Search

Objective Femoral head necrosis is a challenging condition in orthopaedics, and the occurrence of collapse is an important factor affecting the prognosis of femoral head necrosis. Sclerosis bands are known to influence the collapse of the femoral head, yet there is a lack of research on the biomechanical role of sclerosis bands in non‐vascularized fibular grafting surgery. This study aims to evaluate the biomechanical impact of sclerosis bands in femoral head necrosis and their role in non‐vascularized fibular grafting surgery (NVFG) using finite element analysis. Methods We constructed 11 finite element models based on CT scan data of a normal hip joint, simulating different sclerosis band thicknesses and defect scenarios. The models were analyzed for changes in femoral head displacement and von Mises stress. We constructed a hip joint model based on CT data from a normal hip joint, and after reconstruction, assembly, and optimization using 3‐matic. We created five groups consisting of 11 finite element analysis models of the hip joint. Mesh partitioning and mechanical parameter settings were performed in ANSYS. The changes and differences in femoral head displacement and von Mises stress of these models were analyzed. Results Increasing sclerosis band thickness led to reduced peak displacement of the femoral head by 28.6%, 42.9%, and 47.6%, and increased surface von Mises stress by 28.3%, 13.8%, and 13.0%, respectively. Post‐surgery, peak displacement decreased in all groups compared to pre‐surgery levels. Increasing sclerosis band thickness post‐surgery resulted in decreased maximum von Mises stress of the femoral head by 13.9%, 3.0%, and 8.1%. Defect volume in the defect groups correlated with increased peak displacement of the femoral head by 10.0%, 30.0%, and 100.0%, and increased surface maximum von Mises stress of the femoral head by 9.3%, 14.0%, and 15.1%. Conclusion Sclerosis band formation exacerbates von Mises stress concentration on the femoral head surface. However, thicker sclerosis bands improve post‐NVFG stability and mechanical performance. Larger anterior lateral sclerosis band defects significantly compromise postoperative stability, increasing the risk of collapse. Protecting the anterior lateral sclerosis band during NVFG surgery is crucial.

The type I interferon (IFN) pathway is important for eukaryotic cells to resist viral infection, as well as an impediment to efficient virus replication. Therefore, this study aims to create an IFNAR1 knockout (KO) Madin-Darby bovine kidney (MDBK) cell line using CRISPR/Cas9 and investigate its application and potential mechanism in increasing viral replication of bovines. The IFNAR1 KO cells showed increased titers of bovine viral diarrhea virus (BVDV) (1.5 log10), with bovine enterovirus and bovine parainfluenza virus type 3 (0.5-0.8 log10). RNA-seq revealed reduced expression of the genes related IFN-I pathways including IFNAR1, STAT3, IRF9, and SOCS3 in IFNAR1 KO cells compared with WT cells. In WT cells, 306 differentially expressed genes (DEGs) were identified between BVDV-infected and -uninfected cells. Of these, 128 up- and 178 down-regulated genes were mainly associated with growth cycle and biosynthesis, respectively. In IFNAR1 KO cells, 286 DEGs were identified, with 82 up-regulated genes were associated with signaling pathways, and 204 down-regulated genes. Further, 92 DEGs were overlapped between WT and IFNAR1 KO cells including ESM1, IL13RA2, and SLC25A34. Unique DEGs in WT cells were related to inflammation and immune regulation, whereas those unique in IFNAR1 KO cells involved in cell cycle regulation through pathways such as MAPK. Knocking down SLC25A34 and IL13RA2 in IFNAR1 KO cells increased BVDV replication by 0.3 log10 and 0.4 log10, respectively. Additionally, we constructed an IFNAR1/IFNAR2 double-knockout MDBK cell line, which further increased BVDV viral titers compared with IFNAR1 KO cells (0.6 log10). Overall, the IFNAR1 KO MDBK cell line can support better replication of bovine viruses and therefore provides a valuable tool for bovine virus research on viral pathogenesis and host innate immune response., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Geng, Jiang, Yang, Xia, Xu, Yang, Yuan, Chen, Chen, Chen, Zhang, Hu and Guo.)

Objective: To compare the short-term effectiveness of repairing distal tibiofibular syndesmosis with metal screws and absorbable screws., Methods: A retrospective analysis was performed on the clinical data of 63 patients with ankle fracture combined with injury of the distal tibiofibular syndesmosis admitted between January 2017 and January 2020. Among them, 31 patients were treated with absorbable screw fixation of the distal tibiofibular syndesmosis (research group) and 32 patients were treated with metal screw fixation of the distal tibiofibular syndesmosis (control group). There was no significant difference in gender, age, cause of injury, surgical side, time from injury to operation, fracture type, preoperative visual analogue scale (VAS) score, and American Orthopaedic Foot & Ankle Society (AOFAS) score between the two groups ( P >0.05). The operation time and fracture healing time were recorded and compared between the two groups. X-ray film was taken to evaluate the effect of ankle joint reduction and fixation. Olerud-Molander ankle fracture efficacy score (short for OM score), AOFAS score, and VAS score were used to evaluate the effectiveness., Results: There was no significant difference in operation time between the two groups ( t =-0.683, P =0.497). In the control group, 1 case of delayed healing and 1 case of poor healing occurred in the lateral incision after operation, which healed after dressing change; the rest of the patients had primary healing of the incision. Patients in both groups were followed up 12-24 months, with an average of 13.8 months. In the control group, 1 patient with fracture of pronation and external rotation walked with full weight bearing after removing the metal screw of the distal tibiofibular syndesmosis at 8 weeks after operation, the anatomical plate of the lateral malleolus was broken, and the lateral malleolus was fixed again and recovered after 5 months; 1 patient had mild ankle pain after operation, and the pain disappeared after removing the metal screw of the distal tibiofibular syndesmosis at 8 weeks. No complication such as nerve and blood vessel injury occurred in all patients. There was no significant difference in fracture healing time between the two groups ( t =-1.128, P= 0.264). The AOFAS and VAS scores significantly improved in both groups at 12 months after operation ( P <0.05). There was no significant difference between the two groups in the OM scores, and the difference of AOFAS and VAS scores between before and after operation ( P >0.05)., Conclusion: Using absorbable screws to repair the distal tibiofibular syndesmosis can effectively restore the ankle acupoint structure, prevent ankle instability, and restore good ankle function. There is no significant difference in effectiveness between absorbable screws and metal screws, and there is no need for secondary operation to remove screws.

Objective: To investigate the effect of prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery on postoperative C 5 nerve root palsy syndrome., Methods: The clinical data of patients with cervical spondylotic myelopathy (cervical spinal cord compression segments were more than 3) who met the selection criteria between March 2016 and March 2019 were retrospectively analyzed. Among them, 40 patients underwent prophylactic C 4, 5 foraminal dilatation in posterior cervical open-door surgery (observation group) and 40 patients underwent simple posterior cervical open-door surgery (control group). There was no significant difference between the two groups ( P >0.05) in gender, age, disease duration, Nurick grade of spinal cord symptoms, and preoperative diameter of C 4, 5 intervertebral foramen, Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score. The occurrence of C 5 nerve root paralysis syndrome was recorded and compared between the two groups, including incidence, paralysis time, recovery time, and spinal cord drift. VAS and JOA scores were used to evaluate the improvement of pain and function before operation and at 12 months after operation., Results: The incisions of the two groups healed by first intention, and there was no early postoperative complications such as cerebrospinal fluid leakage. Patients of both groups were followed up 12-23 months, with an average of 17.97 months. C 5 nerve root paralysis syndrome occurred in 8 cases in the observation group (3 cases on the right and 5 cases on the left) and 2 cases in the control group (both on the right). There was significant difference of the incidence (20% vs. 5%) between the two groups ( χ 2 =4.114, P =0.043). Except for 1 case in the observation group who developed C 5 nerve root palsy syndrome at 5 days after operation, the rest patients all developed at 1 day after operation; the recovery time of the observation group and the control group were (3.87±2.85) months and (2.50±0.70) months respectively, showing no significant difference between the two groups ( t =-0.649, P =0.104). At 12 months after operation, the JOA score and VAS score of cervical spine in the two groups significantly improved when compared with those before operation ( P <0.05); there was no significant difference in the difference of the cervical spine JOA score and VAS score between at 12 months after operation and before operation and the degree of spinal cord drift between the two groups ( P >0.05)., Conclusion: Prophylactic C 4, 5 foraminal dilatation can not effectively prevent and reduce the occurrence of postoperative C 5 root palsy, on the contrary, it may increase its incidence, so the clinical application of this procedure requires caution.

Objective: To compare the effectiveness of robot assisted internal fixation and traditional open reduction and internal fixation for calcaneal fractures., Methods: The clinical data of 44 patients (44 feets) with calcaneal fracture admitted between October 2017 and December 2018 who met the selection criteria were retrospectively analyzed. According to different operation methods, they were divided into trial group (19 cases, treated with robot assisted percutaneous reduction and cannulated screw fixation through tarsal sinus incision) and control group (25 cases, treated with open reduction and internal fixation via traditional tarsal sinus incision). There was no significant difference in gender, age, injured side, cause of injury, fracture type, time from injury to operation, and preoperative Böhler angle, Gissane angle, calcaneus width, American Orthopedic Foot and Ankle Association (AOFAS) score, and other general data between the two groups ( P >0.05). The operation time, intraoperative fluoroscopy frequency, and fracture healing time were recorded and compared between the two groups. Before operation and at 6 months after operation, the Böhler angle and Gissane angle were measured on the lateral X-ray film, and the calcaneal width was measured on the axial X-ray film of the calcaneus to evaluate the recovery of the deformity and collapse after surgical treatment; the AOFAS score was used to evaluate the function of the affected foot and ankle joint., Results: The operation time of the trial group was significantly longer than that of the control group ( P <0.05), but the intraoperative fluoroscopy frequency was significantly less than that of the control group ( P <0.05). In the control group, 1 case had skin necrosis, and 1 case had a little leakage from the incision; the rest of the two groups had no skin- and incision-related complications. Patients in both groups were followed up 6-12 months, with an average of 9.5 months. At 6 months after operation, the Böhler angle, Gissane angle, and calcaneal width in the two groups were significantly improved when compared with preoperative ones ( P <0.05), and there was no significant difference between the two groups ( P >0.05); the fractures in the two groups were healed, there was no significant difference in healing time ( t =-1.890, P =0.066); the AOFAS scores of the two groups were significantly higher than those before operation ( P <0.05), and the AOFAS score of the trial group was significantly higher than that of the control group ( t =-3.135, P =0.003)., Conclusion: Compared with traditional C-arm fluoroscopic internal fixation for calcaneal fractures, robot-assisted internal fixation via tarsal sinus incision for calcaneal fractures significantly improves the function of the affected foot and maintains the accuracy of nail implantation after fracture reduction, reducing intraoperative fluoroscopy times, and the fracture heals well.