronary heart disease), serological indexes, time from injury to admission, and time from admission to operation. The software of SPSS 19.0 was used for statistical analysis.Results:The incidence of lower limb DVT, before operation was 29.92%, including 26 males (24.07%) and 82 females (75.93%). The results of multivariate logistic regression analysis showed that diabetes mellitus ( OR=2.127, 95% CI: 1.134-3.989, P=0.019), coronary heart disease ( OR=1.692, 95% CI: 1.056-2.713, P=0.029) and the time from injury to admission ( OR=1.677, 95% CI: 1.037-2.712, P=0.035) were independent risk factors for DVT in elderly patients undergoing hip arthroplasty. The incidence of lower limb DVT, after operation was 46.54%. After operation, proximal thrombus were occurred in 2 cases (1.19%), distal thrombus in 143 cases (85.12%), and mixed thrombus in 23 cases (13.69%). Postoperative thrombus was ipsilateral to the fracture limb in 84 cases (50.00%), thrombus was located in the healthy side of the fracture in 19 cases (11.31%), and DVT occurred in 65 cases (38.69%) in both lower limbs. Conclusions:Delayed admission longed than 48 hours, coronary heart disease and diabetes mellitus are the risk factors for the formation of DVT. The thrombus that existed before operation and did not disappear after operation accounted for 48.81% of the total incidence of postoperative thrombosis, and the new thrombus accounted for 51.19% of the total incidence of postoperative thrombosis. For the elderly patients with femoral neck fracture undergoing hip arthroplasty, ultrasonic examination of both lower limbs should be performed before and after operation to find the changes of thrombus in time and do a good job of prevention and treatment.