Evaluating three internal fixation techniques for Pauwels III femoral neck fractures via finite element analysis.

The selection of implants for fixing unstable femoral neck fractures (FNF) remains contentious. This study employs finite element analysis to examine the biomechanics of treating Pauwels type III femoral neck fractures using cannulated compression screws (3CS), biplane double-supported screw fixation (BDSF), and the femoral neck system (FNS). A three-dimensional model of the proximal femur was developed using computed tomography scans. Fracture models of the femoral neck were created with 3CS, BDSF, and FNS fixations. Von Mises stress on the proximal femur, fracture ends, internal fixators, and model displacements were assessed and compared across the three fixation methods (3CS, BDSF, and FNS) during the heel strike of normal walking. The maximum Von Mises stress in the proximal fragment was significantly higher with 3CS fixation compared to BDSF and FNS fixations (120.45 MPa vs. 82.44 MPa and 84.54 MPa, respectively). Regarding Von Mises stress distribution at the fracture ends, the highest stress in the 3CS group was 57.32 MPa, while BDSF and FNS groups showed 51.39 MPa and 49.23 MPa, respectively. Concerning implant stress, the FNS model exhibited greater Von Mises stress compared to the 3CS and BDSF models (236.67 MPa vs. 134.86 MPa and 140.69 MPa, respectively). Moreover, BDSF displayed slightly lower total displacement than 3CS fixation (7.19 mm vs. 7.66 mm), but slightly higher displacement than FNS (7.19 mm vs. 7.03 mm). This study concludes that BDSF outperforms 3CS fixation in terms of biomechanical efficacy and demonstrates similar performance to the FNS approach. As a result, BDSF stands as a dependable alternative for treating Pauwels type III femoral neck fractures.

Diagnosis and Treatment of Varus Posteromedial Rotational Instability of the Elbow Joint in Children: Re-Understanding of the Injury Mechanism Associated With Coronoid Process Fractures.

PURPOSE: To investigate the injury mechanism, diagnosis, and treatment of varus-posteromedial rotational instability of the elbow joint in children. METHODS: According to the diagnostic criteria of varus posteromedial rotational instability of elbow joint, 16 children with coronoid process fractures treated in our department from July 2013 to July 2017 were re-evaluated. There were 14 males and 2 females, aged 7 to 14 years, with an average age of 11.6 years. Eight cases on left and 8 cases on right side. An associated elbow dislocation occurred in 8 of 16 cases. Nine patients were treated with a lateral soft tissue repair only. In 7 other patients in addition to the lateral soft tissue repair, the coronoid process fractures were treated with open reduction and fixation. At the last clinical follow-up, each elbow joint range of motion was recorded, radiographs were obtained, and functional performance was evaluated by the Mayo elbow performance score (MEPS). RESULTS: The average follow-up time was 81.9 months for the 9 patients treated with lateral elbow soft tissue repair. At the last follow-up, 2 of the patients had MEPS scores as excellent, 1 was good, and 6 were rated as moderate or poor. Four patients had a cubitus varus deformity. The average follow-up time was 30.3 months for the 7 patients treated with both soft tissue repair and coronoid fracture stabilization. The elbow joint MEPS scores for each of these 7 patients was excellent at the last follow-up, and no complications such as cubitus varus occurred. CONCLUSION: The results of the study suggest that children could also develop elbow varus-posterior medial rotational instability injuries under the same mechanism. Although the morbidity rate is low, due to insufficient understanding of the injury mechanism, it is prone to missed diagnosis, misdiagnosis, and delayed treatment, resulting in severe complications such as elbow instability, dislocation, traumatic arthritis, and elbow stiffness. On the contrary, according to the treatment principle of the posterior medial rotational instability of the elbow joint in adult, while the lateral repair is carried out, strong and effective reduction and fixation of the coronoid process fractures are adopted, it is expected that such children with rare elbow injuries can obtain excellent treatment outcomes.

Enhanced pyroptosis induction with pore-forming gene delivery for osteosarcoma microenvironment reshaping.

Osteosarcoma is the most common malignant bone tumor without efficient management for improving 5-year event-free survival. Immunotherapy is also limited due to its highly immunosuppressive tumor microenvironment (TME). Pore-forming gasdermins (GSDMs)-mediated pyroptosis has gained increasing concern in reshaping TME, however, the expressions and relationships of GSDMs with osteosarcoma remain unclear. Herein, gasdermin E (GSDME) expression is found to be positively correlated with the prognosis and immune infiltration of osteosarcoma patients, and low GSDME expression was observed. A vector termed as LPAD contains abundant hydroxyl groups for hydrating layer formation was then prepared to deliver the GSDME gene to upregulate protein expression in osteosarcoma for efficient TME reshaping via enhanced pyroptosis induction. Atomistic molecular dynamics simulations analysis proved that the hydroxyl groups increased LPAD hydration abilities by enhancing coulombic interaction. The upregulated GSDME expression together with cleaved caspase-3 provided impressive pyroptosis induction. The pyroptosis further initiated proinflammatory cytokines release, increased immune cell infiltration, activated adaptive immune responses and create a favorable immunogenic hot TME. The study not only confirms the role of GSDME in the immune infiltration and prognosis of osteosarcoma, but also provides a promising strategy for the inhibition of osteosarcoma by pore-forming GSDME gene delivery induced enhanced pyroptosis to reshape the TME of osteosarcoma.

Accuracy and clinical characteristics of robot-assisted cervical spine surgery: a systematic review and meta-analysis.

PURPOSE: To evaluate the accuracy and feasibility of robot-assisted cervical screw placement and factors that may affect the accuracy. METHODS: A comprehensive search was made on PubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang Med for the selection of potential eligible literature. The outcomes were evaluated in terms of the relative risk (RR) or standardized mean difference (MD) and corresponding 95% confidence interval (CI). Subgroup analyses of the accuracy of screw placement at different cervical segments and with different screw placement approaches were performed. A comparison was made between robotic navigation and conventional freehand cervical screw placement. RESULTS: Six comparative cohort studies and five case series studies with 337 patients and 1342 cervical screws were included in this study. The perfect accuracy was 86% (95% CI, 82-89%) and the clinically acceptable rate was 98% (95% CI, 95-99%) in robot-assisted cervical screw placement. The perfect accuracy of robot-assisted C1 lateral mass screw placement was the highest (96%), followed by C6-7 pedicle screw placement (93%) and C2 pedicle screw placement (86%), and the lowest was C3-5 pedicle screw placement (75%). The open approach had a higher perfect accuracy than the percutaneous/intermuscular approach (91% vs 83%). Compared with conventional freehand cervical screw placement, robot-assisted cervical screw placement had a higher accuracy, a lower incidence of perioperative complications, and less intraoperative blood loss. CONCLUSION: With good collaboration between the operator and the robot, robot-assisted cervical screw placement is accurate and feasible. Robot-assisted cervical screw placement has a promising prospect.

Clinical outcomes of olecranon sled fixation in patients with Mayo type II olecranon fractures.

Background: Tension band wiring and plate fixation are common internal fixation methods used for olecranon fractures, but complications and reoperations are common. The purpose of this study is to investigate the clinical outcomes of displaced olecranon fractures treated with olecranon sled internal fixation. Methods: The data of 39 patients with olecranon fractures treated with olecranon sled in the Department of Traumatology of Beijing Jishuitan Hospital between May 2018 and April 2020 were retrospectively analyzed. There were 17 males and 22 females; the mean age was 44.0 ± 15.8 (range, 18-68 years). Preoperative olecranon fractures were classified according to the Mayo classification: 24 cases were type IIA and 15 cases were type IIB. Elbow range of motion (extension and flexion) and forearm rotation (protonation and supination) were observed at the last follow-up. The Mayo elbow performance score (MEPS), Disabilities of the arm, shoulder and hand (DASH) and visual analogue scale (VAS) scores were used to evaluate elbow function and pain, and complications were also recorded. Results: Thirty-nine patients were followed up for 33.6 ± 8.3 months (range, 25-51 months) after the operation. At the last follow-up, the mean flexion-extension arc was 137° ± 15° (range, 60°-160°), and the mean pronation-supination arc was 178° ± 4° (range, 160°-180°). The mean MEPS was 94.9 ± 9.9 (range, 50.0-100.0). The mean DASH score was 5.4 ± 4.3 (range, 0-18.3). The mean VAS score was 0.4 ± 0.8 (range, 0-3). Seven patients developed olecranon skin irritation, and 3 of them had the internal fixation device removed. Two patients developed heterotopic ossification, of whom 1 patient suffered elbow stiffness. Conclusion: Olecranon sled internal fixation has good clinical outcomes in the treatment of Mayo type II olecranon fractures with a low rate of reoperations.

Participants' understanding of informed consent in clinical trials: A systematic review and updated meta-analysis.

Obtaining written informed consent from participants before enrolment in a study is essential. A previous study showed that only 50% of the participants in clinical trials understood the components of informed consent, and the methods of participants' understanding of informed consent were controversial. This updated meta-analysis aimed to estimate the proportion of participants in clinical trials who understand the different informed consent components. PubMed, EMBASE, the Cochrane Library, and Scopus were searched till April 2023. Therapeutic misconception, ability to name one risk, knowing that treatments were being compared, and understanding the nature of the study, the purpose of the study, the risks and side-effects, the direct benefits, placebo, randomization, voluntariness, freedom to withdraw, the availability of alternative treatment if withdrawn from the trial, confidentiality, compensation, or comprehension were evaluated. This meta-analysis included 117 studies (155 datasets; 22,118 participants). The understanding of the risks and side-effects was investigated in the largest number of studies (n = 100), whereas comparehension was investigated in the smallest number (n = 11). The highest proportions were 97.5%(95% confidence interval (CI): 97.1-97.9) for confidentiality, 95.9% (95% confidence interval (CI): 95.4-96.4) for compensation, 91.4% (95% CI: 90.7-92.1) for the nature of study, 68.1% (95% CI: 51.6-84.6) for knowing that treatments were being compared, and 67.3% (95% CI: 56.6-78) for voluntary nature of participants. The smallest proportions were the concept of placebo (4.8%, 95%CI: 4.4-5.2) and randomization(39.4%, 95%CI: 38.3-40.4). Our findings suggested that most participants understood the fundamental components of informed consent (study confidentiality, nature, compensation, voluntariness, and freedom to withdraw). The understanding of other components, such as placebo and randomization was less satisfactory.

Convergent dislocation of the elbow in adults: A retrospective study.

BACKGROUNDS: This study aims to evaluate the surgical treatment and clinical outcomes of convergent dislocation of the elbow (CDE) in adults. METHODS: Between January 2017 and September 2022, we performed a retrospective study of patients with CDE presenting in XXX and XXX Hospital and receiving operative treatments after failed closed reductions. The elbow and the forearm's range of motion (ROM) were measured and compared using a paired t-test between pre- and post-operation. Furthermore, the Mayo Elbow Performance Score (MEPS) assessed objective elbow evaluation and functional outcomes. RESULTS: Eleven patients were followed up for an average period of 9.8 months. Four males and seven females were enrolled, aged 31.5 ± 9.0 years. The average ROM of flexion-extension at the elbow was significantly improved after surgery (27.3 ± 12.3° vs. 116.8 ± 23.7°, p < 0.001). The average pronation-supination also showed a similar increase (21.8 ± 9.3° vs. 106.4 ± 23.4°, p < 0.001). The MEPS of the final follow-up was 95.9 ± 7.0 points. However, seven cases were found to have varying degrees of elbow stiffness. Furthermore, secondary procedures were performed in three cases, including the elbow arthrolysis and the anterior transposition of the ulnar nerve. CONCLUSIONS: Our study showed several operative methods following failed closed reduction attempts where anatomical reduction of humeroulnar and proximal radioulnar joints and instant rehabilitation obtained relatively satisfactory clinical outcomes.

The safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine among patients undergoing elective surgery for closed fractures: A randomized, double-blind, placebo-controlled, multicenter phase 2 clinical trial.

BACKGROUND: Vaccines are urgently required to control Staphylococcus aureus hospital and community infections and reduce the use of antibiotics. Here, we report the safety and immunogenicity of a recombinant five-antigen Staphylococcus aureus vaccine (rFSAV) in patients undergoing elective surgery for closed fractures. METHODS: A randomized, double-blind, placebo-controlled, multicenter phase 2 clinical trial was carried out in 10 clinical research centers in China. Patients undergoing elective surgery for closed fractures, aged 18-70 years, were randomly allocated at a ratio of 1:1 to receive the rFSAV or placebo at a regimen of two doses on day 0 and another dose on day 7. All participants and investigators remained blinded during the study period. The safety endpoint was the incidence of adverse events within 180 days. The immunogenicity endpoints included the level of specific antibodies to five antigens after vaccination, as well as opsonophagocytic antibodies. RESULTS: A total of 348 eligible participants were randomized to the rFSAV (n = 174) and placebo (n = 174) groups. No grade 3 local adverse events occurred. There was no significant difference in the incidence of overall systemic adverse events between the experimental (40.24 %) and control groups (33.72 %) within 180 days after the first immunization. The antigen-specific binding antibodies started to increase at days 7 and reached their peaks at 10-14 days after the first immunization. The rapid and potent opsonophagocytic antibodies were also substantially above the background levels. CONCLUSIONS: rFSAV is safe and well-tolerated in patients undergoing elective surgery for closed fractures. It elicited rapid and robust specific humoral immune responses using the perioperative immunization procedure. These results provide evidence for further clinical trials to confirm the vaccine efficacy. China's Drug Clinical Trials Registration and Information Publicity Platform registration number: CTR20181788. WHO International Clinical Trial Registry Platform identifier: ChiCTR2200066259.

Anxiety and depression are associated with poor outcomes in open elbow arthrolysis.

BACKGROUND: Open elbow arthrolysis (OEA) is an established treatment for posttraumatic elbow stiffness (PTES); however, its efficacy is debatable for some patients. Poor surgical outcomes have been associated with anxiety and depression in other orthopedic conditions, but no studies have examined this association in OEA. In this study, we aimed to determine whether a high preoperative anxiety and depression score is associated with a worse functional outcome in OEA for PTES. METHODS: A retrospective review of prospectively collected data was carried out in patients undergoing OEA between April 2021 and March 2022. Mental state evaluated by Hospital Anxiety and Depression Scale (HADS), subjective elbow function valued by Disabilities of the Arm, Shoulder, and Hand (DASH) score, objective elbow function valued by Mayo Elbow Performance Score (MEPS), pain score measured by visual analog scale (VAS) and the flexion-extension range of motion (ROM) of the affected elbow were collected before and after surgery in outpatient clinic follow-up at 3 months and 6 months. Patient satisfaction was only recorded 6 months postoperatively. All patients were divided into 2 groups based on the preoperative HADS score for analysis: Group A was the nonanxiety-depression group, and Group B was the anxiety-depression group. RESULTS: A total of 49 patients were included. Both groups improved in DASH, MEPS and ROM at 3 months and at 6 months. The HADS score in Group B decreased significantly at 6 months, showing that the mental state of patients in Group B improved after surgery. Group A had a lower DASH at 3 months and 6 months, larger 6-month ROM and higher satisfaction rate than Group B. Comparing the differences between preoperative and postoperative measurements, Group A improved more in ROM at 6 months. There was no significant difference in other outcome measures between the two groups. CONCLUSIONS: OEA is a safe and effective treatment for PTES, and can achieve good clinical outcomes in the short-term follow-up, regardless of whether the patients suffer from anxiety or depression. Patients with a HADS score ≥11 before OEA, however, have worse outcomes than those with a HADS score <11. LEVEL OF EVIDENCE: Level II; Retrospective Design; Prognosis Study.

Discovery of novel serum biomarkers for diagnosing and predicting postmenopausal osteoporosis patients by 4D-label free protein omics.

We aimed to identify protein biomarkers that could rapidly and accurately diagnose osteoporosis patients (OPs) using a highly sensitive proteomic immunoassay. Four-dimensional (4D) label-free proteomics analysis was performed to determine the differentially expressed proteins in serum collected from 10 postmenopausal osteoporosis patients and 6 non-osteoporosis patients. The ELISA method was used to select the predicted proteins for verification. Serum was taken from 36 postmenopausal osteoporosis patients and 36 healthy individuals from normal postmenopausal women. Receiver operating characteristic (ROC) curves were used to determine the diagnostic potential of this method. We validated the expression of these six proteins using ELISA. The CDH1, IGFBP2, and VWF of osteoporosis patients were significantly higher than those of the normal group. PNP was significantly lower than that in the normal group. And using ROC curve calculation, serum CDH1 had a cut-off of 3.78 ng/mL with a sensitivity of 84.4%, and PNP had a cut-off of 944.32 ng/mL with 88.9% sensitivity. These outcomes suggest that serum-level CHD1 and PNP have the potential power as effective indicators for the diagnosis of PMOP. Our results suggest that CHD1 and PNP might be associated with the pathogenesis of OP and would be helpful in diagnosing OP. Therefore, CHD1 and PNP may act as potential key markers in OP.

Risk of ozone exposure-induced fracture.

Introduction: Ozone (O3) is known to induce oxidative stress that influences various cells and tissues, which may further lead to diminished bone mineral density. Nevertheless, few studies have investigated the association between O3 exposure and fractures. Considering the similar growing trends of O3 concentrations and fracture morbidity in recent years, in the present study, we aimed to examine whether O3 exposure is associated with the fracture morbidity. Methods: Using a retrospective cohort study design, we analyzed the records of 8,075 patients with fracture admitted in the warm season to Beijing Jishuitan Hospital from 2014 to 2019 and matched them to the corresponding exposure time and concentration of O3. Results: The results showed that increased odds of fracture were associated with increased O3 concentrations, presumably because O3 induces oxidative stress (OS) that leads to bone mineral density (BMD) loss. Discussion: Our findings suggest that O3 exposure is a risk factor for fractures, providing new evidence of the adverse health effect induced by air pollution. We can conclude that more intensive air pollution control is needed for the prevention of fracture occurrence.

Short-term effect of apparent temperature on daily hospitalizations for osteoporotic fractures in Beijing, China: A retrospective observational study.

BACKGROUND: Studies on the associations between temperature and osteoporotic fractures (OF) hospitalizations are limited. This study aimed to assess the short-term effect of apparent temperature (AT) on the risk of OF hospitalizations. METHODS: This retrospective observational study was conducted in Beijing Jishuitan Hospital from 2004 to 2021. Daily OF hospitalizations, meteorological variables and fine particulate matter were collected. A Poisson generalized linear regression model combined with a distributed lag non-linear model was applied to analyze the lag-exposure-response relationship between AT and the number of OF hospitalizations. Subgroup analysis by gender, age and fracture type was also conducted. RESULTS: Total daily hospitalization visits for OF during the studied period were 35,595. The exposure-response curve of AT and OF presented a non-linear relationship, with optimum apparent temperature (OAT) at 28.40 °C. Taking OAT as the reference, the cold effect (-10.58 °C, 2.5th percentage) on single lag day had statistical significance from the current day of exposure (RR = 1.18, 95 % CI: 1.08-1.28) to lag 4 day (RR = 1.04, 95 % CI: 1.01-1.08), while the cumulative cold effect increased the risk of OF hospitalization visits from lag 0 to 14 days, with the maximum RR over lag 0-14 days (RR = 1.84, 95 % CI: 1.21-2.79). There were no significant risks of OF hospitalizations for warm effects (32.53 °C, 97.5th percentage) on single or cumulative lag days. The cold effect might be more evident among females, patients aged 80 years or older, and patients with hip fractures. CONCLUSION: Exposure to cold temperatures is associated with an increased risk of OF hospitalizations. Females, patients aged 80 years or older and patients with hip fractures might be more vulnerable to the cold effect of AT.

Single-cell RNA sequencing reveals the role of cell heterogeneity in the sex difference in primary hyperparathyroidism.

Objective: To explore the difference in parathyroid tissue-derived cells between male and female PHPT patients. Methods: Resected parathyroid tissues were collected from PHPT patients of both sexes. Single cells were isolated and sequenced for RNA expression profiles. The cell sequencing data were annotated by cell type, followed by population analysis, functional analysis, pathway analysis, cell communication analysis, differential gene expression analysis, and pseudotime trajectory analysis. The subcluster analyses were also performed in the parathyroid cells. Results: No substantial difference in the cell population, function, or communication is found between the two sexes. The interferon-a response, oxidative phosphorylation, and reactive oxygen species pathways are up-regulated in females than in male patients, mainly contributed by fibroblast cells, endothelial cells, parathyroid cells, and myeloid cells, which also have significantly more up-regulated pathways and cellular interactions than the other three cell types. The subcluster analysis of parathyroid cells identified five subpopulations: SPARCL1-OC and ISG15-OC are predominant in females, while more S100A13-PCC and PTHLH-OC are found in males. The cellular functions are also elevated in females compared with males. Cells from female patients show a higher expression level of parathyroid hormone (PTH) but a lower expression level of parathyroid hormone-like hormone (PTHLH). The cell pseudotime trajectory and pathway analyses show that the oxyphil cells may be more mature and functionally active than the chief cells in both sexes. Conclusion: These findings suggest that the sex difference in PHPT may be caused by the differentially expressed genes and activated pathways in different cell types in the parathyroid tissue. The heterogeneity of parathyroid cell subpopulations, especially in oxyphil cells, may be associated with the sex differences in PHPT pathogenesis.

Effectiveness and Accuracy of a Patient-Specific Instrumentation System for Total Hip Arthroplasty.

OBJECTIVE: Traditional total hip arthroplasty (THA) is often performed by visual inspection due to the lack of reliable reference, which results in inappropriate position of prosthesis and poor outcomes. This study attempts to introduce a novel patient-specific instrumentation (PSI) system and assess its effectiveness and accuracy compared with freehand operation and robot system through bone model experiments. METHODS: Equally divide 30 sawbone models into the freehand group, PSI group, and robot group. Ten sets of prosthesis parameters were randomly generated as planning, and the three groups underwent simulated THA depending on these parameters. After the placement of the femoral prosthesis, the acetabular anteversion plan was adjusted in the PSI and robot groups so that the combined anteversion was maintained before and after adjustment. After the surgery, the actual prosthesis parameters of all bone models were measured and analyzed statistically. RESULTS: No statistically significant difference was found in femoral anteversion error among the three groups (p = 0.951). The errors of acetabular cup anteversion, acetabular cup abduction, and combined anteversion in PSI group were 3.92° (2.94°, 4.62°), 5.65° (4.63°, 6.70°), and 3.93° (2.94°, 4.62°), respectively, which were significantly smaller than those in the freehand group [11.84° (9.92°, 13.87°), 13.54° (9.81°, 15.21°), 16.04° (8.18°, 19.25°), respectively, p < 0.05], but significantly larger than those in the robot group [1.34° (0.98°, 1.70°), 1.80° (1°, 2.02°), 1.34° (0.98°, 1.70°), respectively, p < 0.05]. CONCLUSION: Compared with the traditional freehand operation, the patient-specific instrumentation system is feasible in total hip arthroplasty because it improves the accuracy of prosthesis placement. In addition, the rapid measurement of intraoperative femoral prosthesis parameters can help surgeons optimize preoperative planning.

Comparison of Robot-Assisted Percutaneous Cannulated Screws Versus Open Reduction and Internal Fixation in Calcaneal Fractures.

OBJECTIVE: Accurate placement of the screws is challenging in percutaneous cannulated screw fixation of calcaneal fractures, and robot-assisted (RA) surgery enhances the accuracy. We investigated the outcome of percutaneous cannulated screw fixation of Sander's type II and III calcaneal fractures. METHODS: This retrospective study analyzed clinical data of 26 patients with fresh closed calcaneal fractures (28 fractures) who were admitted to our center from January 2022 to July 2022. All fractures were divided into the RA group and the open reduction and internal fixation (ORIF) group according to the surgeries performed. RA surgery was performed by closed reduction or open reduction combined with a tarsal sinus approach. Age, sex, operation time, preoperative waiting time, length of postoperative hospital stay, wound complications, and American Orthopaedic Foot and Ankle Society Ankle Hindfoot Scale (AOFAS) at 3 months postoperatively were compared. Preoperative and postoperative radiographic parameters (calcaneal length, width, height, Böhler angle, and fixation rate of the sustentaculum tali) were documented. The chi-square test, one-way analysis of variance, and Wilcoxon test were used for the comparison of categorical, normally distributed, and nonnormally distributed continuous variables, respectively. RESULTS: The calcaneal width, height, and Böhler angle were significantly corrected postoperatively in both groups. The postoperative calcaneal lengths in both groups were also corrected. However, no significant difference was found. No significant differences in calcaneal length, width, height, and Böhler angle were observed between the two groups. The operation time (p < 0.001), preoperative waiting time (p < 0.001), and length of postoperative hospital stay (p = 0.003) in the RA surgery group were significantly shorter than those in the ORIF group. The fixation rate of the sustentaculum tali (p < 0.001) in the RA surgery group was significantly superior to that in the ORIF group. All wound complications occurred in the ORIF group. All fractures healed within 3 months. The AOFAS scores at 3 months postoperatively were not significantly different. CONCLUSION: RA percutaneous screw fixation of the calcaneal fracture is a safe, effective, rapid, and minimally invasive surgical option for surgeons.

Traumatic divergent dislocation of the elbow in the adults.

PURPOSE: This retrospective study aimed to investigate the clinical outcomes of DDE in adults. METHODS: From September 2010 to March 2020, adult patients with traumatic DDEs admitted to Beijing Chaoyang Hospital and Beijing Jishuitan Hospital were included in this study. Each patient underwent operative or conservative treatment during hospitalization. The clinical and radiological examinations were followed up. The primary outcomes included the Mayo Modified Wrist Score (MMWS), the Mayo Elbow Performance Score (MEPS), the Broberg and Morrey functional index, the Disabilities of the Arm, Shoulder and Hand (DASH) score, and the Visual Analogue Scale (VAS) score that were performed. Post-operative complications and secondary surgery details were also collected. RESULTS: Of the fourteen patients, clinical and radiographic results were reviewed at a mean of 53.2 months (18 to 110 months) postoperatively. There were 11 men and three women with an average age of 31.5 years (17 to 51 years). At the final follow-up, the average MMWS, MEPS, Broberg and Morrey functional index, and DASH scores were 91.4 points, 93.4 points, 92.6 points, and 10.7 points. The mean VAS at rest and during activities was 0.4 and 1.7 points. Two patients required a secondary procedure due to radial malalignment and elbow contracture, respectively. In addition, two patients were found degeneration. CONCLUSIONS: Within the context of high-energy DDE combined with simultaneous upper limb injuries, our study recommended obtaining the mechanical benefit of the forearm ring with concentric elbow stability. Despite the various and complicated traumatic patterns of DDE, great clinical results could be acquired based on adequate surgical treatments and early rehabilitation training.

Biomechanical comparison of three internal fixation configurations for low transcondylar fractures of the distal humerus.

BACKGROUND: We aimed to evaluate the biomechanical stiffness and strength of different internal fixation configurations and find suitable treatment strategies for low transcondylar fractures of the distal humerus. METHODS AND MATERIALS: Thirty 4th generation composite humeri were used to create low transcondylar fracture models that were fixed by orthogonal and parallel double plates as well as posterolateral plate and medial screw (PPMS) configurations (n=10 in each group) using an anatomical locking compression plate-screw system and fully threaded medial cortical screws. Posterior bending (maximum 50 N), axial loading (maximum 200 N) and internal rotation (maximum 10 N·m) were tested, in that order, for each specimen. Stiffness under different biomechanical settings among different configurations were compared. Another 18 sets of fracture models were created using these three configurations (n=6 in each group) and the load to failure under axial loading among different configurations was compared. RESULTS: Under posterior bending, the stiffness of parallel group was higher than orthogonal group (P<0.001), and orthogonal group was higher than PPMS group (P<0.001). Under axial loading, the stiffness of parallel group was higher than orthogonal group (P=0.001) and PPMS group (P<0.001); however, the difference between orthogonal and PPMS group was not statistically significant (P>0.05). Under internal rotation, the stiffness of parallel group was higher than orthogonal group (P=0.044), and orthogonal group was higher than PPMS group (P=0.029). In failure test under axial loading, the load to failure in the orthogonal group was lower than parallel group (P=0.009) and PPMS group (P=0.021), but the difference between parallel group and PPMS group was not statistically significant (P>0.05). All specimens in orthogonal group demonstrated "distal medial failure"; most specimens had "distal medial and trochlear failure" in the parallel group; most specimens exhibited "contact failure" in the PPMS group. CONCLUSION: For treating low transcondylar fractures, the overall stiffness and strength of the parallel configuration were superior to those of the orthogonal and PPMS configurations. Nevertheless, the PPMS configuration can provide adequate stability and stiffness comparable to double-plate configurations under axial loading. Therefore, the PPMS construct may have certain clinical value.