Heavy ions are the positively charged nuclei of the atomic number greater than two in the universe, which mainly comes from the charged particles of the solar system outside. Heavy ions occupy only 1% in cosmic my, but because they are is capable of forming the Bragg peak, resulting in huge energy deposition, they have much more severe biological effects on immune organ than electromagnetic radiation in the cosmic rays. This paper outlines the biological effects of heavy ions on several aspects of immune organs, immune cells and chromosomes, and provide a theoretical basis for the study of the impact of heavy ion radiation on the immune system.

Objective:To compare the clinical outcomes between OTA/AO-C open and closed fractures of the distal humerus treated by open reduction and internal fixation.Methods:The clinical data were retrospectively analyzed of the 70 patients who had been treated at Department of Traumatology and Orthopedics, Beijing Jishuitan Hospital for OTA/AO-C fractures of the distal humerus from January 2014 to June 2017. Of them, 22 suffered from open fractures (Gustilo types Ⅰ/Ⅱ) and 48 closed fractures. There were 18 males and 4 females with an age of (42.6±13.0) years in the open group and 21 males and 27 females with an age of (42.2±17.1) years in the closed group. Analyzed were interval from injury to surgery, hospitalization time, injury energy and functional outcomes which included range of motion (ROM) in elbow flexion and extension, ROM in elbow rotation, Mayo elbow performance score (MEPS), Disabilities of the Arm, Shoulder and Hand (DASH), complications and rate of secondary surgery.Results:There was no significant difference between the 2 groups in age, injury energy or interval from injury to surgery ( P>0.05), but there were significantly more males in the open group than in the closed group ( P=0.011). The follow-up time for all the patients averaged 34.0 months (from 25 to 54 months). There were no statistically significant differences between the 2 groups in hospitalization time [9.5(6.0, 13.0) d versus 8.5 (6.0, 11.0) d], ROM in flexion and extension [120.0° (100.0°, 137.8°) versus 128.5° (110.0°, 140.0°)], ROM in rotation [155.0° (151.3°, 155.0°) versus 155.0° (155.0°, 155.0°)], MEPS [95.0 (80.0, 100.0) versus 95.0 (80.0, 100.0)] or DASH [2.6 (0.63, 9.2) versus 1.7 (0.0, 8.5)] ( P>0.05). There were no statistically significant differences between the 2 groups either in rate of secondary surgery [36.4% (8/22) versus 33.3% (16/48)], ulnar nerve symptoms [54.5% (12/22) versus 60.4% (29/48)], local irritability in the region of internal fixation [9.1% (2/22) versus 6.3% (3/48)] or elbow stiffness [13.6% (3/22) versus 10.4% (5/48)] ( P>0.05). Conclusion:Open reduction and internal fixation can lead to similar clinical outcomes in the treatment of both open (Gustilo types Ⅰ/Ⅱ) and closed distal humeral fractures of OTA/AO-C, with no significant differences in postoperative ROM, functional scores or complications.

Objective To investigate the epidemiology of BDV infection in Yili horses and Yili donkeys and to analyze phylogenetic source of BDV in Yili area, Xinjiang. Methods We established fluo- rescence quantitative nested RT-PCR to detect BDV p24 segment in peripheral blood mononuclear cells (PBMCs) of 518 Yili horses and 206 Yili donkeys in Yili area, Xinjiang. Positive products were validated by detecting BDV p40 segment and plasmid to preclude the contamination, and were sequenced to analyze the homology of gene sequence, amino acid sequence and phylogenetic tree. Results The positive rates of BDV infection in PBMCs of 518 Yili horses and 206 Yili donkeys were 0.97% and 1.94%, respectively. The results of BDV p40 segment verification were positive in all of the samples of BDV p24 positive. All the samples tested were not contaminated by plasmid. There was a homology of the gene sequence of positive PCR samples with strain He/80. And the gene sequence revealed more than 93% identical to H1766 and strain V. Conclusion Our study suggested BDV natural infection in Yili horses and Yili donkeys. The en- demic BDV had a high degree of identity to strain He/80.

Objective:To investigate the efficacy of TiRobot navigation for hinged external fixation in elbow arthrolysis.Methods:The 11 patients were retrospectively analyzed who had been treated by elbow arthrolysis at Department of Traumatology and Orthopedics, Beijing Jishuitan Hospital using TiRobot navigation for hinged external fixation. There were 9 males and 2 females with a mean age of 39.3 years (from 21 to 66 years). Their elbow range of motion (ROM) was compared between preoperation and the final follow-up. Their visual analogue scale (VAS) and Mayo elbow performance score (MEPS) and complications were documented at the final follow-up.Results:The rotation axis of the elbow joint was positioned with the aid of intraoperative robot navigation in 11 patients.The deviation of entry point averaged 0.21 mm (from 0.05 to 0.41 mm) and the deviation of exit point 0.23 mm (from 0.06 to 0.38 mm). The follow-up time for the 11 patients averaged 25.8 months (from 16 to 32 months). Their elbow flexion and extension was 133.0° (134.9°, 138.7°) and rotation 164.6° ±17.5° at the final follow-up, significantly improved compared with their preoperative values [0.8°(0°, 33.7°) and 122.9°±49.0°] ( P<0.05). Their VAS averaged 0.2 (from 0 to 1) and MEPS 96.8 (from 85 to 100) at the final follow-up, giving 9 excellent and 2 good cases. There was no case of radial nerve injury, pin instability, pin breakage, pin infection or peri-pin fracture. Conclusion:When TiRobot navigation is used for hinged external fixation in elbow arthrolysis, the axis of rotation can be accurately located, leading to satisfactory functional outcomes for the patients.

Objective:To study the clinical efficacy of modified open elbow arthrolysis in the treatment of traumatic elbow stiffness.Methods:A retrospective analysis was performed on 120 patients who underwent modified open elbow arthrolysis in Beijing Jishuitan Hospital from January 2018 to December 2020. The age of the included patients was (37.7±12.4) years (ranged 18-64 years), including 54 males and 66 females. The medical records were reviewed, the range of motion (ROM) and functional status of the patients before operation and at the last follow-up were compared including visual analogue scale (VAS), Mayo elbow performance score (MEPS), Disabilities of the arm, shoulder and hand (DASH) score. Complications and secondary operations were also recorded. Measurement data with normal distribution were presented as mean ± standard deviation( ± s) and comparison between groups was conducted using the t-test; Measurement data of skewed distribution were expressed as M ( Q1, Q3), and Rank-sum test was used for inter-group comparison. Results:The preoperative extension of 120 patients was 43.6° (33.8°, 60.1°), the flexion was 78.7° (59.8°, 98.1°), and the flexion-extension ROM was 25.6° (0.0°, 54.5°); the preoperative pronation was 51.8° (33.0°, 67.0°), the supination was 85.1° (65.7°, 90.0°), and the rotation ROM was 136.9° (99.1°, 157.5°). Postoperative extension was 14.2° (7.0°, 24.8°), flexion was 129.5° (120.0°, 138.1°), flexion-extension ROM was 115.5° (94.4°, 127.3°); postoperative pronation was 65.0° (47.1°, 75.0°), the supination was 88.3° (78.6°, 90.0°), and the rotation ROM was 151.9° (131.7°, 163.4°). Postoperative extension, flexion, flexion-extension ROM, pronation, supination, and rotation ROM were all higher than those before operation, and the differences were statistically significant ( P<0.001). The VAS of 120 patients was 1.0 (0.0, 3.0) scores before operation and 0.0 (0.0, 1.0) scores after operation. The MEPS was 60.0 (50.0, 75.0) scores before operation and 100.0 (85.0, 100.0) scores after operation. The preoperative DASH was 37.5 (20.1, 51.3) scores, and the postoperative DASH was 7.9 (3.3, 13.3) scores. The postoperative VAS, MEPS, and DASH were significantly improved compared with those before operation, and the differences were statistically significant ( P<0.001). Residual ulnar nerve symptoms occurred in 18 cases, recurrence of heterotopic ossification in 42 cases, and hematoma in 3 cases. Conclusions:Modified open elbow arthrolysis is a safe and effective surgical method for the treatment of traumatic elbow stiffness. It can significantly improve the function of the patient, reduce the occurrence of elbow instability, avoid the use of external fixators, and reduce the cost of the patient.

Objective:To explore the effect of combined administration of intravenous and topical tranexamic acid on perioperative blood loss in elbow arthrolysis.Methods:A retrospective analysis was conducted of 31 patients who had undergone elbow arthrolysis due to elbow stiffness from April 2019 to November 2020 at Department of Orthopaedic Trauma, Beijing Jishuitan Hospital. An observational group of 15 patients were subjected to combined administration of intravenous and topical tranexamic acid while a control group of 16 patients to no administration of tranexamic acid. In the observational group, 15 mg/kg of tranexamic acid was injected intravenously 5 to 10 minutes before surgery and 1.0 g of tranexamic acid was injected locally in the area of anterior and posterior joint capsules after incision was closed while drainage tubes were clamped for 2 hours before release. In the control group, there was no special operative procedure while drainage tubes were also clamped for 2 hours before release. The 2 groups were compared in terms of blood loss on day 1 and day 3 after operation, drainage volume on day 1 after operation, total drainage volume, time for indwelling drainage tube, complications, and Mayo elbow performance score (MEPS) at 3 months after operation.Results:There were no statistically significant difference in preoperative general data between the 2 groups, showing they were comparable ( P>0.05).On day 1 and day 3 after operation, the blood loss was respectively (533.4±318.3) mL and (792.0±375.6) mL in the observational group, and respectively (866.4±480.5) mL and (1,403.0±636.5) mL in the control group, showing significantly differences between the 2 groups ( P<0.05). The drainage volume on day 1 after operation was (151.3±90.1) mL in the observational group and (235.0±126.1) mL in the control group, showing a significant difference between the 2 groups ( P<0.05). There was no statistically significant difference in total drainage volume or time for indwelling drainage tube between the 2 groups ( P>0.05). There were no such complications as thromboembolic events in either group. There was no significant difference in MEPS between the 2 groups at 3 months after operation ( P>0.05). Conclusions:Combined administration of intravenous 15 mg/kg and topical 1.0 g tranexamic acid may reduce blood loss on day 1 and day 3 after operation and drainage volume on day 1 after operation, and may not increase the risk of thromboembolic events, but cannot reduce total drainage volume or time for indwelling drainage tube. Application of tranexamic acid may not affect early elbow joint function after operation.

Objective To observe the effects of hyperbaric oxygen in the treatment of the rats with optic nerve crush. Methods In this study, 24 rats with traumatic optic nerve injury were recruited. The rats'left eyes were injured in the optic nerve and the right eyes as the controls were applied with sham-operation. The rats were divided into the treatment group and the control group in accordance with the random number table. The experimental group was treated with two-course hyperbaric oxygen one hour a day, 10 days a course. The control group breathed fresh air under standard atmospheric pressure. F-VEP was detected on day 3, 10, 20 during the experiment. Results In the control group, latency of F-VEP delayed (P＜0.05) and the amplitude of P100 decreased (P＜0.05) in the injured eye compared to the normal eye. In the experimental group, no obvious difference was found in the latency of F-VEP and the amplitude of P100 in the injured eye compared to the normal eye (P＞ 0.05) . The comparison of F-VEP data of the injured eyes showed that incubation period was in advance (P＜ 0.05) and amplitude increased (P＜0.05) in the experimental group. The comparison of F-VEP data tested at different time points was statistical significant. Conclusion The rat model of optic nerve injury was successful. Hyperbaric oxygen therapy showed no interference with the F-VEP data of the injured eye by causing no damage to the normal eye and was proved effective. Longer treatment provided better results.

Objective:To study the locational distribution characteristics of the heterotopic ossification (HO) following traumatic elbow stiffness and the risk factors for HO development at different locations.Methods:Consecutively included according to our inclusion criteria in the present study were the patients who had been admitted to Department of Orthopaedic Trauma, Beijing Jishuitan Hospital from January 2018 to December 2018 for elbow release due to traumatic elbow stiffness but developed postoperative HO. Their baseline data and CT data were collected and processed using Mimics 20.0. The HO distribution for each patient was characterized at the anteromedial, anterolateral, posteromedial, posterolateral, posterior, medial, lateral, and proximal radioulnar locations. The patient's original injury was categorized into 5 types: distal humerus fracture, olecranon fracture, radial head fracture, coronoid fracture, and elbow dislocation. After the univariate analysis with the HO occurrence at a specific location as the dependent variable and the original injury and baseline data as the independent variables, the factors with P value less than 0.1 were included in the logistic regression analysis to determine the risk factors for HO at each location.Results:A total of 91 patients were included in this study. Of them, 88 had posteromedial HO (96.7%, 88/91), 62 posterior HO (68.1%, 62/91), 60 posterolateral HO (65.9%, 60/91), 41 anteromedial HO (45.1%, 41/91), 26 anterolateral HO (28.6%, 26/91), 13 proximal radioulnar HO (14.3%, 13/91), 8 lateral HO (8.8%, 8/91), and 7 medial HO (7.7%, 7/91). Logistic regression analysis showed that presence of ulnar nerve symptoms ( OR=4.354, P=0.017) and presence of original elbow dislocation ( OR=2.927, P=0.042) were the independent risk factors for the anteromedial HO development and that presence of original olecranon fracture ( OR=0.277, P=0.023) was the protective factor for the anteromedial HO development. Presence of original radial head fracture was the independent risk factor for the anterolateral HO development ( OR=2.891, P=0.033) and the posterolateral HO development ( OR=3.123, P=0.043). Conclusions:HO development in patients with post-traumatic elbow stiffness is closely related to their original injury. Posteromedial HO may develop in almost all the patients. Patients with ulnar nerve symptoms and original elbow dislocation are more prone to anteromedial HO development, but patients with original olecranon fracture are less likely to develop anteromedial HO. Patients with original radial head fracture are more likely to develop anterolateral and posterolateral HO.