Although intelligent technologies has facilitated the development of precise orthopaedic, simple internal fixation, ligament reconstruction or arthroplasty can only relieve pain of patients in short-term. To achieve the best recover of musculoskeletal injuries, three bottlenecks must be broken through, which includes scientific path planning, bioactive implants and personalized surgical channels building. As scientific surgical path can be planned and built by through AI technology, 4D printing technology can make more bioactive implants be manufactured, and variable structures can establish personalized channels precisely, it is possible to achieve satisfied and effective musculoskeletal injury recovery with the progress of multi-layer intelligent technologies (MLIT).

Objective:To explore the application value and effectiveness of pelvic unlocking closed reduction device for the treatment of unstable pelvic posterior ring disruption.Methods:A retrospective analysis of clinical data of 243 cases of unstable pelvic posterior ring disruption treated with pelvic unlocking closed reduction device in 13 orthopaedic trauma centers across the country between December 2018 and June 2020 was performed. There were 139 males and 104 females; the age ranged from 18 to 92 years, with an average age of 48.5 years. The cause of injury included 132 cases of traffic accident injuries, 102 cases of falling from height, and 9 cases of crushing injuries. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 5 cases of type 61-B1, 13 cases of type 61-B2, 32 cases of type 61-C1.1, 47 cases of type 61-C1.2, 89 cases of type 61-C1.3, 35 cases of type 61-C2, and 22 cases of type 61-C3. The time from injury to operation was 2-121 days, with a median of 10 days. Preoperative preparation time, installation time of unlocking closed reduction device, fracture reduction time, intraoperative fluoroscopy times, intraoperative blood loss, and surgical complications were recorded, and Matta scoring standard was used to evaluate the quality of fracture reduction. According to Matta evaluation results, the patients were divided into two subgroups: excellent-good group and fair-poor group. The differences in gender, age, time from injury to operation, AO/OTA classification, and perioperative clinical indicators were compared between the two groups, and the effects of baseline data and perioperative indicators on the quality of fracture reduction were studied.Results:Pelvic unlocking closed reduction device did not interfere with the display of the pelvic structure and fracture displacement direction during the intraoperative fluoroscopy, effectively correcting the displacement of the pelvic ring. The preoperative preparation time was 17-60 minutes, with an average of 30 minutes; installation time of unlocking closed reduction device was 10-32 minutes, with an average of 21 minutes; intraoperative fracture reduction time was 15-205 minutes, with an average of 49.2 minutes; intraoperative fluoroscopy times were 41-420 times, with an average of 132 times; intraoperative blood loss was 40-1 500 mL, with an average of 71.5 mL. The reduction quality of pelvic fracture was evaluated according to Matta score immediately after operation. The results were excellent in 153 cases, good in 61 cases, fair in 24 cases, and poor in 5 cases. The excellent and good rate was 88.1%. Further subgroup analysis showed that there was no significant difference in other indexes ( P>0.05) between the excellent-good group and the fair-poor group except for the time from injury to operation and AO/OTA classification ( P<0.05). Among them, the excellent-good reduction rate was 92.2% (119/129) in patients with injury-to-operation time less than 10 days, and the fair-poor reduction rate was 25.7% (9/35) and 40.9% (9/22) in patients with AO/OTA 61-C2 and 61-C3 types, respectively. There was no surgery-related complication due to the application of the pelvic unlocked reduction device, no secondary iliac fractures, vascular, or nerve injuries, and postoperative CT showed that all channel screws were located in the osseous channel.Conclusion:The pelvic unlocking reduction device can effectively help to reduce the unstable pelvic posterior ring and maintain reduction, meet the needs of different projection angles of pelvic fracture with intraoperative C-arm fluoroscopy. The system facilitate the operation of pelvic reduction and precise fixation.

OBJECTIVE:To compare treatment effect of monolateral and circular external fixator in infectious tibial nonunion and to explore external fixation structure with better osteogenic ability and fewer complications.METHODS:A retrospective analysis was performed on 150 patients with infectious tibial nonunion admitted from January 2010 to December 2014. Patients who met the inclusion and exclusion criteria were divided into monolateral fixator group and circular fixator group according to the type of external fixation. Demographic and perioperative data of the two groups were collected. New bone quality was assessed by pixels ratio, treatment effect was assessed by complications. Notes for treatment was explored by case analysis.RESULTS:A total of 64 patients with infectious mid-tibial nonunion were included, 26 in monolateral fixator group and 38 in circular fixator group. There was no difference in demographic data between two groups. The pixel ratio of new bone between two groups was from 0.91 to 0.97 with an average of (0.94±0.03), and from 0.93 to 0.97 with an average of(0.95±0.02), respectively, with no statistical significance (P>0.05). The external fixation index was from 34.1 to 50.6 with an average of (42.3±8.3) days /cm in monolateral fixator group and from 44.5 to 56.1 with an average of (45.8±10.3) days/cm in the circular fixator group, and the difference was not statistically significant (P>0.05). There were 7 cases (26.9%) of complications in monolateral fixator group and 5 cases (13.2%) in circular fixator group, the difference was not statistically significant (P>0.05), but 5 cases of foot ptosis in monolateral fixator group and none in circular fixator group. The time of weight bearing in monolateral fixator group was later than that in circular fixator group, and the difference was statistically significant (P<0.05).CONCLUSION:Monolateral and circular fixators can achieve equivalent bone formation in the treatment of infected tibial nonunion. Circular fixator is recommended for patients with severe osteoporosis or concomitant medical diseases requiring early weight bearing. Hydroxyapatite coated screws are recommended if a monolateral external fixator is selected when the expected enlarged length is long and the fixation time is long and close monitoring of the ankle movement is required to avoid foot droop.

Objective How to restrict sliding of cephalomedullary nail and rigid reconstruct medial support for unstable intertrochanteric fractures remains a challenge. This study aims to explore the feasibility of a novel cephalomedullary nail for restriction sliding and reconstruction of medial femoral support to prevent failure in unstable trochanteric fractures through finite element analysis. Methods The DICOM files of a unilateral femur spiral computed tomography (CT) scans from a elderly female were converted into STL files, and the most common clinical trochanteric fracture model with the absence of medial support, AO/OTA 31‐A2.3 was simulated by removing the posterior medial femur. The model of a novel medial sustain nail (MSN‐II) and a widely used nail (proximal femoral nail anti‐rotation PFNA‐II) were modeled according to the manufacturer‐provided engineering drawing. Different loads were applied to the femoral head to simulate the postoperative weight bearing gait. The sliding distance of helical blade in femoral neck, maximum stress of femur and nail, displacement of proximal fragment were analyzed to revealing the mechanical stability of unstable trochanteric fracture stabilized by different implant. Results The sliding distance of helical blade in the femoral neck, the maximum stress on the femur and nail, the displacement of proximal fragment in MSN‐II under 2100N axial load were 0.65 mm, 689 MPa, 1271 MPa, 16.84 mm respectively, while that were 1.43 mm, 720.8 MPa, 1444 MPa, 18.18 mm, respectively in PFNA‐II. The difference between the two groups was statistically significant (P < 0.05) and the stress was mainly distributed in medial distal side of nail but helical blade and the proximal aperture for the nail in MSN‐II. Compared to PFNA‐II, MSN‐II demonstrates biomechanical merit against femur medialization, cut‐out and coax varus. Conclusion The sliding distance of helical blade in femoral neck, the maximum stress on the femur and nail, and the displacement of proximal fragment of MSN‐II were less than those of PFNA‐II in the treatment of unstable intertrochanteric fractures. Therefore MSN‐II has better stability than PFNA‐II and it may have the potential to avoid femur medialization and cut out. It might be an option in unstable trochanteric fracture because of its superiority in restricted sliding and medial support reconstruction.

The purpose of this study was to explore the advantages and disadvantages of a multi-dimensional cross locking plate (MDC-LP) compared with a locking compression plate (LCP) as the augmentation plate (AP) over an intramedullary nail (IMN) for the treatment of femoral shaft nonunion by using finite element analysis. A finite element model of the femur was developed to analyze the maximum stress, stress distribution, displacement of fixation and nonunion site under increasing axial and torsional loads. Some differences in the stress distribution and stress values on the fixations were observed in the five fixation models. The MDC-LP with eight screw fixation showed the lowest variety of nonunion site displacement under the increasing axial and torsional loads. Models of the MDC-LP were more stable with regard to the bending and torsional forces. The short MDC-LP with eight screw insertion as an augmentation plate over intramedullary nail shows biomechanical advantages compared to the LCP. The MDC-LP may be an appropriate and effective treatment option for femoral shaft nonunion.

Robots in orthopedic surgery have been developed rapidly for decades and bring significant benefits to the patients and healthcare providers. However, robotics in fracture reduction remains at the infant stage. As essential components of the current robotic system, external fixators were used in fracture reduction, including the unilateral and Ilizarov-like ring fixators. With emerging of the industrial robots and mechanical arms, their sterilized variants were developed as the serial robots, including the traction device and robotic arm, for fracture reduction. Besides, parallel robots (e.g., Gough–Stewart platform) were devised for lower extremity traction and fracture reduction. After combining the advantages of the serial and parallel mechanisms, hybrid robots can fulfill specific clinical requirements (e.g., the joint fracture, including multiple major fragments). Furthermore, with the aid of intra-operative navigation systems, fracture reduction can be performed under real-time guidance. The paper presents a comprehensive overview of the advancement of the robots in fracture reduction and evaluates research challenges and future perspectives, including ergonomic and economic issues, operation time, artificial realities and intelligence, and telesurgery.

Background: Three-dimensional A-mode ultrasound calibration and registration for robotic orthopedics bone surgery have been studied, but A-mode ultrasound images are less intuitive than B-mode ultrasound 2D images. Methods: A 2D ultrasound image plus stereo camera tracking system was established to obtain three-dimensional ultrasound images. This methodology was used to segment ultrasound image bone surface points automatically. The Iterative Closest Point algorithm was then utilized to complete ultrasound-CT registration and verify the segmentation and registration method, for robotic-assisted femoral shaft fracture reduction. Results: The results show that the automatic B-mode ultrasound image-based segmentation and registration method is robust, stable and reliable, and supports the robotic-assisted system to complete the femoral shaft reduction operation successfully. Conclusion: Experimental results presented herein suggest that the system we have developed is efficient for clinical application, and is in fact greatly improved over the current surgical efficiency of robotic-assisted femoral shaft fracture reduction.

Background In the present study, we evaluated the mechanical outcome of different configurations formed by fully threaded screws and partially threaded screws in the treatment of unstable femoral neck fracture. Methods The Pauwels type III unstable femoral fracture and the models of the fully threaded screw and partially threaded screw were constructed in 3-matic software and UG-NX software respectively. We then assembled the different screw configurations to the fracture model separately to form the fixation models. After meshing the models’ elements, we used Abaqus software to perform the finite element analysis. Parameters of von Mises stress distribution on the screws, peak stress, displacement between fracture fragments, and model principal strains in cancellous bone were reported. Results Our results indicated that the peak von Mises stresses of screws was concentrated in the middle surface of the screw near the fracture line in each group. Peak stress value of the implants was highest in the model of triangle with posterior single screw. And the lowest stress values were observed in the triangular model. Fully threaded screw in each group underwent the most stress while partially threaded screw underwent a little bit of stress. Lowest displacement was observed in the triangular model. The volume of bone susceptible to yielding in the femoral neck region was the lowest for triangular configuration. Conclusions For unstable femoral neck fractures, superior results were obtained by stabilizing the fracture with triangular configuration formed by one superior partially threaded screw and two inferior fully threaded screws. This study will require clinical confirmation as to its practicality in the management of unstable femoral fractures.

Previous studies have reported age-specific pathological and functional outcomes in young and aged patients suffering spinal cord injury, but the mechanisms remain poorly understood. In this study, we examined mice with spinal cord injury. Gene expression profiles from the Gene Expression Omnibus database (accession number GSE93561) were used, including spinal cord samples from 3 young injured mice (2–3-months old, induced by Impactor at Th9 level) and 3 control mice (2–3-months old, no treatment), as well as 2 aged injured mice (15–18-months old, induced by Impactor at Th9 level) and 2 control mice (15–18-months old, no treatment). Differentially expressed genes (DEGs) in spinal cord tissue from injured and control mice were identified using the Linear Models for Microarray data method, with a threshold of adjusted P < 0.05 and |logFC(fold change)| > 1.5. Protein–protein interaction networks were constructed using data from the STRING database, followed by module analysis by Cytoscape software to screen crucial genes. Kyoto encyclopedia of genes and genomes pathway and Gene Ontology enrichment analyses were performed to investigate the underlying functions of DEGs using Database for Annotation, Visualization and Integrated Discovery. Consequently, 1,604 and 1,153 DEGs were identified between injured and normal control mice in spinal cord tissue of aged and young mice, respectively. Furthermore, a Venn diagram showed that 960 DEGs were shared among aged and young mice, while 644 and 193 DEGs were specific to aged and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in osteoclast differentiation, extracellular matrix–receptor interaction, nuclear factor-kappa B signaling pathway, and focal adhesion. Unique genes for aged and young injured groups were involved in the cell cycle (upregulation of PLK1) and complement (upregulation of C3) activation, respectively. These findings were confirmed by functional analysis of genes in modules (common, 4; aged, 2; young, 1) screened from protein–protein interaction networks. Accordingly, cell cycle and complement inhibitors may be specific treatments for spinal cord injury in aged and young mice, respectively.

OBJECTIVE:The hand-eye calibration is used to determine the transformation between the end-effector and the camera marker of the robot. But the robot movement in traditional method would be time-consuming, inaccurate and even unavailable in some conditions. The method presented in this article can complete the calibration without any movement and is more suitable in clinical applications. METHODS:Instead of solving the classic non-linear equation AX = XB, we collected the points on X and Y axes of the tool coordinate system (TCS) with the visual probe and fitted them using the singular value decomposition algorithm (SVD). Then, the transformation was obtained with the data of the tool center point (TCP). A comparison test was conducted to verify the performance of the method. RESULTS:The average translation error and orientation error of the new method are 0.12 ± 0.122 mm and 0.18 ± 0.112° respectively, while they are 0.357 ± 0.347 mm and 0.416 ± 0.234° correspondingly in the traditional method. CONCLUSIONS:The high accuracy of the method indicates that it is a good candidate for medical robots, which usually need to work in a sterile environment.

Various stimulators have been reported to promote MSC osteogenic differentiation via different pathways such as bone morphogenetic protein 9 (BMP9) through influencing COX-2 and miR-548d-5p through targeting peroxisome proliferator-activated receptor- γ (PPAR γ ). Whether synergistic effects between BMP9 and miR-548d-5p existed in promoting osteogenesis from MSCs was unclear. In the study, the potential synergistic effects of BMP9 and miR-548d-5p on human MSC differentiation were investigated. Osteogenic differentiation of MSCs treated with BMP9 or miR-548d-5p was detected with multimodality of methods. The results demonstrated that BMP9 and miR-548d-5p significantly influenced COX-2 and PPAR γ , respectively. BMP9 also influenced the expression of PPAR γ , but no significant effect of miR-548d-5p on COX-2 was observed. When BMP9 and miR-548d-5p were combined, more potent effects on both COX-2 and PPAR γ were observed than BMP9 or miR-548d-5p alone. Consistently, osteogenic analysis at different timepoints demonstrated that osteogenic genes, ALP activity, calcium deposition, OPN protein, and matrix mineralization were remarkably upregulated by BMP9/miR-548d-5p compared with BMP9 or miR-548d-5p alone, indicating the synergetic effects of BMP9 and miR-548d-5p on osteogenic differentiation of MSCs. Our study demonstrated that regulating different osteogenic regulators may be an effective strategy to promote bone tissue regeneration for bone defects.

Objective To compare the clinical efficacy of locking compression plate (LCP) versus intramedullary nail in staged treatment of complex compound tibial fractures.Methods From February 2008 to January 2013,55 cases of complex tibial open fracture were treated at our department.They were 39 men and 16 women,with an average age of 32.5 years (from 17 to 72 years).The fractures were on the left side in 24 patients,on the right side in 28 and both sides in 3.By Gustilo classification,18 fractures were type Ⅰ,24 type Ⅱ and 16 type ⅢA; by AO classification,6 fractures were type 42-A,32 type 42-B,and 20 type 42-C.They were treated by external fixation and vacuun sealing drainage (VSD) at the primary stage followed by fixation with LCP or intramedullary nail at the secondary stage.Locking intramedullary nail was used in 32 patients (34 fractures) and LCP in 23 patients (24 ffractures).The 2 groups were compared in terms of fracture healing time,functional recovery of the affected limbs,and postoperative complications.Results The 55 patients were followed up for 12 to 34 months (average,18 months).All the fractures were healed from 16 to 48 weeks after the staged treatment,with an average of 24.2±5.3 weeks in the intramedullary nail group and 26.1 ± 7.2 weeks in the LCP group.There was no significant difference in the healing time between the 2 groups (P ＞ 0.05).According to the functional assessment by the Johner-Wruhs system,the intramedullary nail group had 13 excellent cases,18 good ones and 3 fair ones (the excellent to good rate,91.2％) while the LCP group had 9 excellent,12 good and 3 fair ones (the excellent to good rate,87.5％),showing no significant between-group difference (P ＞ 0.05).There was no significant difference either between the 2 groups regarding the postoperative complication rate [20.6％ (7/34) for the intramedullary nail group versus 12.5％ (3/24) for the LCP group] (P ＞ 0.05).Conclusion In the staged treatment of complex open tibia fractures,both intramedullary nail and LCP can result in reliable fixation of the fracture ends,a low complication rate and thus satisfactory clinical efficacy.