Discrepancies in Sagittal Alignment of the Lower Extremity Among Different Brands of Robotic Total Knee Arthroplasty Systems.

BACKGROUND: There is an increasing number of different brands of robotic total knee arthroplasty (TKA) systems. Most robotic TKA systems share the same coronal alignment, while the definitions of sagittal alignment vary. The purpose of this study was to investigate whether these discrepancies impact the sagittal alignment of the lower extremity. METHODS: A total of 72 lower extremity computed tomography scans were included in our study, and 3-dimensional models were obtained using software. A total of 7 brands of robotic TKA systems were included in the study. The lower extremity axes were defined based on the surgical guide for each implant. We also set the intramedullary axis as a reference to evaluate the discrepancies in sagittal alignment of each brand of robotic system. RESULTS: On the femoral side, the axis definition was the same for all 7 robotic TKA systems. The robotic TKA axes showed a 2.41° (1.58°, 3.38°) deviation from the intramedullary axis. On the tibial side, the 7 robots had different axis definitions. The tibial mechanical axis of 6 of the TKA systems was more flexed than that of the intramedullary axis, which means the posterior tibial slope was decreased while the tibial mechanical axis of the remaining system was more extended. CONCLUSIONS: The sagittal alignment of the lower extremity for 7 different brands of robotic TKA systems differed from each other and all deviated from the intramedullary axis. Surgeons should be aware of this discrepancy when using different brands of robotic TKA systems to avoid unexpected sagittal alignment and corresponding adverse clinical outcomes. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Robotic-assisted total hip arthroplasty in patients with developmental dysplasia of the hip.

PURPOSES: Due to the morphological diversity of deformities, technical difficulties, improperly designed components, and so on, THA remains a challenging task in dysplastic hips, especially in highly dislocated hips. The purpose of this study was to comprehensively evaluate the clinical outcomes of robot-assisted THA in patients with DDH through a large cohort study, including the precision of acetabular cup positioning, indicators of inflammatory response, indicators of muscle damage, and complications. METHODS: We retrospectively analyzed patients with DDH who underwent THA in our prospectively constructed joint registry between August 2018 and August 2022. Finally, 147 manual THAs and 147 robotic-assisted THAs were included in the final analysis. Patient demographics, indicators of inflammation, indicators of muscle damage, operative time, Harris hip scores (HHS), and forgotten joint score (FJS) were recorded for analysis. The precision of the positioning of the acetabular component was assessed with plain radiographs. RESULTS: In the Crowe II/III groups, the reconstructed center of rotation (COR) in the robotic-assisted group was closer to the anatomical COR with less variation than the manual group (absolute horizontal distances of COR 3.5 ± 2.8 vs. 5.4 ± 4.9 mm, p < 0.05; absolute vertical distances of COR 6.4 ± 4.1 vs. 11.7 ± 8.2 mm, p = 0.001). For all Crowe subtypes, the robotic-assisted THA significantly increased the proportion of acetabular cups located in the safety zone within 5° (all p < 0.05). Interleukin-6 and creatine kinase levels were slightly lower and significantly different in the robotic-assisted group at three days postoperatively (all p < 0.05). CONCLUSIONS: Compared to the manual technique, the robot-assisted technique improved the precision and reproducibility of acetabular component positioning, particularly in DDH patients with Crowe types II/III. The robotic-assisted technique did not increase operative time, bleeding, complications, or revision rates, and had a slighter early inflammatory response and muscle damage.

Diagnostic efficiency of [68 Ga]Ga-DOTA-FAPI-04 in differentiating periprosthetic hip joint infection and aseptic failure.

PURPOSE: To assess the efficiency of [68 Ga]Ga-DOTA-FAPI-04 in diagnosing periprosthetic hip joint infection and establish a diagnostic standard of clinical significance based on uptake pattern. METHODS: [68 Ga]Ga-DOTA-FAPI-04 PET/CT was performed in patients with symptomatic hip arthroplasty from December 2019 to July 2022. The reference standard was based on the 2018 Evidence-Based and Validation Criteria. Two diagnostic criteria, SUVmax and uptake pattern, were used to diagnose PJI. Meanwhile, original data were imported into IKT-snap to draw the view of interest, A.K. was used to extract features of clinical cases, and unsupervised clustering analysis was applied according to the groups. RESULTS: A total of 103 patients were included, 28 of whom had PJI. The area under the curve of SUVmax was 0.898, which was better than that of all of the serological tests. The cutoff value of SUVmax was 7.53, and the sensitivity and specificity were 100 and 72%, respectively. The sensitivity, specificity and accuracy of the uptake pattern were 100, 93.1 and 95%, respectively. In radiomics analysis, the features of PJI were significantly different from those of aseptic failure. CONCLUSION: The efficiency of [68 Ga]Ga-DOTA-FAPI-04 PET/CT in diagnosing PJI showed promising results, and the diagnostic criteria of the uptake pattern were more clinically instructive. Radiomics also showed certain application prospects in the field of PJI. TRIAL REGISTRATION NUMBER: Trial registration: ChiCTR2000041204. Registered 24 September 2019.

Characterization of periprosthetic environment microbiome in patients after total joint arthroplasty and its potential correlation with inflammation.

AIMS: Periprosthetic joint infection (PJI) is one of the most serious complications after total joint arthroplasty (TJA) but the characterization of the periprosthetic environment microbiome after TJA remains unknown. Here, we performed a prospective study based on metagenomic next-generation sequencing to explore the periprosthetic microbiota in patients with suspected PJI. METHODS: We recruited 28 patients with culture-positive PJI, 14 patients with culture-negative PJI, and 35 patients without PJI, which was followed by joint aspiration, untargeted metagenomic next-generation sequencing (mNGS), and bioinformatics analysis. Our results showed that the periprosthetic environment microbiome was significantly different between the PJI group and the non-PJI group. Then, we built a "typing system" for the periprosthetic microbiota based on the RandomForest Model. After that, the 'typing system' was verified externally. RESULTS: We found the periprosthetic microbiota can be classified into four types generally: "Staphylococcus type," "Pseudomonas type," "Escherichia type," and "Cutibacterium type." Importantly, these four types of microbiotas had different clinical signatures, and the patients with the former two microbiota types showed obvious inflammatory responses compared to the latter ones. Based on the 2014 Musculoskeletal Infection Society (MSIS) criteria, clinical PJI was more likely to be confirmed when the former two types were encountered. In addition, the Staphylococcus spp. with compositional changes were correlated with C-reactive protein levels, the erythrocyte sedimentation rate, and the synovial fluid white blood cell count and granulocyte percentage. CONCLUSIONS: Our study shed light on the characterization of the periprosthetic environment microbiome in patients after TJA. Based on the RandomForest model, we established a basic "typing system" for the microbiota in the periprosthetic environment. This work can provide a reference for future studies about the characterization of periprosthetic microbiota in periprosthetic joint infection patients.

A Nomogram That Characterizes a Patient's Odds of Developing Squeaking After Fourth-generation Ceramic-on-ceramic THA.

BACKGROUND: Although ceramic-on-ceramic (CoC) bearings result in the lowest wear rate of any bearing combination, postoperative squeaking remains worrisome. However, data concerning squeaking in long-term follow-up studies are still lacking, especially for fourth-generation CoC THA. QUESTIONS/PURPOSES: (1) After keeping the prosthesis in place for 10 years, what percentage of patients treated with fourth-generation CoC THA implants report squeaking, and are there points in time when squeaking occurs more frequently? (2) What are the characteristics, association with hip function, and factors associated with squeaking? (3) Can we create a nomogram that characterizes a patient's odds of experiencing squeaking based on the factors associated with it? METHODS: Between January 2009 and December 2011, 1050 patients received primary THAs at our institution, 97% (1017) of whom received fourth-generation CoC THAs because this was the preferred bearing during this period. Of the 1017 eligible patients, 5% (54) underwent THAs performed by low-volume surgeons, 3% (30) were implanted with cemented prostheses, 2% (22) died, 1% (10) were immobile, 1% (six) underwent revision surgery, and 17% (169) were lost to follow-up before 10 years, leaving 726 patients for analysis here at a mean of 11 ± 1 years. In the study cohort, 64% (464) were male and 36% (262) were female, with a mean age of 44 ± 13 years at primary THA. We extracted data about articular noise from follow-up records in our institutional database and used a newly developed questionnaire to ascertain the percentage of patients who reported squeaking at the latest follow-up interval. Although not validated, the questionnaire was modeled on previous studies on this topic. The longitudinal pattern for squeaking was explored to find timepoints when squeaking occurs more frequently. Based on the questionnaire data, we calculated the percentages of frequent, reproducible, and avoidable squeaking. Hip function was evaluated with the Harris Hip Score and WOMAC score and compared between the squeaking and nonsqueaking groups. Factors associated with squeaking, which were examined in a multivariate analysis, were used to develop a nomogram. RESULTS: At 10 years, 16% (116 of 726) of patients reported squeaking. Two squeaking peaks were determined, at 0 to 1 year and 8 to 10 years. Frequent, reproducible, and avoidable squeaking accounted for 42% (36 of 86), 20% (17 of 86), and 41% (35 of 86), respectively. The mean Harris Hip Score (93 ± 4 versus 94 ± 5; p = 0.81) and WOMAC score (16 ± 13 versus 15 ± 13; p = 0.23) did not differ between patients with squeaking and those without. After controlling for potential confounding variables such as etiology and head offset, we found that patients younger than 46 years (odds ratio 2.5 [95% confidence interval 1.5 to 5.0]; p < 0. 001), those who were male (OR 2.0 [95% CI 1.1 to 3.5]; p = 0.04), those having a total flexion and extension arc of less than 50° (OR 2.0 [95% CI 1.2 to 3.3]; p = 0.02), and those with the Corail hip implant (OR 4.1 [95% CI 2.1 to 7.7]; p < 0. 001) were more likely to report squeaking. We created a nomogram that can be used at the point of care that can help clinicians identify patients at a higher risk of experiencing squeaking; this nomogram had good performance (area under the receiver operating characteristic curve of 77%). CONCLUSION: As a potential late complication, squeaking after fourth-generation CoC THA is of concern and may be related to increased stripe wear. We recommend that surgeons use this nomogram to assess the odds of squeaking before selecting a bearing, especially in patients at high risk, to facilitate shared decision-making and improve patient satisfaction. Future external validation of the model is still needed to enhance its applicability.Level of Evidence Level III, therapeutic study.

It can be unnecessary to combine common synovial fluid analysis and alpha-defensin tests for periprosthetic joint infection diagnosis.

BACKGROUND: Periprosthetic joint infection is a serious complication after total joint arthroplasty. Despite that alpha-defensin was used as diagnostic test in the 2018 ICM (international consensus meeting) criteria, its position in the PJI diagnostic pipeline was controversial. Therefore, we performed a retrospective pilot study to identify whether synovial fluid alpha-defensin test was necessary when corresponding synovial fluid analysis (WBC count, PMN% and LE tests) was performed. METHODS: Between May 2015 and October 2018, a total of 90 suspected PJI patients who underwent revisions after TJA were included in this study. Based on the 2018 ICM criteria, the interobserver agreements between preoperative diagnostic results and postoperative diagnostic results and the interobserver reliability between preoperative diagnostic results and postoperative diagnostic results with or without synovial fluid alpha-defensin tests were calculated. After that, the ROC analysis, and the direct cost-effectiveness of adding alpha-defensin was performed. RESULTS: There were 48,16 and 26 patients in the PJI group, inconclusive group and non-PJI group, respectively. Adding the alpha-defensin tests into 2018 ICM criteria can't change the preoperative diagnostic results, postoperative diagnostic results, and the concordance between preoperative and postoperative diagnostic results. Moreover, the Risk-benefit Ratio is over 90 per changed decision and the direct cost-effectiveness of alpha-defensin was more than $8370($93*90) per case. CONCLUSIONS: Alpha-defensin assay exhibit high sensitivity and specificity for PJI detection as a standalone test based on the 2018 ICM criteria. However, the additional order of Alpha-defensin can't offer additional evidence for PJI diagnosis when corresponding synovial fluid analysis was performed (synovial fluid WBC count, PMN% and LE strip tests). EVIDENCE LEVEL: Level II, Diagnostic study.

Primary Total Hip Arthroplasty With Ceramic-On-Ceramic Articulations: Analysis of a Single-Center Series of 1,083 Hips at a Minimum of 10-Year Follow-Up.

BACKGROUND: There are limited long-term results of using ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) in a large number of patient cohorts. The purpose of this study was to evaluate the minimum 10-year clinical and radiological outcomes and survivorship in a single surgeon series of CoC-THA. METHODS: Among the 1,039 patients (1,391 hips) who underwent primary THA at our institution between 2008 and 2011, 49 patients (69 hips) experienced paralysis or death, and 194 patients (239 hips, 19%) were lost to follow-up. The remaining 796 patients (1,083 hips) were assessed at a mean of 11 years (range, 10 to 13 years) using the modified Harris hip score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a questionnaire on articular noises. Survival analysis was used to estimate the survivorship. Radiological evaluation was performed on 869 hips at the final follow-up. RESULTS: Survivorship at 11 years was 98.3% for revision or aseptic loosening, and 98.2% for reoperation. At the final follow-up, the mean mHHS and WOMAC scores were 93 (range, 12 to 100) and 14.4 (range, 3 to 66), respectively. There were 131 (12%) hips that experienced squeaking, but no patient required revision. No fracture of the ceramic was observed. Radiological evaluation at the final follow-up revealed that 3 (0.3%) hips exhibited loosening, 2 (0.2%) had femoral osteolysis, 81(9.3%) acquired radiolucencies, and 35 (4%) showed heterotopic ossification. CONCLUSION: This CoC bearing for THA had a high survivorship and excellent functional outcomes for at least 10 years.

Status of robot-assisted artificial total joint arthroplasty in China: a cross-sectional survey of joint surgeons.

PURPOSE: The purpose of this study is to report on the use of Robotic-assisted total joint arthroplasty (RA-TJA) in China as well as the experience and expectations of Chinese doctors regarding this technology. METHOD: A self-administered questionnaire was used to assess the current status of RA-TJA in China, the practical experience and suggestions for improvement of the technology by joint surgeons who have performed RA-TJA, and the interest and expectations of orthopaedic surgeons who have not used RA-TJA. The questionnaire was administered to all the physicians of the Chinese Association of Orthopedic Surgeons (CAOS). RESULT: A total of 372 qualified questionnaires were generated, among which 28% (n = 104) of the respondents had performed RA-TJA, among those who had performed RA-TJA. When asked how helpful the joint replacement robot was actually/expected to be, there was no significant difference between the expected and actual experience of nonusers and users (p ≥ 0.05); the biggest disadvantage of the current development of RA-TJA was perceived as additional charges to the patient by those who had used it, while those who had not used it perceived it as a limitation of their hospital, both of which were significant differences. Most respondents in both groups (used: 94.2%; not used: 91.4%) were confident in the clinical development of the joint replacement robot. CONCLUSION: This survey provides cross-sectional data on the current status of Chinese joint surgeons using or not using robots in their daily clinical practice. Improving surgical precision was the consensus of most respondents, while high surgical costs and limitations of hospital conditions were barriers to its development in China.

Comparison of serum inflammatory indicators and radiographic results in MAKO robotic-assisted versus conventional total knee arthroplasty for knee osteoarthritis: a retrospective study of Chinese patients.

BACKGROUND: The purpose of this study was to compare the serum inflammatory indicators and radiographic results of conventional manual total knee arthroplasty (CM-TKA) with those of MAKO-robotic assisted total knee arthroplasty (MA-TKA). METHODS: We retrospectively analysed 65 patients with knee osteoarthritis who underwent unilateral TKA from December 2020 to November 2021 in our department, which included 34 patients who underwent MA-TKA and 31 patients who underwent CM-TKA. The tourniquet time and estimated blood loss (EBL) were compared between the two groups. Knee function was evaluated using range of motion (ROM), functional score and pain score. Leukocytes, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), creatine kinase (CK), and neutrophil-to-lymphocyte ratio (NLR) were recorded at 3 time points (preoperative, and on the first and third postoperative days). The hip-knee-ankle angle (HKA) and the femoral and tibial component angles in the coronal and sagittal planes were used for postoperative radiographic evaluation. RESULTS: The postoperative MA-TKA group had less EBL (496.9 ± 257.8 vs. 773.0 ± 301.3 ml, p < 0.001). There was no significant difference in knee function scores at 6 weeks postoperatively (p > 0.05). IL-6 levels were significantly lower in the MA-TKA group on the 1st postoperative day (11.4 (5.2, 21.0) vs. 24.6 (86.3, 170.8), p = 0.031). This difference in inflammatory indices became more pronounced at 72 hours after the operation because CRP, ESR, IL-6, and CK values were significantly lower in the MA-TKA group on the 3rd postoperative day (72 h) (p < 0.05). Postoperative radiographic examinations performed 2 days after the MA-TKA group suggested that only 2 cases of HKA had outlier values, which was remarkably better than the 12 cases found in the CM-TKA group (5.9% vs. 38.7%, p < 0.001). The frontal femoral component was significantly closer to the expected value of 90° in the MA-TKA group (90.9 (90.5, 92.3) vs. 92.4 (91.3, 93.7), p = 0.031). The remaining imaging evaluation parameters were not significantly different between the two groups (p > 0.05). CONCLUSIONS: In Chinese patients with OA, there was a milder systemic inflammatory response in the early postoperative period after MA-TKA compared to that of CM-TKA, as well as better radiographic outcomes. However, the tourniquet time was prolonged, and no advantages were observed in terms of functional score or pain score in the short-term follow-up.

Surfactin induces ER stress-mediated apoptosis via IRE1-ASK1-JNK signaling in human osteosarcoma.

Osteosarcoma, one of primary bone tumor in children and young adults, has poor prognosis and drug resistances to chemotherapy. In order to reinforce the conventional therapies and antagonize the osteosarcoma in patients, a novel strategy is required for developing a new treatment. In this study, surfactin, a natural product from Bacillus subtilis, showed the efficiency of cell death in osteosarcoma, but not in normal cells. Surfactin triggers ER stress mechanism by promoting the aberrant Ca2+ release from ER lumen and ER-signaling to mitochondrial dysfunction following caspases activation mediating cell apoptosis. Surfactin-induced ER stress not only upregulated of glucose-regulated protein 78/94 and IRE1-ASK1-JNK pathway but also leading to calpains and Bcl-2 proteins family involving the release of cytochrome c. The releases into cytosol trigger the cleavage of caspase-9 and caspase-3 to induce cell apoptosis. In this study, surfactin demonstrated the potential functions to trigger the ER stress, ER stress-associated IRE1-ASK1-JNK signaling pathway, mitochondrial dysfunction, and caspase activations leading to programmed cell apoptosis. Importantly, implicating the signaling pathway that regulates the connection between ER stress and mitochondrial dysfunction causing apoptosis associated with surfactin. These results indicated a potential application of surfactin strengthen current conventional therapies.

The association between depression and chronic lower back pain from disc degeneration and herniation of the lumbar spine.

OBJECTIVE: Chronic lower back pain induced by lumbar disc degeneration or herniation exerts a great impact on patients' daily lives. Depression and anxiety often exist among patients with lower back pain. Some studies mentioned about mechanisms, such as inflammatory biomarkers, which are commonly seen in herniated intervertebral disc (HIVD) and major depressive disorder (MDD). Method: Our study used a large database from the National Health Insurance to explore the incidence rate of MDD in patients with HIVD and correlated risk factors. A total of 41,874 patients with HIVD were included in this work. The control group was matched by using propensity scores. Results: The results showed a temporal association between prior HIVD and subsequent MDD after adjusting for potential confounding factors. Patients with HIVD were at high risk of developing MDD (hazard ratio, HR: 9.00, 95% confidence interval, CI: 7.196-11.257) even after adjusting for demographic characteristics and comorbidities (HR: 8.47, 95% CI: 6.84-10.49, p < 0.0001). Conclusions: The combination of HIVD and MDD represents an important health problem that is associated with higher disability rates, socioeconomic disadvantage, and greater utilization of health care resources. Early detection and combined treatment of depressive symptoms may benefit patients with HIVD.

Does robotic-assisted computer navigation improve acetabular cup positioning in total hip arthroplasty for Crowe III/IV hip dysplasia? A propensity score case-match analysis.

AIMS: Total hip arthroplasty (THA) in patients with hip-dislocation dysplasia remains challenging. This study aims to evaluate whether these patients may benefit from robotic-assisted techniques. METHODS: We reviewed 135 THAs (108 conventional THAs and 27 robotic-assisted THAs) for Crowe type III or IV from January 2017 to August 2019 in our institution. Robotic-assisted THAs were matched with conventional THAs at a 1:1 ratio (27 hips each group) using propensity score matching. The accuracy of cup positioning and clinical outcomes were compared between groups. RESULTS: The inclination of the cup for conventional THAs and robotic THAs was 42.1 ± 5.7 and 41.3 ± 4.6 (p = 0.574), respectively. The anteversion of the cup for conventional THAs was significantly greater than that of robotic THAs (29.5 ± 8.1 and 18.0 ± 4.6; p < 0.001), respectively. The ratio of the acetabular cup in the Lewinnek safe zone was 37% (10/27) in conventional THAs and 96.3% (26/27) in robotic THAs (p < 0.001). Robotic THAs did not achieve better leg length discrepancy than that of conventional THAs (- 0.4 ± 10.9 mm vs. 0.4 ± 8.8 mm, p = 0.774). There was no difference in Harris Hip Score and WOMAC Osteoarthritis index between groups at the 2-year follow-up. No dislocation occurred in all cases at the final follow-up. CONCLUSION: Robotic-assisted THA for patients with high dislocation improves the accuracy of the implantation of the acetabular component with respect to safe zone.

The LINC00477/miR-128 axis promotes the progression of polycystic ovary syndrome by regulating ovarian granulosa cell proliferation and apoptosis.

BACKGROUND: Long noncoding RNAs (lncRNAs) participate in the pathogenesis of various human diseases. This study aims to investigate the roles of lncRNA LINC00477 in polycystic ovary syndrome (PCOS), especially the impacts of LINC00477 on the proliferation and migration of human granulosa cells and the related mechanisms. METHODS: qRT-PCR analysis was performed to examine the expression pattern of LINC00477 in serum samples of PCOS patients as well as PCOS animal models. The effect of LINC00477 on the viability and apoptosis of ovarian granulosa cells was detected by MTT and flow cytometry assays. The correlation between LINC00477 and miR-128 was verified by bioinformatics analysis and dual-luciferase reporter and RNA pull-down assays. Finally, rescue assays were performed to analyze the effects of the LINC00477-miR-128 axis on the biological behaviors of granulosa cells. RESULTS: LINC00477 was significantly upregulated in the serum of PCOS patients as well as PCOS mouse models. LINC00477 overexpression inhibited the proliferation and promoted the apoptosis of granulosa cells, whereas knockdown of LINC00477 yielded the opposite effects. Moreover, miR-128 mimics partially abrogated the effect of LINC00477 on granulosa cells. CONCLUSION: LINC00477 may function as a ceRNA to inhibit proliferation and apoptosis of granulosa cells by modulating miR-128 expression.

The concordance between preoperative aspiration and intraoperative synovial fluid culture results: intraoperative synovial fluid re-cultures are necessary whether the preoperative aspiration culture is positive or not.

AIMS: Preoperative aspiration culture and intraoperative cultures play pivotal roles in periprosthetic joint infection (PJI) diagnosis and pathogen identification. But the discordance between preoperative aspiration culture and intraoperative synovial fluid culture remains unknown. We aim to determine (1) the discordance between preoperative and intraoperative synovial fluid (SF) culture and. (2) compared to intraoperative synovial fluid cultures, the sensitivity of preoperative aspiration fluid culture. Then the following question is tried to be answered: Are intraoperative synovial fluid re-cultures necessary if the preoperative aspiration culture is positive? MATERIALS AND METHODS: Between 2015 and 2019, 187 PJI patients managed with surgeries were included in this study. Compared to intraoperative synovial fluid culture, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of preoperative aspiration culture were calculated. Then, the discordance between preoperative aspiration culture and intraoperative SF culture was analyzed. RESULTS: The sensitivity of preoperative aspiration culture was 81.29% compared to intraoperative synovial fluid cultures. Concordance was identified in 147 PJI (78.61%) patients and culture discordance occurred in 40 patients (21.39%). In these discordant PJI patients, 24 patients (60%) were polymicrobial and no intraoperative synovial fluid culture growth was found in 16 PJI cases (40%). Preoperative monomicrobial staphylococcus results had a sensitivity of and a specificity of 80.43% and 83.16%, respectively. Preoperative polymicrobial results had the lowest sensitivity. CONCLUSIONS: The intraoperative synovial fluid re-cultures are necessary if the preoperative aspiration culture is positive and the discordance between preoperative aspiration culture and intraoperative synovial fluid culture should be noted especially when Streptococcus spp. and more than one pathogen was revealed by preoperative aspiration culture. LEVEL OF EVIDENCE: Level III.

CTRP9 induces macrophages polarization into M1 phenotype through activating JNK pathway and enhances VSMCs apoptosis in macrophages and VSMCs co-culture system.

Inflammation plays a critical role in the development of atherosclerosis (AS), which has been identified as a major predisposing factor for stroke. Macrophages and VSMCs are associated with plaque formation and progression. Macrophages can dynamically change into two main functional phenotypes, namely M1 and M2, they can produce either pro-inflammatory or anti-inflammatory factors which may affect the outcome of inflammation. As a member of CTRPs family, CTRP9 has been reported play important protective roles in the cardiovascular system. However, whether CTRP9 can regulate macrophage activation status in inflammatory responses and have effect on VSMCs behaviors in co-culture system have not been fully investigated. In the present study, using peritoneal macrophages treated with CTRP9, we found that CTRP9 facilitated macrophages towards M1 phenotype, promoted TNF-α secretion and MMPs expression. CTRP9 showed synergistic effect with LPS in inducing M1 macrophages. In macrophages-VSMCs co-culture system, apoptosis and down-regulated proliferation of VSMCs were accelerated with CTRP9-treated macrophages. Then we attempted to explore the underlying molecular mechanisms of CTRP9 resulting in M1 activation. The c-Jun NH2-terminal kinases (JNK) are members of the mitogen activated protein kinases (MAPK) family, plays a central role in the cell stress response, with outcomes ranging from cell death to cell proliferation and survival. We found JNK expression was upregulated following CTRP9 stimulation, and inhibiting JNK phosphorylation level was associated with decreased expression of M1 markers and TNF-α concentration. Moreover, VSMCs apoptosis were ameliorated after inhibition of JNK. These results suggested that CTRP9 may promote macrophage towards M1 activation status through JNK signaling pathway activation.

What Is the Optimal Timing for Reading the Leukocyte Esterase Strip for the Diagnosis of Periprosthetic Joint Infection?

BACKGROUND: The leucocyte esterase (LE) strip test often is used to diagnose periprosthetic joint infection (PJI). In accordance with the manufacturer's directions, the LE strip test result is read 3 minutes after exposing it to joint fluid, but this has not been supported by robust research. Moreover, we have noted that the results of the LE strip test might change over time, and our previous studies have found that centrifugation causes the results of the LE strip test to degrade. Still, there is no evidence-based recommendation as to when to read the LE strip test to maximize diagnostic accuracy, in general, and the best reading times for the LE strip test before and after centrifugation need to be determined separately, in particular. QUESTIONS/PURPOSES: (1) What is the optimal timing for reading LE strip test results before centrifugation to diagnose PJI? (2) What is the optimal timing for reading LE strip test results after centrifugation to diagnose PJI? METHODS: This study was a prospective diagnostic trial. In all, 120 patients who were scheduled for revision arthroplasty and had signs of infection underwent joint aspiration in the outpatient operating room between July 2018 and July 2019 and were enrolled in this single-center study. For inclusion, patients must have had a diagnosis of PJI or nonPJI, valid synovial fluid samples, and must not have received antibiotics within 2 weeks before arthrocentesis. As such, 36 patients were excluded; 84 patients were included for analysis, and all 84 patients agreed to participate. The 2018 International Consensus Meeting Criteria (ICM 2018) was used for the classification of 49 patients with PJI (score ≥ 6) and 35 without PJI (score ≤ 2). The classification was used as the standard against which the different timings for reading LE strips were compared. All patients without PJI were followed for more than 1 year, during which they did not report the occurrence of PJI. All patients were graded against the diagnostic criteria regardless of their LE strip test results. In 83 patients, one drop of synovial fluid (50 µL) was applied to LE strips before and after centrifugation, and in one patient (without PJI), the sample was not centrifuged because the sample volume was less than 1.5 mL. The results of the strip test were read on an automated colorimeter. Starting from 1 minute after centrifugation, these strips were automatically read once every minute, 15 times (over a period of 16 minutes), and the results were independently recorded by two observers. Results were rated as negative, ±, 1+, and 2+ upon the machine reading. Grade 2+ (dark purple) was used as the threshold for a positive result. An investigator who was blinded to the study performed the statistics. Optimal timing for reading the LE strip before and after centrifugation was determined by using receiver operative characteristic (ROC) analysis. The specificity, sensitivity, and positive predictive and negative predictive values were calculated for key timepoints. RESULTS: Before centrifugation, the area under the curve was the highest when the results were read at 5 minutes (0.90 [95% CI 0.83 to 0.98]; sensitivity 0.88 [95% CI 0.75 to 0.95]; specificity 0.89 [95% CI 0.72 to 0.96]). After centrifugation, the area under the curve was the highest when the results were read at 10 minutes (0.92 [95% CI 0.86 to 0.98]; sensitivity 0.65 [95% CI 0.50 to 0.78]; specificity 0.97 [95% CI 0.83 to 1.00]). CONCLUSION: The LE strip test results are affected by time and centrifugation. For samples without centrifugation, we found that 5 minutes after application was the best time to read LE strips. We cannot deny the use of centrifuges because this is an effective way to solve the sample-mingling problem at present. We recommend 10 minutes postapplication as the most appropriate time to read LE strips after centrifugation. Multicenter and large-sample size studies are warranted to further verify our conclusion. LEVEL OF EVIDENCE: Level II, diagnostic study.

Comparison of the success rate after debridement, antibiotics and implant retention (DAIR) for periprosthetic joint infection among patients with or without a sinus tract.

BACKGROUND: The relevance between the presence of a sinus tract and the failure risk after debridement, antibiotics and implant retention (DAIR) for periprosthetic joint infection (PJI) after hip or knee arthroplasty is still unclear. This study aimed to compare the success rate of DAIR between patients with or without a sinus tract and to explore the possible risk factors for failure after DAIR in patients with a sinus tract. METHODS: Consecutive DAIR cases for PJI after hip or knee arthroplasty between January 2009 and June 2019 with a minimum 1-year follow-up in two tertiary joint arthroplasty centers were included. Patients were classified into the sinus tract group and the non-sinus tract group according to the presence of a sinus tract. The success rate after DAIR were compared using Kaplan-Meier survival analysis. Potential risk factors for failure in the sinus group were also explored. RESULTS: One hundred seven patients were included. At a median 4.4 years of follow-up, 19 of 52 (36.5%) cases failed in the sinus tract group, while 15 of 55 (27.3%) cases failed in the non-sinus tract group. The 1-year and 5-year cumulative success rates were 71.2% (95% confidence interval (CI): 59.8-84.6%) and 56.8% (95% CI: 42.6-75.7%) in the sinus tract group, respectively, which were similar to the counterparts in the non-sinus tract group (P = 0.214). Among patients with a sinus tract, DAIR with the exchange of modular components showed a higher success rate (75.8% versus 47.4%, P = 0.038). CONCLUSIONS: The presence of a sinus tract does not affect the success rate of DAIR. Modular component exchange in DAIR was proposed for patients with a sinus tract for an improved infection control rate.

Comparison of three treatment methods for simple bone cyst in children.

BACKGROUND: The unicameral bone cyst (UBC) is a kind of benign tumor whose clinical treatments and efficacy are controversial. The purpose of this study was to evaluate the efficacy of the elastic stable intramedullary nail (ESIN), the injection of autologous bone marrow (ABM), and the combination of ESIN and ABM in the treatment of bone cyst in children. METHODS: Eighty-three cases with simple bone cyst were analyzed retrospectively. Twenty-eight cases were treated with ABM. Twenty-eight cases were treated with ESIN. Twenty-seven cases were treated with ABM and ESIN. All cases were diagnosed through X-ray, CT, or MRI scans. For the suspicious ones, the pathological biopsy was performed for an accurate diagnosis. X-ray examinations were carried out for the postoperative follow-up. Capanna criteria for bone cyst was used for postoperative evaluation of three methods. RESULTS: All cases accomplished the follow-up. The effective rate of the ABM + ESIN group was significantly higher than that of the ABM group (P < 0.05), and the cure rates of the ESIN group and the ABM + ESIN group were higher than that of the ABM group (P < 0.05, respectively). The cure time in the ESIN group was lower than that of the other two groups (P < 0.05, respectively). The times for admission were 2.0 ± 0.0 in the ESIN group, 5.7 ± 1.9 in the ABM group, and 4.7 ± 2.4 in the ABM + ESIN group (P < 0.05 when compared with each other). CONCLUSIONS: The method of ABM combined with ESIN for children's bone cyst has the highest effective rate and curative rate. For the individual method, ESIN has a higher effective rate and curative rate than that of ABM. Meanwhile, it has the fewest time of hospitalization.

The risk factors of polymicrobial periprosthetic joint infection: a single-center retrospective cohort study.

BACKGROUND: Periprosthetic joint infection is a serious complication after total joint arthroplasty and polymicrobial PJI which compose a subtype of PJI often indicate worse outcomes compared to monomicrobial periprosthetic joint infection. However, a literature review suggested that there were limited number studies evaluating the risk factors of polymicrobial PJI. MATERIALS AND METHODS: Between 2015 January and 2019 December, a total of 64 polymicrobial PJI patients and 158 monomicrobial PJI patients in a tertiary center were included in this study and corresponding medical records were scrutinized. The diagnosis of PJI was based on 2014 MSIS criteria. Logistic regression was used to identify the association between various variables and polymicrobial PJI and ROC curve was used to identify their efficiency. RESULTS: The prevalence of polymicrobial PJI is 28.3% in our cohorts. After adjusting for the presence of sinus, previous and knee infection, isolation of enterococci (OR, 3.025; 95%CI (1.277,7.164) p = 0.012), infection with atypical organisms (OR, 5.032;95%CI: (1.470,17.229) p = 0.01), infection with gram-negative organisms (OR, 2.255; 95%CI (1.011,5.031) p = 0.047), isolation of streptococcus spp. (OR, 6; 95%CI (2.094,17.194) p = 0.001), and infection with CNS (OfR, 2.183;95%CI (1.148,4.152) p = 0.017) were risk factors of polymicrobial PJI compared to monomicrobial PJI. However, knee infection is related to a decreased risk of polymicrobial PJI with an adjusted OR = 0.479 (p = 0.023). CONCLUSION: This study demonstrated that the prevalence of polymicrobial PJI is 28.3% in PJI patients. Moreover, the presence of sinus tract and previous joint revisions were risk factors for identifying different bacterial species in the intraoperative specimens. Therefore, in these PJI cases, it is necessary to examine multiple specimens of both intraoperative tissue and synovial fluid for increasing the detection rate and obtaining resistance information.

A Novel Biomarker to Screen for Malnutrition: Albumin/Fibrinogen Ratio Predicts Septic Failure and Acute Infection in Patients Who Underwent Revision Total Joint Arthroplasty.

BACKGROUND: This study aimed to investigate the efficacy of the albumin/fibrinogen ratio (AFR) in the assessment of malnutrition and to compare its ability to predict early postoperative periprosthetic joint infection (PJI) in patients with aseptic revisions. METHODS: Four hundred sixty-six patients undergoing revision total hip or knee arthroplasty between February 2017 and December 2019 were recruited in this retrospective study. We compared the differences in nutritional parameters between patients undergoing revision for septic and aseptic reasons. We used multivariate logistic regression and assessed the association between nutritional parameters and risk of PJI. 207 patients with aseptic revision were then evaluated for the incidence of acute postoperative infection within 90 days. The predictive ability of nutritional markers was assessed by receiver operating characteristic curves. RESULTS: In the multivariate logistic regression analysis, low albumin level (adjusted OR 1.56, 95% CI 1.16-2.08, P = .003), low prognostic nutritional index (PNI) (adjusted OR 1.57, 95% CI 1.01-2.43, P < .043), and low AFR (adjusted OR 2.54, 95% CI 1.92-3.36, P < .001) were independently associated with revision surgery for septic reasons. In accordance with the receiver operating characteristic analysis, the AFR exhibited a greater area under the curve value (0.721) than did the prognostic nutritional index and albumin. An elevated AFR (≥11.7) was significantly associated with old age, joint type, high Charlson comorbidity index, high American Society of Anesthesiologist, and diabetes (P < .05). CONCLUSION: Our findings demonstrated AFR may be an effective biomarker to assess nutrition status and predict acute PJIs after revision TJA.