Objective To investigate the effect factors of knee function recovery after operation in distal femoral fractures. Methods From January 2001 to May 2007, 92 cases of distal femoral fracture were treated. There were 50 males and 42 females, aged 20-77 years old (average 46.7 years old). Fracture was caused by traffic accident in 48 cases, by fall ing fromheight in 26 cases, by bruise in 12 cases and by tumble in 6 cases. According to Müller’s Fracture classification, there were 29 cases of type A, 12 cases of type B and 51 cases of type C. According to American Society of Anesthesiologists (ASA) classification, there were 21 cases of grade I, 39 cases of grade II, 24 cases of grade III, and 8 cases of grade IV. The time from injury to operation was 4 hours to 24 days with an average of 7 days. Anatomical plate was used in 43 cases, retrograde interlocking intramedullary nail in 37 cases, and bone screws, bolts and internal fixation with Kirschner pins in 12 cases. After operation, the HSS knee function score was used to evaluate efficacy. Ten related factors were appl ied for statistical analysis, to knee function recovery after operation in distal femoral fractures, such as age, sex, preoperative ASA classification, injury to surgery time, fracture type, treatment, reduction qual ity, functional exercise after operation, whether or not CPM functional training and postoperative compl ications. Results Wound healed by first intention in 88 cases, infection occurred in 4 cases. All patients followed up 16-32 months with an average of 23.1 months. Cl inical union of fracture was achieved within 3-7 months after operation. Extensor device adhesions and the scope of activities of lt; 80° occurred in 29 cases, traumatic arthritis in 25 cases, postoperative fracture displacement in 6 cases, mild knee varus or valgus in 7 cases and implant loosening in 6 cases. According to HSS knee function score, the results were excellent in 52 cases, good in 15 cases, fair in 10 cases and poor in 15 cases with an excellent andgood rate of 72.83%. Single factor analysis showed that age, preoperative ASA classification, fracture type, reduction qual ity, whether or not CPM functional exercise, and postoperative compl ications were significantly in knee function recovery (P lt; 0.05). logistic regression analysis showed that the fracture type, qual ity of reduction, whether or not CPM functional exercise, and age were major factors in the knee joint function recovery. Conclusion Age, preoperative ASA classification, fracture type, reduction qual ity, and whether or not CPM functional training, postoperative compl ications factors may affect the knee joint function recovery. Adjustment to the patient’s preoperative physical status, fractures anatomic reduction and firm fixation, early postoperative active and passive functional exercises, less postoperative compl ications can maximize the restoration of knee joint function.
Objective To review the research progress of P75 neurotrophin receptor (P75NTR) so as to clarify its mechanism, and to explore its relationship with nonunion so as to provide a new idea for the treatment of nonunion. Methods The related domestic and foreign literature of P75NTR in recent years was extensively reviewed, summarized, and analyzed to find out the mechanism of action of P75NTR and the pathological factors of nonunion formation. Results P75NTR can express in nonunion tissues and lead to defect of fibrin degradation and inhibition of angiogenesis, which play an important role in the pathogenesis of nonunion. Conclusion It needs to be confirmed by further study whether the purpose of treating nonunion can be achieved by blocking the effects described above of P75NTR.
Objective To analyze the learning curve of unilateral biportal endoscopic lumbar interbody fusion (UBE-LIF). Methods Fifty-five patients with single-segment lumbar degenerative disease treated with UBE-LIF between December 2020 and February 2022 were selected as the research subjects. The patients were grouped according to the operation sequence, the first 27 cases were in the early group, and the last 28 cases were in the late group. There was no significant difference between the two groups in age, gender, disease type, and surgical segment distribution (P>0.05). The operation time, the amount of hemoglobin loss (the difference between 1 day before operation and 3 days after operation), the hospital stay after operation, and the incidence of perioperative complications were recorded; the learning curve of UBE-LIF was analyzed by log-curve regression analysis. Results All the operations were successfully completed without changing to other operations. The operation time, the amount of hemoglobin loss, and hospital stay in the early group were significantly more than those in the late group (P<0.05). Complications occurred in 2 cases (7.4%) in the early group, including 1 case of dural tear during operation and 1 case of epidural hematoma after operation, and 1 case (3.6%) with transient radiculitis in the late group. There was no significant difference in the incidence of complications between the two groups (P=0.518) . The log-curve regression analysis showed that the operation time decreased significantly with the increase of the number of patients (P<0.05). The operation time tended to be stable after the surgeon completed 17 cases. ConclusionFor single-level lumbar degenerative disease, the operation time of UBE-LIF can decrease gradually with the increase of the number of patients, and tend to be stable after 17 cases.
Clinically, fracture nonunion often leads to pain and disability in patients. Fracture nonunion often requires additional surgery to restore skeletal muscle function, so the treatment of fracture nonunion has always been a difficult point in the field of orthopedics. In recent years, with the development of genetic engineering, the technology of using gene to treat fracture nonunion has been widely studied. A large number of experiments have confirmed that the target genes encoding growth factors related to fracture healing are introduced into target cells through different delivery methods in vivo or in vitro, thereby expressing specific growth factors can promote fracture healing, which provides a new way for treating fracture nonunion. This article will discuss the research status of different delivery methods of osteogenic genes, as well as their advantages and disadvantages, in order to provide a theoretical basis for targeted gene therapy for fracture nonunion.
ObjectiveTo investigate the effect of small interfering RNA (siRNA) lentivirus-mediated silencing of P75 neurotrophin receptor (P75NTR) gene on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in rats.MethodsThree lentivirus-mediated P75NTR gene siRNA sequences (P75NTR-siRNA-1, 2, 3) and negative control (NC)-siRNA were designed and transfected into the 3rd generation Sprague Dawley (SD) rat BMSCs. The cells morphological changes were observed under an inverted microscope, and the expressions of P75NTR gene and protein in cells were detected by real-time fluorescence quantitative PCR and Western blot. Then the best silencing P75NTR-siRNA for subsequent osteogenic differentiation experiments was screened out. The 3rd generation SD rat BMSCs were randomly divided into experimental group, negative control group, and blank control group (normal BMSCs). The BMSCs of negative control group and experimental group were transfected with NC-siRNA and the selected P75NTR-siRNA lentiviral vector, respectively. The cells of each group were cultured by osteogenic induction. The expressions of osteogenic related proteins [osteocalcin (OCN) and Runx related transcription factor 2 (Runx2)] were detected by Western blot; the collagen type Ⅰ expression was observed by immunohistochemical staining; the osteogenesis of BMSCs was observed by alkaline phosphatase (ALP) detection and alizarin red staining.ResultsAfter lentivirus-mediated P75NTR transfected into BMSCs, the expressions of P75NTR mRNA and protein significantly reduced (P<0.05), and the best silencing P75NTR-siRNA was P75NTR-siRNA-3. After P75NTR gene was silenced, MTT test showed that the cell proliferation in the experimental group was significantly faster than those in the two control groups (P<0.05). After osteogenic induction, the relative expressions of OCN and Runx2 proteins, collagen type Ⅰ expression, and ALP activity were significantly higher in the experimental group than in the two control groups, the differences were significant (P<0.05). With the prolongation of osteogenic induction, the mineralized nodules in the experimental group gradually increased.ConclusionSilencing the P75NTR gene with siRNA lentivirus can promote the osteogenic differentiation of rat BMSCs and provide a new idea for the treatment of bone defects.
Objective To investigate the effect of NGF on fracture heal ing, and to study the role of BMP-2 induced osteoblast. Methods Sixty cleaned male Kunming mice (aging 6-8 weeks and weighing 23-25 g) were made fracture models in the middle of femoral shaft and randomly divided into four groups (groups A, B, C and D, n=15). Fracture was treated with NGF/ normal sal ine, BMP-2, BMP-2 /NGF/normal sal ine, and normal sal ine in groups A, B, C and D, respectively. After 14, 21 and 28 days, the specimens were selected from 5 mice each group to do the biochemical and histological analysis. Beforethe mice were killed, the arteriovenous blood was taken from their eye-ball to test the ALP activity. Results After 14 days,21 days and 28 days, the gross observation showed that the size and hardness of bone tissue, and callus tissue growth increased in groups A, B and C order and were higher than those in group D; the X-ray films showed that the calcified area increased in groups A, B and C order and were higher than those in group D; the histological observation showed that the trabecular maturity increased in groups A, B and C order and were higher than those in group D. The osteoblast area, the gray degree value of the radiographs in callus tissue, the ALP contents of serum and callus tissue, calcium content of callus tissue and net weight of callus were higher in groups A, B and C than in group D. There were significant differences (P lt; 0.05) in osteoblast area and gray degree values of the radiographs at 14, 21 and 28 days; in ALP contents of serum at 14 days; in ALP contents of callus tissue at 14 days and 21 days; in calcium content of callus tissue at 21 days and 28 days among 4 groups. There were significant differences in net weight of callus between groups B, C and groups A, D at 14 days (P lt; 0.05). At 21 days and 28 days, the trabecular surface index of osteoblast, the average trabecular volume and the mean trabecular width decreased as time went on, having an increase order of groups A, B, C and was higher in groups A, B, C than in group D, showing significant differences among 4 groups (P lt; 0.05). Conclusion NGF promotes the heal ing of fractures. NGF possesses synergistic effect on ectopic bone formation induced by BMP-2.
ObjectiveTo investigate the effects of silencing P75 neurotrophin receptor (P75NTR) and nerve growth factor (NGF) overexpression on the proliferative activity and ectopic osteogenesis ability of bone marrow mesenchymal stem cells (BMSCs) combined with demineralized bone matrix for heterotopic osteogenesis.MethodsBMSCs of Sprague Dawley (SD) rats were cultured and passaged by adherent isolation method. The third generation BMSCs were transfected with lentivirus mediated P75NTR gene silencing (group B), NGF overexpression gene (group C), P75NTR silencing and NGF overexpression double genes (group D), respectively, and untransfected cells as control (group A). After 7 days of transfection, the expression of fluorescent protein of the target gene was observed by fluorescence microscope; cell counting kit 8 method was used to detect the cells activity for 8 days after transfection; the expressions of P75NTR and NGF proteins in each group were detected by Western blot. The adhesion of BMSCs to demineralized bone matrix (DBM) was observed by inverted phase contrast microscope and scanning electron microscope after transfection of p75NTR silencing and NGF overexpression double genes. After transfection, BMSCs and DBM were co-cultured to prepare 4 groups of tissue engineered bone, which were respectively placed in the dorsal subcutaneous tissue of 8-week-old SD rats to construct subcutaneous ectopic osteogenesis model (n=6). HE staining was performed at 4 and 8 weeks after operation. ALP staining was used to observe the formation of calcium nodules at 8 weeks after operation. The expressions of Runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and osteocalcin (OCN) were detected by real-time fluorescent quantitative PCR.ResultsAt 7 days after transfection, there was no fluorescence expression in group A, red fluorescence expression was seen in group B, green fluorescence expression in group C, and red-green compound fluorescence expression in group D. The fluorescence expression rate of target gene was about 70%. Western blot detection showed that the relative expression of P75NTR protein in groups A and C was significantly higher than that in groups B and D, and the relative expression of NGF protein in groups C and D was significantly higher than that in groups A and B (P<0.05). With the passage of time, the cell proliferation activity increased in all groups, especially in group D, which was significantly higher than that in group A at 3-8 days (P<0.05). The results of inverted phase contrast microscope and scanning electron microscope showed that BMSCs could adhere well to DBM. In the subcutaneous ectopic osteogenesis experiment, HE staining showed that at 4 and 8 weeks after operation, the more bone tissue was formed in group D than in the other 3 groups. ALP staining showed that group D had the highest ALP activity and better osteogenic expression. Compared with group A, the relative expressions of Runx2, ALP, and OCN mRNAs in group D were significantly higher than those in group A (P<0.05).ConclusionSilencing P75NTR and NGF overexpression double genes co-transfected BMSCs with DBM to construct tissue engineered bone has good ectopic osteogenic ability. By increasing NGF level and closing P75NTR apoptosis channel, it can not only improve cell activity, but also promote bone tissue regeneration.