Computational Modelling for Managing Pathways to Cartilage Failure.

Over several decades the perception and therefore description of articular cartilage changed substantially. It has transitioned from being described as a relatively inert tissue with limited repair capacity, to a tissue undergoing continuous maintenance and even adaption, through a range of complex regulatory processes. Even from the narrower lens of biomechanics, the engagement with articular cartilage has changed from it being an interesting, slippery material found in the hostile mechanical environment between opposing long bones, to an intriguing example of mechanobiology in action. The progress revealing this complexity, where physics, chemistry, material science and biology are merging, has been described with increasingly sophisticated computational models. Here we describe how these computational models of cartilage as an integrated system can be combined with the approach of structural reliability analysis. That is, causal, deterministic models placed in the framework of the probabilistic approach of structural reliability analysis could be used to understand, predict, and mitigate the risk of cartilage failure or pathology. At the heart of this approach is seeing cartilage overuse and disease processes as a 'material failure', resulting in failure to perform its function, which is largely mechanical. One can then describe pathways to failure, for example, how homeostatic repair processes can be overwhelmed leading to a compromised tissue. To illustrate this 'pathways to failure' approach, we use the interplay between cartilage consolidation and lubrication to analyse the increase in expected wear rates associated with cartilage defects or meniscectomy.

Osteoporotic vertebral compression fracture accompanied with thoracolumbar fascial injury: risk factors and the association with residual pain after percutaneous vertebroplasty.

BACKGROUND: To explore the risk factors involved in the induction of thoracolumbar fascia (TLF) injury by osteoporotic vertebral compression fracture (OVCF), and the association between the residual pain after percutaneous vertebroplasty (PVP) and fascial injury. METHODS: A total of 81 patients with single-segment OVCF, treated between January 2018 and January 2020 were included. The patients were grouped according to the existence of TLF injury. The patients' general, clinical, and imaging data were accessed. RESULTS: There were 47 patients in the TLF group and 34 in the non-injury group (NTLF group). In the TLF group, BMI (Body mass index) was significantly lower, while the prevalence of hypertension and sarcopenia were significantly higher (P < 0.05). The vertebral compression degree was higher, and the kyphosis angle of the injured vertebra was greater in the TLF group (P < 0.05). Cobb's angle was not significantly different between groups. At 3-d after the operation, the VAS (Visual analogue scale) was 4.64 ± 1.78 and 3.00 ± 1.71, and the ODI (Oswestry disability index) was 67.44 ± 11.37% and 56.73 ± 10.59% in TLF and NTLF group, respectively (P < 0.05). However, at 3-m after the operation, the differences in the VAS score and the ODI between groups were not statistically significant. The area of fascial edema was not significantly associated with the pre- and post-operative VAS or ODI, but was positively correlated with the vertebral body compression degree (R = 0.582, P = 0. 029). CONCLUSION: Residual back pain after PVP is associated with TLF injury. Low BMI, hypertension and sarcopenia are risk factors of TLF injury, and sarcopenia may be the major factor.

Calcaneous interlocking nail treatment for calcaneous fracture: a multiple center retrospective study.

BACKGROUND: Minimally invasive treatments for calcaneous fractures have the same outcomes and fewer complications. However, they are technically demanding, and there are a lack reduction tools. To overcome these problems, a calcaneous interlocking nail system was developed that can make reduction and fixation minimally invasive and effective. We retrospectively studied the calcaneous fracture variables intraoperatively and followed up to evaluate the outcomes of patients treated with the calcaneous interlocking nail system. METHODS: All patients in 7 institutions between October 2020 and May 2021 who had calcaneous fractures treated with calcaneous interlocking nails were retrospectively analyzed. The patient characteristics, including age, sex, injury mechanism, Sanders type classification, smoking status, and diabetes were recorded. The calcaneous interlocking nail and standard surgical technique were introduced. The intraoperative variables, including days waiting for surgery, surgery time, blood loss, incision length, and fluoroscopy time, were recorded. The outcomes of complications, AOFAS scores and VAS scores were recorded and compared with other similar studies. RESULTS: Fifty-nine patients were involved in this study; 54 were male; 5 were female; and they had an average age of 47.5 ± 9.2 years (range 25-70). 2 of these fractures were Sanders type I, 28 of these fractures were Sanders type II, 27 of these fractures were Sanders type III, and 2 of these were Sanders type IV. The surgery time was 131.9 ± 50.5 (30-240) minutes on average. The blood loss was 36.9 ± 41.1 (1-250) ml. The average incision length was 3.5 ± 1.8 (1-8) cm; 57 were sinus tarsi incisions; and 2 were closed fixations without incisions. The average fluoroscopy time was 12.3 ± 3.6 (10-25) seconds during the surgery. The VAS score of patients on the day after surgery was 2.4 ± 0.7 (1-3). The AOFAS ankle-hindfoot score in patients who had a follow-up of at 12 months was 93.3 ± 3.6(85-99). During the follow-up, all patients' functional outcomes were good. One patient had a superficial infection. The rate of complications of the 59 patients was 1.7% (1/59). CONCLUSION: The calcaneous interlocking nail system can have satisfactory reduction and fixation in calcaneous fractures, even in Sanders type IV. The outcomes of follow-up showed good function. The calcaneous interlocking nail could be an alternative method for minimally invasive calcaneous fracture fixation.

Long non-coding RNA SNHG5 suppresses the development of acute respiratory distress syndrome by targeting miR-205/COMMD1 axis.

Previous studies have reported the important roles of long non-coding RNAs (lncRNAs) in acute respiratory distress syndrome (ARDS). Here, we focus on the role and regulatory mechanism of lncRNA SNHG5 in ARDS. LPS was used to induce mice to establish ARDS model in vivo and to induce A549 cells to establish ARDS model in vitro. qRT-PCR was performed to determine the expressions of SNHG5, miR-205, and inflammatory cytokines. MTT assay was applied to detect cell viability. Dual-luciferase reporter (DLR) assay was performed to test the interactions among SNHG5, miR-205 and COMMD1. Western blot was used to detect the protein expression of COMMD1. Lung injury was evaluated by evaluating the score of lung injury, lung wet/dry weight ratio, and myeloperoxidase (MPO) activity. SNHG5 was downregulated, while miR-205 was upregulated in the serum of ARDS patients and lung tissues of LPS-induced mice. Upregulation of SNHG5 or down-regulation of miR-205 inhibited inflammation and promoted the viability of LPS-induced A549 cells. SNHG5 alleviated the lung injury of ARDS mice. MiR-205 was a target of SNHG5 and inversely correlated with SNHG5. COMMD1 was targeted by miR-205, and was positively regulated by SNHG5. MiR-205 mimics or sh-COMMD1 reversed the promoting effect of SNHG5 on cell viability and the suppressing effect of SNHG5 on inflammation in cellular model of ARDS. Meantime, miR-205 mimics reversed the relieving effect of SNHG5 on lung injury in mouse model of ARDS. SNHG5 acted as a sponge for miR-205 to ameliorate LPS-induced ARDS by regulating COMMD1.

User testing of the psychometric properties of pictorial-based disability assessment Longshi Scale by healthcare professionals and non-professionals: a Chinese study in Shenzhen.

OBJECTIVE: The aim of this study was to validate a novel pictorial-based Longshi Scale for evaluating a patient's disability by healthcare professionals and non-professionals. DESIGN: Prospective study. SETTING: Rehabilitation departments from a grade A, class 3 public hospital, a grade B, class 2 public hospital, and a private hospital and seven community rehabilitation centers. SUBJECTS: A total of 618 patients and 251 patients with functional disabilities were recruited in a two-phase study, respectively. MAIN MEASURES: Outcome measure: pictorial scale of activities of daily living (ADLs, Longshi Scale). Reference measure: Barthel Index. The Spearman correlation coefficient was used to analyze the validity of Longshi Scale against Barthel Index. RESULTS: In phase 1 study, from March 2016 to August 2016, the results demonstrated that the Longshi Scale was both reliable and valid (intraclass correlation coefficient based on two-way random effect (ICC2,1) = 0.877-0.974 for intra-rater reliability; ICC2,1 = 0.928-0.979; κ = 0.679-1.000 for inter-rater reliability; intraclass correlation coefficient based on one-way random effect (ICC1,1) = 0.921-0.984 for test-retest reliability and Spearman correlation coefficient = 0.836-0.899). In the second phase, in March 2018, results further demonstrated that the Longshi Scale had good inter-rater and intra-rater reliability among healthcare professionals and non-professionals including therapists, interns, and personal care aids (ICC1,1 = 0.822-0.882 on Day 1; ICC1,1 = 0.842-0.899 on Day 7 for inter-rater reliability). In addition, the Longshi Scale decreased assessment time significantly, compared with the Barthel Index assessment (P < 0.01). CONCLUSION: The Longshi Scale could potentially provide an efficient way for healthcare professionals and non-professionals who may have minimal training to assess the ADLs of functionally disabled patients.

The Effects of Dynamic Loading on Bone Fracture Healing Under Ilizarov Circular Fixators.

Early weight bearing appears to enhance bone fracture healing under Ilizarov circular fixators (ICFs). However, the role of early weight bearing in the healing process remains unclear. This study aims to provide insights into the effects of early weight bearing on healing of bone fractures stabilized with ICFs, with the aid of mathematical modeling. A computational model of fracture site was developed using poro-elastic formulation to simulate the transport of mesenchymal stem cells (MSCs), fibroblasts, chondrocytes, osteoblasts, osteogenic growth factor (OGF), and chondrogenic growth factor (CGF) and MSC differentiation during the early stage of healing, under various combinations of fracture gap sizes (GS), ICF wire pretension forces, and axial loads. 1 h of physiologically relevant cyclic axial loading followed by 23 h of rest in the post-inflammation phase (i.e., callus with granulation tissue) was simulated. The results show that physiologically relevant dynamic loading could significantly enhance cell and growth factor concentrations in the fracture site in a time and spatially dependent manner. 1 h cyclic loading (axial load with amplitude, PA, of 200 N at 1 Hz) increased the content of chondrocytes up to 37% (in all zones of callus), CGF up to 28% (in endosteal and periosteal callus) and OGF up to 50% (in endosteal and cortical callus) by the end of the 24 h period simulated. This suggests that the synergistic effect of dynamic loading-induced advective transport and mechanical stimuli due to early weight bearing is likely to enhance secondary healing. Furthermore, the study suggests that relatively higher PA values or lower ICF wire pretension forces or smaller GS could result in increased chondrocyte and GF content within the callus.

Structural Health Monitoring of Underground Structures in Reclamation Area Using Fiber Bragg Grating Sensors.

The long-term structural performance of underground structures in reclamation areas is very sensitive to the vibrations caused by vehicles passing above the structures and environmental factors (e.g., tide levels, rainfall and temperature). In the present study, an integrated remote real-time structural health monitoring system using fiber Bragg grating sensors was developed to assess the structural performance of underground structures. Using a composite road box-type structure project in a reclamation area in Southern China as a case study, the developed real-time system was implemented to investigate the effects of changes in tide levels, rainfall, temperature and vehicle induced vibrations on crack propagation in the structure. The results show that the change in tide levels has little influence on the change in crack width in the structure, whereas variations in temperature could significantly influence the crack width with an average Pearson correlation of around 0.8. In addition, the crack width generally decreases with an increase in rainfall. Furthermore, a relatively low frequency (<25 Hz) induced by the traffic could result in a relatively larger crack width.

Virulence analysis of Staphylococcus aureus in a rabbit model of infected full-thickness wound under negative pressure wound therapy.

The aim of this study was to evaluate the virulence of Staphylococcus aureus in a controlled animal study using the standard sterile gauze and negative pressure wound therapy (NPWT), including activation of agr, gene expression and production of virulence foctors and depth of bacterial invasion. The tissue specimens were harvested on days 0 (6 h after bacterial inoculation), 2, 4, 6, and 8 at the center of wound beds. Laser scanning confocal microscopy was performed to obtain bioluminescent images which were used to measure the depth of bacterial invasion. The agrA expression of S.aureus and the transcription and production of virulence factors including Eap, Spa and α-toxin were significantly different. The bacterial invasion depth was significantly less with effect of NPWT. The markedly different activation of quorum sensing systems that enable cell-to-cell communication and regulation of numerous colonization and virulence factors result in distinct gene expression and pathogenicity over time in different microenvironment. Thus, the agr system represents a fundamental regulatory paradigm that can encompass different adaptive strategies and accommodate horizontally acquired virulence determinants.

Establishment of fluoroscopy views and standardized procedure of percutaneous magic screw insertion for acetabulum fractures.

BACKGROUND: To place the magic screw more simply, we established a set of reproducible fluoroscopic views and a standardized procedure of magic screw insertion. MATERIALS AND METHODS: This study on the magic screw tunnel uses a three-dimensional reconstruction model and a skeleton projection. The 3D model of the pelvis was made to be transparent and it was rotated to the place where the ischial spine was just sheltered by the posterior wall of the acetabulum. The angles of this view projection were recorded in the transverse plane and coronal plane. Six cadaveric pelvises (three males, three female) were used to validate the proper projection angle of the C-arm fluoroscopy. The skeleton specimens were all positioned latericumbent on a radiolucent table. RESULT: In all pelvis 3D models, all magic cylinders with a 7.3 mm diameter were successfully inserted along the bone structure tunnel in 30 3D pelvic models. The average angle of the transverse view rotated by the C-arm fluoroscopy was 162° in males and 157° in females, the angle of the coronal plane was 22° in males and 24° in females. The average distance between the front wheel of the C-arm machine and the middle axial line of the radiolucent bed was 43 cm in males and 43 cm in females. In skeleton pelvis research, all the screws were safely inserted using this method. CONCLUSION: The magic screw technique could be a good choice for the treatment of acetabular fractures, especially quadrilateral plate fractures. If the proper fluoroscopy view technique is used properly, the magic screw can be inserted rapidly and safely.

Sensitivity Analysis of Geometrical Parameters on the Aerodynamic Performance of Closed-Box Girder Bridges.

In this study, the influence of two critical geometrical parameters (i.e., angles of wind fairing, α; and lower inclined web, β) in the aerodynamic performance of closed-box girder bridges was systematically investigated through conducting a theoretical analysis and wind tunnel testing using laser displacement sensors. The results show that, for a particular inclined web angle β, a closed-box girder with a sharper wind fairing angle of α = 50° has better flutter and vortex-induced vibration (VIV) performance than that with α = 60°, while an inclined web angle of β = 14° produces the best VIV performance. In addition, the results from particle image velocimetry (PIV) tests indicate that a wind fairing angle of α = 50° produces a better flutter performance by inducing a single vortex structure and a balanced distribution of the strength of vorticity in both upper and lower parts of the wake region. Furthermore, two-dimensional three-degrees-of-freedom (2D-3DOF) analysis results demonstrate that the absolute values of Part A (with a reference of flutter derivative A2*) and Part D (with a reference of A1*H3*) generally decrease with the increase of β, while the change of the participation level of heaving degrees of freedom (DOF) in torsion-dominated coupled flutter initially increases, reaches its peak, and then decreases with the increase of β.

Application of FRP Bolts in Monitoring the Internal Force of the Rocks Surrounding a Mine-Shield Tunnel.

Monitoring the internal force of the rocks surrounding a mine-shield tunnel for the initial support of a mine-shield tunnel, in complex geological and hydrological environments, requires bolts with specific features such as high tensile strength, low shear strength, good insulation and resistance to corrosion. As such, internal force monitoring has become an important issue in safety monitoring for such tunneling projects. In this paper, the adaptability of a mine-shield tunnel project in a corrosive environment is investigated. A fiberglass reinforced plastic (FRP) bolt with high tensile strength, low shear strength, resistance to fatigue, non-conductivity and resistance to corrosion is used as a probe in tandem with an anchor-head dynamometer to monitor the internal force of the rocks surrounding a mine-shield tunnel for initial support. Additionally, solar energy collection technology is introduced to create a remote monitoring system. Using a 2.5 km long railway tunnel located in the northeast of the Pearl River Delta of China as a case study, the present study shows that, compared with a conventional steel bolt, the FRP bolt has advantages, such as avoidance of the risks associated with the shield machine, insulation and resistance to corrosion. As a probe, the response of the FRP bolt to events such as a blasting vibration and a construction disturbance that results in internal changes in the surrounding rock demonstrates a clear pattern that is appropriate for monitoring the internal force of the rocks surrounding a mine-shield tunnel in a corrosive environment. FRP bolt-based monitoring not only provides new technological support for controlling the risk involved in the initial support of a mine-shield tunnel but can also be widely deployed in projects with special requirements for disassembly, conductivity and corrosion.

Late function and complications of hook plate implantation for distal-third clavicle fractures : a retrospective study.

In this study, the examined data was analysed from61 patients with Neer type II clavicle fractures treated with hook plate implantation between January 2008 and February 2011. The patients were divided into three groups depending on the removing time of plates after the fractures healing : early removal (<3 months, n=20), delayed removal (3-6 months, n=35), and retained plate (>6 months, n=6). All patients underwent clinical and radiographic follow-up in the outpatient department for a median of 18 months and every fracture healed eventually. Shoulder function was evaluated using the Constant shoulder score. The mean Constant shoulder score was greater, indicating better function, in the early removal group than the delayed removal and retained plategroups (96 [range 89-100] vs. 77 [65-89] and 61 [57-78], respectively ; p=0.000). The complication rateswere10%, 22.9%, and 50% in the early, delayed removal and retained plate groups, respectively (p=0.043). As a conclusion, the removal timing of the hook plate for distal clavicle fractures plays an important role in subsequent shoulder function and complications.

Comparison of the Efficacy Between Two Micro-Operative Therapies of Old Patients With Osteoporotic Vertebral Compression Fracture: A Network Meta-Analysis.

Osteoporotic vertebral compression fracture (OVCF) afflicts most aged people. Except for conservative therapy (CT), percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are another two the common choices, but current evaluation of their efficacy is not performed. All the trial data were originated from electronic database including PubMed, Embase, and Cochrane Library. Four indicators with mean difference (MD) or odd ratio (OR) with their 95% credible interval (95% CrI) were analyzed to evaluate the efficacy, including the value of visual analog scale (VAS), Oswestry disability index (ODI), relieving kyphotic angle (KA), and rate of fracture. Besides, the results were demonstrated in the forest plots and slash tables. Furthermore, the surface under the cumulative ranking curve (SUCRA) was calculated. A total of 32 trials among 2,852 patients are included. Using network comparison, we found that PKP and PVP both have good performance as OVCF treatments. However, in different aspects, PKP seemed to be the best to eliminate pain with high value of SUCRA on ODI and VAS (0.624 and 0.588, respectively), and PVP had better performance in KA and decreasing incidence of fracture. The micro-operative therapy, both PKP and PVP, had better efficacy than CT in four aspects. And PKP was better in pain alleviating, according to VAS and ODI results, while PVP had the superiority in KA and reducing the incidence of fracture. J. Cell. Biochem. 118: 3205-3212, 2017. © 2017 Wiley Periodicals, Inc.

Late function and complications of hook plate implantation for distal-third clavicle fractures : a retrospective study.

In this study, the examined data was analysed from61 patients with Neer type II clavicle fractures treated with hook plate implantation between January 2008 and February 2011. The patients were divided into three groups depending on the removing time of plates after the fractures healing: early removal (<3 months, n=20), delayed removal (3-6 months, n = 35), and retained plate (>6 months, n = 6). All patients underwent clinical and radiographic follow-up in the outpatient department for a median of 18 months and every fracture healed eventually. Shoulder function was evaluated using the Constant shoulder score. The mean Constant shoulder score was greater, indicating better function, in the early removal group than the delayed removal and retained plategroups (96 [range 89-100] vs. 77 [65-89] and 61 [57-78], respectively; p = 0.000). The complication rateswere10%, 22.9%, and 50% in the early, delayed removal and retained plate groups, respectively (p = 0.043). As a conclusion, the removal timing of the hook plate for distal clavicle fractures plays an important role in subsequent shoulder function and complications.

Investigation of proteome changes in osteoclastogenesis in low serum culture system using quantitative proteomics.

BACKGROUND: RAW 264.7 cells can differentiate into osteoclasts when cultured in medium supplemented with 1 % FBS. However, the proteomic changes in the development of RAW 264.7 cells into osteoclasts in low serum culture system have not been elucidated. Therefore, we conducted quantitative proteomics analysis to investigate proteomic changes during osteoclastogenesis in low serum culture system. RESULTS: Our study confirmed that mature multinucleated osteoclasts were generated in a low serum culture system, validated by upregulated expression of 15 characteristic marker proteins, including TRAP, CTSK, MMP9, V-ATPase and ITGAV. Proteomics results demonstrated that 549 proteins expressed differentially in osteoclastogenesis in low serum culture system. In-depth bioinformatics analysis suggested that the differentially expressed proteins were mainly involved in mitochondrial activities and energy metabolism, including the electron transport chain pathway, TCA cycle pathway, mitochondrial LC-fatty acid beta-oxidation pathway and fatty acid biosynthesis pathway. The data have been deposited to the ProteomeXchange with identifier PXD001935. CONCLUSION: Osteoclast formation is an ATP consuming procedure, whether occurring in a low serum culture system or a conventional culture system. In contrast to osteoclasts formed in conventional culture system, the fatty acid biosynthesis pathway was upregulated in osteoclasts cultured in low serum condition.

Evaluation of Elastic Stiffness in Healing Achilles Tendon After Surgical Repair of a Tendon Rupture Using In Vivo Ultrasound Shear Wave Elastography.

BACKGROUND There has been no published report assessing the mechanical properties of a repaired Achilles tendon after surgery using shear wave elastography (SWE). The aim of this study was to investigate the changes in mechanical properties of the healing Achilles tendon after surgical repair of a tendon rupture using ultrasound SWE and how these changes correlate with tendon function. MATERIAL AND METHODS Twenty-six patients who underwent surgical repair for Achilles tendon rupture were examined with ultrasound SWE coupled with a linear array transducer (4-15 MHz). The elasticity values of the repaired Achilles tendon in a longitudinal view were measured at 12, 24, and 48 weeks postoperatively. Functional outcomes were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system at 12, 24, and 48 weeks postoperatively. General linear regression analysis and correlation coefficients were used to analyze the relationship between elasticity and the AOFAS score. RESULTS There were significant differences with respect to the mean elasticity values and functional scores of the repaired Achilles tendon at 12, 24, and 48 weeks postoperatively (all P<0.05). Tendon function was positively correlated with the elasticity of the repaired Achilles tendon (P=0.0003). CONCLUSIONS Our findings suggest that SWE can provide biomechanical information for evaluating the mechanical properties of healing Achilles tendon and predict Achilles tendon function.

Long-Term Follow-Up of the Repair of the Multiple-Branch Facial Nerve Defect Using Acellular Nerve Allograft.

PURPOSE: To assess the clinical efficacy of the repair of facial nerve defects by allograft transplantation using acellular facial nerves. MATERIALS AND METHODS: Seven patients with facial nerve defects, ranging from damage to 1 facial nerve branch to combined defects of all branches, were enrolled. Defects ranged from 3 to longer than 4 cm. All defects were repaired by transplantation of acellular facial nerve allografts. Static and dynamic symmetry and facial expressions were evaluated using the House-Brackmann classification and the functional status of the facial nerve was assessed electromyographically. No patient received immunosuppressive therapy. RESULTS: All wounds healed well, with no swelling or inflammatory exudation. The patients recovered facial nerve function to various extents. Six months postoperatively, 4 of 7 patients showed static facial asymmetry. Twelve months postoperatively, 3 patients had static facial asymmetry with normal eye closure, and only careful observation could detect slight asymmetry of forehead movement. Two of 7 patients showed moderate facial nerve dysfunction. Ipsilateral facial movement and facial asymmetry were obvious in the patient whose defect affected the common trunk and all facial nerve branches. Two years postoperatively, 5 of 7 patients had mild facial nerve dysfunction, with symmetric faces and incomplete eye occlusion. Six years postoperatively, these patients continued to show symmetric faces and incomplete ipsilateral eye occlusion, but facial muscle function was considerably restored. Follow-up electromyography showed neurologic recovery in all patients. CONCLUSION: The repair of a facial nerve defect by transplantation of an acellular facial nerve allograft is feasible.

Experimental study on treatment of acetabular anterior column fractures: applyment of a minimally invasive percutaneous lag screw guide apparatus.

BACKGROUND: The aim of this study was to design a new minimally invasive percutaneous lag screw guide apparatus and to verify its adjuvant treatment of acetabular anterior column fracture on pelvis specimens. METHODS: This guide apparatus was self-developed based on the principles of "two points form a line" and "Rectangle". Using C-arm fluoroscopy, this guide apparatus was used to conduct minimally invasive percutaneous lag screw internal fixation of acetabular anterior column fractures. Ten hollow lag screws were placed into 5 pelvis specimens. RESULT: Result showed no sign of any screws puncturing the cortex or entering into the hip joint on radiological assessment. The cross-section reconstructed vertical distance to the screw, on the cross-section acetabular notch and the cross-section of the screw where the distance of between the screw and the iliopectineal line's arc roof was at its shortest, indicate that at all points (T, R-r) under the line with an inclination of 1 (namely T = R-r) the screw is within the cortex and does not puncture the acetabula anterior column or enter into the hip joint. CONCLUSIONS: We may conclude that this self-developed guide apparatus solves the screw precision problem during the treatment of acetabular anterior column fractures through a minimally invasive percutaneous lag screw.

Double locking plate fixation for femoral shaft nonunion.

INTRODUCTION: Nonunions after operative fixation of the femur, although infrequent, remain a challenge for orthopedic surgeons. The aim of this study was to assess the effectiveness of double locking plate fixation in the treatment for femoral shaft nonunions. MATERIALS AND METHODS: From 2009 to 2013, 21 patients with femoral nonunions (mean age 46.9 years, range 25-81) were treated and evaluated utilizing double locking plate fixation. Patients were followed for at least 6 months postoperatively or until they achieved complete union to investigate bone healing and functional outcomes in femoral shaft nonunions treated with double locking plate and autogenous cancellous bone graft. RESULTS: The main outcomes evaluated were the presence of bony union, time to achieve union, and SF-36 score. All 21 femoral nonunions healed (100 % union rate). The average time to bony union was 5.3 months (range, 4-7). The mean follow-up duration time was 24.8 months (range, 6-60). Average scores of the physical function and bodily pain components of the SF-36 were 96 (range, 90-99) and 94.2 (range, 92-99), respectively. No significant complications were noted postoperatively. CONCLUSION: Because of the high union rates and lack of significant complications in our series, double locking plate fixation can serve as an effective method of addressing femoral shaft nonunions. No significant complications were found postoperatively.

The Role Of Semaphorin 3A In The Skeletal System.

Semaphorin 3A (Sema3A), characterized by a conserved N-terminal "Sema" domain, was originally described as an axon guidance molecule. Recent research indicates that it performs a critical function in the skeletal system. This review highlights recent advances in understanding of the role of Sema3A in the skeletal system as a regulator of bone metabolism and as a potential drug target for bone disease therapy. We summarize Sema3A functions in osteoblastogenesis and osteoclastogenesis, as well as in innervation, and we discuss its multifunctional role in various bone diseases such as osteoporosis and low back pain. Despite limited research in this field, our aim is to promote further understanding of the function of Sema3A in the skeletal system.