Adipose-derived mesenchymal stem cells overexpressing prion improve outcomes via the NLRP3 inflammasome/DAMP signalling after spinal cord injury in rat.

Traumatic spinal cord injury (SCI) is a highly destructive disease in human neurological functions. Adipose-derived mesenchymal stem cells (ADMSCs) have tissue regenerations and anti-inflammations, especially with prion protein overexpression (PrPcOE ). Therefore, this study tested whether PrPcOE -ADMSCs therapy offered benefits in improving outcomes via regulating nod-like-receptor-protein-3 (NLRP3) inflammasome/DAMP signalling after acute SCI in rats. Compared with ADMSCs only, the capabilities of PrPcOE -ADMSCs were significantly enhanced in cellular viability, anti-oxidative stress and migration against H2 O2 and lipopolysaccharide damages. Similarly, PrPcOE -ADMSCs significantly inhibited the inflammatory patterns of Raw264.7 cells. The SD rats (n = 32) were categorized into group 1 (Sham-operated-control), group 2 (SCI), group 3 (SCI + ADMSCs) and group 4 (SCI + PrPcOE -ADMSCs). Compared with SCI group 2, both ADMSCs and PrPcOE -ADMSCs significantly improved neurological functions. Additionally, the circulatory inflammatory cytokines levels (TNF-α/IL-6) and inflammatory cells (CD11b/c+/MPO+/Ly6G+) were highest in group 2, lowest in group 1, and significantly higher in group 3 than in group 4. By Day 3 after SCI induction, the protein expressions of inflammasome signalling (HGMB1/TLR4/MyD88/TRIF/c-caspase8/FADD/p-NF-κB/NEK7/NRLP3/ASC/c-caspase1/IL-ß) and by Day 42 the protein expressions of DAMP-inflammatory signalling (HGMB1/TLR-4/MyD88/TRIF/TRAF6/p-NF-κB/TNF-α/IL-1ß) in spinal cord tissues displayed an identical pattern as the inflammatory patterns. In conclusion, PrPcOE -ADMSCs significantly attenuated SCI in rodents that could be through suppressing the inflammatory signalling.

Automatic Detection of Two Synovial Fluid Periprosthetic Joint Infection Biomarkers on an Integrated Microfluidic System.

Post-arthroplasty periprosthetic joint infection (PJI) is a serious ailment that can be difficult to diagnose. Herein, we developed a novel integrated microfluidic system (IMS) capable of detecting two common PJI biomarkers, alpha defensin human neutrophil peptide 1 (HNP-1) and C-reactive protein (CRP), from synovial fluid (SF). A magnetic bead-based one-aptamer-one-antibody assay was carried out automatically within 45 min on a single chip for simultaneous detection of both biomarkers at concentration ranges of 0.01-50 (HNP-1) and 1-100 (CRP) mg/L. It is the first report for utilizing these two biomarkers as targets to establish the new one-aptamer-one-antibody assay to detect PJI on-chip, and the aptamers demonstrated high specificity to their SF targets. As 20 clinical samples were correctly diagnosed with our IMS (verified by a common gold standard kit), it could serve as a promising tool for PJI diagnostics.

Impaction Bone Grafting Augmented With a Wire Coil by the Lightbulb Technique for Osteonecrosis of the Femoral Head.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a debilitating disease that primarily affects the hips of young adults. The purpose of this study is to report the mid-term results of impaction bone grafting augmented with a wire coil using the lightbulb technique for ONFH. METHODS: From 1998 to 2016, 50 hips with late precollapsed or early postcollapsed ONFH (28 hips with Association Research Circulation Osseous [ARCO] IIC and 22 with IIIA) were treated by impaction bone grafting augmented with a wire coil using the lightbulb technique. The survival rate was analyzed with conversion to total hip arthroplasty (THA) as the end point. RESULTS: Thirty-one of the 50 hips had a successful clinical result without conversion to THA at a mean follow-up of 109.2 months. The 5-year survival rate was 68%, 82.1%, and 50% for the entire cohort, ARCO stage IIC, and ARCO stage IIIA, respectively. The 19 hips that had failed were converted to THA at an average of 52.8 months. The multivariable Cox proportional hazards model showed that an ARCO stage IIIA disease, a lateral lesion, and a necrotic index ≥0.67 were the independent risk factors for conversion to THA. CONCLUSION: As a head-preserving procedure, the lightbulb technique using impaction bone grafting augmented with a wire coil is worthwhile for patients in an earlier stage of disease and smaller lesion size to postpone the need for THA.

Outcome and Predictors of Septic Failure Following Total Joint Arthroplasty for Prior Septic Arthritis of Hip and Knee Joint.

BACKGROUND: Arthroplasty patients with prior septic arthritis are at a high risk of developing periprosthetic joint infection (PJI). The aims of this study are to investigate the outcome and predictors of septic failure following total joint arthroplasty (TJA) for prior septic arthritis. In addition, the optimal timing of TJA is also discussed. METHODS: A retrospective review of 105 TJA patients with prior septic arthritis between January 2000 and December 2019 was performed. Patient-specific and surgery-related factors, organism profiles, and other relevant variables were recorded. RESULTS: At a mean follow-up of 10.3 years, the PJI rate was 16.2%. The adjusted Cox proportional hazards model showed that male gender (HR, 9.95; P < .01), end-stage renal disease (HR, 37.34; P < .01), debridement surgery ≥3 times (HR,4.75; P = .04) and polymicrobial infection in primary septic arthritis (HR, 10.02; P = .02) were independent risk factors for PJI. Neither the types of initial debridement, nor one-stage vs two-stage arthroplasty was related to the risk of PJI. While delaying the timing of TJA did not correlate with a reduction of PJI rate, there was a higher risk of PJI re-infection by the same microorganisms isolated in prior septic arthritis if TJA was performed within 6 months after septic arthritis. CONCLUSIONS: Our study demonstrated that male gender, end-stage renal disease (ESRD), multiple debridement surgeries and polymicrobial septic arthritis predisposed septic failure of TJA following prior septic arthritis. Surgeons should counsel patients with the potential complications, and be cognizant about the risk factors pertaining to septic failure when considering TJA.

The 2021 Association Research Circulation Osseous Classification for Early-Stage Osteonecrosis of the Femoral Head to Computed Tomography-Based Study.

BACKGROUND: The Association Research Circulation Osseous developed a novel classification for early-stage (precollapse) osteonecrosis of the femoral head (ONFH). We hypothesized that the novel classification is more reliable and valid when compared to previous 3 classifications: Steinberg, modified Kerboul, and Japanese Investigation Committee classifications. METHODS: In the novel classification, necrotic lesions were classified into 3 types: type 1 is a small lesion, where the lateral necrotic margin is medial to the femoral head apex; type 2 is a medium-sized lesion, with the lateral necrotic margin being between the femoral head apex and the lateral acetabular edge; and type 3 is a large lesion, which extends outside the lateral acetabular edge. In a derivation cohort of 40 early-stage osteonecrotic hips based on computed tomography imaging, reliabilities were evaluated using kappa coefficients, and validities to predict future femoral head collapse by chi-squared tests and receiver operating characteristic curve analyses. The predictability for future collapse was also evaluated in a validation cohort of 104 early-stage ONFH. RESULTS: In the derivation cohort, interobserver reliability (k = 0.545) and intraobserver agreement (63%-100%) of the novel method were higher than the other 3 classifications. The novel classification system was best able to predict future collapse (P < .05) and had the best discrimination between non-progressors and progressors in both the derivation cohort (area under the curve = 0.692 [0.522-0.863], P < .05) and the validation cohort (area under the curve = 0.742 [0.644-0.841], P = 2.46 × 10-5). CONCLUSION: This novel classification is a highly reliable and valid method of those examined. Association Research Circulation Osseous recommends using this method as a unified classification for early-stage ONFH. LEVEL OF EVIDENCE: Level III, diagnostic study.

Overexpression of miR-19a and miR-20a in iPS-MSCs preserves renal function of chronic kidney disease with acute ischaemia-reperfusion injury in rat.

This study tested the hypothesis that therapy with double overexpression of miR-19a-3p and miR-20a-5p (miRDOE ) to human inducible pluripotent stem cell-derived mesenchymal stem cells (iPS-MSCs) was superior to iPS-MSCs alone for preserving renal function in rat with pre-existing chronic kidney disease (CKD), followed by ischaemia-reperfusion (IR) injury. In vitro study demonstrated that the protein expressions of oxidative stress (NOX-1/NOX-2/NOX4/oxidized protein/p22phox), inflammatory downstream signalling (TLR2&4/MyD88/TRAF6/IKK-ß/p-NFκB/IL-1ß/IL-6/MMP-9) and cell apoptosis/death signalling (cleaved caspase-3/mitochondrial Bax/p-ERKs/p-JNK/p-p38) at time-points of 24-hour/48-hour cell cultures were significantly increased in p-Cresol-treated NRK-52E cells than in the control that was significantly reversed by miR-19a-3p-transfected iPS-MSC (all P < .001). Animals were categorized into group 1 (sham-operated control), group 2 (CKD-IR), group 3 (CKD-IR + oligo-miRDOE of iPS-MSCs/6.0 ×105 /intra-renal artery transfusion/3 hours after IR procedure), group 4 (CKD-IR + iPS-MSCs) and group 5 (CKD-IR + miRDOE of iPS-MSCs/6.0 ×105/ intra-renal artery transfusion/3 hour after IR procedure). By day 35, the creatinine/BUN levels were lowest in group 1, highest in group 2 and significantly lower in group 5 than in groups 3 and 4 (all P < .0001) but they showed no difference between the latter two groups. The protein expressions of oxidative stress, inflammatory downstream signalling and cell apoptosis/death signalling exhibited an identical pattern of creatinine level among the five groups (all P < .00001). Also, the microscopic findings demonstrated that the kidney injury score/fibrotic area/number of inflammatory cells (CD14+/CD68+) exhibited an identical pattern of creatine level (all P < .0001). The miRDOE of iPS-MSCs was superior to iPS-MSCs for preserving the residual kidney function and architecture in CKD-IR rat.

ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH) is a devastating disease frequently leading to femoral head collapse and hip arthritis. Specifically, non-traumatic ONFH primarily affects young and middle-aged adults. Although compromised local circulation of the femoral head seems to be pathognomonic for the disease, the pathogenesis is perplexing and continues to be an area of scrutiny and research. Comprehension of the pathogenesis is of crucial importance for developing and guiding treatments for the disease. Therefore, we provide an up-to-date consensus on the pathogenesis of non-traumatic ONFH.

Osteonecrosis of the Femoral Head: an Updated Review of ARCO on Pathogenesis, Staging and Treatment.

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Survival Analysis of Allografting and Antiprotrusio Cage in Treating Massive Acetabular Bone Defects.

BACKGROUND: Massive acetabular bone defects reconstructed with allografting and antiprotrusio cage in revision hip arthroplasty is less reported in the literature. We here report a series of 84 antiprotrusio cages and analyze the risk factors associated with failure. METHODS: All instances of use of an antiprotrusio cage for massive acetabular defect (Paprosky type IIc, III, and pelvic discontinuity) between 2002 and 2017 in the authors' institute were reviewed after institutional review board's approval. Survival analyses based on clinical data, bone defect (Paprosky system), type of allograft, size of cage, fixation quality, and position of cage were performed. Failure was defined as cage loosening or breakage, poor hip function, or cage revision for any reason. RESULTS: A total of 84 cages in 77 patients (mean age, 62.9 years), with a mean follow-up period of 6.2 years, had a survival rate of 82.1%. Failure was noted in 15 hips, including mechanical failure in 8 hips, recurrent dislocation in 1 hip, poor hip function in 1 hip, and periprosthetic joint infection in 5 hips. Pelvic discontinuity, reconstruction with morselized allograft alone, and fewer than 4 fixation points to the host bone were associated with higher failure rates (hazard ratios, 4.02, 3.42, and 9.9, respectively). CONCLUSION: We found that an antiprotrusio cage combined with strut allografts, fixed securely to the host bone (>4 fixation points), are beneficial for the management of massive acetabular bone defects. However, pelvic discontinuity remains a challenge that warrants the further study of technical or prosthetic innovations, such as triflange implants, cup cage, and 3D-printed implants.

Diagnosis and Treatment of Femoral Head Osteonecrosis: A Protocol for Development of Evidence-Based Clinical Practice Guidelines.

INTRODUCTION: There are many treatment options for patients who have osteonecrosis of the femoral head (ONFH) and management strategies vary widely both among and within individual countries. Although many researchers have attempted to elucidate the optimal strategies for managing this disease, the lack of large-scale randomized control trials and the lack of agreement on disease staging have curtailed the development of clear-cut guidelines. MATERIALS AND METHODS: The Association Research Circulation Osseous (ARCO) group sought to address three questions for the management of patients who have ONFH: 1) What imaging studies are most sensitive and specific for the diagnostic evaluation of patients who have ONFH?; 2) What is the best treatment strategy for preventing disease progression in patients who have pre-collapse lesions?; and 3) What is the best treatment strategy for patients who have post-collapse disease? The Patient, Intervention, Comparison, and Outcome (PICO) format was used to formulate the search strategy for each research question. A systematic review will be performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. ARCO participants have been allocated to three groups, each representing one of the PICO questions. After qualitative and quantitative analysis of the data extracted from studies pertaining to each of the three research questions, a set of evidence-based clinical practice guidelines will be proposed for the management of patients who have ONFH. DISCUSSION: It is not always clear which treatment method is optimal for the management of ONFH. Thus, many surgeons have developed and performed various procedures based on patient-specific factors. As there is no consensus on the optimal treatment for various stages of disease, it was clear that developing evidence-based clinical practice guidelines would provide more structure and uniformity to management of these patients. Therefore, the results of this systematic review will lead to the development guidelines that may improve patient-care strategies and result in better outcomes for patients who have ONFH.

Intravenous administration of iPS-MSCSPIONs mobilized into CKD parenchyma and effectively preserved residual renal function in CKD rat.

This study traced intravenously administered induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (MSC) and assessed the impact of iPSC-MSC on preserving renal function in SD rat after 5/6 nephrectomy. The results of in vitro study showed that FeraTrack™Direct contrast particles (ie intracellular magnetic labelling) in the iPSC-MSC (ie iPS-MSCSPIONs ) were clearly identified by Prussian blue stain. Adult-male SD rats (n = 40) were categorized into group 1 (SC), group 2 [SC + iPS-MSCSPIONs (1.0 × 106 cells)/intravenous administration post-day-14 CKD procedure], group 3 (CKD), group 4 [CKD + iPS-MSCSPIONs (0.5 × 106 cells)] and group 5 [CKD + iPS-MSCSPIONs (1.0 × 106 cells)]. By day-15 after CKD induction, abdominal MRI demonstrated that iPS-MSCSPIONs were only in the CKD parenchyma of groups 4 and 5. By day 60, the creatinine level/ratio of urine protein to urine creatinine/kidney injury score (by haematoxylin and eosin stain)/fibrotic area (Masson's trichrome stain)/IF microscopic finding of kidney injury molecule-1 expression was lowest in groups 1 and 2, highest in group 3, and significantly higher in group 4 than in group 5, whereas IF microscopic findings of podocyte components (ZO-1/synaptopodin) and protein levels of anti-apoptosis ((Bad/Bcl-xL/Bcl-2) exhibited an opposite pattern to creatinine level among the five groups (all P < .0001). The protein expressions of cell-proliferation signals (PI3K/p-Akt/m-TOR, p-ERK1/2, FOXO1/GSK3ß/p90RSK), apoptotic/DNA-damage (Bax/caspases8-10/cytosolic-mitochondria) and inflammatory (TNF-α/TNFR1/TRAF2/NF-κB) biomarkers displayed an identical pattern to creatinine level among the five groups (all P < .0001). The iPS-MSCSPIONs that were identified only in CKD parenchyma effectively protected the kidney against CKD injury.

Human Umbilical Cord-Derived Mesenchymal Stem Cells for Acute Respiratory Distress Syndrome.

OBJECTIVES: To investigate the safety, feasibility, and possible adverse events of single-dose human umbilical cord-derived mesenchymal stem cells in patients with moderate-to-severe acute respiratory distress syndrome. DESIGN: Prospective phase I clinical trial. SETTING: Medical center in Kaohsiung, Taiwan. PATIENTS: Moderate-to-severe acute respiratory distress syndrome with a PaO2/FIO2 ratio less than 200. INTERVENTIONS: Scaling for doses was required by Taiwan Food and Drug Administration as follows: the first three patients received low-dose human umbilical cord-derived mesenchymal stem cells (1.0 × 10 cells/kg), the next three patients with intermediate dose (5.0 × 10 cells/kg), and the final three patients with high dose (1.0 × 10 cells/kg) between December 2017 and August 2019. MEASUREMENTS AND MAIN RESULTS: Nine consecutive patients were enrolled into the study. In-hospital mortality was 33.3% (3/9), including two with recurrent septic shock and one with ventilator-induced severe pneumomediastinum and subcutaneous emphysema. No serious prespecified cell infusion-associated or treatment-related adverse events was identified in any patient. Serial flow-cytometric analyses of circulating inflammatory biomarkers (CD14CD33/CD11b+CD16+/CD16+MPO+/CD11b+MPO+/CD14CD33+) and mesenchymal stem cell markers (CD26+CD45-/CD29+CD45-/CD34+CD45-/CD44+CD45-/CD73+CD45-/CD90+CD45-/CD105+CD45-/CD26+CD45-) were notably progressively reduced (p for trend < 0.001), whereas the immune cell markers (Helper-T-cell/Cytotoxity-T-cell/Regulatory-T-cell) were notably increased (p for trend < 0.001) after cell infusion. CONCLUSIONS: The result of this phase I clinical trial showed that a single-dose IV infusion of human umbilical cord-derived mesenchymal stem cells was safe with favorable outcome in nine acute respiratory distress syndrome patients.

Use of Antimicrobial-Impregnated Incise Drapes to Prevent Periprosthetic Joint Infection in Primary Total Joint Arthroplasty: A Retrospective Analysis of 9774 Cases.

BACKGROUND: Antimicrobial-impregnated incise drapes are often used despite any literature that demonstrates a reduction in the rate of periprosthetic joint infection (PJI). The aim of this study is to compare the efficacy of antimicrobial-impregnated incise drapes with nonantimicrobial-impregnated incise drapes for the prevention of PJI in patients undergoing total joint arthroplasty (TJA). METHODS: A retrospective study of 9774 primary TJAs from 2000 to 2012 was performed. Patients who received an antimicrobial-impregnated incise drape (n = 5241) were compared with patients who received a nonantimicrobial-impregnated incise drape (n = 4533). The decision to use an antimicrobial drape was based on the surgeon's discretion. Patients who developed PJI within 1 year after index surgery were identified. Multivariate logistic regression analysis and sensitivity analysis using propensity score matching were performed to control for potential confounders. RESULTS: The overall PJI rate was 1.14% (60 of 5241) for patients who received an antimicrobial-impregnated incise drape compared with 1.26% (57 of 4533) for those with a nonantimicrobial-impregnated incise drape. There was no difference in the PJI rate between patients with an antimicrobial-impregnated incise drape and those who received nonantimicrobial-impregnated incise drape in the univariate (odds ratio [OR] = 0.91; 95% confidence interval [CI] = 0.63-1.30), multivariate (adjusted OR = 0.92; 95% CI, 0.63-1.34), or propensity score matching analysis (OR = 0.84; 95% CI = 0.52-1.35). CONCLUSION: Despite the increasing adoption of the use of antimicrobial-impregnated incise drapes in our institute, this study suggests that antimicrobial-impregnated incise drapes do not reduce PJI in patients undergoing primary TJAs.

The 2019 Revised Version of Association Research Circulation Osseous Staging System of Osteonecrosis of the Femoral Head.

BACKGROUND: The Association Research Circulation Osseous (ARCO) presents the 2019 revised staging system of osteonecrosis of the femoral head (ONFH) based on the 1994 ARCO classification. METHODS: In October 2018, ARCO established a task force to revise the staging system of ONFH. The task force involved 29 experts who used a web-based survey for international collaboration. Content validity ratios for each answer were calculated to identify the levels of agreement. For the rating queries, a consensus was defined when more than 70% of the panel members scored a 4 or 5 rating on a 5-point scale. RESULTS: Response rates were 93.1%-100%, and through the 4-round Delphi study, the 1994 ARCO classification for ONFH was successfully revised. The final consensus resulted in the following 4-staged system: stage I-X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II-X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III-fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV-X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. This revised staging system does not incorporate the previous subclassification or quantitation parameters, but the panels agreed on the future development of a separate grading system for predicting disease progression. CONCLUSION: A staging system has been developed to revise the 1994 ARCO classification for ONFH by an expert panel-based Delphi survey. ARCO approved and recommends this revised system as a universal staging of ONFH.

Progress on Range of Motion After Total Knee Replacement by Sensor-Based System.

For total knee replacement (TKR) patients, rehabilitation after the surgery is key toregaining mobility. This study proposes a sensor-based system for effectively monitoringrehabilitation progress after TKR. The system comprises a hardware module consisting of thetriaxial accelerometer and gyroscope, a microcontroller, and a Bluetooth module, and a softwareapp for monitoring the motion of the knee joint. Three indices, namely the number of swings, themaximum knee flexion angle, and the duration of practice each time, were used as metrics tomeasure the knee rehabilitation progress. The proposed sensor device has advantages such asusability without spatiotemporal constraints and accuracy in monitoring the rehabilitation progress.The performance of the proposed system was compared with the measured range of motion of theCybex isokinetic dynamometer (or Cybex) professional rehabilitation equipment, and the resultsrevealed that the average absolute errors of the measured angles were between 1.65° and 3.27° forthe TKR subjects, depending on the swing speed. Experimental results verified that the proposedsystem is effective and comparable with the professional equipment.

Correction: Bacterial detection and identification from human synovial fluids on an integrated microfluidic system.

Correction for 'Bacterial detection and identification from human synovial fluids on an integrated microfluidic system' by Ting-Hang Liu et al., Analyst, 2019, 144, 1210-1222.

Bacterial detection and identification from human synovial fluids on an integrated microfluidic system.

Periprosthetic joint infections (PJIs) are among the most severe complications emerging from prosthetic joint replacement surgeries. In order to possess a rapid means of diagnosing PJIs, an integrated microfluidic system was developed herein for detecting and identifying bacteria in human synovial fluid (HSF). The entire molecular diagnostic process, including (1) sample treatment, (2) bacterial isolation, (3) bacterial lysis, (4) nucleic acid amplification (via polymerase chain reaction (PCR)), and (5) optical detection, could be automated on a single chip. First, N-acetyl-l-cysteine was used to decrease the viscosity of HSF samples and consequently enhance bacterial isolation with vancomycin-coated nano-magnetic beads. Then, a universal 16S ribosomal ribonucleic acid PCR primer set and four species-specific primer sets were used for PCR-based detection and identification of four common bacteria previously associated with PJIs, including Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli, and Acinetobacter baumannii. With this approach, the limit of detection was as low as 100 colony forming units (CFUs) per milliliter (or 20 CFUs per reaction), which is suitable for clinical diagnostics and for making informed decisions regarding post-operative antibiotic administration. More importantly, bacterial detection and identification data could be acquired within 90 minutes, representing a significant improvement over traditional culture-based methods (3-7 days). The developed microfluidic system may therefore serve as a promising tool for rapid diagnosis of PJIs.

Mechanical failure of articulating polymethylmethacrylate (PMMA) spacers in two-stage revision hip arthroplasty: the risk factors and the impact on interim function.

BACKGROUND: This study aimed to investigate the risk factors for mechanical failure of cement spacers and the impact on hip function after two-stage exchange arthroplasty for periprosthetic joint infection (PJI). METHODS: Thirty-one patients (19 males and 12 females) with hip PJIs underwent resection arthroplasty and implantation of cement spacers from January 2014 to December 2015. Patients who encountered spacer-associated mechanical complications in the interim period (14 of 31) were compared with those without complications (17 of 31). Complications were defined as spacer dislocation, spacer fracture, spacer fracture with dislocation, and femoral fracture during or following spacer implantation. Hip functional outcome was assessed using the Harris hip score (HHS). Treatment success was defined according to the following criteria: (1) no symptoms or signs indicative of infection; (2) no PJI-related mortality; and (3) no subsequent surgical intervention for infection after reimplantation surgery. Multivariate logistic regression and Kaplan-Meier survival curves were used for analysis. RESULTS: Fourteen patients (14/31 = 45%) suffered at least one spacer-related complication within the interim period. The development of spacer complications was associated with a younger age (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.83-1.00, p = 0.045) and chronic PJI (OR 14.7, 95% CI 1.19-182, p = 0.036). Patients with spacer complications also had a lower median HHS (37 vs. 60, p < 0.001) before reimplantation in comparison to those without spacer complications. After reimplantation, the two groups had a similar median HHS (90 vs. 89, p = 0.945). Two patients did not undergo reimplantation due to extensive comorbidities, and subsequently retained the antibiotic spacer for definitive treatment. The 2-year treatment success rate was 84.6% in the spacer-complication group and 87.5% in the non-spacer-complication group (p = 0.81). CONCLUSION: There was a high complication rate for articulating PMMA spacers during the interim period of two-stage revision total hip arthroplasty. A young age and chronic infection were the primary risk factors associated with mechanical complications. Patients at high risk of spacer-related mechanical complications should be advised accordingly by surgeons. Knowing the possible risk factors, surgeons should educate patients thoroughly to avoid spacer complications, thereby increasing patient satisfaction in the interim stage. LEVEL OF EVIDENCE: Prognostic Level III.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 1: Glucocorticoid-Associated Osteonecrosis.

BACKGROUND: Glucocorticoid usage, a leading cause of osteonecrosis of the femoral head (ONFH), and its prevalence was reported in 25%-50% of non-traumatic ONFH patients. Nevertheless, there have been no unified criteria to classify glucocorticoid-associated ONFH (GA-ONFH). In 2015, the Association Research Circulation Osseous addressed the issue of developing a classification scheme. METHODS: In June 2017, a task force was set up to conduct a Delphi survey concerning ONFH. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey consists of questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, the panel reached a consensus on the classification criteria. The response rates were 100% (Round 1), 96% (Round 2), and 100% (Round 3), respectively. RESULTS: The consensus on the classification criteria of GA-ONFH included the following: (1) patients should have a history of glucocorticoid use >2 g of prednisolone or its equivalent within a 3-month period; (2) osteonecrosis should be diagnosed within 2 years after glucocorticoid usage, and (3) patients should not have other risk factor(s) besides glucocorticoids. CONCLUSION: Association Research Circulation Osseous established classification criteria to standardize clinical studies concerning GA-ONFH.