Objective:To analyze the clinical efficacy of internal fixation and prosthesis revision in the treatment of periprosthesis fracture after total knee arthroplasty.Methods:A total of 35 patients (35 knees) with periprosthetic fractures after total knee arthroplasty were retrospectively analyzed from January 2008 to January 2022 in the Department of Orthopaedics, West China Hospital, Sichuan University, including 13 males and 22 females, aged 71.4±4.1 years (range, 62-81 years). Left knee 19 cases, right knee 16 cases. There were 20 cases of Rorabeck type II and 15 cases of Rorabeck type III. The initial replacement was performed using a fixed platform post-stabilized knee prosthesis, which was fixed with bone cement. Patients with Rorabeck type II were treated with internal fixation alone (internal fixation group) and patients with Rorabeck type III underwent revision with replacement prosthesis (revision group). The Hospital for Special Surgery (HSS) score, range of motion (ROM) of knee joint, alignment of lower extremity and incidence of postoperative complications were compared between the two groups.Results:All patients successfully completed the operation and were followed up for 5.2±3.6 years (range, 1-12 years). Intraoperative blood loss was 680±102 ml (range, 420-1100 ml). The operative time in the internal fixation group was 105±17 min, which was less than 140±21 min in the revision group, and the difference was statistically significant ( t=-5.450, P<0.001). There was no complication of nerve or blood vessel injury during the operation. Five cases in the internal fixation group had unsatisfactory lower extremity force lines (>3° deviation from normal) after surgery, and all lower extremity force lines in the revision group were satisfied, and the difference in the satisfaction rate of lower extremity force lines between the two groups was not statistically significant ( P=0.057). The fracture healing time, knee ROM and HSS scores at the last follow-up were 5.1±1.3 months, 86°±5° and 84±5 in the internal fixation group and 4.8±1.5 months, 83°±6° and 82±4 in the revision group. One case in the revision group was diagnosed postoperatively with periprosthetic infection with pathogen culture suggestive of Candida albicans, recurrent anterior knee sinus tracts and patellar ectasia, which progressed to osteomyelitis, and mid-thigh amputation was performed 1 year after revision. Conclusion:The stability of prosthesis is an important reference for the treatment of periprosthetic fractures after total knee arthroplasty. Strong internal fixation in patients with unloosened prosthesis and revision with replacement of prosthesis in patients with loose prosthesis can achieve good knee joint function.

Femoral neck fracture (FNF) in the elderly patients is currently a major health challenge worldwide, with excessive consumption of medical resources, high incidence of complications as well as suboptimal outcome and prognosis. Hip joint arthroplasty (HJA) has been the mainstream treatment for FNF in the elderly, but the conventional surgical approaches and techniques are still confronted with a series of bottlenecks such as dislocation, limp and limb length discrepancy. In recent years, direct anterior approach (DAA) for HJA (DAA-HJA) has been a major new choice in the field of joint replacement, which achieves improved clinical effectiveness of HJA in the treatment of elderly FNF, due to the fact that DAA approach involves the neuromuscular interface and accords with the idea of soft tissue retention and enhanced recovery after surgery. However, there is still a lack of unified understanding of standard technique and procedure of DAA-HJA in the treatment of elderly FNF. Therefore, relevant experts from the Hip Joint Group of Chinese Orthopedics Association of Chinese Medical Association, Youth Arthrology Group of Orthopedic Committee of PLA, Orthopedic Committee of Chongqing Medical Association, Branch of Orthopedic Surgeons of Chongqing Medical Doctor Association and Sport Medicine Committee of Chongqing Medical Association were organized to formulate the " Chinese expert consensus on the technical standard of direct anterior hip arthroplasty for elderly femoral neck fracture ( version 2023)" based on evidence-based medicine. This consensus mainly proposed 13 recommendations covering indications, surgical plans, prosthesis selections, surgical techniques and processes, and postoperative management of DAA-HJA in elderly patients with FNF, aiming to promote standardized, systematic and patient-specific diagnosis and treatment to improve the functional prognosis of the patients.

Effective bone repair and regeneration is crucial for treating skeletal tissue defects, including osteonecrosis, nonunion fractures, osteoporosis, and various other bone deficiencies. Exosomes, as cellular secretory vesicles, are pivotal in mediating intercellular communication through their cargo of proteins, lipids, and nucleic acids. Mesenchymal stem cell-derived exosomes, in particular, have emerged as promising agents in bone repair and regeneration, showing potential for practical application and clinical translation. Nonetheless, their functional capacity and therapeutic efficacy require enhancement. This review delineates exosome optimization strategies aimed at augmenting secretion and functionality, alongside the incorporation of exosome-functionalized biomaterials for bone healing. Evidence indicates that physical stimulation, molecular interventions, and small-molecule or biomaterial stimuli are effective in increasing exosome output. Moreover, engineering exosomes and their parental cells can further potentiate their therapeutic function. The amalgamation of exosomes with biomaterials represents a burgeoning approach in bone tissue engineering, offering novel therapeutic avenues. This comprehensive analysis aims to guide future applications and the clinical adoption of exosomes in bone tissue restoration.

Humans ; Tranexamic Acid ; Atrial Fibrillation ; Antifibrinolytic Agents ; Arthroplasty ; Blood Loss, Surgical ; Arthroplasty, Replacement, Hip

Objective:To investigate the effects of Connexin-43 (Cx43) on osteoblasts proliferation and osteogenic differentiation and its regulatory mechanism.Methods:Osteoblasts were isolated and cultured in vitro. The osteogenic activity of osteoblasts was detected by alizarin red staining and alkaline phosphatase (ALP) staining after dexamethasone treatment. The expression of Cx43, Runt-related transcription factor 2 (Runx2), ALP, collagen I type (COL-I) and proliferation-related proteins PCNA and CDK4 in osteoblasts were detected by Western-blot. The expressions of osteoblast proteins were detected by immunofluorescence staining. The proliferation of osteoblasts was detected by CCK8 assay. The lentivirus-mediated Cx43 gene overexpression plasmid (Lv-Cx43) was constructed and transfected into osteoblasts. The osteogenic activity and proliferation ability of osteoblasts were further detected by the above methods. Cx43 in osteoblasts was overexpressed by pretreating PD98059. The osteogenic activity and proliferation of Cx43 in overexpressed osteoblasts was detected by CCK8 and alizarin red staining.Results:The isolated osteoblasts have osteogenic differentiation ability. Compared with the control group, 1×10 -6 mol/L dexamethasone treatment could reduce the formation of calcium nodules in osteoblasts. With the increase of dexamethasone treatment duration, the protein expression of Cx43, Runx2, ALP and COL-I in osteoblasts decreased gradually, while the expression of PCNA, CDK4 and p-ERK1/2 decreased. The OD values of normal osteoblasts at 0, 1, 2, 3 and 4 d were 0.316±0.043, 0.891±0.623, 1.683±0.154, 2.315±0.721 and 2.891±0.323, respectively. However, The OD values of osteoblasts treated with dexamethasone were 0.376±0.021, 0.657±0.121, 1.124±0.285, 1.521±0.272, 1.987±0.584, respectively. OD values of dexamethasone treated osteoblasts were lower than those of normal group at 2, 3 and 4 days ( P<0.05). The relative expression levels of Cx43 mRNA in control group, Lv-NC group and Lv-Cx43 group were 0.541±0.086, 0.598±0.018 and 1.000±0.082, respectively. The mRNA expression level of Cx43 in Lv-Cx43 group was higher than that in control group and Lv-NC group ( P<0.05). The ratio of Cx43 protein band to the gray value of GAPDH band in control group, Lv-NC group and Lv-Cx43 group were 0.816±0.737, 0.738±0.643 and 1.145±1.101, respectively. The expression level of Lv-Cx43 was higher than that in control group and Lv-NC group ( P<0.05). The expressions of Runx2, ALP, COL-I mRNA and related marker proteins in Lv-Cx43 group were higher than those in control group and Lv-NC group ( P<0.05). The number of calcium nodules in the Lv-Cx43 group was significantly higher than that in the control group and Lv-NC group. The OD value of osteoblasts and the number of calcium nodules in Lv-Cx43+PD98059 group were significantly lower than those in Lv-Cx43 group ( P<0.05). Conclusion:The proliferation and differentiation ability of osteoblasts is significantly decreased after the treatment of dexamethasone with decreased expression of Cx43. Overexpression of Cx43 can promote the proliferation and osteogenic differentiation of osteoblasts, which may be regulated through the ERK1/2 pathway.

Osteonecrosis of the femoral head (ONFH) is caused by the blockage of the blood supply of the femoral head due to by a variety of reasons, resulting in the death of the bone in the femoral head, which is characterized by osteonecrosis occurdead bone resorption-new bone formation. And total hip arthroplasty (THA) is the final choice for the vast majority of these patients. Though treating hard, it is necessary to choose an appropriate head-preserving treatment in the early stage to delay the time of THA.Methods to treat femoral head necrosis varies, however, it is still hard to have a uniform standard until now. Thus, this paper discusses the epidemiological characteristics, related risk factors, pathology, stage, current head-preserving methods and prognostic factors of femoral head necrosis, so as to further enhance clinicians' understanding of osteonecrosis of the femoral head and provide reference to choose more appropriate head-preserving methods for those patients. As demonstrated in literatures, in China, the incidence of non-traumatic ONFH in males is significantly higher than that in females, and it is more common in northern residents and urban residents. In addition, glucocorticoid intake, hyperlipidemia, heavy smoking and alcohol abuse tend to increase the risk of ONFH; Histologically, osteonecrosis and repair of the femoral head occurred after blood supply was blocked; In terms of pathological staging, Ficat staging is the most commonly used and most directly classification method; core decompression, non-vascularized bone grafting, vascularized bone grafting and osteotomy are still the mainstream surgical methods at present. Patient's age, etiology, stage, etc are important factors affecting the prognosis of ONFH. Therefore, surgeons can choose the most appropriate treatment for the patients according to their specific conditions and prognostic factors.

Objective:To investigate the expression of connexin-43 (Cx43) in steroid-induced osteonecrosis of femoral head and osteoblasts in rats and its regulation mechanism.Methods:The model of steroid-induced osteonecrosis of femoral head (SIONFH) of rat was established. Micro-CT and HE staining were used to observe the degree of bone trabecular destruction and the incidence of empty lacunae. The expression levels of Cx43 and PI3K/Akt signaling pathway related molecules and osteoblast-related proteins in model group and control group were detected by RT-PCT and Western blot. The osteoblast (OB) of rats was further isolated and cultured in vitro. Under treatment of dexamethasone (Dex), Cx43 expression in OB cells was detected by Western blot and immunofluorescence. Western blot was used to detect the effect of glucocorticoid (GC) on the expression of related molecules of PI3K/Akt/β-catenin signaling pathway. Akt activator (SC79) and PI3K inhibitor (LY294002) were used to study the molecular mechanism of Dex regulation on Cx43 expression in OB cells. The regulatory relationship between β-catenin and Cx43 was investigated by immunoprecipitation and small interfere RNA (siRNA) technology.Results:The model of SIONFH in rats was successfully established, which proved that Cx43 expression level in the SIONFH model group was significantly lower than that in the control group, and the expression level of Cx43 was positively correlated with the expression of PI3K/Akt signaling pathway related molecules and osteoblast-related proteins Runx2, ALP and Collagen I Type (COL). In addition, in vitro culture of isolated rat OB cells, the expression of Cx43, p-PI3K, P-Akt and β-catenin in OB cells decreased gradually as the Dex action time went on. Moreover, SC79 pretreatment could significantly reverse the inhibitory effect of GCs on Cx43 expression, while LY294002 could significantly enhance the inhibitory effect of GCs on Cx43. In addition, the immunoprecipitation results showed that β-catenin expression was closely related to Cx43 expression, and further studies showed that β-catenin-siRNA could significantly down-regulate the expression of Cx43.Conclusion:Under the action of GC, the expression level of Cx43 in bone tissue and OB cells decreased significantly, and the possible mechanism was that GCs inhibited the expression of Cx43 by inhibiting the PI3K/Akt/β-catenin signaling pathway, which laid a new theoretical foundation for the further study of the role of Cx43 in the pathogenesis of steroid-induced femoral head necrosis.

Revision total hip arthroplasty is becoming more common due to an increasing number of primary total hip arthroplasty procedures being performed annually. Chronic pelvic discontinuity is an important and difficult complication after primary total hip arthroplasty. It is estimated that chronic pelvic discontinuity account for 1%-5% of all acetabular revisions. Pelvic discontinuity occurs mostly in female patients or patients with a history of prior pelvic radiation or rheumatoid arthritis. There are three following crucial factors in regards to achieving satisfied outcomes in treating pelvic discontinuity, the amount of bone stock remaining, biologic in-growth potential and the healing potential of the discontinuity. Treatment approaches include cage reconstruction with bulk acetabular allograft, custom triflange acetabular component, a cup-cage construct, jumbo acetabular cup with porous metal augments, and acetabular distraction with a porous tantalum shell with or without modular porous augments. The present course reported the classification, evaluation, reconstruction options and outcomes of chronic pelvic discontinuity.

Periprosthetic femoral fracture (PFF) is one of severe complications after total hip arthroplasty (THA). As the number of patients receiving THA increased recently, the incidence of PFFs also increased dramatically. There are a number of risk factors for PFFs, such as age, sex, falling and prosthesis loosening. The Vancouver classification system is the most commonly used classification method for PFFs. According to the fracture location, PFFs can be divided into type A intertrochanteric fracture, type B fracture around the stem and type C fracture beyond the stem. The Vancouver type B PFF is further subdivided into type B1 with a well-fixed prosthesis, type B2 with a loose prosthesis but with adequate bone stock, and type B3 with a loose prosthesis and poor proximal bone stock simultaneously. Currently, there are some controversies in treating PFFs, mainly including whether the stem is fixed or not, whether the prosthesis needs to be revised, the selection of the stem, the reconstruction of bone defects, and the methods of fracture fixation. We searched literatures related to PFFs after THA. The incidence, risk factors, classification methods, treatment principles and strategies of PFFs were summarized in the present study. Based on our long-term clinical experience, we evaluated the advantages and disadvantages of each treatment method and provided considerations for the clinical research and selection in treating PFFs.

Objective To study the feasibility and value of magnetic resonance diffusion tensor imaging (DTI) to monitor non?arteritic anterior ischemic optic neuropathy (NAION). Methods Thirty eight NAION patients (56 eyes) were divided into acute period in 17 eyes, progressive period in 16 eyes and chronic period in 23 eyes at the base of onset time. According to matching principle, 56 eyes in 38 normal controls (NCs) were enrolled. All the patients and NCs underwent MR and DTI scan. The raw data were processed by two experienced radiologists, mean diffusivity (MD), axial diffusivities (λ//), radial diffusivities (λ┴), fractional anisotropy (FA) and Length value were got. The independent sample t test was used for the parameter values between the NAION group and the NCs group. A single factor variance analysis was used to compare the parameters among different stages of NAION group. Results Compared to the NCs group, the values of FA and Length in NAION group were reduced [0.20±0.11 vs 0.31±0.12, (5.85±0.92) vs (65.11± 6.89) mm], and the differences were statistically significant (t=-4.28,-5.25;P<0.05). The values of MD andλ┴were increased [(0.16±0.04)×10-3 vs (0.10±0.04)×10-3 mm2/s, (0.16±0.05)×10-3 vs (0.09±0.03)×10-3 mm2/s] in NAION group and the differences were statistically significant (t=6.83, 7.10;P<0.05). The value of FA and Length in acute period, progressive period and chronic period of the NAION group decreased differently compared to the NCs group. At the same time, the value of MD value and λ┴in the three periods of the NAION group increased compared to the NCs groupand the differences were statistically significant (P<0.05). The value of FA between the acute period, the progressive period, and the chronic period of NAION group were statistically signficant (F=10.88, P<0.05). However, no significant differences were found in the values of MD, λ┴and Length of the NAION group (F=0.23, 0.64, 0.33, 1.38;P=0.79, 0.54, 0.72, 0.27). Conclusion The parameters of DTI can be used to monitor the damage of optic nerve and development in NAION.