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 effects of preoperative nutritional status on postoperative functional prognosis in elderly patients with proximal humerus fracture.Methods:From January 2020 to December 2020, 103 elderly patients (≥65 years old) were treated for proximal humerus fractures by open reduction and internal fixation at Department of Traumatology, Honghui Hospital Affiliated to Xi'an Jiaotong University. Upon admission, according to the Geriatric Nutrition Risk Index (GNRI), they were assigned into a normal nutrition group (55 cases, with GNRI≥92) and a malnutrition group (48 cases, with GNRI<92). The baseline data, preoperative hemoglobin level, time from injury to operation, intraoperative blood transfusion, postoperative complications, 1-year mortality, and Neer shoulder functional scores at 3 months, 6 months and the last follow-up were compared between the 2 groups.Results:The 2 groups were comparable because there were no significant differences in gender, injury side, Neer fracture classification, injury cause, or American Society of Anesthesiologists (ASA) grading ( P>0.05). The age of the malnutrition group was significant older than that of the normal nutrition group ( P<0.05). All patients were followed up for 9 to 16 months (mean, 13.6 months) after surgery. In the normal nutrition group and the malnutrition group, respectively, the preoperative hemoglobin level was (10.24±0.68) g/dL and (8.94±0.89) g/dL, the time from injury to operation (3.9±1.3) d and (5.8±1.2) d, the rate of intraoperative blood transfusion 14.5%(8/55) and 60.4%(29/48), the rate of postoperative complications 20.0%(11/55) and 39.6%(19/48), the 1-year mortality 1.8%(1/55)、4.2%(2/48), and the Neer shoulder function score (46.7±8.8) points and (43.2±5.6) points at 3 months after operation, (67.6±6.2) points and (76.3±5.5) points at 6 months after operation, and (80.4±5.0) points and (76.3±5.5) points at the last follow-up. Comparisons of all the above items showed significant differences between the 2 groups (all P<0.05). Conclusions:Preoperative malnutrition in elderly patients with proximal humerus fracture has adverse effects on preoperative waiting time, intraoperative blood transfusion, complications and postoperative shoulder function. Therefore, perioperatively, attention should be paid to the nutritional status of elderly patients to reduce their stress responses to fracture, surgery and anesthesia, and to improve their postoperative function and quality of life.

As varus posteromedial rotatory instability (VPMRI) is not common, its injury mechanisms are complex and presents no obvious dislocation on X-ray, it may be considered as a simple coronoid fracture, likely leading to a missed diagnosis or misdiagnosis. Moreover, the treatment of VPMRI is also controversial. Conservative treatment or improper treatment can cause serious complications. Therefore, this review expounds on the injury mechanisms, anatomical structure, O'Driscoll classification, imaging examination, treatment and postoperative rehabilitation of this complicated elbow injury which is rare and difficult to treat clinically.

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.

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.

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 occurrence of deep venous thrombosis (DVT) in the perioperative period of patients with fracture distal to the knee,so that clinicians have a better understanding of the occurrence of DVT in the perioperative period of the fracture distal to the knee.Methods A retrospective analysis of the clinical data of 365 patients with distal knee fractures who underwent surgery in the Department of Orthopaedics Trauma,Xi'an Jiaotong University Medical College Red Cross Hospital from June 2014 to March 2018 was conducted.There were 213 males and 152 females,aged (45.05 ± 15.24) years,with an age range of 17-83 years.Classification of fracture sites:177 cases of tibiofibular shaft fracture,130 cases of ankle fracture,and 58 cases of foot fracture.According to whether thrombosis occurred or not,the patients were divided into thrombotic group and non-thrombotic group before and after operation.There were 66 patients with thrombosis before operation,299 patients without thrombosis before operation,88 patients with thrombosis after operation,and 277 patients without thrombosis after operation.The incidence of thrombosis and the location of the thrombus were recorded.The sex,age,fracture site,ASA score,operation time,the time from injury to admission,the time from injury to surgery,intraoperative tourniquet time,intraoperative blood transfusion volume,intraoperative blood loss,intraoperative transfusion volume,hemoglobin volume at admission and 1 day after operation,D-dimer level at admission and 1 day after operation,multiple injuries,chronic hepatitis and medical diseases were analyzed.The measuremernt data of normal distribution and homogeneity of variance were expressed as mean ± standard deviation (Mean ± SD),the t test was used for comparison between two groups.The comparison of count data was performed by x2 test or Fisher exact probability method,and multivariate logistic regression analysis was performed on the risk factors affecting the occurrence of DVT in both lower extremities.Results The preoperative DVT rate was 18.1％ (66/365).In patients with thrombosis,distal thrombosis accounted for 93.94％ (62/66),and mixed thrombosis accounted for 6.06％ (4/66).The incidence of postoperative DVT was 24.1％ (88/365).In patients with thrombosis,distal thrombosis accounted for 94.32％ (83/88),proximal thrombosis accounted for 1.14％ (1/88),and mixed thrombus accounted for 4.55％ (4/88).Fracture site,ASA score,operation time,intraoperative tourniquet time,intraoperative blood transfusion volume,intraoperative blood loss,intraoperative transfusion volume were not statistically significant(P ＞0.05).Age ≥ 40 years (OR =2.691,95％ CI:1.422-5.093,P =0.002),the time from injury to admission ＞ 3 days (OR =1.927,95 ％ CI:1.072-3.463,P =0.028)were independent risk factors for DVT formation in fracture distal to the knee before operation.Age ≥ 40 years (OR =3.925,95 ％ CI:2.161-7.129,P =0.000),the time from injury to surgery ＞ 5 days (OR =1.835,95 ％ CI:1.080-3.119,P =0.025),D-dimer level at 1 day after operation (OR =1.191,95％ CI:1.096-1.293,P =0.000),combined with multiple injuries (OR =1.981,95％ CI:1.006-3.902,P =0.048),combined with coronary atherosclerotic heart disease (OR =2.692,95％ CI:1.112-6.517,P =0.028) were independent risk factor for DVT formation after operation for fracture distal to the knee.Conclusions The occurrence of DVT before and after the fracture of the knee is mainly caused by distal thrombosis,and proximal thrombosis also occurs.Those patients aged≥40 years,combined with multiple injuries and coronary heart disease,should focus on preventing the occurrence of DVT.After the injury,the patient is immediately admitted to the hospital for DVT screening,and when the general condition allowed,shortening the preoperative waiting time can reduce the occurrence of DVT.