Effect of Schatzker type VI tibial plateau fractures combined with a proximal fibular and/or posterolateral joint facet fracture on early postoperative functional recovery.

PURPOSE: The objective of this study was to investigate the effect of proximal fibular and/or posterolateral joint facet (PJF) fractures on early functional recovery after Schatzker type VI tibial plateau fractures (TPFs). METHODS: Seventy-nine patients with Schatzker type VI TPFs sustained from November 2016 to February 2021 were divided into three groups according to the integrity of the proximal fibula and PJF (groups A, B, and C). Details including demographics, duration of surgery, and complications were recorded. The Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) score, Hospital for Special Surgery (HSS) score, lateral knee pain and lateral hamstring tightness were ascertained at the final follow-up. The HSS and WOMAC scores have high reliability in evaluating knee function and osteoarthritis. RESULTS: There was a significant difference in the HSS score between groups A and C (P < 0.001) and between groups B and C (P = 0.036). The hospital stay was significantly different between groups A and C (P = 0.038) and between groups B and C (P = 0.013). There was a significant difference in lateral knee pain and lateral hamstring tightness between groups A and C (P < 0.001) and between groups B and C (P < 0.001). CONCLUSION: Our study demonstrates that proximal fibular and PJF fractures do not increase the time from injury to surgery, the incidence of complications, or the duration of surgery for Schatzker type VI TPFs. However, fractures of the proximal fibula significantly increase the hospital stay, reduce knee function, and cause lateral knee pain and lateral hamstring tightness. Combined proximal fibular fracture is more decisive than PJF involvement for prognosis.

Dynamics and calculation of the basic reproduction number for a nonlocal dispersal epidemic model with air pollution.

In order to reflect the dispersal of pollutants in non-adjacent areas and the large-scale movement of individuals, this paper proposes an epidemic model of nonlocal dispersal with air pollution, where the transmission rate is related to the concentration of pollutants. This paper checks the uniqueness and existence of the global positive solution and defines the basic reproduction number, R0. We simultaneously explore the global dynamics: when R0<1, the disease-free stable point is global asymptotic stability; when R0>1, the disease is uniformly persistent. Additionally, in order to approximate R0, a numerical method has been introduced. Illustrative examples are used to verify the theoretical outcomes and show the effect of the dispersal rate on the basic reproduction number R0.

CD146 is closely associated with the prognosis and molecular features of osteosarcoma: Guidance for personalized clinical treatment.

Background: Osteosarcoma (OSA), a focus for orthopedic surgeons, always results in severe death due to metastasis. CD146 is severely expressed in several tumors, indicating its potential as a biomarker for OSA. Method: Two OSA cohorts were enrolled in this study. A Therapeutically Applicable Research to Generate Effective Treatments-Osteosarcoma (TARGET-OS) cohort was used as a training cohort, and GSE21257 was used as the external validation cohort. The R package "limma" was used to discriminate the differentially expressed genes among CD146-high and CD146-low patients and was further annotated by the enriched signaling pathways. The R package MOVICS was used to evaluate immune infiltration and the response to chemotherapy and immunotherapy. All statistical analyses were performed by R version 4.0.2, and p < 0.05 was considered statistically significant. Result: CD146 plays an important role in promoting the progression, invasion, and metastasis of several tumors. In the current study, we first revealed an integrative unfavorable prognosis in patients with tumors (p < 0.01, HR: 1.10, 95% CI: 1.07-1.14). CD146 is tightly correlated with m5C RNA methylation modification genes in OSA. Furthermore, we revealed that CD146 acts as an oncogene in OSA patients and is linked to poor prognosis in both the TARGET-OS cohort (p = 0.019, HR: 2.61, 95% CI: 1.171-5.834) and the GSE21257 cohort (p = 0.005, HR: 3.61, 95% CI: 1.474-8.855), with a total of 137 patients, regardless of whether they were adjusted for clinical pathological features. Highly-expressed CD146 impacts the signaling pathways of cytokine‒cytokine receptor interactions and is associated with the high infiltration of immunocytes. Moreover, patients with high CD146 expression were more likely to be sensitive to anti-PD-1 immunotherapy, while patients with low expression of CD146 were more likely to be sensitive to cisplatin and doxorubicin chemotherapy. Conclusion: Overall, CD146 is an independent prognostic factor for OSA patients and can help doctors select clinical treatment strategies.

Conductive Collagen-Based Hydrogel Combined With Electrical Stimulation to Promote Neural Stem Cell Proliferation and Differentiation.

Injectable biomimetic hydrogels are a promising strategy for enhancing tissue repair after spinal cord injury (SCI) by restoring electrical signals and increasing stem cell differentiation. However, fabricating hydrogels that simultaneously exhibit high electrical conductivities, excellent mechanical properties, and biocompatibility remains a great challenge. In the present study, a collagen-based self-assembling cross-linking polymer network (SCPN) hydrogel containing poly-pyrrole (PPy), which imparted electroconductive properties, is developed for potential application in SCI repair. The prepared collagen/polypyrrole (Col/PPy)-based hydrogel exhibited a continuous and porous structure with pore sizes ranging from 50 to 200 µm. Mechanical test results indicated that the Young's moduli of the prepared hydrogels were remarkably enhanced with PPy content in the range 0-40 mM. The conductivity of Col/PPy40 hydrogel was 0.176 ± 0.07 S/cm, which was beneficial for mediating electrical signals between tissues and accelerating the rate of nerve repair. The investigations of swelling and degradation of the hydrogels indicated that PPy chains interpenetrated and entangled with the collagen, thereby tightening the network structure of the hydrogel and improving its stability. The cell count kit-8 (CCK-8) assay and live/dead staining assay demonstrated that Col/PPy40 coupled with electrical simulation promoted the proliferation and survival of neural stem cells (NSCs). Compared with the other groups, the immunocytochemical analysis, qPCR, and Western blot studies suggested that Col/PPy40 coupled with ES maximally induced the differentiation of NSCs into neurons and inhibited the differentiation of NSCs into astrocytes. The results also indicated that the neurons in ES-treated Col/PPy40 hydrogel have longer neurites (170.8 ± 37.2 µm) and greater numbers of branch points (4.7 ± 1.2). Therefore, the prepared hydrogel system coupled with ES has potential prospects in the field of SCI treatment.

Minimally invasive versus traditional inverted "L" approach for posterior cruciate ligament avulsion fractures: a retrospective study.

Purpose: To evaluate the clinical efficacy of a minimally invasive arthroscopic approach and to compare it with the traditional inverted "L" approach for the treatment of posterior cruciate ligament (PCL) avulsion fractures. Methods: From January 2016 to January 2020, the clinical data from patients with PCL avulsion fracture of the tibial insertion were analyzed retrospectively. They were divided into two groups based on surgical approaches: minimally invasive approach group (n = 15) and traditional inverted "L" group (n = 15 cases). The operation time, incision length, intraoperative blood loss, hospitalization time and complications were all recorded and compared between the two groups. The fracture healing time, knee range of motion (ROM), and residual relaxation degree were compared between the two groups after regular follow-up. The International Knee Documentation Committee (IKDC) and Lysholm scores were used to assess knee joint function. Results: There were no significant differences between the two groups in terms of gender, age, side, body mass index, cause of injury, Meyers McKeever classification and time from injury to operation (P > 0.05). The incision length and intraoperative bleeding in the minimally invasive group were significantly lower (P < 0.05) than those in the traditional group. There were no significant differences between the two groups in terms of operative time, fracture healing time, or residual relaxation (P > 0.05). The Lachman test and posterior drawer test were both negative, and there were no postoperative complications. The VAS pain score within 2 weeks and ROM within 4 weeks in the minimally invasive group were significantly better (P < 0.05) than those in the traditional inverted "L" approach group. The knee joint stability of both groups was good 12 months after surgery, and there were no significant differences in IKDC score, Lysholm score and ROM (P > 0.05) between the two groups. Conclusion: The minimally invasive approaches for the treatment of PCL avulsion fractures provide adequate exposure without the surgical complications associated with traditional open surgical approaches. The procedure is safe, fast and minimally invasive, and does not need a long learning curve.

D-4F, an apolipoprotein A-I mimetic, promotes the clearance of myelin debris and the reduction of foamy macrophages after spinal cord injury.

After spinal cord injury (SCI), a large number of blood-derived macrophages infiltrate the lesion site and phagocytose myelin debris to become foamy macrophages, which leads to chronic inflammation. The drug D-4F, an apolipoprotein A-I peptidomimetic made of D-amino acids, has been reported to promote the lipid metabolism of foamy macrophages in atherosclerosis. However, the role and mechanism of D-4F in SCI are still unclear. In this study, we found that D-4F can promote the removal of myelin debris, reduce the formation of foamy macrophages in the lesion core and promote neuroprotection and recovery of motor function after SCI. These beneficial functions of D-4F may be related to its ability to upregulate the expression of ATP-binding cassette transporter A1 (ABCA1), the main transporter that mediates lipid efflux in foamy macrophages because inhibiting the activity of ABCA1 can reverse the effect of D-4F in vitro. In conclusion, D-4F may be a promising candidate for treating SCI by promoting the clearance of myelin debris by foamy macrophages via the ABCA1 pathway.

SU16f inhibits fibrotic scar formation and facilitates axon regeneration and locomotor function recovery after spinal cord injury by blocking the PDGFRß pathway.

BACKGROUND: Excessively deposited fibrotic scar after spinal cord injury (SCI) inhibits axon regeneration. It has been reported that platelet-derived growth factor receptor beta (PDGFRß), as a marker of fibrotic scar-forming fibroblasts, can only be activated by platelet-derived growth factor (PDGF) B or PDGFD. However, whether the activation of the PDGFRß pathway can mediate fibrotic scar formation after SCI remains unclear. METHODS: A spinal cord compression injury mouse model was used. In situ injection of exogenous PDGFB or PDGFD in the spinal cord was used to specifically activate the PDGFRß pathway in the uninjured spinal cord, while intrathecal injection of SU16f was used to specifically block the PDGFRß pathway in the uninjured or injured spinal cord. Immunofluorescence staining was performed to explore the distributions and cell sources of PDGFB and PDGFD, and to evaluate astrocytic scar, fibrotic scar, inflammatory cells and axon regeneration after SCI. Basso Mouse Scale (BMS) and footprint analysis were performed to evaluate locomotor function recovery after SCI. RESULTS: We found that the expression of PDGFD and PDGFB increased successively after SCI, and PDGFB was mainly secreted by astrocytes, while PDGFD was mainly secreted by macrophages/microglia and fibroblasts. In addition, in situ injection of exogenous PDGFB or PDGFD can lead to fibrosis in the uninjured spinal cord, while this profibrotic effect could be specifically blocked by the PDGFRß inhibitor SU16f. We then treated the mice after SCI with SU16f and found the reduction of fibrotic scar, the interruption of scar boundary and the inhibition of lesion and inflammation, which promoted axon regeneration and locomotor function recovery after SCI. CONCLUSIONS: Our study demonstrates that activation of PDGFRß pathway can directly induce fibrotic scar formation, and specific blocking of this pathway would contribute to the treatment of SCI.

M1-type microglia can induce astrocytes to deposit chondroitin sulfate proteoglycan after spinal cord injury.

After spinal cord injury (SCI), astrocytes gradually migrate to and surround the lesion, depositing chondroitin sulfate proteoglycan-rich extracellular matrix and forming astrocytic scar, which limits the spread of inflammation but hinders axon regeneration. Meanwhile, microglia gradually accumulate at the lesion border to form microglial scar and can polarize to generate a pro-inflammatory M1 phenotype or an anti-inflammatory M2 phenotype. However, the effect of microglia polarization on astrocytes is unclear. Here, we found that both microglia (CX3CR1+) and astrocytes (GFAP+) gathered at the lesion border at 14 days post-injury (dpi). The microglia accumulated along the inner border of and in direct contact with the astrocytes. M1-type microglia (iNOS+CX3CR1+) were primarily observed at 3 and 7 dpi, while M2-type microglia (Arg1+CX3CR1+) were present at larger numbers at 7 and 14 dpi. Transforming growth factor-ß1 (TGFß1) was highly expressed in M1 microglia in vitro, consistent with strong expression of TGFß1 by microglia in vivo at 3 and 7 dpi, when they primarily exhibited an M1 phenotype. Furthermore, conditioned media from M1-type microglia induced astrocytes to secrete chondroitin sulfate proteoglycan in vitro. This effect was eliminated by knocking down sex-determining region Y-box 9 (SOX9) in astrocytes and could not be reversed by treatment with TGFß1. Taken together, our results suggest that microglia undergo M1 polarization and express high levels of TGFß1 at 3 and 7 dpi, and that M1-type microglia induce astrocytes to deposit chondroitin sulfate proteoglycan via the TGFß1/SOX9 pathway. The study was approved by the Institutional Animal Care and Use Committee of Anhui Medical University, China (approval No. LLSC20160052) on March 1, 2016.

[Comparison of femoral neck system and inverted triangle cannulated screws fixations in treatment of Pauwels typle â ¢ femoral neck fractures].

OBJECTIVE: To compare the effectiveness of the femoral neck system (FNS) and inverted triangle cannulated screws (ITCS) for the treatment of Pauwels type Ⅲ femoral neck fractures. METHODS: The clinical data of 59 patients with Pauwels type Ⅲ femoral neck fractures treated between May 2019 and November 2020 were retrospectively analysed. The patients were divided into FNS group (28 cases) and ITCS group (31 cases) according to the different internal fixation. There was no significant difference in gender, age, affected side, body mass index, cause of injury, smoking history, alcohol abuse history, Pauwels angle, Garden classification, AO/Orthopaedic Trauma Association (AO/OTA) classification, and time from injury to operation between the two groups ( P>0.05). The operation time, incision length, intraoperative blood loss, extra assisted reduction procedures (Kirschner wire prying reduction or open reduction), hospitalization stay, and early complications were recorded and compared between the two groups. Garden index and Haidukewych score were used to evaluate fracture reduction. Fracture healing time, lateral thigh irritation, time of partial or total weight-bearing postoperatively, shortening length and degree of femoral neck, change of caput-collum-diaphysis (CCD) angle (the difference of CCD angle between immediate after operation and last follow-up), incidence of osteonecrosis of femoral head and revision surgery were recorded and compared between the two groups. Hip joint function were evaluated by Harris score. RESULTS: The operation time of FNS group was significantly shorter than ITCS group, and the incision length was significantly longer than ITCS group ( P<0.05). There was no significant difference in intraoperative blood loss, assisted reduction, Garden index, Haidukewych score, and hospitalization stay between the two groups ( P>0.05). All the incisions healed by first intention. There were 2 deep vein thrombosis in the FNS group and 1 pulmonary infection and 1 deep vein thrombosis in the ITCS group. No significant difference was found in the incidence of early postoperative complications (7.1% vs. 6.5%) between the two groups ( P=1.000). Patients in both groups were followed up 3-14 months, and there was no significant difference in follow-up time between the two groups ( t=-0.553, P=0.582). The fracture healing time, Harris score, and the partial weight-bearing time after operation of the FNS group were significantly better than those of the ITCS group ( P<0.05). However, there was no significant difference in total weight-bearing time between the two groups ( Z=-1.298, P=0.194). No lateral thigh irritation was found in the FNS group, while 10 patients in the ITCS group had lateral thigh irritation, and the incidence between the two groups (0 vs. 32.3%) was significant ( P=0.001). At last follow-up, the shortening length and degree of femoral neck and the change of CCD angle in FNS group were significantly less than those in ITCS group ( P<0.05). There was no patient with osteonecrosis of femoral head or reoperation in the FNS group, while 4 patients in the ITCS group underwent reoperation (including 2 cases of osteonecrosis of the femoral head). However, the incidences (0 vs. 6.5%; 0 vs.12.9%) between the two groups were not significant ( P=0.493; P=0.114). CONCLUSION: Using FNS to treat Pauwels type Ⅲ femoral neck fracture is simple as well as able to reduce the shortening of the femoral neck and the change of the CCD angle. Also, FNS is conducive to the recovery of hip joint function, which should be considered as a new choice for the treatment of young femoral neck fracture patients.

Transcranial direct current stimulation treated by multilead brain reflex instrument accelerates neural functional recovery in a rat model of stroke.

PURPOSE: Clinical research suggests that transcranial direct current stimulation (tDCS) at bilateral supraorbital foramen and inferior orbital rim and nose intersections may facilitate rehabilitation after stroke. However, the underlying neurobiological mechanisms of tDCS remain poorly understood, impeding its clinical application. Here, we investigated the effect of tDCS applied after stroke on neural cells. MATERIALS AND METHODS: Middle cerebral arterial occlusion (MCAO) reperfusion was induced in rats. Animals with comparable infarcts were randomly divided into MCAO group and MCAO + tDCS group. Recovery of neurological function was assessed behaviorally by modified neurological severity score (mNSS). Ischemic tissue damage verified histologically by TTC and HE staining. Immunohistochemical staining, real-time qPCR, and western blot were applied to determine the changes of neural cells in ischemic brains. RESULTS: The results reveal that tDCS treated by multilead brain reflex instrument can promote the recovery of neurological function, remarkably reduce cerebral infarct volume, promote brain tissue rehabilitation, and can effectively inhibit astrocytosis and enhance neuronal survival and synaptic function in ischemic brains. CONCULSIONS: Our study suggests that tDCS treated by multilead brain reflex instrument could be prospectively developed into a clinical treatment modality.

TrkA regulates the regenerative capacity of bone marrow stromal stem cells in nerve grafts.

We previously demonstrated that overexpression of tropomyosin receptor kinase A (TrkA) promotes the survival and Schwann cell-like differentiation of bone marrow stromal stem cells in nerve grafts, thereby enhancing the regeneration and functional recovery of the peripheral nerve. In the present study, we investigated the molecular mechanisms underlying the neuroprotective effects of TrkA in bone marrow stromal stem cells seeded into nerve grafts. Bone marrow stromal stem cells from Sprague-Dawley rats were infected with recombinant lentivirus vector expressing rat TrkA, TrkA-shRNA or the respective control. The cells were then seeded into allogeneic rat acellular nerve allografts for bridging a 1-cm right sciatic nerve defect. Then, 8 weeks after surgery, hematoxylin and eosin staining showed that compared with the control groups, the cells and fibers in the TrkA overexpressing group were more densely and uniformly arranged, whereas they were relatively sparse and arranged in a disordered manner in the TrkA-shRNA group. Western blot assay showed that compared with the control groups, the TrkA overexpressing group had higher expression of the myelin marker, myelin basic protein and the axonal marker neurofilament 200. The TrkA overexpressing group also had higher levels of various signaling molecules, including TrkA, pTrkA (Tyr490), extracellular signal-regulated kinases 1/2 (Erk1/2), pErk1/2 (Thr202/Tyr204), and the anti-apoptotic proteins Bcl-2 and Bcl-xL. In contrast, these proteins were downregulated, while the pro-apoptotic factors Bax and Bad were upregulated, in the TrkA-shRNA group. The levels of the TrkA effectors Akt and pAkt (Ser473) were not different among the groups. These results suggest that TrkA enhances the survival and regenerative capacity of bone marrow stromal stem cells through upregulation of the Erk/Bcl-2 pathway. All procedures were approved by the Animal Ethical and Welfare Committee of Shenzhen University, China in December 2014 (approval No. AEWC-2014-001219).

A safe percutaneous technique for the reduction of irreducible femoral neck fractures using ultrasound localization of the femoral vascular and nervous structures at the hip.

We present a safe percutaneous technique for the placement of Kirschner wires into the femoral head to assist in the reduction of irreducible femoral neck fractures using ultrasound to identify the vascular and nervous structures about the hip.From January 2011 to June 2014, a total of 36 patients (25 males and 11 females) were enrolled in this study. Patients were placed on a fracture reduction table for limb traction. After 3 unsuccessful reductions with limb traction, ultrasound-guided localization of the patient's femoral artery, vein, and nerve at the hip was performed. These structures were marked on the overlying skin and then Kirschner wires were inserted into the femoral head avoiding these marked structures. After the surgery, the Kirschner wire insertions were routinely reviewed by ultrasound, the hip fracture reduction and the femoral nerve sensorimotor function were routinely examined as well.All 36 patients with an irreducible variant of a femoral neck fracture showed anatomic reduction under C-arm fluoroscopy using ultrasound to avoid K wire injury to the femoral vascular structures and nerve. No major vascular injury during operation. In post-surgical ultrasound examination, local hematoma formation was not evident. There was normal function of the femoral nerve. On follow-up, there were no infections, wound problems, recurrence of fracture displacement, laxity, or implant breakage.Preoperative ultrasonic localization of the femoral artery, vein, and femoral nerve safely allowed. Kirschner wire placement under C-arm fluoroscopy into the femoral head to assist in fracture reduction. This assisted reduction method for irreducible femoral neck fractures had a number of advantages, including closed anatomic reduction with minimal attempts, used simple equipment, and avoided further destruction of the blood supply to the femoral head.

Accessory Anteromedial Portal may not Provide Clinically Superior Results Compared with the Anteromedial Portal in Anterior Cruciate Ligament Reconstruction.

Techniques using the anteromedial portal (AMP) and accessory anteromedial portal (AAMP) are commonly used in anterior cruciate ligament (ACL) reconstruction. The aim of this study was to investigate the radiological and clinical outcomes of arthroscopic single-bundle ACL reconstruction using the AMP or AAMP technique to drill the femoral tunnel. The records of 157 patients who underwent single-bundle ACL reconstruction using the AMP or AAMP technique between 2011 and 2015 were reviewed. The femoral tunnel clock-face position and femoral tunnel and tibial tunnel anterior-posterior (AP) inclination angles were assessed on axial or AP magnetic resonance images. At last follow-up, the Lachman test and pivot-shift test were used to evaluate AP and rotational stability, respectively. The Lysholm knee scoring scale and the International Knee Documentation Committee (IKDC) form were used to evaluate clinical and functional results. No statistically significant differences were found between the groups in patient age, sex, follow-up period, or affected side distribution. The mean femoral tunnel inclination angle was 31.13 ± 8.06 degrees in the AMP group and 30.17 ± 9.02 degrees in the AAMP group (p = 0.513). The tibial tunnel inclination angle in the AMP group (16.28 ± 7.89 degrees) was not different from that in the AAMP group (13.70 ± 6.08 degrees). No significant differences were observed between the two groups in the Lachman test, pivot-shift test, Lysholm knee scoring scale, or IKDC scores. The AAMP technique was not clinically superior to the AMP technique in ACL reconstruction. This is a retrospective comparative study and its level of evidence is III.

Early results of the proximal femoral nail antirotation-Asia for intertrochanteric fractures in elderly Chinese patients.

OBJECTIVE: To report early efficacy and safety of the proximal femoral nail antirotation-Asia for intertrochanteric fractures in elderly Chinese patients. METHODS: This retrospective study was carried out in the Second Hospital of Anhui Medical University, Anhui, China between June 2009 and December 2012. A total of 108 patients with intertrochanteric fractures were available for the outcome analysis in the study. There were 62 female and 46 male patients with a mean age of 75 +/= 10 years. The stable group included 18 cases of 31 A1 fractures, the unstable group included 68 cases of 31 A2 fractures, and 22 cases of 31 A3 fractures. Follow-up evaluations were performed at 1, 3, 6, 9, and 12 months, and every year thereafter. RESULTS: During the average 29 +/= 9 months early follow-up period, 4 patients (4%) were lost, and 6 patients (6%) died within 6 months due to causes unrelated to the fracture. Fracture union occurred in all patients, 83 patients (85%) showed an excellent, or good outcome. The mean Harris Hip Score was 85.2 +/= 7.5 points. Mechanical failures, such as bending, or breaking of the implant were not seen, and cut-outs were not observed. CONCLUSION: The results suggest that proximal femoral nail antirotation-Asia is effective and safe in the treatment of inter-trochanteric fractures in elderly Chinese patients.