BACKGROUND:Orthopedic robots have been widely used in clinical practice,and relevant reports have shown that they have many advantages such as minimal trauma and short surgical time.However,there is currently no clear report on how accurate they are. OBJECTIVE:To evaluate the accuracy of robot-assisted sacroiliac screw insertion. METHODS:A total of 131 patients with sacroiliac joint fracture and dislocation and sacral fracture admitted to the Department of Trauma Surgery,Gansu Provincial Hospital from January 2020 to April 2023 were retrospectively collected,including 131 S1 screws and 46 S2 screws,totaling 177 screws.They were divided into two groups based on whether robot-assisted navigation was performed.There were 63 cases of sacroiliac screws inserted under robot-assisted navigation(observation group),with 36 males and 27 females,aged 19-72 years,with a mean age of(45.3±17.6)years.Among them,39 cases were fixed with only S1 screws,while 24 cases were fixed with S1S2 screws,resulting in a total of 87 sacroiliac screws.Under C-arm fluoroscopy,68 cases of sacroiliac screws were inserted with bare hands(control group),including 41 males and 27 females,aged 23-67 years,with a mean age of(42.6±21.3)years.Among them,46 cases were fixed with simple S1 screws,while 22 cases were fixed with S1S2 screws,resulting in a total of 90 sacroiliac screws.A postoperative CT scan was performed to evaluate the number of S1 screws,S2 screws,total screw level,and calculate accuracy based on the method introduced by SMITH et al. RESULTS AND CONCLUSION:(1)In the observation group,62 S1 screws were accurately placed(62/63),with an accuracy rate of 98%.24 S2 screws were accurately placed(24/24),with an accuracy rate of 100%.The total number of screws accurately placed was 86(86/87),with an accuracy rate of 99%.(2)In the control group,58 S1 screws were accurately inserted(58/68),with an accuracy rate of 85%.19 S2 screws were accurately inserted(19/22),with an accuracy rate of 86%.The total number of screws accurately inserted was 77(77/90),with an accuracy rate of 86%.(3)There was a statistically significant difference in the accuracy of the S1 screw,S2 screw,and total screw between the two groups(P<0.05).It is suggested that the placement of sacroiliac screws under robot navigation has higher accuracy compared to manual placement under C-arm fluoroscopy,but still has a lower error rate in placement.

Hepatocellular carcinoma (HCC) has an insidious onset, and most patients are in the advanced stage when attending the hospital and thus lose the opportunity for radical surgical resection, which results in the poor prognosis of patients. With the development of clinical treatment, the treatment of advanced HCC has gradually transitioned from the relatively single and limited treatment options in the past to the new model of comprehensive treatment. In recent years, immunotherapy, represented by immune checkpoint inhibitors (ICIs), has become widely used in clinical practice. At present, a number of clinical studies have been conducted for immunotherapy combined with local and targeted antitumor therapy, and in particular, ICIs combined with targeted therapy have become a research hotspot in the field of HCC treatment. This article reviews the research advances in immunotherapy for the treatment of HCC.

Traumatic brain injury ( TBI ) has caused serious economic and social burdens, but due to its heterogeneity, there is no effective treatment. In TBI with different severity, diffuse axonal injury (DAI) incidenceis high. The investigation on DAI will contribute to the diagnosis and treatment of TBI. In this study, the classification of TBI and the research status of DAI were summarized. The method to judge the severity of TBI and DAI, and animal experimental models and related injury criteria and thresholds were reviewed. The result show that DAI is mainly generated by rotational acceleration and it is related to angular acceleration, angular velocity and duration. Several TBI animal models can induce the pathology of DAI, and inertial rotation models which can produce only rotational acceleration have been developed. However, these models are instantaneous rotation models, and the rotation duration is uncontrollable, thus a longer duration is impossible, and DAI severity under long rotational motion cannot be studied. The study proposes that a new rotation animal model which can control rotation duration should be developed. The development of the animal model and investigation on pathomechanism of the model will contribute to the prevention and treatment of DAI.

Objective To explore the spatial distribution of microstructural parameters and mechanical properties for trabecular bone in the femoral head with osteonecrosis. Methods Microstructural parameters and mechanical properties of trabecular bone in different regions were analyzed by combined use of imaging measurements and numerical simulation method, and the spatial distribution of biomechanical properties for trabecular bone along coronal, sagittal and vertical directions was investigated. Results Microstructural characteristics and mechanical properties of trabecular bone were Y-shaped distributed along coronal and sagittal directions, and mechanical properties of trabecular bone in Y-shaped region were higher than those in the other regions. Such distribution characteristics was consistent with the location of principle compressive group in the femoral head. Conclusions Necrotic lesions in Y-shaped region had a greater influence on stress distribution of the femoral head and might cause the deterioration of osteonecrosis. The spacial correlation between necrotic lesions and Y-shaped region should be fully considered during clinical diagnosis.

Objective To make classification and segment measurement for the cases with tibiofibular and ankle fractures in parachuting landing, and investigate main classification types of parachuting fractures and fracture segments of high risk.Methods A total of 56 fracture cases in parachuting landing were collected, and the tibiofibula and ankle fractures were classified according to AO-OTA or Lauge-Hansen classification standards respectively based on their digital X-ray images. The medium plane between talus and tibia joint planes in ankle joint was defined as the reference plane. The highest and lowest injury points of tibia and fibula were marked respectively, and the fracture segment was defined between the highest and lowest point for statistical analysis.Results For tibiofibular and ankle fracture cases in parachuting landing, fracture at both tibia and fibula accounted for 80.4%. The major classification of tibiofibula fracture was 42-D/5.2 (45.8%) and 42-D/5.1 (16.7%). The major classification for ankle fracture was pronation-external rotation (PER, 59.4%) and supination-external rotation (SER, 37.5%). When tibiofibular and ankle fracture cases in parachuting landing occurred, the fracture segment of the tibia was mainly from 57 to 143 mm above the reference plane and from 6 mm below the reference plane to 24 mm above the reference plane, while the fracture segment of the fibula was 4-45 mm and 74-83 mm above the reference plane. Injury risks of all above segments were higher than 50%.Conclusions For protection of lower limbs in parachuting landing, the fracture at both tibia and fibula should be highly noticed. The ankle motion of PER and SER should be especially restricted in parachuting ankle protection.

Objective To study effects of backpack gravity center position on kinetics and kinematics of lower-extremity joints in parachuting landing and evaluate the injuries. Methods Seven participants performed parachuting landing with backpack gravity center on three positions: low-back (position 1), upper-back (position 2) and abdomen (position 3). Results The peak vertical ground reaction force (GRF) with backpack on position 2 was significantly lower than that on position 1. The joint moment on sagittal plane of the hip with backpack on position 2 was significantly higher than that on position 1 and position 3. The joint energy absorption of the hip with backpack on position 2 was significantly higher than that on position 1. The angular displacement of the hip on sagittal plane with backpack on position 2 was significantly higher than that on position 1 and was significantly lower than that on position 3. The angular velocity of the hip on sagittal plane with backpack on position 2 was significantly lower than that on position 3. Conclusions Different positions of backpack gravity center could significantly influence kinetic and kinematic parameters of the hip. Backpack gravity center on upper-back position could decrease the lower-extremity injuries. The results can provide evidences for evaluating backpack gravity center and decreasing injuries in parachuting landing.

Objective To measure mechanical properties of calcified tissues from human aortic valve by nanoindentation test. Methods Leaflets from 5 patients with aortic stenosis were collected. Elastic modulus and hardness of the calcified leaflets were obtained by nanoindentationtest. Results The elastic modulus and hardness of the calcified leaflets were (15.69±3.89) GPa and (0.59±0.15) GPa, respectively. Conclusions The elastic modulus and hardness of the calcified valve tissues can be obtained by nanoindentationtest, which provides experimental data for biomechanical research of the valve.

Objective To study the relationship between pulsatile tinnitus and temporal bone pneumatization grade. Methods Through the in vitro experiment, the generation and transmission pathways of the venous sound were simulated. The sound signals at the position of eardrum were recorded and analyzed. Results In case of cortical plate dehiscence, the high pressure and pulse-synchronous venous sounds were received at eardrum. The highest sound pressure occurred in the normal pneumatization case. In case of cortical plate intactness, the non-pulsatile venous sounds with pressure close to the background control sound were received at eardrum. Temporal bone air cells (TBAC) with different pneumatization grades would transmit venous sound in different frequency ranges. Conclusions Normal pneumatization TBAC exhibited the highest amplification on venous sound, while hypopneumatization TBAC exhibited the lowest amplification on venous sound. The pneumatization grade of TBAC is neither the sufficient nor essential condition of pathogenic venous sound, while the cortical plate dehiscence is the sufficient or necessary condition of pathogenic venous sound.

Objective To improve the clinical application of using rehabilitation robot for hand rehabilitation and solve the current shortcomings of rigid hand rehabilitation robot, such as complex structure, heavy weight, potential safety hazard, a new soft and wearable robotic glove was proposed. Methods The robotic glove was driven by McKibben pneumatic artificial muscles (PAMs). The tendon drive system was designed based on simulation of human hand anatomy and physiology structure, which could transmit forces and torques through the user’s own skeleton and joints. The normal hand movement could be simulated and this design pattern highly reduced the weight of the robotic glove. Meanwhile a surface electromyogrphy (sEMG) collecting circuit was developed to acquire sEMG signals from the forearm. User intent could be detected by measuring the sEMG of flexor digitorum superficialis and extensor digitorum communis on the forearm. Results The results of the experiment investigation on characteristics of the soft robotic glove showed that the robotic glove could effectively assist people completing daily activities and grasping daily necessities. The feasibility and scientificity of the robotic glove was validated. Conclusions The soft and wearable robotic glove has an advantage of light weight, easy operation and high comfortableness, and it can provide references for the study and design of similar hand rehabilitation devices.

Objective To study the change patterns of bone microstructural parameters around the magnesium based- implants after implantation in rabbit femur at different implantation time points. Methods The threaded and non-threaded high-purity magnesium (HP Mg, 99.99 wt.%) screws, with a 2 mm diameter and a 7 mm length, were implanted into the femoral condyle of the rabbits. The control group was the drilled and healthy group. Micro-CT scanning and analysis were performed at 8th, 12th and 16th week after operation. The obtained microstructural parameters included bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp). Results At 8th week, BMD and BV/TV in non-threaded magnesium screw group were significantly higher than those in healthy group, Tb.N was significantly higher than that in drilled and healthy group, and Tb.Sp was significantly lower than that in healthy group. At 12th week, BMD, BV/TV and Tb.N in threaded magnesium screw group were significantly higher than those in drilled and healthy group, Tb.Th was significantly higher than that in healthy group, and Tb.Sp was significantly lower than that in drilled and healthy group. At 16th week, BMD, BV/TV and Tb.N in non-threaded magnesium screw group were significantly higher than those in drilled and healthy group, and Tb.Sp was significantly lower than that in drilled and healthy group. Conclusions The magnesium based-implant promoted higher BMD, BV/TV, Tb.Th, Tb.N and lower Tb.Sp of surrounding implant, indicating that osseointegration and bone growth were in good condition. Magnesium based-implant could effectively promote the regeneration of bone. The results provide a theoretical basis for the orthopedic application of magnesium based-implants in clinic.