Sodium benzoate (NaB) is a commonly used food ingredient that is also found in cosmetics and medicines. Previous studies have demonstrated that long-term NaB intake has detrimental effects on human health, while its effects on bone mass remain unknown. In the present study, intragastric NaB administration was found to decrease bone mass and deteriorate bone microstructure in vivo, while prolonged NaB gavage further accelerated bone loss. The in vitro study revealed that NaB inhibited osteoblast differentiation of bone marrow mesenchymal stem cells and MC3T3-E1 cells. Mechanistically, RNA sequencing analysis elucidated that NaB greatly suppressed fibroblast growth factor 2 (FGF2) expression. Further studies revealed that NaB inhibited p38/RUNX2 signaling transduction, which was downstream of FGF2 for modulating osteoblast differentiation. The rescue studies suggested that NaB inhibited RUNX2 expression and osteoblast differentiation through the p38/MAPK signaling pathway. Collectively, NaB accelerated bone loss by inhibiting osteoblast differentiation through downregulating FGF2/p38/RUNX2 signaling pathway. The present study revealed that the long-term intake of NaB-containing food increased the risk of bone loss and osteoporosis (OP). Therefore, a reasonable oral intake of NaB-containing food is an important but convenient initiative for preventing OP.

This study aims to analyze the differences in mechanical stability of OTA/AO 31A1.3 intertrochanteric fractures under various reduction conditions. Twenty standard synbone artificial femur test bones were selected for the OTA/AO 31A1.3 intertrochanteric fracture model. The models were divided into five groups according to their reduction state: positive support, neutral support, negative support, varus fixation, and valgus fixation, with four specimens in each group. All models were fixed using PFNA intramedullary fixation and subjected to static axial compression tests. The subsidence displacement of the proximal femur under different loads and the axial stiffness of the model were measured to verify the mechanical stability of the OTA/AO 31A1.3 intertrochanteric fracture under different reduction conditions. After the static axial compression test, the proximal femoral subsidence displacement in the positive support and neutral support groups was lower than that in the negative support, valgus fixation, and varus fixation groups (p < 0.001). The axial stiffness of the model was highest in the positive support group. Significant differences in subsidence displacement and axial stiffness were found between the groups (p < 0.001). The positive support group demonstrated the best mechanical stability, while the varus fixation group showed the poorest performance. Positive support of the medial cortex can be regarded as the best reduction state for OTA/AO 31A1.3 intertrochanteric fractures, suggesting that this approach should be preferred during surgery to enhance mechanical stability and improve clinical outcomes. Conversely, varus fixation should be avoided due to its inferior stability.

[目的]通过生物力学研究,分析3种类型股骨粗隆间骨折内侧阳性、中性及阴性支撑下的稳定性差异.[方法]使用SYNBONE人工股骨标准试验骨分别制作A1.1/A2.1/A3.2 3种粗隆间骨折模型,并使用股骨近端抗旋髓内固定,根据不同的复位状态分为阳性、中性及阴性支撑组,通过静态轴向压缩试验分析在不同载荷下的股骨近端下沉位移值以及模型轴向刚度值.[结果]A1.1型骨折阳性及中性支撑模式股骨近端下沉位移均小于阴性支撑,且前2模式的轴向刚度均大于阴性支撑模式(P＜0.05).A2.1型骨折股骨近端下沉位移依次为:阳性支撑＜中性支撑＜阴性支撑;刚度依次为阳性支撑＞中性支撑＞阴性支撑;组间差异均有统计学意义(P＜0.05).A3.2型骨折中性支撑组位移显著小于阳性支撑及阴性支撑,而刚度显著大于后两者(P＜0.05).[结论]内侧皮质阳性支撑可视为A1.1和A2.1型粗隆间骨折的最优复位状态,而A3.2型反粗隆间骨折应最大程度获得解剖复位中性支撑.

Abstract Rationale: Open total dislocation of ankle joint is rare and often caused by high-energy injury. The present study describes a patient with open total lateral dislocation of ankle joint without fractures and obtained a satisfactory clinical result following early debridement and irrigation, one-stage repairment of ligaments, and plaster external fixation. Patient concerns: The patient, a 45-year-old male, complained of right foot pain with bleeding and limited motion. Physical examination showed a 15-cm open wound at the medial ankle region, with soft tissues impaired and ankle bones exposed. The 3 dimensional reconstruction computed tomography (CT) examination showed an open total dislocation of ankle joint without concomitant fractures. Diagnoses: open total lateral dislocation of ankle joint without fractures Interventions: Early modern wound care including thorough debridement and irrigation on the wound was performed to remove contaminated soft tissues. Subsequently, the dislocated ankle joint was reduced by hand and the medial and lateral collateral ligaments were repaired using wire anchors. Outcomes: The medial wound healed at 2 weeks after surgery, and several common complications such as infection and skin necrosis did not occur. The last follow-up showed a good range of metatarsal flexion and extension of the injured foot, and obvious signs of traumatic arthritis were not observed. According to Kaikkonen ankle function score, the patient was assessed with 90 points. Lessons: For open total dislocation of ankle joint, early treatment should focus on debridement and irrigation, reduction and fixation of the dislocated ankle, protection of the weak soft tissues, and stable external fixation to promote wound healing and reduce the incidence of related complications.

4D生物制造是近年发展起来的一种新兴技术，其基于3D生物打印，将第四维度"时间"融入其中，使用的智能生物打印材料具有响应环境刺激的能力，使其对所制造的构件既有空间控制，又有时间控制，可以更准确地模拟自然组织的动态变化，在再生医学领域创建高分辨率的复杂动态结构方面具有巨大的潜力。

Fracture combined with traumatic brain injury (TBI) is a common traumatic disease. MicroRNAs (miRNA, miR) play an important role in the influence of traumatic brain injury on fracture healing. Numerous studies have shown that brain injury accelerates fracture healing, and miRNA play an important role in this process. miRNA regulate fracture healing by influencing the generation of osteoblasts and osteoclasts through various mechanisms. Currently, the treatment using miRNA as targeted drugs for fracture healing is in the primary stage of development, and it is a promising fracture healing treatment method.

The structural and functional repair of bone defects remains one of the greatest challenges in regenerative medicine.3D bioprinting is a kind of additive manufacturing technology, which can produce grafts that are more in line with natural bone tissue structure and biological function, reduce the distance between bioengineering tissue structure and physiological tissue, and improve the effect of implantation, it has obvious advantages in the field of bone defect repair and regeneration. This paper reviews the research progress of 3D bioprinting technology in the field of bone defect repair in recent years, discusses its current challenges, and looks forward to its application in the field of bone defect repair.

Background To compare the efficacy of three-point locating versus routine locating techniques for implanting helical blades for proximal femoral nail anti-rotation-II in the treatment of trochanteric fractures. Methods From January 2010 to June 2013, 90 patients with intertrochanteric fractures were surgically treated, including 48 males and 42 females with an average age of 70.5 ± 7.2 years. According to the AO classification, there were 45 cases of A2.1, 35 cases of A2.2, and 10 cases of A2.3. Based on locating techniques, the 90 patients were divided into two groups: the three-point group and the routine group, with 45 patients in each group. All operations were performed by the same group of surgeons using proximal femoral nail anti-rotation (PFNA); the helical blade was inserted into the femoral neck with the three-point locating technique or by the usual method according to treatment group. Several figures including total operation time, elapsed time for implanting the helical blade, intraoperative blood loss, X-ray exposure time, and tip-apex distance (TAD) were measured and compared. Results The three-point group was significantly superior as compared to the routine group in terms of total operation time [(59.34 ± 9.42) min vs (67.61 ± 12.63) min, P < 0.01], elapsed time for implanting the helical blade [(4.58 ± 1.25) min vs (7.82 ± 2.19) min, P < 0.01], intraoperative blood loss [(92.78 ± 34.09) ml vs (154.01 ± 39.10) ml, P < 0.01], X-ray exposure time [(8.84 ± 1.45) vs (14.62 ± 2.91), P < 0.01], and tip-apex distance [(16.78 ± 1.55) mm vs (21.91 ± 3.01) mm, P < 0.01]. Among the 90 patients, 80 were followed up for an average time of 12 months (10–15 months), including 42 patients who were part of three-point group and 38 patients who were part of the routine group. No spiral blade cut was found on the femoral head in any patient in the three-point group, whereas it occurred in 2 patients in the routine group 1 month after surgery. However, there was no significant difference in the Harris score between the two groups 6 months after the operation. Conclusion The three-point locating method is faster and more accurate than the routine locating method.

Background: To explore a new classification of femoral shaft fracture combined with femoral artery injury and to summarize and analyse the characteristics of various types of injury to formulate a correct early diagnosis and treatment strategy. Methods: The data of 21 patients with femoral shaft fracture combined with femoral vascular injury from December 2009 to March 2019 were analysed retrospectively, including 20 males and 1 female aged (40 ±15.5) years. The causes of injury were traffic injury (n = 16), heavy object injury (n = 3), fall injury (n = 1), crush injury (n = 1), open fracture (n = 12) and closed fracture (n = 9). The patients were classified according to whether the femoral shaft fracture was open, the location of femoral artery injury and whether it was combined with a severe multiple injury. The open femoral shaft fracture with femoral artery injury was type I, in which a similar location of fracture and vascular injury comprised type Ia, while different locations comprised type Ib. The closed femoral shaft fracture with femoral artery injury was type II, in which fracture and vascular injury at same level comprised type IIa and different levels comprised type IIb. Patients with severe multiple injuries had a type III fracture. The location of femoral shaft fracture, femoral artery injury and injury; main signs; diagnosis time; waiting time before operation; operation time; times of operations; hospitalization time; and Enneking lower limb function score were recorded. Results: According to our classification, there were 7 cases of type Ia, 4 cases of type Ib, 6 cases of type IIa, 3 cases of type IIb and 1 case of type III. The location of femoral fracture (lower segment in 7 cases, middle segment in 9 cases, proximal segment in 5 cases) and feoral artery injury (adductor tendon fissure in 12 cases, superior popliteal fossa in 7 cases, proximal deep femoral artery bifurcation in 2 cases) and the type of femoral artery injury (contusion and embolization in 3 cases, complete rupture in 18 cases) were compared. The diagnosis time for type I patients were 2.0 (1.0, 2.0) h, the preoperative waiting time was 3.5 (3.0, 5.0) h, the first operation time was 405.0 (335.0, 540.0) min, the number of operations was 2.0 (2.0, 4.0) times, the length of hospital stay was 49.0 (21.0, 71.0) days, the fracture healing time was 7.0 (5.0, 9.0) months, and the Enneking lower extremity function score was 20.0 (19.0, 22.0) points. The diagnosis time for type II patients was 7.0 (6.0, 18.5) h, the waiting time before surgery was 9.0 (8.3,20.5) hours, the first operation time was 385.0 (319.5, 490.0) min, the number of operations was 3.0 (2.0, 3.5) times, the length of hospital stay was 57.0 (29.0, 111.5) days, the fracture healing time was 6.00 (5.50, 7.50) months, and the Enneking lower limb function score was 14.0 (13.0, 15.5) points. All patients had signs of obvious weakening or disappearance of dorsal pedis artery pulsation, all type II patients had blue ecchymosis signs at the site of vascular injury, 6 patients had normal muscle strength and sensation of lower limbs, 12 patients had dorsal extension dysfunction, and 1 patient underwent thigh amputation. Conclusion: The new classification of femoral shaft combined with femoral artery injury is helpful in the diagnosis, treatment and prognosis of the injury. Generally speaking, the diagnosis time of type I injury is faster than that of type II injury, the waiting time before operation is shorter, and the prognosis of lower limb function is better. Sufficient attention should be paid to the type II injury.Weakening or disappearance of dorsal pedis artery pulsation and blue ecchymosis signs are typical signs .