Mefenamic acid exhibits antitumor activity against osteosarcoma by impeding cell growth and prompting apoptosis in human osteosarcoma cells and xenograft mice model.

The study investigates the anticancer activity of mefenamic acid against osteosarcoma, shedding light on its underlying mechanisms and therapeutic potential. Mefenamic acid exhibited robust inhibitory effects on the proliferation of MG-63, HOS, and H2OS osteosarcoma cells in a dose-dependent manner. Moreover, mefenamic acid induced cellular toxicity in MG63 cells, as evidenced by LDH leakage, reflecting its cytotoxic impact. Furthermore, mefenamic acid effectively suppressed the migration and invasion of MG-63 cells. Mechanistically, mefenamic acid induced apoptosis in MG-63 cells through mitochondrial depolarization, activation of caspase-dependent pathways, and modulation of the Bcl-2/Bax axis. Additionally, mefenamic acid promoted autophagy and inhibited the PI3K/Akt/mTOR pathway, further contributing to its antitumor effects. The molecular docking studies provide compelling evidence that mefenamic acid interacts specifically and strongly with key proteins in the PI3K/AKT/mTOR pathway, suggesting a novel mechanism by which mefenamic acid could exert anti-osteosarcoma effects. In vivo studies using a xenograft mouse model demonstrated significant inhibition of MG-63 tumor growth without adverse effects, supporting the translational potential of mefenamic acid as a safe and effective therapeutic agent against osteosarcoma. Immunohistochemistry staining corroborated the in vivo findings, highlighting mefenamic acid's ability to suppress tumor proliferation and inhibit the PI3K/AKT/mTOR pathway within the tumor microenvironment. Collectively, these results underscore the promising therapeutic implications of mefenamic acid in combating osteosarcoma, warranting further investigation for clinical translation and development.

Tumor-derived microparticles promoted M2-like macrophages polarization to stimulate osteosarcoma progression.

Microparticles (MPs) are a heterogeneous subpopulation of extracellular vesicles that originate from the plasma membranes of cells. There is increasing evidence that tumor-derived MPs (T-MPs) play a significant role in tumor progression and immune response in cancer. In our study, we found an increased secretion of MPs in osteosarcoma tissues obtained from metastatic patients. These T-MPs promoted polarization of M2-like macrophages and stimulated the migration and chemoresistance of osteosarcoma cells. Mechanistically, T-MPs promoted macrophage polarization to an M2-like phenotype through TBK1-STAT6 signaling. Consequently, these M2-like macrophages mediated osteosarcoma cell migration via CCL18/STAT3 signaling. Blockade of STAT3 signaling pathway improved the outcome of chemotherapy in LM8-bearing osteosarcoma mice model. Thus, our study reveals how tumor cells regulate macrophage polarization by releasing MPs and provides new insights into clinical osteosarcoma therapy.

Quercetin-loaded PLGA nanoparticles coating with macrophage membranes for targeted delivery in acute liver injury.

Quercetin (QU), a natural flavonoid with potent anti-inflammatory and antioxidant properties, holds promise in treating acute liver injury (ALI). Nonetheless, its limited solubility hampers its efficacy, and its systemic distribution lacks targeting, leading to off-target effects. To address these challenges, we developed macrophage membrane-coated quercetin-loaded PLGA nanoparticles (MVs-QU-NPs) for active ALI targeting. The resulting MVs-QU-NPs exhibited a spherical morphology with a clear core-shell structure. The average size and zeta potential were assessed as 141.70 ± 0.89 nm and -31.83 ± 0.76 mV, respectively. Further studies revealed sustained drug release characteristics from MVs-QU-NPs over a continuous period of 24 h. Moreover, these MVs-QU-NPs demonstrated excellent biocompatibility when tested on normal liver cells. The results of biodistribution analysis in ALI mice displayed the remarkable ALI-targeting ability of MVs-DiD-NPs, with the highest fluorescence intensity observed in liver tissue. This biomimetic approach combining macrophage membranes with nanoparticle delivery, holds great potential for targeted ALI treatment.

Nanotechnology-Based Drug Delivery Systems for Honokiol: Enhancing Therapeutic Potential and Overcoming Limitations.

Honokiol (HNK) is a small-molecule polyphenol that has garnered considerable attention due to its diverse pharmacological properties, including antitumor, anti-inflammatory, anti-bacterial, and anti-obesity effects. However, its clinical application is restricted by challenges such as low solubility, poor bioavailability, and rapid metabolism. To overcome these limitations, researchers have developed a variety of nano-formulations for HNK delivery. These nano-formulations offer advantages such as enhanced solubility, improved bioavailability, extended circulation time, and targeted drug delivery. However, existing reviews of HNK primarily focus on its clinical and pharmacological features, leaving a gap in the comprehensive evaluation of HNK delivery systems based on nanotechnology. This paper aims to bridge this gap by comprehensively reviewing different types of nanomaterials used for HNK delivery over the past 15 years. These materials encompass vesicle delivery systems, nanoparticles, polymer micelles, nanogels, and various other nanocarriers. The paper details various HNK nano-delivery strategies and summarizes their latest applications, development prospects, and future challenges. To compile this review, we conducted an extensive search using keywords such as "honokiol", "nanotechnology", and "drug delivery system" on reputable databases, including PubMed, Scopus, and Web of Science, covering the period from 2008 to 2023. Through this search, we identified and selected approximately 90 articles that met our specific criteria.

Candy box technique for the fixation of inferior pole patellar fractures: finite element analysis and biomechanical experiments.

BACKGROUND: Maintaining effective reduction and firm fixation in inferior pole patellar fractures is a highly challenging task. There are various treatment methods available; although tension-band wiring combined with cerclage wiring (TBWC) is the mainstream approach, its effectiveness is limited. Herein, we propose and evaluate a new technique called candy box (CB), based on separate vertical wiring (SVW), for the treatment of inferior pole patellar fractures. Specifically, we provide biomechanical evidence for its clinical application. METHODS: Five fixation models were built: SVW combined with cerclage wiring (SVWC); TBWC; modified SVW with the middle (MSVW-A) or upper (MSVW-B) 1/3 of the steel wire reserved, and CB. A finite element analysis was performed to compare the displacement and stress under 100-N, 200-N, 300-N, 400-N and 500-N force loads. Three-dimensional printing technology was utilized to create fracture models, and the average displacement of each model group was compared under a 500-N force. RESULTS: The results of the finite element analysis indicate that CB technology exhibits significantly lower maximum displacement, bone stress, and wire stress compared to that with other technologies under different loads. Additionally, in biomechanical experiments, the average force displacement in the CB group was significantly smaller than that with other methods under a 500-N force (P < 0.05). CONCLUSIONS: CB technology has the potential to overcome the limitations of current techniques due to its superior biomechanical characteristics. By incorporating early functional exercise and ensuring strong internal fixation, patient prognosis could be enhanced. However, further clinical trials are needed to fully evaluate the therapeutic effects of CB technology.

Long-term outcome of flexor hallucis longus tendon transfer for chronic Achilles tendon rupture with large defect: A retrospective series.

There are multiple surgical options for treatment of chronic Achilles tendon (AT) rupture according to the classifications and length of defect. However, no gold standard method has been confirmed, and there is no clear evidence to support the superiority of 1 procedure over others. This study aimed to evaluate the long-term clinical outcome of flexor hallucis longus tendon (FHL) transfer for chronic AT rupture with large defect. Clinical data of patients treated with FHL transfer due to chronic AT rupture between January 2009 and October 2019 were reviewed retrospectively. All cases were presented with AT rupture for more than 4 weeks after injury. The gap between ruptured ends was > 5 cm after debridement in all patients. The harvest of FHL was performed through a single incision in accordance with AT rupture debridement in all cases. Clinical outcomes were assessed with AOFAS ankle-hindfoot scale, Achilles tendon total rupture score and AOFAS hallux metatarsophalangeal-interphalangeal scale. Twenty-eight patients were followed successfully for 62.6 ±â€…22.2 months. According to the complete datasets obtained from 28 patients, none of the tendons re-ruptured. The AOFAS ankle-hindfoot scale and Achilles tendon total rupture score at last follow-up visit was 90.4 ±â€…5.7 and 89.8 ±â€…5.3 respectively, which revealed statistically significant improvement from the preoperative score of 61.1 ±â€…6.7 and 53.8 ±â€…8.3. The AOFAS hallux metatarsophalangeal-interphalangeal scale at last follow-up visit was 87.5 ±â€…6.1. The FHL transfer through a single incision for chronic AT rupture with large defect is a safe and simple method with low risk of morbidity and complications.

Increased Risk of Rheumatoid Arthritis in Patients With Asthma: A Genetic Association Study Using Two-Sample Mendelian Randomization Analysis.

OBJECTIVE: Observational studies have explored the association between asthma and some types of arthritis, including rheumatoid arthritis and osteoarthritis, but the results are largely contradictory. We aimed to investigate the causal effects of asthma on arthritis, including osteoarthritis, rheumatoid arthritis, gout, and ankylosing spondylitis. METHODS: Two-sample Mendelian randomization (MR) analysis was used to investigate the causal effects of asthma on each arthritis. The genetic instruments for asthma were obtained from a large genome-wide association study of asthma. The inverse-variance weighted (IVW) method was used as the main analysis of MR. Bonferroni-adjusted P value threshold was used to account for multiple comparisons. RESULTS: MR-IVW analysis suggested that adult-onset asthma (AOA) was associated with increased risk of rheumatoid arthritis. The odds ratio for rheumatoid arthritis associated with AOA and childhood-onset asthma (COA) were 1.018 (95% confidence interval [95% CI], 1.011-1.025; P < 0.001) and 1.006 (95% CI 1.001-1.012; P = 0.046), respectively. For osteoarthritis, gout, or ankylosing spondylitis, all the MR analyses showed no significant causal effects of AOA or COA on them. We also performed a reverse MR analysis to explore the causal effects of rheumatoid on all asthma, allergic asthma, or nonallergic asthma and found no significant causal effects on them. CONCLUSION: Genetically predicted AOA predisposes patients to an increased risk of rheumatoid arthritis but has no causal effects on osteoarthritis, gout, and ankylosing spondylitis. The result of COA on rheumatoid arthritis is suggestive of potential causal relationship but needs to be confirmed in further studies.

Denosumab for giant cell tumors of bone from 2010 to 2022: a bibliometric analysis.

Giant cell tumors of the bone (GCTB) are considered moderately malignant bone tumors. Denosumab, as a neoadjuvant therapy, provides new possibilities for treating GCTB. However, even after multiple studies and long-term clinical trials, there are limitations in the treatment process. Research data and Medical Subject Headings terms related to denosumab and GCTB were collected from January 2010 to October 2022 using the Web of Science and MeSH ( https://meshb.nlm.nih.gov ) browsers. These data were imported into CiteSpace and VOSviewer softwares for bibliometric analysis. Overall, 445 publications on denosumab and GCTB were identified. Over the last 12 years, the growth rate of the total number of publications has remained relatively stable. The USA published the highest number of articles (83) and had the highest centrality (0.42). Amgen Inc. and Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) First Ortoped Rizzoli were identified as the most influential institutions. Many authors have made outstanding contributions to this field. Lancet Oncology had the highest journal impact factor (54.433). Local recurrence and drug dosage are current research hotspots, and future development trends will mainly focus on prognostic markers of GCTB and the development of new therapies. Further research is required to analyze denosumab's safety and efficacy and understand its local recurrence of GCTB, to identify the optimal dose. Future progress in this field will likely focus on exploring new diagnostic and recurrence markers to monitor disease progression and examine new therapeutic targets and treatment strategies.

Finite element analysis of a novel anatomical locking plate for scapular neck fracture.

OBJECTIVES: Reconstruction plates (RPs) are commonly used in scapular neck fractures (SNFs): however, RPs have many defects. In this study, we evaluated a newly designed scapular neck anatomical locking compression plate (SNALCP). METHODS: An SNF finite element model (Miller-type IIB) was constructed. Plates were subsequently implanted into the scapula and fixed with screws that were grouped according to the plate used: SNALCP (A) and RP (B). Finally, loads were applied to record and analyze performance. RESULTS: Under lateral, anteroposterior, and vertical compression loads, the maximum von Mises stresses on the scapula and implants of group A were smaller than those of group B. There were some differences in stress distribution between the two groups. CONCLUSIONS: SNALCP can effectively reduce the stress of the scapula and implant, making stress distribution more uniform and continuous, and has mechanical conduction advantages. Compared to RP, it provides improved stability and more reliable fixation.

TGF-ß protects osteosarcoma cells from chemotherapeutic cytotoxicity in a SDH/HIF1α dependent manner.

BACKGROUND: In the widespread adoption of chemotherapy, drug resistance has been the major obstacle to tumor elimination in cancer patients. Our aim was to explore the role of TGF-ß in osteosarcoma-associated chemoresistance. METHODS: We performed a cytotoxicity analysis of methotrexate (MTX) and cisplatin (CIS) in TGF-ß-treated osteosarcoma cells. Then, the metabolite profile of the core metabolic energy pathways in Saos-2 and MG-63 cell extracts was analyzed by 1H-NMR. We detected the expression of succinate dehydrogenase (SDH), STAT1, and hypoxia-inducible factor 1α (HIF1α) in TGF-ß-treated osteosarcoma cells and further tested the effects of these molecules on the cytotoxicity induced by chemotherapeutic agents. Using in vivo experiments, we examined the tumor growth and survival time of Saos-2-bearing mice treated with a combination of chemotherapeutic agents and a HIF1α inhibitor. RESULTS: The metabolic analysis revealed enhanced succinate production in osteosarcoma cells after TGF-ß treatment. We further found a decrease in SDH expression and an increase in HIF1α expression in TGF-ß-treated osteosarcoma cells. Consistently, blockade of SDH efficiently enhanced the resistance of Saos-2 and MG-63 cells to MTX and CIS. Additionally, a HIF1α inhibitor significantly strengthened the anticancer efficacy of the chemotherapeutic drugs in mice with osteosarcoma cancer. CONCLUSION: Our study demonstrated that TGF-ß attenuated the expression of SDH by reducing the transcription factor STAT1. The reduction in SDH then caused the upregulation of HIF1α, thereby rerouting glucose metabolism and aggravating chemoresistance in osteosarcoma cells. Linking tumor cell metabolism to the formation of chemotherapy resistance, our study may guide the development of additional treatments for osteosarcoma.

Secondary below-knee amputation following open reduction and internal fixation of a closed pilon fracture: A case report and algorithm for management.

RATIONALE: Despite significant advances in surgical techniques and implants, the clinical outcome of high-energy pilon fractures remains unsatisfactory, which continues to represent numerous challenges for orthopedic trauma surgeons. PATIENT CONCERNS: A 62-year-old man injured his right ankle after falling from a 3 m high place. There were no open wounds or other complications. DIAGNOSES: According to the X-ray and CT scans, the patient was diagnosed with pilon fracture (type AO-43-C2) and lateral malleolus fracture of the right limb. INTERVENTIONS: The patient was initially treated with calcaneal traction upon admission to a primary hospital. Five days after the injury, the patient underwent open reduction and internal fixation (ORIF) of the fracture and vacuum sealing drainage (VSD) for wound closure. OUTCOMES: The patient presented to our hospital on the 9th day after the first ORIF operation because of critical ischemia of the affected foot and distal lower leg. Blood circulation did not improve after a series of salvage treatments, and below-knee amputation was ultimately performed. LESSONS: This is a rare case of complete ischemic necrosis following ORIF surgery of a closed pilon fracture due to iatrogenic damage. Standardized treatment that strictly follows the guidelines, instructions, or expert consensus should be promoted in this kind of complicated pilon fracture.

Codelivery of survivin inhibitor and chemotherapeutics by tumor-derived microparticles to reverse multidrug resistance in osteosarcoma.

Reportedly, the elevated expression of survivin has been observed in several tumor types, strictly involved in tumor development. In the present study, we detected elevated survivin expression in tumor tissues derived from patients with chemoresistant osteosarcoma when compared with those from chemosensitive patients. Importantly, knockdown of survivin in osteosarcoma cells significantly suppressed cell proliferation and chemoresistance both in vitro and in vivo. Simultaneously, chemotherapy mediates the upregulation of survivin in osteosarcoma cells through a survivin-based selective killing effect, resulting in the development of multidrug resistance. The utilization of tumor-derived microparticles to coencapsulate the survivin inhibitor YM155 and chemotherapeutic agents could effectively reverse multidrug resistance, leading to improved anticancer effects, as well as reduced systemic toxicity. In summary, the expression of survivin contributes to resistance toward osteosarcoma drugs, whereas employing survivin inhibiting combination therapy, based on a microparticle codelivery system, could efficiently reverse resistance and avoid potential systemic toxicity.

Extracellular Collagen Mediates Osteosarcoma Progression Through an Integrin α2ß1/JAK/STAT3 Signaling Pathway.

BACKGROUND: Osteosarcoma development is a complex set which is determined by various factors. Many patients suffered from sustained osteosarcoma growth and revealed poor response to clinical interventions. However, the underlying mechanisms of osteosarcoma development still remain unclear. METHODS: In our study, we isolated osteosarcoma tissues from clinical patients, which were divided into high degree group (stage G1~G2) and low degree group (stage G0). The expression of type I collagen, integrin and STAT3 in tumor tissues were analyzed by immunohistochemistry or immunofluorescence. The collagen-induced cells proliferation was detected by CCK8 and colony formation analysis. The activation of JAK/STAT3 signal was examined by Western blotting and immunofluorescence. The anticancer effects of integrin α2ß1 peptide were analyzed by Sao-2-bearing mice model. RESULTS: Our results implicated that type I collagen could facilitate malignant osteosarcoma development in patients. In vitro, 2D collagen culture also efficiently mediated the stemness up-regulation of osteosarcoma cells, resulting in the strengthened capability of cells proliferation and tumorigenesis. In mechanism, we found that type I collagen could facilitate the activation of JAK/STAT3 signals through integrin α2ß1, which elicited tumor-sustained growth and cancer relapse. In tumor-bearing mice model, integrin α2ß1 signals inhibitor significantly suppressed the osteosarcoma cells proliferation and their tumorigenic ability, which improved the outcome of chemotherapy/radiotherapy. CONCLUSION: Our study demonstrated that type I collagen could mediate osteosarcoma development through an integrin α2ß1/JAK/STAT3 signaling pathway. Blockade of integrin α2ß1 by α2ß1 inhibitor efficiently improved outcome of chemotherapy/radiotherapy, which provided new insights for eradicating tumors in clinic.

Medical waste management practice during the 2019-2020 novel coronavirus pandemic: Experience in a general hospital.

It is currently a critical period for the prevention and control of the COVID-19 pandemic. Since the medical waste disposal could be an important way to control the source of infection, standardization, and strict implementation of the management of COVID-19 related medical waste should be with careful consideration to reduce the risk of epidemic within hospitals. This study illustrates the practice of medical waste disposal responding to the 2019-2020 novel coronavirus pandemic.

[Early effectiveness of minimally invasive open reduction and internal fixation versus arthroscopic double-tunnel suture fixation for tibial avulsion fracture of posterior cruciate ligament].

OBJECTIVE: To compare the early effectiveness of minimally invasive open reduction and internal fixation via posterior median approach versus arthroscopic double-tunnel suture fixation in treatment of tibial avulsion fracture of the posterior cruciate ligament (PCL). METHODS: A clinical data of 31 patients with the tibial avulsion fracture of the PCL and met the criteria between January 2015 and January 2019 was retrospectively analyzed. Nineteen patients (group A) were treated with open reduction and internal fixation with cannulated screw via posterior median approach. The other 12 patients (group B) were treated with arthroscopic double-tunnel suture fixation technique. There was no significant difference between the two groups ( P>0.05) in the gender, age, side of effected limb, the injury cause, the time from injury to operation, the combined meniscus injury, Meyers & McKeever classification and preoperative Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) score, and the difference of tibial posterior displacement between bilateral knees. The operation time, postoperative complications, fracture healing, and the difference of tibial posterior displacement between bilateral knees, Lysholm score, Tegner score, and IKDC score were recorded. RESULTS: Group B spent significantly longer operation time than group A ( t=7.347, P=0.000). No postoperative complication occurred in group B, and 1 patient in group A had a screw breakage. All patients were followed up 6-36 months (mean, 22 months). X-ray films showed that all fractures healed at 3 months after operation. At last follow-up, there was no significant difference in the patients with normal knee range of motion between the two groups ( P=0.510). At last follow-up, the difference of tibial posterior displacement between bilateral knees, Lysholm score, Tegner score, and IKDC score in the two groups were superior to those before operation ( P<0.05); while there was no significant difference between the two groups ( P>0.05). CONCLUSION: For the tibial avulsion fracture of PCL, the minimally invasive open reduction and internal fixation and arthroscopic double-tunnel suture fixation can obtain similar early effectiveness. However, arthroscopic surgery has the advantages of being able to simultaneously deal with intra-articular combined injuries, avoiding internal fixator complications, and eliminating the need for secondary operation.

[Comparison of early effectiveness and safety of simultaneous and staged bilateral unicompartmental knee arthroplasty for bilateral anteromedial compartment osteoarthritis].

OBJECTIVE: To compare the early effectiveness and safety of simultaneous bilateral and staged bilateral unicompartmental knee arthroplasty (UKA) in treatment of anteromedial compartment osteoarthritis. METHODS: The clinical data of 31 patients with bilateral anteromedial compartment osteoarthritis who underwent bilateral UKAs between January 2015 and January 2017 was retrospectively analyzed. Of them, 17 patients were treated with simultaneous bilateral UKAs (simultaneous group) and 14 patients with staged bilateral UKAs (staged group). There was no significant difference in gender, age, body mass index, osteoarthritis grading, and preoperative hip-knee-ankle angle, knee society score (KSS), visual analogue scale (VAS) score, and range of motion (ROM) of knee between the two groups ( P>0.05). The operation time, blood loss, hospitalization stay, minimum hemoglobin value during 10 days after operation, and hospitalization cost were recorded. The staged group was compared by the sum of two operations. The effectiveness was evaluated by KSS score, VAS score, ROM at 3, 6, 12 months after operation, and patient satisfaction scores were recorded at 12 months after operation. RESULTS: The operation time, hospitalization stay, and hospitalization cost of the simultaneous group were significantly lower than those of the staged group ( P<0.05). There was no significant difference in blood loss and the minimum hemoglobin value during 10 days after operation between the two groups ( P>0.05). Superficial infection occurred in 1 side of 1 case (7.1%) in staged group. Postoperative delirium occurred in 1 case (5.9%) in simultaneous group. There was no significant difference in incidence of postoperative complications between the two groups ( P=1.000). Patients in both groups were followed up 12-32 months (mean, 24.7 months). There was no significant difference in KSS score between the two groups at 3 months after operation ( t=0.896, P=0.392). KSS scores were significanly higher in simultaneous group than in staged group at 6 and 12 months after operation ( P<0.05). There was no significant difference in ROM and VAS scores between the two groups at 3, 6, and 12 months after operation ( P>0.05). At 12 months after operation, the patient satisfaction scores were significantly higher in simultaneous group than in staged group ( P<0.05). X-ray films showed no loosening of the prosthesis in the two groups. CONCLUSION: Simultaneous bilateral UKAs has the same security as staged bilateral UKAs. Meanwhile knee function recovery was better, hospitalization stay and hospitalization cost reduced, and patient satisfaction was higher in simultaneous bilateral UKAs.

Role of magnetic resonance imaging versus ultrasound for detection of plantar plate tear.

BACKGROUND: Plantar plate tears could be the reason of forefoot pain, affecting foot function. Magnetic resonance imaging (MRI) and ultrasound (US) were commonly used for the diagnosis of plantar plate tears. The decision of whether to use MRI or US carried some controversy. Our study aimed to find out the diagnostic accuracy of MRI versus US for plantar plate tears. METHODS: The database of the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, and relative orthopedic meetings until May 2016 were searched. Studies involved in the diagnostic detection of MRI or ultrasound for plantar plate tears with surgical criteria as the reference test were included. Data was analyzed by meta-analysis. We compared sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and summary receiver operating characteristic (sROC) plot of both MRI and US. RESULTS: Seven studies involving 246 plantar plate tears were included. The MRI showed more diagnostic accuracy than US for the detection of plantar plate tears. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of MRI were 95%, 54%, 2.08, and 0.08, respectively, while the same values for US were 93%, 33%, 1.20, and 0.35, respectively. And the sROC showed more superior diagnostic accuracy than the US. CONCLUSION: The current result suggests that MRI has better accuracy than US for detection of plantar plate tears.

[Research progress of three-dimensional printing technique in foot and ankle surgery].

Objective: To review the current research progress of three-dimensional (3-D) printing technique in foot and ankle surgery. Methods: Recent literature associated with the clinical application of 3-D printing technique in the field of medicine, especially in foot and ankle surgery was reviewed, summarized, and analyzed. Results: At present, 3-D printing technique has been applied in foot and ankle fracture, segmental bone defect, orthosis, corrective surgery, reparative and reconstructive surgery which showed satisfactory effectiveness. Currently, there are no randomized controlled trials and the medium to long term follow-up is necessary. Conclusion: The printing materials, time, cost, medical ethics, and multi-disciplinary team restricted the application of 3-D printing technique, but it is still a promising technique in foot and ankle surgery.

Tissue-engineered nerve graft with tetramethylpyrazine for repair of sciatic nerve defects in rats.

A tissue-engineered nerve with tetramethylpyrazine (TMP) was repaired for sciatic nerve defects in rats. A total of 55 adult Sprague Dawley (SD) rats were classified into 4 groups, with 15 rats in each of groups A, B, and C as well as 10 rats in group D. About 1.5cm of a sciatic nerve of the right hind limb located 0.5cm below the inferior margin of the piriformis was resected to form the defects. Four types of nerve grafts used for bridging nerve defects in the SD rats corresponded to the 4 groups: tissue-engineered nerves with TMP in group A, tissue-engineered nerves without TMP in group B, acellular nerve grafts (ANGs) in group C, and autologous nerves in group D. Twelve weeks post-surgery, the sciatic functional index, nerve conduction velocity, and gastrocnemius wet weight of groups A and D were higher than those of groups B and C (P<0.05). Results of fluorescence microscopy and histological staining indicated that group A performed better than groups B and C (P<0.05). Similarly, the number of horseradish peroxidase-labeled positive cells was significantly larger in group A than in groups B and C. Regenerative nerve fibers were abundant in group A and consisted mainly of myelinated nerve fibers, which were better than those in groups B and C (P<0.05). The study demonstrated that tissue-engineered nerves constructed by ANGs seeded with neural stem cells and combined with TMP can effectively repair sciatic nerve defects in rats.

[MINIMALLY INVASIVE FIXATION UNDER COMPUTER-ASSISTED NAVIGATION FOR TREATMENT OF PERIACETABULAR FRACTURES, ANTERIOR AND POSTERIOR PELVIC RING FRACTURES].

OBJECTIVE: To investigate the application and technical essentials of computer-assisted navigation in the surgical management of periacetabular fractures and pelvic fractures. METHODS: Between May 2010 and May 2011, 39 patients with periacetabular or anterior and posterior pelvic ring fractures were treated by minimally invasive fixation under computer-assisted navigation and were followed up more than 2 years, and the clinical data were analyzed retrospectively. There were 21 males and 18 females, aged 15-64 years (mean, 36 years). Fractures were caused by traffic accident in 23 cases, crush injury in 6 cases, and falling from height in 10 cases. Of them, 6 cases had acetabular fractures; 6 cases had femoral neck fractures; 18 cases had dislocation of sacroiliac joint; and 15 cases had anterior pelvic ring injuries. All patients were treated with closed or limited open reduction and screw fixations assisted with navigation. RESULTS: Eighty-nine screws were inserted during operation, including 8 in the acetabulum, 18 in the neck of the femur, 33 in the sacroiliac joint, and 30 in the symphysis pubis and pubic rami. The mean time of screw implanted was 20 minutes (range, 11-38 minutes), and the average blood loss volume was 20 mL (range, 10-50 mL). The postoperative pelvic X-ray and three dimensional CT scan showed good reduction of fractures and good position of the screws. No incision infection, neurovascular injury, or implant failure occurred. All patients were followed up 27-33 months with an average of 29.6 months. The patients could walk with full weight loading at 6-12 weeks after operation (mean, 8 weeks); at last follow-up, the patients could walk on the flat ground, stand with one leg, and squat down, and they recovered well enough to do their job and to live a normal life. CONCLUSION: Minimally invasive fixation under computer-assisted navigation may be an excellent method to treat some specific types of periacetabular and anterior and posterior pelvic ring fractures because it has the advantages of less trauma and blood loss, lower complication incidence, and faster recovery.