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The use of primary or revision stem during revision total hip arthroplasty (THA) for aseptic stem loosening with Paprosky type I/II femoral defect remains controversial. The aim of this study was to compare the outcomes of patients who underwent revision THA with a primary or revision stem.We retrospectively reviewed 78 patients who received revision THA for aseptic stem loosening using primary (N = 28) or revision stems (N = 50). The bone defects were classified as Paprosky type I or II. The mean follow-up duration was 72.3 ± 34.7 months. The primary outcome domains included surgical complications and implant failures. The secondary outcome domains included medical complications, 30- and 90-day readmission, and Harris hip score (HHS).The use of revision stem was associated with a higher incidence than primary stem of patient complications (60.0% vs. 32.1%, p = 0.018), including intraoperative femur fracture (28.0% vs. 7.1%, p = 0.029) and greater trochanter fracture (16.0% vs. 0%, p = 0.045). The implant survival rate was comparable between groups. HHS at the final follow-up was similar.With a lower risk of surgical complications and a similar rate of mid-term implant survival, cementless primary stem appears superior to revision stem in revision THA for aseptic stem loosening with Paprosky type I/II femoral defect.

BACKGROUND Total knee replacement (TKR) surgery is a treatment option for advanced hemophilic arthropathy. Due to its rarity and complexity, previous reports could only demonstrate the results of single-site studies including few cases. This population-based study aimed to investigate the major epidemiological characteristics, mean consumption of coagulation factors, length of hospital stays, complications, and failure rate of primary TKR for severe hemophilia patients in Taiwan. METHODS A cohort of 996 hemophilia patients registered between 1995 and 2011 were included, and 103 primary TKRs were performed on 75 patients. Unilateral TKR was performed on 47 patients and bilateral TKRs on the remaining 28 patients, including 12 simultaneous and 16 staged surgeries. The mean age at surgery was 32.3 years (range: 17.3-55.7), and the mean follow-up duration was 77.9 months (range: 2.3-176.8). RESULTS Failure was noted in 8 patients (8.5%) at mean 32.8 months (range: 2.3-95) after surgery. Four patients revealed aseptic loosening, whereas infection in 4. The 10-year prosthesis survivorship was 88.6%. For patients receiving unilateral TKR, the mean length of hospital stay was 15 days (range: 7-32). The mean cost of factor supplement was USD 43,543 with a mean 4-unit packed RBC transfusion (range: 0-38). The total admission cost was USD 48,326 (range: USD 4,165-262,619). CONCLUSION The prevalence of TKA for hemophilia patients was 7.5% in Taiwan. The mean hospital stays was 14 days and the 10-year prosthesis survivorship was 88.6%. The mean daily factors usage was decreased from 235.7 unites preoperatively to 202.1 units postoperatively. In comparison with the staged-bilateral TKRs, the simultaneous procedures significantly reduced the mean total cost from USD 101,923 to USD 61,587 (p=0.023). Therefore, in terms of cost-effectiveness, bilateral simultaneous TKR is more preferable than staged procedures.

The interspace between popliteal artery and the capsule of posterior knee (iPACK) block was proposed in recent years to relieve posterior knee pain. Since adductor canal block (ACB) and iPACK involve different branches of the sensory nerves, it is theoretically feasible to combine iPACK block and ACB to relief pain after total knee arthroplasty (TKA). We aim to validate the efficacy of adding iPACK block to ACB in the setting of a multimodal pain management protocol following TKA. A comprehensive literature review on Web of Science, Embase, the Cochrane Library, and PubMed was performed. Eight studies (N = 1,056) that compared the efficacy of iPACK block + ACB with ACB alone were included. Primary outcomes consisted of Visual Analogue Scale (VAS) score at rest or during activity at various time points. Secondary outcomes include opioids consumption, walking distance, and length of hospital stay (LOS). Compared to ACB alone, VAS scores at rest (standardized mean difference [SMD]: –1.18; 95% confidence interval [CI]: –2.05 to –0.30) and during activity (SMD: –0.26; 95% CI: –0.49 to –0.03) on the day of surgery were lower in the iPACK block + ACB group. However, the difference did not reach the minimal clinically important difference. Opioids consumption at postoperative 24 hours was lower in the iPACK + ACB group (SMD: –0.295; 95% CI: –0.543 to –0.048). VAS score on postoperative day (POD) 1 and POD2, opioids consumption from 24 to 48 hours, walking distance, and LOS were not different. In conclusion, the addition of iPACK block to ACB in a multimodal pain management protocol can effectively reduce opioids consumption in the early postoperative period. This is a level III, meta-analysis study.

Angiogenesis plays an important role in the development of bone and bone regeneration to provide the required molecules. Mesenchymal stem cells (MSCs) are pluripotent, self-renewing, and spindle-shaped cells, which can differentiate into multiple lineages such as chondrocytes, osteocytes, and adipocytes. MSCs derived from bone marrow (BMMSCs), adipose tissue (ADMSCs), and Wharton’s jelly (UCMSCs) are popular in the field of tissue regeneration. MSCs have been proposed that can promote bone regeneration by enhancing vascularization. In this study, the angiogenic potential of secretomes of undifferentiated and osteo-differentiated BMMSCs, ADMSCs, and UCMSCs seeded on human decellularized allogeneic bone were compared. Human umbilical vein endothelial cells (HUVECs) were treated with MSC secretomes. Cell growth, cell migration, and angiogenesis of HUVECs were analyzed by MTT, wound healing, and tube formation assays. Angiogenic gene expression levels of MSCs were evaluated using real-time quantitative PCR. Antibody neutralization was performed to validate the candidate target. Our study demonstrates that the angiogenic gene expression profile is tissue-dependent and the angiogenic ability of secretomes is independent of the state of differentiation. We also explore that IL-1b is important for MSC angiogenic potential. Taken together, this study proves that IL-1b in the secretomes plays a vital role in angiogenesis.

Patients with end-stage renal disease (ESRD) have inferior outcomes after hip and knee total joint arthroplasty (TJA), with higher risk for surgical site complications (SSC) and periprosthetic joint infection (PJI). We conducted a systematic review and meta-analysis regarding outcomes after hip and knee TJA in ESRD patients who have received dialysis or a kidney transplant (KT) using PubMed, MEDLINE, Cochrane Reviews, and Embase in order to: (1) determine the mortality and infection rate of TJA in patients receiving dialysis or KT and (2) to identify risk factors associated with the outcome. We included 22 studies and 9384 patients (dialysis, n = 8921, KT, n = 463). The overall mortality rate was 14.9% and was slightly higher in KT patients (dialysis vs. KT, 13.8% vs. 15.8%). The overall SSC rate was 3.4%, while dialysis and KT patients each had an incidence of 3.3% and 3.6%, respectively. For PJI, the overall rate was 3.9%, while the incidence for dialysis patients was 4.0% and for KT patients was 3.7%. Using multi-regression analysis, age, sex, the type of arthroplasty (knee or hip) performed, and the form of renal replacement therapy (dialysis or KT) were not significant risk factors. In patients on dialysis or who had received a KT, TJA is associated with a slight increase in mortality, SSC and PJI rates. Cite this article: EFORT Open Rev 2021;6:618-628. DOI: 10.1302/2058-5241.6.200116

Aims The aims of this study were to validate the outcome of total elbow arthroplasty (TEA) in patients with rheumatoid arthritis (RA), and to identify factors that affect the outcome. Methods We searched PubMed, MEDLINE, Cochrane Reviews, and Embase from between January 2003 and March 2019. The primary aim was to determine the implant failure rate, the mode of failure, and risk factors predisposing to failure. A secondary aim was to identify the overall complication rate, associated risk factors, and clinical performance. A meta-regression analysis was completed to identify the association between each parameter with the outcome. Results A total of 38 studies including 2,118 TEAs were included in the study. The mean follow-up was 80.9 months (8.2 to 156). The implant failure and complication rates were 16.1% (95% confidence interval (CI) 0.128 to 0.200) and 24.5% (95% CI 0.203 to 0.293), respectively. Aseptic loosening was the most common mode of failure (9.5%; 95% CI 0.071 to 0.124). The mean postoperative ranges of motion (ROMs) were: flexion 131.5° (124.2° to 138.8°), extension 29.3° (26.8° to 31.9°), pronation 74.0° (67.8° to 80.2°), and supination 72.5° (69.5° to 75.5°), and the mean postoperative Mayo Elbow Performance Score (MEPS) was 89.3 (95% CI 86.9 to 91.6). The meta-regression analysis identified that younger patients and implants with an unlinked design correlated with higher failure rates. Younger patients were associated with increased complications, while female patients and an unlinked prosthesis were associated with aseptic loosening. Conclusion TEA continues to provide satisfactory results for patients with RA. However, it is associated with a substantially higher implant failure and complication rates compared with hip and knee arthroplasties. The patient’s age, sex, and whether cemented fixation and unlinked prosthesis were used can influence the outcome. Level of Evidence: Therapeutic Level IV. Cite this article: Bone Joint J 2020;102-B(8):967–980.

The purpose of this study was to investigate the safety of Simultaneous, bilateral TKA (SiTKA). Furthermore, we also assessed the cost reduction of SiTKA in comparison with Staged, bilateral TKA (StTKA). We retrospectively review all patients that underwent SiTKA or StTKA due to osteoarthritis (OA) or spontaneous osteonecrosis of the knee (SONK).We assessed length of stay, transfusion rate, early postoperative complications, 30-day and 90-day readmission rate, 1-year reoperation rate and the indication for reoperation. Furthermore, we analyzed the total cost of the two groups, reimbursement from the national health insurance (NHI), cost of the procedures, and net income from each case. A total of 2016 patients (1565 SiTKA and 451 StTKAs) were included in this study. There were no significant differences in terms of complication rates, 30-day and 90-day readmission, and 1-year reoperations between the two groups. The total length of stay was on average 5.0 days longer for StTKA (p

Background The choice of femur stems during the hip arthroplasty procedures for patients with treatment failure of intertrochanteric fractures (ITF) remains controversial. We aimed to compare the surgical complication and reoperation rates between cementless primary and revision stems in the early (≤3 months) and late (> 3 months) fixation failures of ITF. Methods This was a retrospective, cohort study conducted in a single, tertiary referral hospital of Taipei, Taiwan. We included hip arthroplasty procedures for failed ITF using cementless primary or revision stems. There were 40 and 35 patients who had early and late fixation failure of ITF, respectively. The patient demographics, time to fixation failure, surgical complications and medical complications were recorded for analysis. Results We included 75 patients that underwent hip arthroplasty procedure for failed ITF using cementless primary (n = 38) or revision (n = 37) stems. The mean age was 79.3 years and 56% of the patients were female. In the early fixation failure group, the complication rate was similar between the primary and revision stems (44% vs. 29%, p = 0.343). However, there was a trend toward a higher reoperation rate (31% vs. 8%, p = 0.061) of using the primary stem, compared with the revision stem. In the late fixation failure group, the rate of complication and reoperation was similar between the two stem types. Conclusion For early fixation failures of ITFs, we caution against the use of cementless primary stems due to a trend towards an increased risk of reoperations compared to the use of cementless revision stems. However, in late fixation failures of ITFs, there is a role for cementless primary stems. Level of evidence III, retrospective cohort study.

IntroductionThe use of primary or revision stem during the first-time revision total hip arthroplasty(THA) procedure for aseptic stem loosening remains controversial. The aim of this study was to compare the outcome of patients that underwent revision THA with a primary or revision stem.Materials and MethodsWe retrospectively reviewed 78 patients that received first-time revision THA for aseptic stem loosening using primary(N=28) or revision stems(N=50). The bone defects were classified as Paprosky type I or II. The mean follow-up duration was 72.3±34.7 months. The primary outcome domains included surgical complications and implant failures. The secondary outcome domains included medical complications, 30-day and 90-day readmission, and Harris hip score (HHS).ResultsThe use of revision stem was associated with higher incidence of patient having complications (60.0% vs. 32.1%, p=0.018), including intraoperative femur fracture (28.0% vs. 7.1%, p=0.029) and greater trochanter fracture (16.0% vs. 0%, p=0.045), compared with the use of primary stem. The implant survival was comparable in both groups. HHS at the final follow-up was similar.ConclusionWith a lower risk of surgical complication and similar mid-term implant survival, cementless primary stem might be a better alternative to revision stem in the first-time revision THA for aseptic stem loosening.

Background The administration of an intra-articular injection (IAI) of tranexamic acid (TXA) has been demonstrated to be effective in reducing both blood loss and transfusion rate during total knee arthroplasty (TKA); however, few studies have reported the efficiency of a peri-articular injection (PAI) of TXA. We studied the efficiency of a PAI of TXA in reducing blood loss during TKA. Methods Fifty patients undergoing primary simultaneous bilateral TKA were enrolled in this retrospective study. The right knee received a PAI of 1 g of TXA (Group I), and the left knee received an IAI of 1 g of TXA (Group II). The clinical outcome measures were a change in blood loss from Hemovac drains and surgical time. Results The decrease in blood loss from the Hemovac was significantly lower in Group I (460.1 ± 36.79 vs. 576.0 ± 34.01, P Conclusions A PAI of TXA may reduce blood loss more efficiently than an IAI of TXA during TKA without increased complications such as surgical site infection, poor wound healing, skin necrosis, pulmonary embolism, and deep vein thrombosis.

Aims The aim of this meta-analysis was to compare the outcome of total elbow arthroplasty (TEA) undertaken for rheumatoid arthritis (RA) with TEA performed for post-traumatic conditions with regard to implant failure, functional outcome, and perioperative complications. Materials and Methods We completed a comprehensive literature search on PubMed, Web of Science, Embase, and the Cochrane Library and conducted a systematic review and meta-analysis. Nine cohort studies investigated the outcome of TEA between RA and post-traumatic conditions. The preferred reporting items for systematic reviews and meta-analysis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)) guidelines and Newcastle-Ottawa scale were applied to assess the quality of the included studies. We assessed three major outcome domains: implant failures (including aseptic loosening, septic loosening, bushing wear, axle failure, component disassembly, or component fracture); functional outcomes (including arc of range of movement, Mayo Elbow Performance Score (MEPS), and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire), and perioperative complications (including deep infection, intraoperative fracture, postoperative fracture, and ulnar neuropathy). Results This study included a total of 679 TEAs for RA (n = 482) or post-traumatic conditions (n = 197). After exclusion, all of the TEAs included in this meta-analysis were cemented with linked components. Our analysis demonstrated that the RA group was associated with a higher risk of septic loosening after TEA (odds ratio (OR) 3.96, 95% confidence interval (CI) 1.11 to 14.12), while there was an increased risk of bushing wear, axle failure, component disassembly, or component fracture in the post-traumatic group (OR 4.72, 95% CI 2.37 to 9.35). A higher MEPS (standardized mean difference 0.634, 95% CI 0.379 to 0.890) was found in the RA group. There were no significant differences in arc of range of movement, DASH questionnaire, and risk of aseptic loosening, deep infection, perioperative fracture, or ulnar neuropathy. Conclusion The aetiology of TEA surgery appears to have an impact on the outcome in terms of specific modes of implant failures. RA patients might have a better functional outcome after TEA surgery. Cite this article: Bone Joint J 2019;101-B:1489–1497

Recycled autografts have been commonly used in biological reconstruction in conjunction with wide bone resection. Extracorporeal irradiation (ECIR) and freezing are the two major options for pretreating tumor-bearing autografts before transplant. This study, for the first time, compared the effects of these two techniques on bone morphogenetic protein (BMP)-2 activity. Bone tissue extracted from human femoral heads were treated through either ECIR at different doses (5000, 15,000, and 30,000 rad) or liquid nitrogen (LN) freezing for different durations (5, 10, and 15 min). The amount of BMP was analyzed through enzyme-linked immunosorbent assay (ELISA assay). Furthermore, we also used tandem mass spectrometry to analyze change of BMP-2 and BMP-7 expression after high dosage of irradiation (30,000 rad) and long-time of freezing (15 min). To directly evaluate the effect of ECIR or LN freezing treatment on the activity of BMP, commercial recombinant human BMP-2 (rhBMP-2) was added to the culture of human mesenchymal stem cells (hMSCs). The post-treatment activity of rhBMP-2 was quantitated by measuring the osteogenic differentiation of hMSCs with Alizarin Red S staining. Through Western blotting, the activation of the BMP signaling pathway by phospho-Smad antibodies was analyzed. Our results showed that post-treatment levels of BMP did not differ among the ECIR and LN freezing treatments in ELISA assay, but tandem mass spectrometry showed significantly lower expression of BMP-2 after 30,000 rad of irradiation. Both ECIR and freezing lowered the expression of regulatory factors involved in the BMP-activated signaling cascades and similar results were also observed in osteogenic differentiation of hMSCs. However, LN freezing preserved better bioactivity of rhBMP-2 whereas dosage-dependent declination was observed in ECIR groups. In conclusion, considering BMP-2 activity, LN freezing-treated autografts may result in a better osteoinduction outcomes than those treated using ECIR. Further investigation of the factors involved in bone formation is required.

BACKGROUND To evaluate a single surgeon's experience with minimally invasive total knee arthroplasty (MIS-TKA) and report the 9-year learning curve and trends in clinical outcomes based on assessment of surgical skills, radiographic alignments, and patient's function scores. METHODS This retrospective study included a total of 4107 knees from 3403 patients undergoing bilateral or unilateral MIS-TKA between March 2004 and February 2013. MIS-TKA was performed through a modified mini-midvastus approach. Postsurgical care regime was standardized for all patients. Data of consecutive 3-month intervals were collected and compared for changes of trends in outcomes over time, including tourniquet time, intraoperative complications, radiographic alignment, the Knee Society Score (KSS), and functional scores. RESULTS Significant increase in the number of cases undergoing MIS-TKA per 3-month interval over the study period was observed. As surgeon's experience increased over time, tourniquet time was decreased from an average of 70 minutes to approximately 35 minutes. A total of 65 (1.68%) intraoperative complications were recorded and the frequencies were in a significant decreasing trend. The rate of malalignment was in a decreasing trend and steady desired alignment (6°) was achieved at the 15th three-month interval. KSS and function scores increased from 87.4 to 91.5 and 92.6 to 96.8, respectively. CONCLUSION Although a surgeon may become competent with MIS-TKA and achieved the preliminary learning curve within one year, experience accumulation continuously improved technical proficiency in MIS-TKA. This study confirmed significant improvements in surgical skills, postoperative alignment, and patients' function over time.

Purpose:The aim of this study was to evaluate outcomes of internal fixation for displaced femoral neck fracture (FNF) between 50 and 60 years old. The patient and surgical factors for the failure were identified.Methods:We retrospectively reviewed the records of 102 displaced FNF patients between 50 and 60 years old (mean age 54.9 years) who had undergone internal fixation between 2005 and 2016. The minimum follow-up was 12 months. Primary end points included loss of reduction, non-union, and osteonecrosis of the femoral head (ONFH). Preoperative Pauwel’s angle, fixation timing and methods, reduction quality, removal of implant and medical comorbidities were analysed.Results:The overall failure rate was 44.1%. In multivariate logistic regression analysis, poor reduction quality (adjusted odds ratio [aOR] 4.38; 95% confidence interval [CI], 1.54–12.46) and internal fixation delayed more than 6 hours (aOR 3.24; 95% CI, 1.08–9.69) were risk factors for all causes of failure. In a stratified analysis, poor reduction quality (aOR 3.81; 95% CI, 1.11–13.04) and a history of alcohol dependency (aOR 4.91; 95% CI, 1.09–22.13) were risk factors for loss of reduction. Internal fixation delayed >6 hours (aOR 3.67; 95% CI, 1.05–12.77) and removal of implant (aOR 3.32; 95% CI, 1.02–10.77) were risk factors for ONFH.Conclusions:The outcome of internal fixation of displaced FNF in patients between 50 and 60 years old is suboptimal. The patient selection is important. Non-alcohol dependency lowered early failure. Implant retention reduced ONFH. Surgery within 6 hours and good quality of reduction yield better results.

Background The aim of this study was to evaluate the influence of leg length discrepancy in geriatric patients with early failure of bipolar hemiarthroplasty and to identify related failure patterns and risk factors. Methods In this retrospective study, the risk factors of early acetabulum failure within 5 years of hemiarthroplasty for displaced femoral neck fracture were compared with a control group of patients who had implant survival for at least 5 years after hemiarthroplasty. The basic data, leg length discrepancy, femoral offset, and the shell size were evaluated. Results Of all risk factors, there was a significant difference in increased leg length between the two groups. The mean difference in leg length was 7.8 ± 5.9 mm in the early acetabular failure group and -1.7 ± 6.2 mm in the control group. For an increase in leg length of >6 mm, the odds ratio of early acetabular failure was 25-fold greater when compared with the control group. Conclusion Increased leg length was significantly associated with early acetabular failure after bipolar hemiarthroplasty for femoral neck fracture among geriatric patients. It is critical to avoid increase in leg length after bipolar hemiarthroplasty.

Background Dialysis-dependent patients undergoing primary total knee and total hip arthroplasty have been associated with higher in-hospital mortality and complication rates. We investigated the mid-term implant survival, patient survival, and functional outcomes in these patients and reviewed our complications. Methods We retrospectively reviewed dialysis-dependent patients undergoing primary total knee or total hip arthroplasty in our hospital between November 2004 and January 2015, with a minimum follow-up of 24 months. Thirty-four patients with 39 total knee arthroplasties were included (M:F, 33.3%:66.7%, mean age: 68.8 years, mean follow-up: 55.9 ± 28.3 months). Twenty-seven patients with 31 total hip arthroplasties were included (M:F, 22.6%:77.4%, mean age: 62.3 years, mean follow-up: 55.8 ± 23.4 months). Results In the total knee arthroplasty group, there were two in-hospital mortality cases (3.5%) and two cases of implant failure (5.1%). The mean Knee Society Score was 84.0 ± 20.7. In the total hip arthroplasty group, there were three cases of implant failure (9.7%). The mean Harris Hip Score was 81.1 ± 23.9. The complications we encountered for both groups were instability and infection. Conclusion Dialysis-dependent patients who had undergone total joint arthroplasty are associated with high mortality rate. In our experience, satisfactory mid-term results can be achieved in these patients with manageable complications and low-implant failure rates.

Background Evidence about the risk of bleeding and thromboembolism because of aspirin mono-therapy in total knee arthroplasty (TKA) is scant. We wanted to validate the risks of bleeding and thromboembolism with continued aspirin mono-therapy in unilateral and simultaneous bilateral TKA. Methods We enrolled a series of 1655 patients who underwent unilateral or simultaneous bilateral TKA between December 2010 and December 2012. Drainage amount, postoperative hemoglobin level, change in hemoglobin, calculated blood loss, incidence and the amount of blood transfused, and the proportion of thromboembolic events were compared between patients who were and patients who were not on continued aspirin mono-therapy. Results Calculated blood loss (969.1 ± 324.9 vs. 904.0 ± 315.5 ml), transfusion amounts (1.3 ± 1.5 vs. 1.0 ± 1.3 IU), and percentage of transfused patients (53.0% vs. 40.2%) were higher in unilateral TKA patients on continued aspirin mono-therapy. Outcome parameters and the proportion of DVT between groups were not significantly different. One patient (0.3%) not on aspirin mono-therapy developed a pulmonary embolism, and two others (0.6%) had cerebrovascular events. Conclusion Despite the slightly higher risks of bleeding, continuing aspirin mono-therapy during TKA might be safe with low risks of perioperative cerebrovascular, cardiovascular, and venous thromboembolic events.

Background The aims of this meta-analysis were to: (1) validate the outcome of modern dual mobility (DM) designs in patients who had undergone primary and revision total hip arthroplasty (THA) procedures and (2) to identify factors that affect the outcome. Methods We searched for studies that assessed the outcome of modern DM-THA in primary and revision procedures that were conducted between January, 2000 to August, 2020 on PubMed, MEDLINE, Cochrane Reviews and Embase. The pooled incidence of the most common failure modes and patient reported outcomes were evaluated in patients who have received: (1) primary THA, (2) revision THA for all causes or (3) for recurrent dislocation. A meta-regression analysis was performed for each parameter to determine the association with the outcome. The study design of each study was assessed for potential bias and flaws by using the quality assessment tool for case series studies. Results A total of 119 studies (N= 30016 DM-THAs) were included for analysis. The mean follow-up duration was 47.3 months. The overall implant failure rate was 4.2% (primary: 2.3%, revision for all causes: 5.5%, recurrent dislocation: 6.0%). The most common failure modes were aseptic loosening (primary: 0.9%, revision for all causes: 2.2%, recurrent dislocation: 2.4%), septic loosening (primary:0.8%, revision for all causes: 2.3%, recurrent dislocation: 2.5%), extra-articular dislocation (primary:0.6%, revision for all causes:1.3%, recurrent dislocation:2.5%), intra-prosthetic dislocation (primary:0.8%, revision for all causes:1.0%, recurrent dislocation:1.6%) and periprosthetic fracture (primary:0.9%, revision for all causes:0.9%, recurrent dislocation:1.3%). The multi-regression analysis identified younger age (β=-0.04, 95% CI -0.07 – -0.02) and female patients (β=3.34, 95% CI 0.91–5.78) were correlated with higher implant failure rate. Age, gender, posterolateral approach and body mass index (BMI) were not risk factors for extra-articular or intra-prosthetic dislocation in this cohort. The overall Harris hip score and Merle d’Aubigné score were 84.87 and 16.36, respectively. Level of evidence of this meta-analysis was IV. Conclusion Modern dual-mobility designs provide satisfactory mid-term implant survival and clinical performance. Younger age and female patients might impact the outcome after DM-THA. Future research directions should focus on, (1) long-term outcome of modern dual-mobility design, including specific concerns such as intra-prosthetic dislocation and elevated metal ion, and (2) cost-effectiveness analysis of dual-mobility implant as an alternative to conventional THA for patients who are at high risk of dislocation.

This retrospective, single-centre study compares the clinical and radiographic outcomes of limb reconstruction using recycled autografts to that using allografts. Patients with histopathologically verified high-grade osteosarcoma treated with wide bone resection and limb reconstruction using allografts or recycled autografts from January 1998 through December 2012 were retrospectively screened for enrolment eligibility. The final study cohort included 255 patients (allograft, 91; recycled autograft, 164). Data regarding post-operative complications, salvage treatment, and graft survival were collected. A modified International Society of Limb Salvage classification system was used to evaluate the radiographic findings. The time to graft–host union did not differ significantly between the two graft types. Patients receiving recycled autografts had fewer complications compared than did those receiving allografts (recycled autografts vs. allograft: structural failure, 4.3 vs. 13.2%; late infection, 2.4 vs. 7.7%; all p

Background Coronavirus disease 2019 (COVID-19) posed a major threat to the clinical practice of orthopedic surgeons, especially in the emergency department. We aim to present: (1) the criteria established by the Surgery Management Committee of Taipei Veterans General Hospital in response to COVID-19 and (2) the impact of COVID-19 screening on orthopedic trauma patients in the emergency department. Methods From April 1 to April 30, 2020, all orthopedic trauma patients in the emergency department were screened for COVID-19 if they fulfilled any of the following: (1) travel from abroad within 14 days, (2) high-risk occupation, (3) contact or cluster history with a COVID-19-positive patient, and (4) any associated symptom, including fever up to 38°C, cough, sore throat, rhinorrhea, loss of taste or smell, muscle soreness, malaise, or shortness of breath. We recorded details on the injury, fever, management, and associated outcomes. Results Of the 163 orthopedic trauma patients presenting to the emergency department, 24 were screened for COVID-19; of these, 22 received surgery. Sixty-two patients received surgery without screening for COVID-19. Fever was the most common reason to screen for COVID-19 (N = 20; 83.3%). No patients were COVID-19 positive. Screened patients had a significantly longer mean interval from presentation to the emergency department to surgery (2.7 ± 2.5 vs. 1.5 ± 0.8 days, p = 0.037). Of the 20 patients screened because of fever, the focus was not identified in 12 (60.0%) patients. The other eight had urinary tract infection (N = 6; 27.2%), septic hip (N = 1; 4.6%), and concomitant pneumonia and urinary tract infection (N = 1; 4.6%). The mean duration of fever and hospital stay was 4.3 ± 4.6 and 8.7 ± 4.9 days, respectively. There were no thromboembolic events, surgical complications, or in-hospital mortality. Conclusion We developed safe and reliable screening criteria for this COVID-19 pandemic. The delay in surgery was reasonable and did not adversely affect in-patient outcomes.

Background Elderly patients with femoral neck fractures are at a higher risk of dislocation after hip arthroplasty procedures. In comparison with total hip arthroplasty (THA), bipolar hemiarthroplasty (HA) and dual-mobility total hip arthroplasty (DM-THA) can be an effective alternative treatment which increases the effective head size and overall stability of the prosthesis. We aim to review the current evidence on the outcome after DM-THA and HA for femoral neck fractures in the elderly. Methods We performed a comprehensive review of literatures on PubMed, Embase, Web of Science, and the Cochrane Library for randomized controlled trials and comparative interventional studies. Of the 936 studies identified, 8 met the inclusion criteria (541 DM-THA and 603 HA procedures). Two reviewers independently reviewed and graded each study and recorded relevant data including dislocation rate, implant failure rate, reoperation rate, 1-year mortality rate, Harris hip score (HHS), operation time, and intraoperative blood loss. Results DM-THA was associated with a lower dislocation rate (OR 3.599; 95% CI 1.954 to 6.630), a lower reoperation rate (OR 2.056; 95% CI 1.211 to 3.490), an increased operation time (SMD − 0.561; 95% CI − 0.795 to − 0.326) and more intraoperative blood loss (SMD − 0.778; 95% CI − 1.238 to − 0.319), compared with the HA group. Moreover, the multivariate regression analysis revealed that age, female sex, posterolateral surgical approach, and choice of DM-THA or HA were not associated with dislocation or reoperation. Conclusions Based on the current evidence, the advantages reported for DM-THA over HA with regard to dislocation and reoperation rate in elderly patients with FNF remain inconclusive. High-quality studies on the high-risk patients with cognitive disorder or dementia are necessary to validate the value of DM-THA.

Introduction Type I, flat-wedge and type II, dual-wedge stems are currently two common stem types used in primary, uncemented hip arthroplasty. The prevalence of periprosthetic femur fracture is higher in type I stems, possibly because of the different shapes and areas of bone contact. We aimed to compare the fracture pattern, stem stability during the fracture and type of subsequent procedures in periprosthetic femur fractures between type I and II stems. Materials and Methods This was a retrospective, cross-sectional study conducted in a single tertiary referral hospital of Taipei, Taiwan. We included primary hip arthroplasty procedures using type I or type II stems complicated with postoperative periprosthetic femur fractures. We recorded the age, sex, ASA grade, index procedure, institution of where the index procedure was performed, trauma mechanism, time from index procedure to fracture, procedure for periprosthetic fracture and radiographic parameters including Dorr type, Vancouver classification, stem stability, fracture pattern, type and brand of the stems for analysis. Results We included 132 patients who had undergone surgery for periprosthetic femur fracture for type I (N = 46) or type II (N = 86) stems. The mean age was 74.5 years and 52.3% of the patients were female. Type I stems were associated with a higher proportion of a complex fracture pattern (52.2% vs. 8.2%), femoral stem loosening (78.2% vs. 60.4%) and a higher rate of revision stem procedures (69.6% vs. 50.0%) compared with type II stems. Using multivariate analysis, type I stem was the only factor for a complex fracture pattern in the overall population (aOR: 23.60, 95% CI: 6.54–85.16), hemiarthroplasty (aOR: 160.50, 95% CI: 9.77–2635.95) and total hip arthroplasty (aOR: 14.17, 95% CI: 2.92–68.79) subgroups. Conclusion We observed a difference in fracture patterns between type I and type II stems. Type I stems appear to be an independent risk factor for a complex fracture pattern in patients who had undergone primary hip arthroplasty.

Background The aims of this meta-analysis were to: (1) validate the outcome of modern dual mobility (DM) designs in patients who had undergone primary and revision total hip arthroplasty (THA) procedures and (2) to identify factors that affect the outcome.Methods We searched for studies that assessed the outcome of modern DM-THA in primary and revision procedures that have been conducted between January, 2000 to August, 2020 on PubMed, MEDLINE, Cochrane Reviews and Embase. The pooled incidence of common failure modes and functional scores were evaluated in patients who have received: (1) primary THA, (2) revision THA for all causes or (3) for recurrent dislocation. A meta-regression analysis was performed for each parameter to determine the association with the outcome.Results A total of 120 studies (N= 30016 DM-THAs) were included for analysis. The mean follow-up duration was 47.3 months. The overall implant failure rate was 4.2% (primary: 2.3%, revision for all causes: 5.5%, recurrent dislocation: 6.0%). The most common failure modes were aseptic loosening (primary: 0.9%, revision for all causes: 2.2%, recurrent dislocation: 2.4%), septic loosening (primary:0.8%, revision for all causes: 2.3%, recurrent dislocation: 2.5%), extra-articular dislocation (primary:0.6%, revision for all causes:1.3%, recurrent dislocation:2.5%), intra-prosthetic dislocation (primary:0.8%, revision for all causes:1.0%, recurrent dislocation:1.6%) and periprosthetic fracture (primary:0.9%, revision for all causes:0.9%, recurrent dislocation:1.3%). The multi-regression analysis identified younger age (β=-0.04, 95% CI -0.07 – -0.02) and female patients (β=3.34, 95% CI 0.91–5.78) were correlated with higher implant failure rate. Age, gender, posterolateral approach and body mass index (BMI) were not risk factors for extra-articular or intra-prosthetic dislocation in this cohort. The overall Harris hip score and Merle d’Aubigné score were 84.87 and 16.36, respectively.Conclusion Modern dual-mobility designs provide satisfactory mid-term implant survival and clinical performance. Younger age and female patients might impact the outcome after DM-THA.

Background Femoral neck fracture (FNF) is among the commonest fractures affecting the geriatric population. Hemiarthroplasty (HA) is a standard treatment procedure and has been performed by hip surgeons for decades. Recently, primary total hip replacement has proved advantageous for the treatment of such fractures. The aim of this study is to retrospectively review all causes of failure of all patients who underwent HA in our institute and reevaluated whether HA remains a favourable choice of treatment for patients with displaced FNFs. Methods A total of 4516 patients underwent HA at our centre from 1998 to 2017. The HA implants included unipolar and bipolar prostheses. Patients diagnosed with displaced FNF, underwent primary HA initially, required second revision procedures, and followed up for a minimum of 36 months were included in this study. Data were collected and comprehensively analysed. Results In 4516 cases, 99 patients underwent second surgeries. The revision rate was 2.19%. Reasons for failure were acetabular wear (n = 30, 30.3%), femoral stem subsidence (n = 24, 24.2%), periprosthetic fracture (n = 22, 22.2%), infection (n = 16, 16.2%), and recurrent dislocation (n = 7, 7.1%). The mean follow-up period was 78.1 months. The interval between failed HA and revision surgery was 22.8 months. Conclusion HA has a low revision rate and remains a favourable choice of treatment for patients with displaced FNFs. Levels of evidence Level III, Retrospective Cohort Study, Therapeutic Study.

Background Administration of an intra-muscular injection (IMI) of tranexamic acid (TXA) had been demonstrated to be effective in reducing both blood loss and the transfusion rate during total knee arthroplasty (TKA). However, few studies have reported on the efficiency of IMI of TXA. We studied the efficiency of IMI of TXA to reduce blood loss during TKA. Methods In this prospective study, 50 patients undergoing primary simultaneous bilateral TKA were enrolled. The right knee received a IMI of 1 g of TXA (Group I), and the left knee received an intra-articular injection (IAI) of 1 g of TXA (Group II). The clinical outcome measures were a change in hemoglobin levels, blood loss from Hemovac, and number of allogeneic blood units. Results Compared with Group II, the decrease in blood loss from Hemovac was significantly less for Group I (460.1 ± 36.79 vs. 576.0 ± 34.01, P

Background Cementation of a highly cross-linked polyethylene liner into a well-fixed acetabular shell provided a good durability for liner wear. However, its efficacy in treating recurrent instability due to malposition cup is less reported. The aim of this study is to evaluate the outcome of this surgical technique to treat hip instability. Methods From 2009 to 2019, we have identified 38 patients who had been surgically treated for recurrent instability, including cementation liner (N=20) and revision cup (N=18) procedures. Patients were followed for a mean of 45.66 months. We have recorded and analyzed all causes of implant failure including recurrent instability. Clinical outcomes were assessed including complication and Harris Hip Score (HHS) preoperatively and at the latest follow-up. Results Revision-free survivorship for any cause was 95.0% at 1 year, and 84.4 % at 5 years in cementation liner group and 88.9% at 1 year and 5 years in revision cup group. Mean Harris hip score improved from 48.3 points preoperatively to 79.5 points at the last follow-up in cementation liner group and mean HHS improved from 43.3 points preoperatively to 77.2 points in revision cup group. There were two implant failures in each group, including One is due to persistent hip instability and the other is due to periprosthetic joint infection in the cementation liner group and two implant failure are due to persistent hip instability in the revision cup group. Functional scores and implant survival were similar in both groups. Conclusion We demonstrated that orientation correction via the cementation of the polyethylene liner into well-fixed acetabular shell is a promising option to treat and prevent instability.

BackgroundFemoral neck fracture (FNF) is among the commonest fractures affecting the geriatric population. Hemiarthroplasty (HA) is a standard treatment procedure and has been performed by hip surgeons for decades. Recently, primary total hip replacement has proved advantageous for the treatment of such fractures. This study analysed the causes of HA failure and reevaluated whether HA remains a gold standard treatment for patients with displaced FNFs.MethodsA total of 4516 patients underwent HA at our centre from 1998 to 2017. The HA implants included unipolar and bipolar prostheses. Patients were enrolled who received the diagnosis of a displaced FNF, underwent primary HA initially, required second revision procedures, and were followed up for a minimum of 36 months. Data were collected and comprehensively analysed.ResultsIn 4516 cases, 99 patients underwent second surgeries. The revision rate was 2.19%. Reasons for failure were acetabular wear (n = 30, 30.3%), femoral stem subsidence (n = 24, 24.2%), periprosthetic fracture (n = 22, 22.2%), infection (n = 16, 16.2%), and recurrent dislocation (n = 7, 7.1%). The mean follow-up period was 78.1 months. The interval between failed HA and revision surgery was 22.8 months.ConclusionHA has an extremely low revision rate and remains a gold standard treatment for patients with displaced FNFs.Levels of Evidence: Level III, Retrospective Cohort Study, Therapeutic Study

Background Chondrosarcoma is the second most common primary sarcoma of the bone. Surgery remains the gold standard for treatment due to chemotherapy and radiotherapy resistance in chondrosarcoma. The main aim of our study was to analyze patients with primary chondrosarcoma of the bone who were treated in a single tumor center. Our study team identified the prognostic factors for overall survival, metastasis-free survival, and recurrence-free survival. Methods From 1998 to 2012, 55 consecutive patients were treated surgically. All patients were followed for local recurrence or distant metastasis. Uni- and multivariate analyses were performed for overall, metastasis-free, and recurrence-free survival. Results Local recurrence developed in 29 of the 55 patients (52.7%). Recurrence-free survival in the multivariate analysis showed a significant association with the surgical margin, and high-grade lesions were an independent factor for local recurrence. In total, 11 patients died of the disease in the study, and the 5- and 10-year survival rates were 84.4% and 78.1%, respectively. The tumor grade and local recurrence were significant factors in the univariate analysis but were insignificant in the Cox regression with time-dependent covariates (p = 0.327 and p = 0.82, respectively). The development of distant metastasis was a significant poor prognostic factor in both the uni- and multivariate analyses. Conclusion Chondrosarcoma of the bone is a disease with surgery-dependent outcomes; but, however, patients often develop subsequent recurrence of the disease. The surgical margins were statistically associated with the risk of subsequent local recurrence but did not predict survival. The development of distant metastases was an independent prognostic factor for poor survival.

Freezing nitrogen ethanol composite (FNEC) showed effective cryoablative ability for bone tumor ex vivo and in vivo comparable to liquid nitrogen (LN). We therefore wished to compare the radiant cooling damage of the surrounding tissue between FNEC and LN. The evaluation of the radiant cooling damage was demonstrated human bone xenograft transplantation (HXT) in a mouse model. Characterizations and quantifications of the damaging effects on morphologic features and apoptosis of the cryoablative surrounding bone tissue, muscle and epidermal layer of skin were compared. The radiant cooled damaging effects including epidermal rupture, hair follicle atrophy, dermis and subcutaneous crystal vacuolation of skin were significantly greater in LN than FNEC. Muscular apoptosis, structural shrinkage and bone cellular apoptosis were supposedly 15%-33% destroying degrees of LN more than FNEC. We concluded that FNEC is an innovative cryogenic material, and it could cause less cryoablative damage to surrounding normal tissue than LN. The findings might support the safety of FNEC being applied in clinical cryoablation therapy.

Background: Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor that typically affects young patients. Similar to other soft tissue sarcomas, it has high pulmonary metastasis ability, whereas compared with other soft tissue sarcomas, it has high brain metastasis ability. Because of the rarity of the disease, most studies on ASPS have been case reports and small series studies. Method: We performed a retrospective study to evaluate the clinical and pathological features and oncological results in a consecutive series of patients with localized or metastatic ASPS treated at our institute between 1994 and 2014. Demographics, location, severity of disease, treatment provided, progression-free survival, and overall survival were evaluated. Results: A total of 13 patients were investigated. The most common locations of primary tumor were the thigh (n = 6, 47%), followed by the flank (n = 3, 23%), forearm (n = 2, 15%), and calf (n = 2, 15%). Three patients were initially diagnosed as having hemangiomas elsewhere. These patients received unplanned intralesional excision. All the patients received wide tumor resection at our institute. Over the average follow-up period of 80.5 months (range: 36–133 months), the 5-year overall survival rate was 67.5%. Four patients were continuously disease free (31%), six were living with disease (46%), and three died of disease (23%). Of nine patients who presented with distant pulmonary metastasis, two had bony and brain metastases. The 5-year survival rate was 66.7% in patients who received chemotherapy and those who did not (p = 0.941). Conclusion: The treatment strategy for ASPS is wide resection, and postoperative chemotherapy may be crucial for long-term survival. In addition, this type of tumor has a high distant metastasis rate at the time of diagnosis, particularly in the lungs and brain. Keywords: Alveolar soft part sarcoma, Chemotherapy, Metastasis, Surgery

Background: Subsidence remains a common complication after revision hip arthroplasty which may lead to prolonged weight-bearing restrictions, leg-length discrepancies or considerable loss of function. We evaluated the effectiveness of cement augmentation in the proximal femoral metaphysis during a revision of femoral components to prevent post-operative stem subsidence. Methods: Forty patients were enrolled. Follow-up averaged 67.7 months (range: 24–149). Twenty-seven patients had a Paprosky type II defect and 13 had a type IIIa defect. All revision hip arthroplasty used a cementless, cylindrical, non-modular cobalt–chromium stem. The defect in the metaphysis was filled with antibiotic-loaded bone cement. Thirteen patients who had undergone stem revision only was allowed to walk immediately without weight-bearing restrictions. Twenty-seven patients who had undergone revision total hip arthroplasty was allowed partial weight-bearing within 6 weeks after surgery in the consideration of acetabular reconstruction. Results: Three patients (7.5%) had post-surgery stem subsidences of three mm, five mm, and 10 mm, respectively, at three, one, and 14 months. There were no acute surgical site infections. There were three femoral stem failures: two delayed infections and one periprosthetic Vancouver B2 fracture. Both five- and 10-year survivorships of the femoral implant were 90.1%. Conclusion: An adequate length of the scratch-fit segment and diaphyseal ingrowth remain of paramount importance when revising femoral components. To fill metaphyseal bone defects with antibiotic-loaded bone cement may be an alternative method in dealing with proximal femoral bone loss during a femoral revision. Keywords: Bone defect, Cement augmentation, Femur, Revision hip arthroplasty, Subsidence

Allogeneic bone grafts are a promising material for bone implantation due to reduced operative trauma, reduced blood loss, and no donor-site morbidity. Although human decellularized allogeneic bone (hDCB) can be used to fill bone defects, the research of revitalizing hDCB blocks with human mesenchymal stem cells (hMSCs) for osteochondral regeneration is missing. The hMSCs derived from bone marrow, adipose tissue, and Wharton’s jelly (BMMSCs, ADMSCs, and UMSCs, respectively) are potential candidates for bone regeneration. This study characterized the potential of hDCB as a scaffold for osteogenesis and chondrogenesis of BMMSCs, ADMSCs, and UMSCs. The pore sizes and mechanical strength of hDCB were characterized. Cell survival and adhesion of hMSCs were investigated using MTT assay and F-actin staining. Alizarin Red S and Safranin O staining were conducted to demonstrate calcium deposition and proteoglycan production of hMSCs after osteogenic and chondrogenic differentiation, respectively. A RT-qPCR was performed to analyze the expression levels of osteogenic and chondrogenic markers in hMSCs. Results indicated that BMMSCs and ADMSCs exhibited higher osteogenic potential than UMSCs. Furthermore, ADMSCs and UMSCs had higher chondrogenic potential than BMMSCs. This study demonstrated that chondrogenic ADMSCs- or UMSCs-seeded hDCB might be potential osteochondral constructs for osteochondral regeneration.

Background Cut-out failure is one of the most common complications in the Gamma3 nail fixation system. The purpose of this retrospective study was to determine pre-operative or intra-operative risk factors for cut-out failure of lag screws in unstable, intertrochanteric fractures fixed with short Gamma3 nails. Methods One hundred and seventy-six patients over 60 years of age, with unstable intertrochanteric fractures (AO/OTA 31-A2, 31-A3) treated with short Gamma3 nails were included in this study. All patients completed a minimum of 1-year follow-up. Analysis of post-operative radiographs included assessment for cut-out failure of lag screw, appropriateness of the entry point, posterior lag screw axis, fracture gaps, posterior displacement of the proximal fragment, and tip-apex distance. Results Of the 176 patients in this study, 22 patients were identified with cut-out failure. Multivariate logistic regression analysis revealed that improper entry point in an antero-posterior projection (odds ratio 10.39, 95% confidence interval 1.74–78.4), posterior displacement distance of the proximal fragment in a lateral projection (odds ratio 1.35, 95% confidence interval 1.17–1.59), and female sex (odds ratio 17.14, 95% confidence interval 1.88–876.11) were correlated with cut-out failure. Conclusion This study emphasizes the importance of an optimal position of reduction in the lateral projection in reducing the risk of cut-out failure. In addition, sex difference in bone mineral density, proximal femur geometry, and the bone strength in elderly females may explain why female sex is a risk factor.