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.

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.

Total hip arthroplasty with porous tantalum trabecular metal pads in patients with Crowe IV developmental dysplasia of the hip: a midterm followup study.

PURPOSE: Crowe IV developmental dysplasia of the hip (DDH) is a catastrophic hip disease. Moreover, obtaining ideal clinical efficacy in conventional total hip arthroplasty (THA) is often difficult. In this study, we aimed to assess the mid-term clinical results of THA with porous tantalum trabecular metal (TM) pads for acetabular reconstruction in the treatment of Crowe IV DDH. METHODS: A cohort of 28 patients (32 hips) diagnosed with Crowe type IV DDH who underwent acetabular reconstruction during THA using TM pads with scheduled follow-up between 2011 and 2018, were included in this study. Eight cases were men and 24 were women, with a mean age of 48.4 years (range, 36-72 years) and a mean follow-up was 74.3 months (range, 42-132 months). All patients underwent acetabular reconstruction using TM pads and total hip replacement with subtrochanteric osteotomy. RESULTS: At the final follow-up, 28 hips (87.5%) demonstrated mild or no postoperative limping. The Harris Hip Score improved from 58.4 ± 10.6 preoperatively to 85.6 ± 8.9. The mean pain, stiffness, and function scores on the Western Ontario and McMaster University Osteoarthritis index were 86.5 ± 10.2, 87.3 ± 12.4 and 85.4 ± 11.6 respectively. The mean score of patient satisfaction was 90.4 ± 7.6. Additionally, the SF-12 physical summary score was 41.8 ± 5.6 and the SF-12 mental summary score was 51.6 ± 5.4. TM construct survivorship due to all-cause failure was 90.6% at 5 years with 3 hips at risk, 87.5% at 10 years with 4 hips at risk. The survivorship due to failure from aseptic loosening was 96.9% at 5 years with 1hips at risk and 93.75% at 10 years with 2 hips at risk. CONCLUSION: This study demonstrated satisfactory mid-term clinical and radiological results with the application of TM pads for acetabular reconstruction combined with THA in patients with Crowe IV DDH. TRIAL REGISTRATION NUMBER: ChiCTR1800014526, Date: 18/01/2018.

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.

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.

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.

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.

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.

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.

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.

Femoral Head and Neck Fenestration Through a Direct Anterior Approach Combined With Compacted Autograft for the Treatment of Early Stage Nontraumatic Osteonecrosis of the Femoral Head: A Retrospective Study.

BACKGROUND: This study aimed to evaluate the effect of femoral head and neck fenestration combined with compacted autograft (light bulb procedure) through a direct anterior approach for early stage nontraumatic osteonecrosis of the femoral head. METHODS: We conducted a retrospective cohort study investigating 66 hips undergoing the light bulb procedure through the direct anterior approach (light bulb group) and 59 hips undergoing traditional core decompression (control group). Visual analog scale pain scores and range of hip motion were evaluated before discharge to assess the quality of functional recovery. Follow-up was conducted at 6 weeks, 3 months, 6 months, and annually after surgery until 4 years. The clinical effectiveness was evaluated by Harris hip score and the University of California Los Angeles activity-level score. Patients were followed up with postoperative X-ray and computed tomography. Survival was compared between the 2 groups by radiographic progression and receiving total hip arthroplasty. RESULTS: There was no significant difference in quality of functional recovery between the 2 groups. There were no significant differences in clinical outcomes within 1 year after surgery. Patients in the light bulb group had significantly better Harris hip scores and University of California Los Angeles activity-level scores from 2 years after surgery to the end of follow-up. During the 4-year follow-up, significantly fewer patients in light bulb group had radiographic progression (22.7% vs 44.1%) or received total hip arthroplasty (15.2% vs 30.5%). CONCLUSIONS: The light bulb procedure through a direct anterior approach offers significantly better results for the treatment of early stage nontraumatic osteonecrosis of the femoral head compared with traditional core decompression.

Hemostatic and Anti-Inflammatory Effects of Carbazochrome Sodium Sulfonate in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Postoperative recovery after total knee arthroplasty (TKA) is associated with postoperative anemia, allogeneic transfusion, and stress immune responses to surgery. Carbazochrome sodium sulfonate (CSS) reduces bleeding through several mechanisms. We assessed the effect of CSS combined with tranexamic acid (TXA) on postoperative anemia, blood transfusion, and inflammatory responses. METHODS: This study was designed as a randomized, placebo-controlled trial of 200 patients undergoing unilateral primary TKA. Patients were divided into 4 groups: group A received TXA plus topical and intravenous CSS; group B received TXA plus topical CSS only; group C received TXA plus intravenous CSS only; group D received TXA only. RESULTS: Total blood loss in groups A (609.92 ± 221.24 mL), B (753.16 ± 247.67 mL), and C (829.23 ± 297.45 mL) was lower than in group D (1158.26 ± 334.13 mL, P < .05). There was no difference in total blood loss between groups B and C. We also found that compared with group D, the postoperative swelling rate, biomarker level of inflammation, visual analog scale pain score, and range of motion at discharge in groups A, B, and C were significantly improved (P < .05). No thromboembolic complications occurred. There were no differences in transfusion rate, intraoperative blood loss, platelet count, or average length of stay among the 4 groups (P > .05). CONCLUSION: CSS combined with TXA was more effective than TXA alone in reducing perioperative blood loss and inflammatory response and did not increase the incidence of thromboembolism complications.

Glucocorticoid Enhanced the Expression of Ski in Osteonecrosis of Femoral Head: The Effect on Adipogenesis of Rabbit BMSCs.

Glucocorticoid (GC)-induced osteonecrosis has been considered as the most serious side effect in long-term or over-dose steroid therapy. The decreased bone mass and increased marrow fat tissue demonstrated that GC can destroy the normal differentiation of bone marrow mesenchymal stem cells (BMSCs), which accelerates adipogenesis but not osteogenesis. However, the underlying mechanisms are still unclear. Ski, an evolutionary conserved protein, is a multifunctional transcriptional regulator that involved in regulating signaling pathways associated with adipogenesis differentiation, but the concrete function remains unclear. In this work, we first established a methylprednisolone (MPS)-induced osteonecrosis of femoral head (ONFH) rabbit model, in which the expression of Ski, PPAR-γ, and FABP4 was up-regulated compared with control group, and then we induced the isolated BMSCs from rabbit with dexamethasone (Dex) in vitro and the results showed that the Ski expression was up-regulated by Dex in a dose- and time-dependent manner. Therefore, we demonstrated that the expression of Ski was up-regulated in glucocorticoid-related osteonecrosis disease in vivo and in vitro. Moreover, the adipogenesis differentiation capacity of BMSCs was enhanced after induced by Dex, which was identified by Oil Red O staining, and the up-regulated PPAR-γ and FABP4 expression. To further study the function of Ski in BMSC after induced by Dex, Ski specific small interfering RNA (Ski-siRNA) was used. Results showed that knockdown of Ski obviously decreased adipogenesis differentiation evident by Oil Red O staining, and the expression of PPAR-γ and FABP4 was down-regulated simultaneously. Collectively, our findings suggest that Ski increased significantly during glucocorticoid-induced adipogenic differentiation of BMSCs, and the expression level was consistent with adipogenic-related proteins including PPAR-γ and FABP4. Based on the above data, we believe that Ski might become a new molecule in the treatment of GC-induced ONFH and our study could provide a basis for further study on the detailed function of Ski in ONFH.

Efficacy of Single-Shot Adductor Canal Block Combined With Posterior Capsular Infiltration on Postoperative Pain and Functional Outcome After Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study.

BACKGROUND: Adductor canal block (ACB) may preserve muscle strength and promote faster recovery than other methods of analgesia following total knee arthroplasty (TKA). However, there are contradictory reports on the efficacy of ACB. Here, we evaluated the efficacy of single-shot ACB combined with posterior capsular infiltration (PCI) vs multimodal periarticular infiltration analgesia in treating postoperative pain. METHODS: This study involved patients undergoing unilateral primary TKA at our institution from January 2018 to January 2019. Patients were randomized into 2 groups, one of which was treated with ACB combined with PCI, and the other with periarticular infiltration analgesia. Primary outcomes included postoperative pain as assessed by the visual analog scale (VAS) and consumption of morphine hydrochloride. The secondary outcome was functional recovery, as assessed by range of knee motion, quadriceps strength, and daily ambulation distance. Tertiary outcomes included the duration of hospital stay and postoperative adverse effects. RESULTS: Patients treated with ACB and PCI had lower resting VAS scores at 8 and 24 hours after surgery, and lower VAS scores during motion within 48 hours after surgery. Patients treated with ACB and PCI also consumed less morphine. There was no difference in functional recovery, duration of hospitalization, or incidence of adverse events. CONCLUSION: The ACB combined with PCI can reduce postoperative pain sooner after TKA without affecting postoperative functional recovery and increasing complications.

Effect of Intravenous Corticosteroids on Pain Management and Early Rehabilitation in Patients Undergoing Total Knee or Hip Arthroplasty: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Corticosteroids are frequently used for the treatment of postoperative nausea and vomiting, and have also been reported to have an effect on postoperative analgesia. This study was conducted to assess the pain management effect of perioperative intravenous corticosteroids in patients undergoing total knee or hip arthroplasty and evaluate their early rehabilitation. METHOD: Randomized controlled trials (RCTs) were searched from electronic databases, including PubMed, Web of Science, Embase (Ovid interface), and the Cochrane Library (Ovid interface). Among 932 records identified, 14 RCTs involving 1,023 patients were eligible for data extraction and meta-analysis. RESULTS: The use of intravenous steroids was associated with reduced pain at rest and with activity during the first 24 hours after operation (P < 0.05). Patient steroid groups had less opioid consumption (P < 0.05). Additionally, patients using intravenous corticosteroids had better outcomes, in terms of nausea and vomiting (both P < 0.05). Moreover, corticosteroids were effective in decreasing the inflammatory marker interleukin-6 (P < 0.05). Complications such as deep infection and pruritus showed similar occurrence in both the corticosteroid groups and control groups (P > 0.05), while the occurrence of venous thromboembolism was lower in the corticosteroid groups, with a marginally significant difference. In addition, no significant difference in length of hospital stay was observed, irrespective of whether patients received intravenous corticosteroids (P > 0.05). CONCLUSION: Our results show that intravenous corticosteroids have good efficacy and safety when used perioperatively in total knee or hip arthroplasty.

Evaluation of the osteogenesis and angiogenesis effects of erythropoietin and the efficacy of deproteinized bovine bone/recombinant human erythropoietin scaffold on bone defect repair.

Erythropoietin (EPO) could promote the angiogenesis and may also play a role in bone regeneration. This study was conducted to evaluate the osteogenesis and angiogenesis effects of EPO and the efficacy of deproteinized bovine bone/recombinant human EPO scaffold on bone defect repair. Twenty-four healthy adult goats were chosen to build goat defects model and randomly divided into four groups. The goats were treated with DBB/rhEPO scaffolds (group A), porous DBB scaffolds (group B), autogenous cancellous bone graft (group C), and nothing (group D). Animals were evaluated with radiological and histological methods at 4, 8 and 12 weeks after surgery. The grey value of radiographs was used to evaluate the healing of the defects and the outcome revealed that the group A had a better outcome of defect healing compared with group B (P < 0.05). However, the grey values in group A were lower than group C at week 4 and week 8 (P < 0.05), but at week 12 their difference had no statistical significance (P > 0.05). The newly formed bone area was calculated from histological sections and the results demonstrated that the amount of new bone in group A increased significantly compared with that in group B (P < 0.05) but was inferior to that in group C (P > 0.05) at 4, 8, 12 weeks respectively. In addition, the expression of vascular endothelial growth factor (VEGF) by immunohistochemical testing and real-time polymerase chain reaction at 12 weeks in group A was significantly higher than that in group B (P < 0.05), and also better than that in group C at week 4 and week 8 (P < 0.05), but at week 12 their difference had no statistical significance (P > 0.05). Therefore, EPO has significant effects on bone formation and angiogenesis, and has capacity to promote the repair of bone defects. It is worthy of being recommended to further studies.

Adductor canal block provides better performance after total knee arthroplasty compared with femoral nerve block: a systematic review and meta-analysis.

PURPOSE: The methods for pain control after total knee arthroplasty (TKA) vary and have been extensively studied in recent years. Femoral nerve block (FNB) is used as the standard method due to its effective pain control following TKA, but it may weaken the quadriceps strength. Adductor canal block (ACB) is a newly developing analgesic protocol with fast functional recovery and good pain control after TKA. A meta-analysis was conducted to try to find out if ACB is better than FNB in pain treatment and joint functional recovery after TKA. METHODS: The databases PubMed, Web of Science, Embase, and Cochrane Library were systematically searched. Of 66 records identified, eight randomised controlled trials (RCT) involving 434 patients (504 knees) were eligible for data extraction and meta-analysis according to criteria included. RESULTS: Meta-analysis showed that ACB can significantly decrease visual analogue scale (VAS) score at rest within eight hours (p < 0.001) and at 24 hours (p < 0.001) after operation compared to FNB after TKA, and improve quadriceps strength (p < 0.001) and mobilization ability (p < 0.001). However, the differences in VAS score at rest at 48 hours, VAS score with activity within two days after operation, opioid consumption, hip adductor strength, patient satisfaction, and tourniquet times were not significant between the two groups. CONCLUSION: ACB provide better ambulation ability, faster functional recovery and better pain control at rest after TKA compared to FNB. The use of ACB post TKA is worthy of being recommended to replace FNB as a standard analgesic protocol for pain treatment after TKA.

Does patellar denervation reduce post-operative anterior knee pain after total knee arthroplasty?

PURPOSE: The effectiveness of patellar denervation in reducing anterior knee pain and improving patient satisfaction and quality of life after total knee arthroplasty (TKA) is still controversial. A meta-analysis was conducted to try to settle the controversy. METHODS: The electronic databases PubMed, Web of Science, Embase, and Cochrane Library were systematically searched. Of 374 papers identified, seven randomised controlled trials involving 898 patients (983 knees) were eligible for data extraction and meta-analysis. RESULTS: Analysis showed that patellar denervation can significantly improve clinical outcomes for the first 12 months of follow-up after TKA, including anterior knee pain incidence (P = 0.008), visual analogue scale score (P < 0.001), patellar score (P < 0.001), Knee Society Score (P = 0.03), Knee Society Score function score (P = 0.03), and knee range of motion (P = 0.008). However, no statistical significance in outcomes was found between the patellar denervation group and no-denervation group for any of those parameters after 12 months of follow-up. CONCLUSION: The best currently available evidence suggests that patellar denervation can significantly reduce anterior knee pain incidence and improve early clinical outcomes after TKA. However, after a prolonged period of follow-up, this advantage seems to disappear. Even so, the use of patellar denervation in primary TKA is recommended because it is safe and produces good early clinical outcomes. LEVEL OF EVIDENCE: Therapeutic study, Level II.

Total Hip Arthroplasty for Failed Internal Fixation After Femoral Neck Fracture Versus That for Acute Displaced Femoral Neck Fracture: A Comparative Study.

The outcome of total hip arthroplasty (THA) for failed internal fixation after femoral neck fracture (FNF) versus that for acute displaced femoral neck fracture is still controversial. This study retrospectively analyzed a consecutive series of 130 THAs for acute displaced FNF (64, group I) and for failed internal fixation (66, group II). Results showed THAs in group II were more technically demanding procedures with longer operative time and larger amounts of drainage compared to that in group I. Furthermore, multivariate analysis revealed that the associations between THAs (group II) and hip complications were notable (OR=4.15, P=0.017). These increased risks should be paid much attention to, not only for choosing the appropriate treatment option, but also for providing effective perioperative care.

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.