Bio-mechanical effects of femoral neck system versus cannulated screws on treating young patients with Pauwels type III femoral neck fractures: a finite element analysis.

INTRODUCTION: As a novel internal fixation for femoral neck fractures, the femoral neck system has some advantages for young Pauwels type III femoral neck fractures without clear biomechanical effects and mechanisms. Thus, the objection of the study is to realize the biomechanical effects and mechanism of FNS cannulated screws on treating young patients with Pauwels type III femoral neck fractures compared to cannulated screws which are commonly used for femoral neck fractures by finite element analysis. METHODS: Firstly, the model of young Pauwels type III femoral neck fractures, femoral neck system (FNS), and three cannulated screws (CS) arranged in an inverted triangle were established, and the internal fixations were set up to fix young Pauwels type III femoral neck fractures. Under 2100 N load, the finite element was performed, and the deformation, peak von Mises stress (VMS), and contact at fracture segments were recorded to analyze the biomechanical effects and mechanism of FNS and three-CS fixing young Pauwels type III femoral neck fractures. RESULTS: Compared to three-CS, the deformation of the whole model, internal fixation, and fracture segments after FNS fixation were lower, and the peak VMS of the whole model and the internal fixation after FNS were higher with lower peak VMS of the distal femur and the fracture segments. With a sticking contact status, the contact pressure at fracture segments after FNS fixation was lower than that of three-CS. CONCLUSIONS: FNS can provide better mechanical effects for young patients with Pauwels type III femoral neck fractures, which may be the mechanical mechanism of the clinical effects of FNS on femoral neck fracture. Although there is high stress on FNS, it is still an effective and safe internal fixation for young patients with Pauwels type III femoral neck fractures.

Neuroprotective effects of tetramethylpyrazine on spinal cord injury-Related neuroinflammation mediated by P2X7R/NLRP3 interaction.

OBJECTIVE: The inflammatory response is acknowledged as a crucial pathological aspect of spinal cord injury (SCI). Tetramethylpyrazine (TMP) has been demonstrated to possess neuroprotective properties within the central nervous system via its anti-inflammatory mechanisms. This study aims to investigate the molecular mechanism by which TMP alleviates SCI from an anti-inflammatory standpoint. METHODS: The SCI model was established using the MASCIS impactor device. The Basso-Beattie-Bresnahan (BBB) locomotor rating scale was utilised to assess rat locomotion. Nissl and Golgi staining were used to observe neuron and dendritic spine morphology, respectively. A transmission electron microscope was used to observe the microcosmic morphology of the axon. ELISA kits were used to measure the concentrations of IL-1ß and IL-18 in the spinal cord. Immunofluorescence staining was used to detect P2X7R+/IBA-1+ cells, and Western blot and RT-qPCR were used to analyze the protein and mRNA expression of P2X7R in the spinal cord. Additionally, Western blot was used to detect NLRP3 and Cleaved-Caspase-1 (p20), the critical proteins in the NLRP3 inflammasome pathway. RESULTS: TMP ameliorated the microcosmic morphology of the axon and had an inhibitory effect on the concentrations of IL-1ß and IL-18 after SCI. Furthermore, TMP inhibited the expression of both P2X7R and critical proteins of the NLRP3 inflammasome pathway on microglia after SCI. The aforementioned effects of TMP exhibit similarities to those of BBG (P2X7R antagonist); however, they can be effectively reversed by BzATP (P2X7R activator). CONCLUSION: TMP alleviated SCI via reducing tissue damage, neuroinflammation, and the expression of P2X7R, NLRP3, IL-1ß, and IL-18.

Femoral neck system vs. cannulated screws on treating femoral neck fracture: a meta-analysis and system review.

Objective: This meta-analysis aimed to compare the relative safety and efficacy of cannulated compression screw (CCS) and femoral neck system (FNS) in treating patients with femoral neck fractures and to provide evidence-based medical evidence for FNS in treating femoral neck fractures. Methods: PubMed, Embase, Cochrane, and China National Knowledge Infrastructure databases were searched to collect outcomes related to femoral neck fractures treated with FNS and CCS, including time to fracture healing, incidence of non-union, incidence of osteonecrosis of the femoral head, incidence of failure of internal fixation, rate of femoral neck shortening, Harris hip score, Barthel index, operative time, intraoperative blood loss, fluoroscopy frequency, and complications. A meta-analysis was performed using RevManv5.4 (The Cochrane Collaboration) and Stata v14.0 software. Results: This analysis included 21 studies involving 1,347 patients. The results showed that FNS was superior to CCS in terms of fracture healing time [mean difference (MD) = -0.75, 95% CI = (-1.04, -0.46), P < 0.05], incidence of bone non-union [odds ratio (OR) = 0.53, 95% CI = (0.29, 0.98), P = 0.04], incidence of osteonecrosis of the femoral head [OR = 0.49, 95% CI = (0.28, 0.86), P = 0.01], incidence of internal fixation failure [OR = 0.30, 95% CI = (0.18, 0.52), P < 0.05], rate of femoral neck shortening [OR = 0.38, 95% CI = (0.27, 0.54), P > 0.05], Harris hip score [MD = 3.31, 95% CI = (1.99, 4.63), P < 0.001], Barthel index [MD = 4.31, 95% CI = (3.02, 5.61), P < 0.05], intraoperative bleeding [MD = 14.72, 95% CI = (8.52, 20.92), P < 0.05], fluoroscopy frequency [OR = 0.53, 95% CI = (0.29, 0.98), P = 0.04], and complications [OR = 0.31, 95% CI = (0.22, 0.45), P < 0.05]. The difference between FNS and CCS in operative time was not statistically significant [MD = -2.41, 95% CI = (-6.88, 2.05), P = 0.29]. Conclusion: FNS treatment of femoral neck fracture can shorten the fracture healing time; reduce the incidence and translucent rate of bone non-union, osteonecrosis of the femoral head, and internal fixation failure; reduce intraoperative blood loss and postoperative complications; and improve hip joint function and activity. We are confident in the findings that FNS, an effective and safe procedure for internal fixation of femoral neck fractures, is superior to CCS.

The reconstruction of fingertip injury by mini hallux toenail flap pedicled with the hallux transverse artery and toe pulp vein transplantation technique based on the equivalent design theory.

INTRODUCTION: How to reconstruct the damaged fingertip is a clinical problem. Our team propose the theory of equivalent design and use the mini toenail flap pedicled with the hallux transverse artery and toe pulp vein transplantation technique to reconstruct Allen's type II fingertip injury. Thus, we perform the retrospective study to evaluate the effects of this technique on fingertip injury. MATERIALS AND METHODS: A retrospective analysis was performed on 56 patients admitted to our hospital from January 2015 to January 2020 who used equivalently designed miniature hallux toenail flaps for the plastic repair of fingertip damage. We recorded the size of the miniature hallux toenail flap, operation time, intraoperative blood loss, and complications and calculated the survival rate of the transplanted miniature hallux toenail flap. During routine follow-up after surgery, we recorded nail growth time and observed finger appearance. At the last time of follow-up, we recorded Semmes-Weinstein evaluating tactile sensation and Two-point discrimination testing (TPD). The efficacy was evaluated by Zook score evaluation. RESULTS: The size of the mini hallux toenail flap was 0.71 cm × 1.22 cm to 0.88 cm × 1.71 cm. The operation time was (3.54 ± 0.58) hours, the intraoperative blood loss was (20.66 ± 4.87) ml, and the survival rate of mini hallux toenail flaps was 100%. The postoperative follow-up time was (30.82 ± 11.21) months, and the total nail growth time was (9.68 ± 2.11) months. The average tactile sensation evaluated by the Semmes-Weinstein test was (0.32 ± 0.14) g, and the average TPD was (7.33 ± 1.02) mm. According to Zook score, the curative effect of fifty-six cases were all excellent or good with 100% excellent and good rate, and all patients had beautiful appearances and good function of damaged fingertips. CONCLUSIONS: Based on the equivalent design theory, the mini hallux toenail flap pedicled with the hallux transverse artery and toe pulp vein transplantation technique is an effective method to reconstruct Allen's type II fingertip injury with a beautiful appearance and good function. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.