Lithium prevents glucocorticoid-induced osteonecrosis of the femoral head by regulating autophagy.

Autophagy may play an important role in the occurrence and development of glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH). Lithium is a classical autophagy regulator, and lithium can also activate osteogenic pathways, making it a highly promising therapeutic agent for GC-ONFH. We aimed to evaluate the potential therapeutic effect of lithium on GC-ONFH. For in vitro experiments, primary osteoblasts of rats were used for investigating the underlying mechanism of lithium's protective effect on GC-induced autophagy levels and osteogenic activity dysfunction. For in vivo experiments, a rat model of GC-ONFH was used for evaluating the therapeutic effect of oral lithium on GC-ONFH and underlying mechanism. Findings demonstrated that GC over-activated the autophagy of osteoblasts and reduced their osteogenic activity. Lithium reduced the over-activated autophagy of GC-treated osteoblasts through PI3K/AKT/mTOR signalling pathway and increased their osteogenic activity. Oral lithium reduced the osteonecrosis rates in a rat model of GC-ONFH, and restrained the increased expression of autophagy related proteins in bone tissues through PI3K/AKT/mTOR signalling pathway. In conclusion, lithium can restrain over-activated autophagy by activating PI3K/AKT/mTOR signalling pathway and up-regulate the expression of genes for bone formation both in GC induced osteoblasts and in a rat model of GC-ONFH. Lithium may be a promising therapeutic agent for GC-ONFH. However, the role of autophagy in the pathogenesis of GC-ONFH remains controversial. Studies are still needed to further explore the role of autophagy in the pathogenesis of GC-ONFH, and the efficacy of lithium in the treatment of GC-ONFH and its underlying mechanisms.

Hypobaric hypoxia aggravates osteoarthritis via the alteration of the oxygen environment and bone remodeling in the subchondral zone.

A high prevalence of osteoarthritis (OA) has been observed among individuals living at high altitudes, and hypobaric hypoxia (HH) can cause bone mass and strength deterioration. However, the effect of HH on OA remains unclear. In this study, we aimed to explore the impact of HH on OA and its potential mechanisms. A rat knee OA model was established by surgery, and the rats were bred in an HH chamber simulating a high-altitude environment. Micro-computed tomography (Micro-CT), histological analysis, and RNA sequencing were performed to evaluate the effects of HH on OA in vivo. A hypoxic co-culture model of osteoclasts and osteoblasts was also established to determine their effects on chondrogenesis in vitro. Cartilage degeneration significantly worsened in the HH-OA group compared to that in the normoxia-OA (N-OA) group, 4 weeks after surgery. Micro-CT analysis revealed more deteriorated bone mass in the HH-OA group than in the N-OA group. Decreased hypoxia levels in the cartilage and enhanced hypoxia levels in the subchondral bone were observed in the HH-OA group. Furthermore, chondrocytes cultured in a conditioned medium from the hypoxic co-culture model showed decreased anabolism and extracellular matrix compared to those in the normoxic model. RNA sequencing analysis of the subchondral bone indicated that the glycolytic signaling pathway was highly activated in the HH-OA group. HH-related OA progression was associated with alterations in the oxygen environment and bone remodeling in the subchondral zone, which provided new insights into the pathogenesis of OA.

Prevalence and risk factors of osteoporotic fracture among the elderly population in China: a multicenter cross-sectional study.

PURPOSE: Prevalence of osteoporotic fracture (OPF) is increasing with ageing, resulting in a significant financial burden for healthcare. However, research on the nationwide epidemiological data of OPF in Chinese elderly is still scarce. The aim of this study was to investigate the prevalence and risk factors of OPF in Chinese population aged 60 years or order. METHODS: A cross-sectional survey was conducted in an elderly Chinese population in five centres. Questionnaire investigation and imaging examination were taken in all participants to identify OPF prevalence and risk factors. Diagnosis of OPF was determined based on imaging of vertebral fractures or history of fall-related fractures. We then used multivariate logistic regression model to analyze the associations between the potential risk factors and OPF. RESULTS: The overall prevalence of OPF in population aged 60 years or older was 24.7% (1,071/4,331), showing an increasing trend with age (P < 0.001). The prevalence of OPF was geographically distinct (P < 0.001), but similar between men and women (P > 0.05). Up to 96.8% of OPFs consisted of vertebral fractures, especially involving T11, T12, and L1 segments. Advanced age (≥ 80), vision loss, severe hearing loss, multiple exercise forms, chronic kidney disease, osteoarthritis, and trauma-related vertebral fractures were significantly associated with risk factors, while education level and vitamin D supplementation were associated with protective factors of OPF. CONCLUSION: High prevalence of OPF is a serious threat to bone health among elderly people in China. There is an urgent need for effective strategies to diagnose, prevent, and treat OPF in elderly adults.

Immune regulation enhances osteogenesis and angiogenesis using an injectable thiolated hyaluronic acid hydrogel with lithium-doped nano-hydroxyapatite (Li-nHA) delivery for osteonecrosis.

Osteonecrosis is a devastating orthopedic disease in clinic that generally occurs in the femoral head associating with corticosteroid use up to 49 % in patients. In particular, glucocorticoids induced osteonecrosis of the femoral head is closely related to the local immune response that characterized by abnormal macrophage activation and inflammatory cell infiltration at the necrotic site, forming a pro-inflammatory microenvironment dominated by M1 macrophages, and thus leads to failure of bone repair and regeneration. Here, we report a bone regeneration strategy that constructs an immune regulatory biomaterial platform using an injectable thiolated hyaluronic acid hydrogel with lithium-doped nano-hydroxyapatite (Li-nHA@Gel) delivery for osteonecrosis treatment. Li-nHA@Gel achieved a sustain and longterm release of Li ions, which might enhance M2 macrophage polarization through the activation of the JAK1/STAT6/STAT3 signaling pathway, and the following induced pro-repair immune microenvironment mediated the enhancement of the osteogenic and angiogenic differentiation. Moreover, both in vitro and in vivo studies indicated that Li-nHA@Gel enhanced M2 macrophage polarization, osteogenesis, and angiogenesis, and thus promoted the bone and blood vessel formation. Taken together, this novel bone immunomodulatory biomaterial platform that promotes bone regeneration by enhancing M2 macrophage polarization, osteogenesis, and angiogenesis could be a promising strategy for osteonecrosis treatment.

Retraction: Enhanced bone defect repairing effects in glucocorticoid-induced osteonecrosis of the femoral head using a porous nano-lithium-hydroxyapatite/gelatin microsphere/erythropoietin composite scaffold.

Retraction of 'Enhanced bone defect repairing effects in glucocorticoid-induced osteonecrosis of the femoral head using a porous nano-lithium-hydroxyapatite/gelatin microsphere/erythropoietin composite scaffold' by Donghai Li et al., Biomater. Sci., 2018, 6, 519-537, https://doi.org/10.1039/C7BM00975E.

Efficacy of Modified Lightbulb Technique by Percutaneous Femoral Neck-Head Fenestration Combined With Compacted Artificial Bone Graft for Treating Precollapse Osteonecrosis of the Femoral Head.

BACKGROUND: Whether artificial bone provides comparable outcomes to autogenous bone has not been determined for osteonecrosis of the femoral head (ONFH). This study was conducted to compare the clinical outcomes of autogenous and artificial bone grafting (demineralized bone matrix/calcium sulfate [DBM/CaS]) through a modified lightbulb technique by percutaneous femoral neck-head fenestration for treating precollapse ONFH. METHODS: A total of 73 Association Research Circulation Osseous Stage Ⅱ ONFH patients (81 hips) who had a mean follow-up of 61 months (range, 52 to 74) were included in this retrospective study. Among them were 40 hips treated with autogenous bone and 41 hips treated with DBM/CaS grafting through the percutaneous femoral neck-head fenestration. The Harris scores, radiographic progressions, clinical success rates, and survival analyses were analyzed. RESULTS: At final follow-up, the mean Harris score was 80 points (range, 63 to 92) in the DBM/CaS group and 76 points (range, 69 to 91) in the autogenous bone group (P = .751). The radiographic progression rate was 29.9% in the DBM/CaS group, without significant difference from the autogenous bone group, which was 37.5% (P = .43). About 73.2% of patients in the DBM/CaS group and 75% in the autologous bone group avoided a total hip arthroplasty (P = .85). Survival analysis for femoral head protection revealed similar outcomes between the 2 groups (P > .05). CONCLUSION: Percutaneous femoral neck-head fenestration combined with artificial bone (DBM/CaS) grafting had comparable clinical outcomes to autologous bone grafting on preventing femoral head collapse and rescuing THA at a mean of 61-month follow-up for treating early ONFH.

Hydrophobic Cellulose Acetate Aerogels for Thermal Insulation.

As naturally derived material, cellulose aerogels have excellent thermal insulation properties due to their unique high porosity and three-dimensional mesoporous structure. However, its hydrophilic properties limit its application in the field of building insulation. Here, we propose a method to prepare high hydrophobicity by adopting the sol-gel method and chemical vapor reaction strategy using cellulose acetate type II as raw material and 2,4-toluene diisocyanate as the cross-linking agent. Thermal properties of cellulose acetate aerogels (CAAs) were measured, where pyridine was the catalyst, acetone was the solvent, and perfluorodecyltriethoxysilane (PFDS), hexamethyldisilazane (HMDS), and methyltriethoxysilane (MTES) were used as hydrophobic agents (by process hydrophobic test). Compared with MTES-modified cellulose acetate aerogels (M-CAAs) and HMDS (H-CAAs)-modified cellulose acetate aerogels, PFDS-modified (P-CAAs) cellulose acetate aerogels are the most hydrophobic. By implementing hydrophobic modification of PFDS both inside and outside the structure of cellulose acetate aerogels, the water contact angle can reach up to 136°, strongly demonstrating the potential of PFDS as a hydrophobic agent. The results show that the thermal conductivity and compressive strength of cellulose acetate aerogel with the best hydrophobic properties are 0.035 W m-1 K-1 at normal pressure and 0.39 MPa at 3% strain, respectively. This work shows that the highly hydrophobic cellulose acetate aerogel has potential as a waterproof material in the field of building thermal-insulation materials.

Copper-Lithium-Doped Nanohydroxyapatite Modulates Mesenchymal Stem Cells Homing to Treat Glucocorticoids-Related Osteonecrosis of the Femoral Head.

In situ tissue regeneration has been demonstrated to promote bone repair. To identify a better approach for treating osteonecrosis of the femoral head (ONFH), we prepared scaffolds using copper-lithium-doped nanohydroxyapatite (Cu-Li-nHA), which has the potential to modulate mesenchymal stem cells (MSCs) homing. The scaffold was fabricated using the gas foaming method and the migration, angiogenesis, and osteogenesis activities of MSCs were detected using Transwell assays, tube formation assays, alkaline phosphatase and alizarin red S staining, respectively. We then implanted the Cu-Li-nHA scaffold into the femoral heads of ONFH rabbits, and CFSE labeled exogenous MSCs were injected intravenously to verify cell homing. The repair effect was subsequently examined using micro-CT and histological analysis in vivo. The results showed that Cu-Li-nHA significantly promoted MSCs migration and homing by upregulating the HIF-1α/SDF-1 pathway. The Cu-Li-nHA group showed optimal osteogenesis and angiogenesis and greater improvements in new bone formation in ONFH rabbits. To summarize, Cu-Li-nHA promoted homing and induced the osteogenic differentiation of MSCs, thereby enhancing bone regeneration during ONFH repair. Thus, Cu-Li-nHA implantation may serve as a potential therapeutic strategy for ONFH in the future.

The effects of body mass index on insulin resistance in patients undergoing total hip arthroplasty: a pilot study.

PURPOSE: We aimed to examine the effects of body mass index (BMI) on insulin resistance (IR), glycaemic control and adverse events in patients undergoing total hip arthroplasty (THA). METHODS: A total of 118 patients undergoing THA were enrolled in this prospective cohort study and divided into two groups based on their BMI: Group A (n = 50, 18.5 ≤ BMI < 24 kg/m2) and Group B (n = 68, BMI ≥ 24 kg/m2). IR was calculated using Homeostasis Model Assessment 2 (HOMA2). Insulin resistance indicators, fasting plasma glucose (FPG), inflammatory markers, blood loss, length of stay and complications were compared between the two groups. RESULTS: Multivariate analysis using generalized estimating equations revealed that BMI and surgery stress were risk factors for IR (P < 0.001). These two factors exhibited significant interactions for HOMA2-IR on post-operative day one (Exp (B) = 1.880, P = 0.003), accompanied by a higher level of FPG (Group B versus Group A, P = 0.004). Furthermore, subgroup analysis based on the IR value demonstrated that patients in Group B with a HOMA2-IR greater than 2.25 after surgery were at increased risk of wound complications (P = 0.045). Similarly, our results showed that the rate of post-operative hyperglycaemia was notably higher in Group B than in Group A (P = 0.013). CONCLUSION: Patients with high BMI may experience significantly elevated IR and increased risk of hyperglycaemia and wound complications after THA. Therefore, routine glycaemia monitoring should be suggested for those patients during peri-operative period to optimize surgical stress management.

Core Decompression Prevents Progression of Asymptomatic Type C Osteonecrosis of Femoral Head According to the Japanese Investigation Committee Classification: A Retrospective Study.

OBJECTIVE: To evaluate whether core decompression could prevent progression of asymptomatic type C osteonecrosis of the femoral head (ONFH) according to the Japanese Investigation Committee (JIC) classification. METHODS: This retrospective cohort study included 124 hips (117 patients) with asymptomatic type C ONFH. Seventy-one hips (67 patients) received core decompression (core decompression group) and 53 hips (50 patients) received no surgical treatment (control group). Clinical and radiological follow-up was conducted at 6 and 12 months, then annually until 5 years. Clinical outcomes were evaluated in terms of the Oxford hip score and UCLA Activity Level rating. Radiological outcomes were evaluated using X-ray and magnetic resonance imaging. Survival analysis was performed based on collapse of the femoral head as the first endpoint and total hip arthroplasty (THA) as the second endpoint. RESULTS: There were no significant differences in clinical outcomes between the core decompression group and the control group within 2 years after surgery. Patients in the core decompression group had significantly better Oxford hip score and UCLA Activity Level from year 3 to the end of follow-up (P < 0.05). In year 5, the absolute difference in Oxford hip score (5.3 points) exceeded the reported minimal clinically important difference (MCID, 5.2 points). In years 3-5, the absolute difference in UCLA Activity Level rating (0.95 points, 0.95 points, and 0.99 points, respectively) exceeded the reported MCID (0.92 points). By 5-year follow-up, significantly fewer patients in the core decompression group had experienced femoral head collapse (40.8% vs 62.3%, P = 0.011) or received THA (26.8% vs 45.3%, p = 0.022). CONCLUSIONS: Core decompression can prevent progression of asymptomatic type C ONFH according to the JIC classification, leading to better medium-term hip function and activity levels than no surgical treatment. Core decompression is recommended for early intervention against asymptomatic type C ONFH.

Porous tantalum shell and augment for acetabular defect reconstruction in revision total hip arthroplasty: a mid-term follow-up study.

AIM: The use of porous tantalum trabecular metal (TM) shell and augment to reconstruct acetabular defects in revision total hip arthroplasty (THA) is a reliable technique. We evaluated the mid-term implant survival, clinical, and radiological outcomes of our first 48 revisions using this technique. PATIENTS AND METHODS: A total of 45 patients (48 hips) who had acetabular revision of THA between 2011 and 2017 using TM shell and augment with possible mid-term follow-up were included. Twenty-two patients were men (49%) and 23 were women (51%), mean age was 62.5 years (34 to 85) and mean follow-up was 75 months (54 to 125). Twenty-four hips (50%) had a Paprosky IIIA defect, 14 (29.2%) had a type IIIB defect, six (12.5%) had a type IIC defect, and four hips (8.3%) had a type IIB defect. None of the patients had pelvic discontinuity (PD). RESULTS: At a mean 6.25 years follow-up, all hips remained well-fixed and implant survival of 100% with the need of re-revision as the end point. Screw fixation was used for all shells; augments and the shell-augment interface was cemented. Excellent pain relief (mean WOMAC score pain 90.5, (38.3 to 100)), and functional outcomes (mean WOMAC function 88.3 (31.9 to 100), mean OHS 89.2 (31.8 to 100)) were noted. Patient satisfaction scores were excellent. CONCLUSION: This study demonstrated satisfactory mid-term clinical and radiological outcomes of using TM shell and augment for reconstructing major acetabular defects without PD in revision THA.

Delivery of MiR335-5p-Pendant Tetrahedron DNA Nanostructures Using an Injectable Heparin Lithium Hydrogel for Challenging Bone Defects in Steroid-Associated Osteonecrosis.

Corticosteroids-induced Dickkopf-1 (DKK1) upregulation and Wnt signaling inhibition result in bone metabolism disorder and steroid-associated osteonecrosis (SAON). Implanting biomaterials to regulate the Wnt pathway is a promising method to repair challenging bone defects associated with SAON. Here, tetrahedral DNA nanostructures (TDNs) are fabricated as gene carriers to deliver MiR335-5p, which targets DKK1 translation. Heparin lithium hydrogel (Li-hep-gel) is synthesized to act as a lithium and MiR@TDNs delivery agent. Finally, the repair effects on challenging bone defect in SAON using a MiR@TDNs/Li-hep-gel composite are assessed in vivo. The results reveal that MiR@TDNs are absorbed by bone mesenchymal stem cells (BMSCs) and increase cell viability and reduce apoptosis. Moreover, MiR@TDNs promote alkaline phosphatase expression and calcium nodular deposition, decrease lipid droplet expression of BMSCs, and improve vascular endothelial growth factor secretion and vascular-like structure formation in vitro. After MiR@TDNs/Li-hep-gel is implanted into the SAON model, the internal bone defect of osteonecrosis is repaired with a large area of new bone accompanied with neovascularization and reduced empty lacunae. In conclusion, MiR@TDNs/Li-hep-gel can provide dual delivery of lithium and MiR@TDNs, which synergistically upregulate the Wnt signaling pathway, enhancing bone regeneration in challenging bone defects, and can be potentially used in SAON repair.

Additional nerve blocks are not superior to multiple-site infiltration analgesia in total knee arthroplasty under adductor canal block.

BACKGROUND: Adductor canal block (ACB) with additional nerve blocks (ANBs) is reported to provide adequate analgesia and enhanced functional rehabilitation in total knee arthroplasty (TKA). The present study aims to evaluate whether ANBs are superior to multiple-site infiltration analgesia (MIA) in patients undergoing TKA under ACB. METHODS: We enrolled 530 patients undergoing primary TKA from 2015 to 2019 at our institution in this retrospective cohort study. Patients were divided into two groups: Group A was treated with ANBs + ACB; Group B was treated with MIA + ACB. Primary outcomes were pain scores and morphine consumption. Functional recovery was the secondary outcome. Other outcomes included satisfaction score, cost-effectiveness, adverse events, and length of hospital stay (LOS). RESULTS: Pain scores at rest and morphine consumption were slightly lower in the ANBs + ACB group than in the MIA + ACB group. No significant difference was found in functional recovery, post-operative complications or LOS between the groups. Meanwhile, the cost of analgesic intervention in the MIA + ACB group was less than that in the ANBs + ACB group. CONCLUSION: The present study suggests that ANBs do not provide superior pain relief compared to MIA for patients undergoing TKA under ACB. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2100043227. Registered 9 February 2021, https://www.chictr.org.cn/showproj.aspx?proj=121745 .

Construction and Nanostructure of Chitosan/Nanocellulose Hybrid Aerogels.

Biomass aerogels have received extensive attention due to their unique natural characteristics. However, biomass-based chitosan aerogels are often confronted with the traditional issue concerning a weak skeleton structure, namely, the corresponding huge shrinkage for chitosan aerogels in the stage from the final gel to the aerogel. Herein, we put forward a new approach to enhance chitosan aerogels by introducing natural biomaterial cellulose nanocrystal (CNC). CNC is applied to connect/cross-link chitosan chains to form its networking construction through supramolecular interaction/physical entanglement, eventually realizing the enhancement of the chitosan aerogel network structure. Chitosan aerogels modified with CNC exhibit a high specific surface area of 578.43 cm2 g-1, and the pore size distribution is in the range of 20-60 nm, which is smaller than the mean free path of gas molecules (69 nm), triggering a "no convection" effect. Hence, the gaseous heat transfer of chitosan aerogel is effectively suppressed. Chitosan aerogels with the addition of CNC show an excellent thermal insulation property (0.0272 W m-1 K-1 at ambient condition) and an enhanced compressive strength (0.13 MPa at a strain of 3%). This improvement method of chitosan aerogel in enhancing the skeleton structure aspect provides a new kind of idea for strengthening the nanoscale morphology structure of biomass aerogels.

Effect of carbazochrome sodium sulfonate combined with tranexamic acid on blood loss and inflammatory response in patients undergoing total hip arthroplasty.

AIMS: The purpose of this study was to examine the efficacy and safety of carbazochrome sodium sulfonate (CSS) combined with tranexamic acid (TXA) on blood loss and inflammatory responses after primary total hip arthroplasty (THA), and to investigate the influence of different administration methods of CSS on perioperative blood loss during THA. METHODS: This study is a randomized controlled trial involving 200 patients undergoing primary unilateral THA. A total of 200 patients treated with intravenous TXA were randomly assigned to group A (combined intravenous and topical CSS), group B (topical CSS), group C (intravenous CSS), or group D (placebo). RESULTS: Mean total blood loss (TBL) in groups A (605.0 ml (SD 235.9)), B (790.9 ml (SD 280.7)), and C (844.8 ml (SD 248.1)) were lower than in group D (1,064.9 ml (SD 318.3), p < 0.001). We also found that compared with group D, biomarker level of inflammation, transfusion rate, pain score, and hip range of motion at discharge in groups A, B, and C were significantly improved. There were no differences among the four groups in terms of intraoperative blood loss (IBL), intramuscular venous thrombosis (IMVT), and length of hospital stay (LOS). CONCLUSION: The combined application of CSS and TXA is more effective than TXA alone in reducing perioperative blood loss and transfusion rates, inflammatory response, and postoperative hip pain, results in better early hip flexion following THA, and did not increase the associated venous thromboembolism (VTE) events. Intravenous combined with topical injection of CSS was superior to intravenous or topical injection of CSS alone in reducing perioperative blood loss. Cite this article: Bone Joint Res 2021;10(6):354-362.

Analgesic Effects of Ultrasound-Guided Iliohypogastric/Ilioinguinal Nerve Block Combined with Lateral Femoral Cutaneous Nerve Block in Total Hip Arthroplasty via Direct Anterior Approach: A Retrospective Cohort Study.

OBJECTIVE: This study aimed to explore the efficacy and safety of the combination of lateral femoral cutaneous nerve blocks (LFCNB) and iliohypogastric/ilioinguinal nerve blocks (IHINB) on postoperative pain and functional outcomes after total hip arthroplasty (THA) via the direct anterior approach (DAA). METHODS: In this retrospective cohort study, patients undergoing THA via the DAA between January 2019 and November 2019 were stratified into two groups based on their date of admission. Sixty-seven patients received LFCNB and IHINB along with periarticular infiltration analgesia (PIA) (nerve block group), and 75 patients received PIA alone (control group). The outcomes included postoperative morphine consumption, postoperative pain assessed using the visual analogue scale (VAS), the QoR-15 score, and functional recovery measured as quadriceps strength, time to first straight leg rise, daily ambulation distance, and duration of hospitalization. The Oxford hip score and the UCLA activity level rating were assessed at 1 and 3 months after surgery. In addition, postoperative complications were recorded. Patients were also compared based on the type of incision used during surgery (traditional longitudinal or "bikini" incision). RESULTS: Patients in the nerve block group showed significantly lower postoperative morphine consumption, lower resting VAS scores within 12 h postoperatively, lower VAS scores during motion within 24 h postoperatively, and better QoR-15 scores on postoperative day 1. These patients also showed significantly better functional recovery during hospitalization. At 1-month and 3-month outpatient follow up, the two groups showed no significant differences in Oxford hip score or UCLA activity level rating. There were no significant differences in the incidence of postoperative complications. Similar results were observed when patients were stratified by type of incision, except that the duration of hospitalization was similar. CONCLUSION: Compared to PIA alone, a combination of LFCNB and IHINB along with PIA can improve early pain relief, reduce morphine consumption, and accelerate functional recovery, without increasing complications after THA via the DAA.

Ultrasound-guided adductor canal block combined with lateral femoral cutaneous nerve block for post-operative analgesia following total knee arthroplasty: a prospective, double-blind, randomized controlled study.

PURPOSE: The purpose of this study was to investigate whether adductor canal block (ACB) combined with lateral femoral cutaneous nerve block (LFCNB) could improve the efficacy of post-operative analgesia in a comparison with a standard peri-articular infiltration analgesia (PIA) after a total knee arthroplasty (TKA). METHODS: One hundred and sixty patients of scheduled unilateral primary TKA were randomly allocated into two groups for post-operative analgesia. Eighty cases were treated with ACB combined with LFCNB and the other eighty treated with PIA. The primary outcomes were pain visual analogue scale (VAS) and rescue pain killer consumption, and the secondary outcomes were knee active range of motion (ROM), quadriceps strength, patients' ambulation ability, Knee Society Score (KSS), length of hospital stay, and adverse events. RESULTS: We found that ACB combined with LFCNB was better on decreasing the post-operative pain score within 12 hours at rest and 8 h with activity (p < 0.05) and provided longer duration of analgesia (19.91 ± 5.09 VS 12.06 ± 3.67 h, p < 0.01) and less rescue morphine consumption (13.63 ± 9.84 vs 18.00 ± 11.52 mg, p = 0.011) than the PIA. There was no significant difference between the two groups (p > 0.05) in terms of knee ROM, quadriceps strength, daily mobilization distance, KSS, and complication occurrence. CONCLUSIONS: ACB combined with LFCNB provides a significantly better pain control, less opioid consumption, and longer duration of analgesia than peri-articular infiltration while preserving muscle function without affecting knee functional recovery nor the length of stay or side effects occurrence.

A bone regeneration strategy via dual delivery of demineralized bone matrix powder and hypoxia-pretreated bone marrow stromal cells using an injectable self-healing hydrogel.

Demineralized bone matrix (DBM) powder is a potential alternative bone grafting material due to its bone regeneration capacity when the supply of autogenous bone is insufficient. However, the use of DBM powder alone remains challenging in many aspects in the clinic, such as its unstable osteoinductivity due to inactivation of growth factors during the preparation process, lack of bone regeneration cells, and difficulty in handling. Herein, we report a strategy that adopts a dual delivery of DBM powder and hypoxia-pretreated bone marrow stromal cells (BMSCs) using an injectable self-healing hydrogel to enhance bone regeneration and repair a cranial bone defect in a rabbit model. The injectable self-healing hydrogel was prepared based on a double crosslinking architecture, which comprised a dynamically cross-linked Schiff-base network as a self-healing component and a borax ion cross-linked physical network that strengthened its mechanical properties. The handling of the DBM powder was improved by mixing with the hydrogel, and, more importantly, the expression of osteocalcin (OCN) and vascular endothelial growth factor (VEGF) of the encapsulated BMSCs in the hydrogel was significantly up-regulated after hypoxia-pretreatment. The in vivo study demonstrated that the use of the hydrogel alone cannot heal the cranial bone defect, while the hydrogel/BMSC composite could increase the bone formation but was inferior to the hydrogel/DBM composite. Finally, the hydrogel/DBM/BMSC composite exhibited the best bone defect repairing effects among all groups. Overall, our results demonstrate that this dual delivery approach is a promising strategy to enhance bone regeneration for bone defect repair.

Comparison of Postoperative Outcomes Between Traditional Longitudinal Incision and Bikini Incision in Total Hip Arthroplasty via Direct Anterior Approach: A Randomized Controlled Trial.

BACKGROUND: The purpose of this study is to compare a traditional longitudinal incision to an oblique "bikini" incision during total hip arthroplasty (THA) via direct anterior approach (DAA), in terms of the aesthetic appearance of the scar, postoperative functional recovery, and complications. METHODS: This study is a single-surgeon experience in the Chinese population. Patients who came to our institute needing a THA via DAA were enrolled in our randomized controlled trial and randomly allocated to undergo traditional longitudinal incision (control) or bikini incision. Primary outcomes were measured using the scar cosmesis assessment and rating scale, the visual analog scale for pain, Oxford hip score, and University of California Los Angeles activity-level rating. Secondary outcomes were postoperative serum markers of muscle damage, inflammation, hemoglobin drop, and implant stability. The occurrence of postoperative complications, such as nerve and wound healing, was also recorded. RESULTS: There were no differences in demographic or clinical characteristics before surgery. A greater proportion of patients in the bikini group were satisfied with the appearance of their scar, giving significantly better scar cosmesis assessment and rating scores. There was no difference in postoperative functional recovery, levels of serum markers, or positioning of the implant components. Incision type had no effect on duration of hospitalization. The incidence of complications did not differ significantly between groups. CONCLUSION: The bikini incision can improve patients' subjective satisfaction with scar aesthetics after THA via DAA and does not detract from a quick functional recovery. Studies with larger sample sizes should be conducted to further investigate associated complications. THE CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR1900022870.

Intravenous tranexamic acid for reducing perioperative blood loss during revision hip arthroplasty: A retrospective study.

OBJECTIVE: This study aimed to explore the efficacy and safety of intravenous tranexamic acid (TXA) for reducing perioperative blood loss and allogeneic blood transfusions in revision hip arthroplasty. METHODS: TXA was routinely administered as an intravenous preoperative dose in all the revision hip arthroplasty cases in our institution from December 2012. We retrospectively reviewed 803 patients who underwent revision hip arthroplasty from January 2008 to September 2018. These patients were divided into 2 groups based on whether they received intravenous TXA (n=482; 231 men and 251 women; mean age: 63.27±11.73 years) or not (n=321; 159 men and 162 women; mean age: 63.91±11.69 years). The 2 groups were compared in terms of estimated intraoperative blood loss, visible blood loss, hidden blood loss, the rate and volume of allogeneic blood transfusions, and the incidence of symptomatic venous thromboembolism. The patients were also compared depending on whether they underwent total hip revision, isolated acetabular revision, or isolated femoral revision. RESULTS: Regardless of the type of revision involved, the patients who received TXA showed significantly lower estimated intraoperative blood loss, visible blood loss, hidden blood loss, and allogeneic blood transfusion rate and volume (all p values were less than 0.001). Use of TXA was not associated with significant changes in the incidence of postoperative symptomatic venous thromboembolism (p=0.911). Similar results were obtained with subgroups of patients who underwent different types of revision surgeries, except hidden blood loss (p=0.994) of patients in the isolated femoral revision subgroup. CONCLUSION: The administration of intravenous TXA can safely and effectively reduce the perioperative blood loss and allogeneic blood transfusions in revision hip arthroplasty. LEVEL OF EVIDENCE: Level III, Therapeutic study.