Introduction: Achieving sagittal plane balance is important to total knee arthroplasty (TKA) for providing mid-flexion stability and potentially increasing patient’s satisfaction. This study aimed to compare the sagittal plane parameters, range of motion (ROM), and patient-reported outcomes (PROMs) between patients received the cruciate retaining (CR) and the patients received medial-pivot (MP) in the restricted kinematic alignment TKA. Methods This retrospective study including a total of 124 patients who underwent TKA in Department of Orthopedics of Peking Union Medical College Hospital between February 2024 and January 2025. Patients were assessed preoperatively and 12 months postoperatively. All patients taken X-ray imaging in pre-operation and on the third day after the operation. Clinical assessments including the Forgotten Joint Score (FJS), physical examination including the assessment of the active ROM of the knee. The HKA (Hip-Knee-Angle), LDFA (Lateral Distal Femoral Angle), MPTA (Medial Proximal Tibial Angle), LFCA (Lateral Femoral Component Angle), LTCA (Lateral Tibial Component Angle), patella thickness, patella length, posterior femoral condylar offset (PCO), Coronal femoral width (LFW), PCO ratio, and posterior tibial slope (PTS) were taken from the X-ray imaging. Results There were 60 patients in the MP-TKA group and 64 patients in the CR-TKA group. Pre-operatively, there were no significant differences between the two groups in terms of demographic data, HKA, LDFA, MPTA, sagittal plane parameters, and FJS (p > 0.05). The MP group was more advantageous in changes of PCO (MP group changes of PCO: 2.42 ± 1.52 mm vs CR group changes of PCO: 3.62 ± 2.11 mm p < 0.001), the post-operation PCO and PCO ratio was significantly less in the MP group (MP group PCO: 26.11 ± 4.08mm vs CR group PCO: 27.65 ± 3.36mm p = 0.024; MP group PCO ratio: 0.45 ± 0.06 vs CR group PCO ratio: 0.48 ± 0.05 p = 0.001), there were no significant differences between the two groups in terms of the post-operation HKA, LDFA, MPTA and others sagittal plane parameters (p > 0.05). The post-operative ROM was significantly better in the MP group in 3-days post-operation and the 12-months post-operation (3-days post-operation in MP group:102.92°±7.93 vs 3-days post-operation in CR group:97.34°±5.49 p < 0.001, 12-months post-operation in MP group:103.35 ± 6.10 vs 12-months post-operation in CR group: 100.52 ± 4.97 p = 0.024) . Conclusion The MP design achieves better sagittal plane balance compared with the CR design TKA.

BackgroundThis study aimed to compare the impact of mechanical alignment (MA), anatomic alignment (AA), kinematic alignment (KA), and restrictive KA (rKA) on native coronal alignment in Asian osteoarthritic knees undergoing total knee arthroplasty (TKA). It also assessed the proportion of KA patients requiring rKA adjustment and compared early postoperative function between the two.MethodsA retrospective analysis of 700 knees involved measuring lateral distal femoral and medial proximal tibial angles on long-leg radiographs. Coronal plane alignment of the knee (CPAK) classification was determined using the arithmetic hip-knee-ankle angle and joint line obliquity (JLO). Simulations of MA, AA, KA, and rKA were performed to observe changes. The proportion of patients requiring adjustment to the rKA safe range was recorded. Postoperative functional scores at 1 year were compared between KA and rKA groups.ResultsKA preserved native coronal alignment entirely. MA and AA altered constitutional alignment in 71.1% and 71.7% of cases, respectively, versus 8.9% for rKA. CPAK classification changed in 91.7% (MA), 80.0% (AA), and 31.7% (rKA) of cases. Only 31.9% of patients fell within the rKA safe range without adjustment; 68.2% required corrective osteotomy. No significant difference in 1-year functional scores was found between KA and rKA groups.ConclusionsKA preserves native alignment, while rKA causes the least alteration among alternative techniques. Early functional outcomes are similar, though most patients require adjustment to meet rKA's safe coronal alignment boundaries.

Osteonecrosis of the femoral head (ONFH) is a debilitating bone disorder characterized by ischemic degeneration with limited therapeutic options. Piezo1, a mechanosensitive ion channel, transduces physical stimuli into intracellular signals regulating osteogenesis and angiogenesis. Here, we developed a 3D-printed Ti6Al4V scaffold conformally coated with photocrosslinked hyaluronic acid hydrogel that retains and releases Piezo1-engineered exosomes (P-Exos), forming a hybrid construct (P-Exos@HAMA/Ti) with cancellous-bone-like stiffness and sustained bioactivity. In vitro studies demonstrated that P-Exos enhanced BMSC viability, migration, and osteogenic differentiation (ALP/ARS; Runx2, Osterix, OCN) while promoting endothelial proliferation and network formation (CD31, VEGFA). RNA-seq and mechanistic validation revealed Ca2+-responsive YAP1/β-catenin signaling, characterized by elevated intracellular Ca2+ levels, upregulated YAP1/β-catenin expression, and nuclear localization, underpinning the scaffold’s osteo-angiogenic synergy. In a rat ONFH model, P-Exos@HAMA/Ti restored trabecular architecture and bone volume, improved micro-CT indices (increased BV/TV, Tb.N, Tb.Th; decreased Tb.Sp), and enhanced osteogenic/angiogenic marker expression, alongside superior locomotor recovery. This multifunctional platform couples mechanical stabilization with Piezo1-mediated mechanotransduction, establishing a pro-regenerative niche integrating biomechanical support with sustained exosomal signaling for effective repair of ischemic bone defects.

Abstract Background Robotic-assisted total joint arthroplasty (rTJA) has witnessed rapid adoption across the Asia-Pacific region. However, practice heterogeneity and conflicting evidence regarding its clinical value necessitate standardized guidance. Therefore, this expert consensus aims to establish consensus-based recommendations to guide and standardize the clinical application of rTJA. Methods The Arthroplasty Society in Asia (ASIA) convened a panel of 45 experts. A modified Delphi technique was employed across three rounds. A systematic literature review informed the generation of consensus statements, which were finalized through anonymous voting. Consensus was defined as ≥ 75% agreement. Results The panel reached consensus on 18 critical clinical questions spanning general principles, total hip arthroplasty, and total knee arthroplasty. Key consensus points include: (1) rTJA demonstrates superior accuracy in implant positioning and alignment restoration compared to manual techniques (98%); (2) current evidence does not yet support a definitive superiority in long-term survivorship or PROMs (77%); (3) robotic platforms are enabling technologies that make personalized alignment philosophies technically reproducible (100%); and (4) soft-tissue balancing should take precedence over rigid mechanical alignment targets in rTKA when conflicts arise(91%). Conclusion This consensus statement provides a comprehensive framework for the application of robotic technology in hip and knee arthroplasty, emphasizing safety, precision, and the need for rigorous training.

Robotic-assisted total knee arthroplasty (RA-TKA) has emerged as an advanced surgical technique. However, direct comparisons between Chinese and American robotic systems are limited. Exploratory comparison of surgical accuracy and short-term clinical outcomes between Chinese HURWA and American MAKO robotic systems in total knee arthroplasty. A prospective exploratory cohort study was conducted from September 2023 to January 2024. Eighty-five patients were assigned to undergo RA-TKA with either the HURWA system (n = 43) or the MAKO system (n = 42) based on the sequential clinical introduction of the systems. The primary outcomes were radiographic accuracy, including the restoration of the mechanical axis within ± 3°. Secondary outcomes encompassed surgical efficiency metrics and patient-reported clinical scores (WOMAC, HSS, VAS) assessed preoperatively and at one-year postoperatively. All included patients have completed surgery and follow-up.The two systems achieved a comparable and high proportion of mechanical axis restoration within ± 3° (HURWA: 86.05

Abstract Background Patients with dermatomyositis (DM) are predisposed to osteonecrosis of the femoral head (ONFH), frequently requiring total hip arthroplasty (THA). However, limited evidence exists regarding postoperative outcomes in this population. This study aimed to evaluate functional outcomes and complication rates after THA in patients with DM compared to a matched cohort of patients without DM. Methods A retrospective case-control study was conducted using our institution’s arthroplasty registry. We identified 18 patients (21 operations) with DM who underwent primary THA and matched them in a 1:2 ratio to 36 patients (42 operations) who underwent THA for hip osteoarthritis, alcohol-induced ONFH, or Crowe I-II developmental dysplasia of hips (DDH). Functional outcomes and health-related quality of life (QoL) were assessed, and postoperative complications were recorded. Results At a mean follow-up of 4.87 years, both cohorts demonstrated comparable improvements in all functional and QoL measures (all postoperative comparisons, p > 0.05). The rate of complications, including dislocation, periprosthetic joint infection, and revision, was not significantly different between groups. However, respiratory complications occurred more frequently in the DM cohort (4/21 vs. 0/42, p = 0.010). Within the DM group, postoperative respiratory complications showed a preliminary association with higher preoperative D-dimer levels (p = 0.040). Conclusions Patients with DM can achieve excellent functional outcomes after THA, comparable to those of patients without rheumatic autoimmune disease. Although most complication rates are similar, DM patients have an elevated risk of postoperative respiratory complications. Preoperative assessment of D-dimer levels and pulmonary function, along with proactive postoperative respiratory rehabilitation, may help reduce this risk in this vulnerable population.

Geriatric femoral neck fracture (FNF) represents a pressing global health challenge, imposing substantial burdens on medical resources while being associated with high complication rates and suboptimal clinical outcomes. In recent years, the direct anterior approach (DAA) has emerged as a mainstream surgical strategy for hip joint arthroplasty (HJA) in developed countries, owing to its minimally invasive nature, neuromuscular-sparing anatomical interval, preservation of soft tissue integrity, and alignment with enhanced recovery after surgery principles, collectively contributing to significant improvements in clinical outcomes of HJA for elderly patients with FNF. However, no unified consensus exists regarding standardized techniques and procedural protocols for DAA-HJA in this specific patient population. Consequently, there is an urgent need to develop an evidence-based expert consensus to address key clinical dilemmas inherent to DAA-HJA in geriatric FNF. Sponsored by the Joint Surgery Group of the Chinese Medical Association, this expert consensus builds upon the foundational Chinese Expert Consensus on Direct Anterior Approach Hip Arthroplasty for the Surgical Treatment of Geriatric Femoral Neck Fracture (2023 Edition). A multidisciplinary expert panel was convened to standardize core issues and procedural norms for DAA-HJA in geriatric FNF. Two rounds of modified Delphi questionnaires and one consensus conference were conducted for voting, with a predefined consensus threshold of ≥ 70

Objective To evaluate long-term survival and clinical outcomes of patients with knee osteo-arthritis undergoing total knee arthroplasty(TKA)through long-term follow-up.Methods This study was based on a previous cohort study that had completed follow-up.We retrospectively collected clinical data of patients with knee arthropathy(including knee osteoarthritis and knee rheumatoid arthritis)who received the first TKA opera-tion in Peking Union Medical College Hospital from 1993 to 2002 and were followed up for more than 20 years,and conducted a unified follow-up on them in November 10,2024(the last follow-up).Kaplan-Meier curve was used to evaluate the survival rate.Hospitals for special surgery(HSS)scores and joint range of motion(ROM)were compared before surgery,10 years after surgery and at the last follow-up to evaluate the clinical efficacy of TKA.Likert scale was used to evaluate patient satisfaction at the last follow-up.Results A total of 226 patients(246 knees)received their first TKA in Peking Union Medical College Hospital from 1993 to 2002 and were fol-lowed up for more than 10 years.Among them,104 patients(131 knees)were included in the study at the last follow-up,including 21 patients(24 knees)with prosthesis in place,18 patients(18 knees)who underwent reo-peration for various reasons,and 65 patients(89 knees)who died from non-TKA surgical causes.Up to the last follow-up,there were 29 patients(35 knees)with an average follow-up of more than 20 years,and 12 patients(16 knees)completed HSS score,ROM measurement and patient satisfaction evaluation.Kaplan-Meier curve showed that the 10-year,15-year,20-year,and 25-year survival rates were 93.6％,92.4％,89.8％,and 71.8％,respectively.The HSS score at the last follow-up was lower than that at 10-year postoperative follow-up[(84.69±11.03)scores vs.(95.25±13.32)scores,P＜0.05],but significantly improved compared with the preoperative[(84.69±11.03)scores vs.(58.75±7.19)scores,P＜0.05].The ROM of knee joint were(93.44±17.30)°,(101.88±13.33)°,and(91.56±15.98)° at preoperative,10-year of postoperative and last follow-up,respectively,and there was no statistical significance between the groups(P＞0.05).In terms of pa-tient satisfaction,the 10 knees(62.50％)scored 4 points(very satisfied),the remaining 6 knees(37.50％)scored 3 points(satisfied),and the satisfaction rate was 100％.Conclusion TKA treatment for knee arthropathy has high long-term prosthesis survival rate,significant improvement of knee joint function and high patient satis-faction.

Femoral neck fracture (FNF) in the elderly poses significant challenge for global health, consuming substantial medical resources, and resulting in high complication rates and suboptimal outcomes. Hip joint arthroplasty (HJA) is currently the primary treatment for elderly FNF, but traditional surgical approaches still face issues such as dislocation, limping, and leg length discrepancy. In the recent years, direct anterior approach (DAA) has become the mainstream for HJA in developed countries, due to its minimal invasive philosophy, neuromuscular interval, soft tissue retention and accelerated recovery, and it significantly improves the clinical outcomes of HJA for elderly FNF. However, there is currently a lack of unified understanding regarding the techniques and processes for DAA-HJA in treating elderly FNF. Therefore, the expert panel of this consensus previously published the "Chinese Expert Consensus on the Surgical Treatment of Femoral Neck Fracture by Direct Anterior Approach Hip Arthroplasty for Elderly Patient (2023 Edition)", which normalized the indications, surgical techniques, and standard procedures for DAA-HJA in elderly FNF. With the rapid progress of robotic technology in joint surgery and the extensive investigation probing its clinical value, we have supplemented and revised the application of robotic surgery in elderly FNF with 9 modified recommendations. These recommendations aim to further promote standardized, systematic, and individualized diagnostic and treatment concepts, ultimately improving patients' functional prognosis.

Osteoarthritis (OA), particularly in the knee and hip, poses a significant global health challenge due to limited therapeutic options. To elucidate the molecular mechanisms of OA and identify potential biomarkers and therapeutic targets, we utilized genome-wide association studies (GWAS) and cis-miRNA expression quantitative trait loci (cis-miR-eQTL) datasets to identify miRNAs associated with OA, revealing 16 that were linked to knee OA and 21 to hip OA. Among these, hsa-miR-1303 was significantly upregulated in both knee and hip OA (IVW: p = 6.8164×10−36 and 4.7919×10−2 respectively, OR > 1) and identified as a key factor in disease progression. Hsa-miR-1303 potentially regulates 30 genes involved in critical signaling pathways, such as the neurotrophin signaling pathway, and interacts with competing endogenous RNAs (ceRNAs) like circ_0041843 and LINC01338, thereby influencing key regulatory proteins such as SUMO2 and PARP1. Pharmacologically, hsa-miR-1303 targets nine druggable genes, including NRAS, H2AZ1, and RPS3, which have implications for drugs like cantharidin and diindolylmethane, potentially critical for developing novel OA treatments. Conversely, hsa-miR-125a-5p and hsa-miR-125b-5p, which are downregulated in both knee and hip OA, are associated with pathways such as HIF-1 and JAK-STAT, which modulate apoptotic signaling and transcriptional regulation. These miRNAs also interact with ceRNAs such as circ_0000254 and SPACA6P-AS, impacting proteins like STAT3, MCL1, and TRAF6. A drug interaction analysis identified 47 potential treatments, including Resveratrol and Acetaminophen, suggesting new therapeutic possibilities for OA management. This study not only highlights the role of miRNAs like hsa-miR-1303 and hsa-miR-125 in OA but also opens avenues for miRNA-based therapeutic development.

Aims:The aim of this study was to explore the relationship between the femoral head diameter (FHD) and the degree of subluxation in developmental dysplasia of the hip (DDH) patients, and develop a machine-learning model for predicting acetabular component size in total hip arthroplasty (THA) according to demographic data and FHD. Methods:The FHD of 469 DDH patients from Longwood Valley medical database was measured, after excluding those with severe femoral head destruction, bone grafting, or augments. Its distribution and difference across Crowe and Hartofilakidis classifications were also assessed. Five machine-learning algorithms were developed to predict the size of the acetabular component, and the best model was determined according to the mean square error (MSE), root mean square error (RMSE), and R-squared values. The accuracy of the best model's cup size prediction was validated by comparing it with acetate templating and CT-based planning in a consecutive cohort from an independent institution. Results:The FHD gradually decreased with increasing Crowe and Hartofilakidis classifications. The Pearson correlation coefficient between FHD and the size of the acetabular component was 0.60, indicating a moderate correlation. In the test set, the random forest model outperformed the other four models in terms of MSE (0.904), RMSE (0.951), and R-squared (0.919). In the external validation, the accuracy of this model was not significantly different from CT-based planning (80.0% vs 87.5%, p > 0.05), but outperformed acetate templating (80.0% vs 52.5%, p < 0.05), particularly for Crowe Type IV (81.8% vs 27.3%, p < 0.05). Conclusion:The FHD decreases with increasing degree of subluxation in DDH patients. The machine-learning model constructed by combining demographic parameters and FHD demonstrates significantly higher accuracy in acetabular component size planning compared to templating methods. This approach serving as an effective auxiliary tool or alternative when CT is unavailable.

Background:Chondrocyte senescence significantly impairs extracellular matrix (ECM) synthesis and accelerates cartilage degradation, driving osteoarthritis (OA) progression. Although gene therapies targeting senescent chondrocytes are promising for OA, developing strategies that simultaneously rejuvenate cartilage function and precisely modulate the inflammatory microenvironment remains challenging. Methods:We developed an optimized lipid nanoparticle (LNP)-based delivery platform for the efficient co-delivery of transcription factors SOX5 and SOX9 mRNAs into chondrocytes. The physicochemical properties and biosafety of the formulations were systematically characterized. Additionally, the therapeutic efficacy of these formulations was evaluated in senescent chondrocyte cultures and an ACLT-induced osteoarthritis (OA) rat model. Results:The synergistic action of SOX5 and SOX9 markedly enhanced anabolic signaling, promoting synthesis of critical cartilage ECM components (type II collagen and aggrecan). The combination also reduced inflammation-mediated matrix degradation in vitro and in vivo. In a rat OA model, this optimized LNP-mediated co-delivery substantially improved cartilage regeneration, suppressed joint inflammation, and restored joint function compared to single-gene treatment or untreated controls. Conclusion:This work provides an advanced, synergistic mRNA therapeutic approach employing optimized LNPs to alleviate chondrocyte senescence and stimulate cartilage regeneration, representing a promising strategy for OA intervention.

BACKGROUND:The primary aim of this study was to compare the accuracy of component positioning between robotic-assisted total hip arthroplasty (R-THA) and manual total hip arthroplasty (M-THA) and to determine whether there are differences in achieving the minimal clinically important improvement (MCII) in functional outcomes. In addition, surgical trauma and complications were also compared. METHODS:This study included 132 patients from three centers who were randomly assigned to either the R-THA group or the M-THA group. The absolute errors in predicting component size, acetabular component position, limb-length discrepancy, hip offset, and center of rotation were compared. In addition, the Harris Hip Scores at three months postoperatively and one year postoperatively, as well as the proportion of patients who achieved MCII, were compared. The blood loss, inflammatory markers, and complications were also compared between the groups. RESULTS:The absolute errors for the abduction and anteversion angles in the R-THA group were smaller than those in the M-THA group (P < 0.05). The proportion of patients who had cups in the Callanan safe zone was greater in the R-THA group (P < 0.05). In addition, the R-THA group outperformed the M-THA group in controlling limb-length discrepancy and hip offset (P < 0.05). The R-THA demonstrated significantly greater accuracy in predicting component size (P < 0.05). Although R-THA patients had higher Harris Hip Scores at three and 12 months postoperatively, there was no significant difference in the proportion of patients who achieved an MCII (P > 0.05). The R-THA group had a shorter operative time, but there was no difference in blood loss, inflammatory response, or complications. CONCLUSIONS:Compared to manual THA, R-THA improves surgical accuracy without increasing surgical trauma, contributing to the restoration of the patient's original hip biomechanics. However, it does not offer an advantage in achieving the MCII postoperatively.

As an effective treatment for end-stage knee osteoarthritis, total knee arthroplasty (TKA) has been extensively performed globally over the past years. Despite its effectiveness, patients who undergo TKA are at risk of a series of complications, from infection to thromboembolism,[1] and substantial blood loss, which remains a concern among orthopedic surgeons, causing increased possibility for blood transfusion, prolonged hospitalization, and higher cost.[2,3] Postoperative TKA blood loss is now partially reduced due to the progress of surgical techniques and adjuvant medications. And many efforts on preoperative estimation of postoperative blood loss have been made over the past decade. However, there are still no systemic ways to assess the independent predictive value of potentially correlated risk factors; therefore, it is clinically critical to identify patients at an increased risk of blood loss and establish an effective blood management strategy.[4] This study analyzed total blood loss in patients receiving primary TKA, aiming to (i) identify influence factors for blood loss after TKA, especially among hematological parameters; (ii) develop a model for individualized prediction of blood loss following TKA using readily available clinical variables; and (iii) propose potential management strategies for adverse outcomes. This study was approved by the Institutional Review Board of the Peking Union Medical College Hospital (No. S-K2005), and because this was a retrospective study, the patients' informed consent was waived. The flowchart for experimental design is shown in Supplementary Figure 1, https://links.lww.com/CM9/C355. For all 1587 patients, the age, gender, body mass index (BMI), tobacco use (a positive status was defined as current smoker within 1 year, 1+ pack/day), alcohol use (a positive status was defined as current drinker within 1 year, 1+ drink/day) were recorded.[5] In addition, perioperative laboratory parameters were recorded. Total blood loss was calculated using Rosencher et al's[6] formula: Total red blood cell (RBC) loss (mL) = [Uncompensated RBC loss (mL)] + [Compensated RBC loss (mL)] Uncompensated RBC loss (mL) = [Initial RBC (mL)] – [Final RBC (mL)] Compensated RBC loss = [Sum of RBCs received from the various sources of transfusion] Initial RBC = [Estimated blood volume (mL)] × [Initial Hematocrit (HCT) level (%)] at Day – 1 Final RBC (mL) = [Estimated blood volume (mL)] × [Final HCT level (%)] at Day + 3 The estimated blood volume in milliliters was calculated for women and men separately with the use of the formulas[7]: Women: [Body surface area (m2)] × 2430 Men: [Body surface area (m2)] × 2530 where body surface area was calculated as: 0.0235 × [height (cm)]0.42246 × [weight (kg)]0.51456 Finally, the total blood loss was obtained at a HCT level of 35%: Total blood loss (mL) = [Total RBC loss (mL)]/0.35 Analyses were performed using SPSS software version 22.0 (SPSS Inc, Chicago, USA) and RStudio version 1.1.461 (RStudio, Boston, USA). Multivariable stepwise linear regression were established to determine potential independent influence factors for blood loss. P <0.05 was considered statistically significant. Considering that when blood loss is over 1500 mL, patients' physical condition and prognosis will be greatly reduced, so we converted the dependent variables into binary categorical variables at the threshold of 1500. The association between the pre-specified predictors and the primary outcome was assessed using LASSO Cox regression model analysis. And we used the Cox regression coefficients to generate nomograms. The model was internally validated using 1000 bootstrap samples. At the same time, the model was externally validated using another cohort of patients from January 2021 to December 2023. Agreement between predicted and observed outcomes was also evaluated graphically using receiver operating characteristic (ROC) analysis and the area under curve (AUC). The calibration curve was plotted to evaluate the agreement between nomogram-derived probability and actual observations of the model. A decision curve analysis (DCA) was also performed to evaluate the clinical benefit of our model. In this study, the total blood loss on the third day after the TKA surgery reached 961.29 ± 489.40 mL. Male patients lost an average of 1218.33 ± 549.67 mL of blood, whereas female patients lost an average of 898.89 ± 452.53 mL. We conducted a multivariate analysis of demographics, clinical, surgical variables, peroperative hematological parameters. Results were summarized in Supplementary Table 1, https://links.lww.com/CM9/C355. For these variables showing a correlation with postoperative blood loss, they were used for LASSO Cox regression model analysis, and the results are presented in Figure 1 and Supplementary Table 2, https://links.lww.com/CM9/C355.Figure 1: Development and performance of the nomogram. (A) Tuning parameter (λ) selection in the LASSO model used 10-fold cross-validation via minimum criteria. The AUC curve was plotted versus log (λ). Dotted vertical lines were drawn at the optimal values by using the minimum criteria and the 1 standard error of the minimum criteria (the 1-SE criteria). A λ value of 0.01623, with log (λ), 10 was chosen (1-SE criteria) according to 10-fold cross-validation. (B) LASSO coefficient profiles of the 13 features. A coefficient profile plot was produced against the log (λ) sequence. Vertical line was drawn at the value selected using 10-fold cross-validation, where optimal λ resulted in 10 non-zero coefficients. (C) A nomogram was created to evaluate the possibility of postoperative hemorrhage (total blood loss >1500 mL). To use the nomogram, find the position of each variable on the corresponding axis, draw a line to the points axis, add the points for the ten variables to create a total point value, and draw a line to the possibility axis to determine the probability on the lower line of the nomogram. ALB: Albumin; APTT: Activated partial thromboplastin time; BMI: Body mass index; HCT: Hematocrit; MONO: Monocyte; PLT: Blood platelet; TBIL: Total bilirubin.These independently associated risk factors were used to form a blood loss risk estimation nomogram [Figure 1C]. The optimal cutoff value of the total nomogram scores was determined to be 200. The sensitivity, specificity, positive predictive value, and negative predictive value when used in predicting risk of postoperative hemorrhage were 81%, 65%, 24%, and 96%, respectively. The resulting model was internally validated using the bootstrap validation method. The nomogram demonstrated good accuracy in estimating the risk of blood loss, with an unadjusted C index of 0.78 and a bootstrap-corrected C index of 0.77. ROC analysis and AUC graphically showed good agreement on the presence between the risk estimation by the nomogram (the mean AUC of the nomogram was 0.784), with high sensitivity and specificity of 79% and 64%, respectively, which indicated good discrimination. The calibration curve suggested that the nomogram had good calibration and fit in the internal validation set. The DCA results demonstrated that the nomogram added more net benefit than the "treat all" strategy or the "treat none" strategy in the training cohort. Overall, 500 patients after TKA from January 2021 to December 2023 from another center were finally included for external validation of the nomogram. The area under the ROC curve remained stable in the external validation (0.774). The calibration plots of the nomogram showed high consistency between the ideal line and the observed survival probability in the external validation cohorts. In the external validation, the DCA also revealed that the nomogram had an overall net benefit. The results of intetnal and external validation are shown in Supplementary Figure 2, https://links.lww.com/CM9/C355. In this study, we developed a prediction model based on demographics and hematological characteristics to improve the prediction of risk of hemorrhage after surgery for patients with TKA. Our results showed that this model can predict patients with high risk of postoperative blood loss (>1500 mL). Few studies investigated the relationship between smoking and postoperative blood loss. Nordestgaard et al[8] reported two potential mechanisms of smoking's influence on surgical bleeding. The chemicals inside the tobacco increased the recruitment of inflammatory cells to the vessel wall, causing injury to endothelial cells and vessel walls to be more fragile, resulting in increased perioperative bleeding. The other mechanism is reduced oxygenation and altered function of inflammatory cells during the initial healing process, which would increase short-term bleeding risk (within 72 hours). McCunniff et al[9] found platelet membrane change and impaired function caused by tobacco use. Tobacco use was also found to alter the membrane of red blood cells to be more fragile and hemolytic, causing postoperative blood loss. Multivariate analysis showed a positive correlation between preoperative HCT and postoperative blood loss (P <0.001). In a postoperative bleeding study in cervical cancer, Zhao et al[10] reported a significant positive correlation between preoperative HCT and insidious postoperative blood loss (P = 0.003), because high HCT level could increase blood accumulation in interstitial space by participating in postoperative hyperfibrolysis, thus increasing total blood loss by adding to insidious loss. In addition, for the same volume of blood loss, a higher HCT level means more lost visible components in the blood, resulting in more relative blood loss. We also found a positive relationship between preoperative ALB and postoperative blood loss. Possible explanations include compromised coagulation and inhibited platelet aggregation by albumin, as reported in a previous study.[11] Second, a relatively higher level of albumin could maintain colloid osmotic pressure, which would help replenish circulation volume, resulting in a higher relative volume of blood loss. Moreover, elevated preoperative albumin would cause volume expansion secondary to increased colloid osmotic pressure and diluting clotting factors, resulting in more bleeding intraoperative and postoperatively bleeding. Herein, we have explored many demographic and hematological parameters for blood loss after TKA, and developed a prediction model to improve the prediction of risk of hemorrhage after surgery for patients with TKA. The use of the nomogram in estimating the risk of a patient harboring postoperative hemorrhage to direct clinical treatment is a new concept. For clinical use of the model, we summarized the sensitivity, specificity, negative predictive value, and positive predictive value in estimating the risk of postoperative hemorrhage using 200 as the cutoff value. Patients with a score of 200 or more are a high-risk subgroup of blood loss. Based on these preoperative and postoperative predictions, the nomogram might serve as a tool to select patients at an increased risk of blood loss and establish an effective blood management strategy. This study still had some limitations. There is a geographical limitation as the sample was sourced from a single center. And the study adopted a retrospective design and relied on past medical records. The completeness and accuracy of the data may be constrained by the standard of medical record keeping. A further prospective study is needed to verify some hypotheses we proposed. Conflicts of interest None. Funding This work was supported by CAMS Innovation Fund for Medical Sciences (CIFMS) (No. 2023-I2M-C&T-B-044).

Introduction Preoperative patients with knee osteoarthritis have a significantly increased risk of venous thromboembolism (VTE). While the Caprini risk assessment model offers some clinical guidance in predicting deep vein thrombosis (DVT), it has a relatively low predictive accuracy. Enhancing the model by integrating biomarkers, such as D-dimers, can potentially improve its accuracy. In this study, we explored the effectiveness of combining the Caprini risk model with D-dimer levels for individualized DVT risk assessment in patients with knee osteoarthritis. Materials and Methods This retrospective cohort study included 1605 knee osteoarthritis patients scheduled for total knee arthroplasty from Peking Union Medical College Hospital, screened between January 2015 and December 2018. A revised Caprini risk stratification model was developed, and a predictive DVT model was developed based on this revised system. The sensitivity, specificity, and the area under the curve (AUC) were used to determine predictive effectiveness of the model. Results In the revised Caprini risk stratification, the incidence of DVT increased with higher risk levels: 2.52% in the low-risk group (scores 0-2), 2.88% in the moderate-risk group (score 3), 6.47% in the high-risk group (score 4), and 9.09% in the highest-risk group (score ≥ 5). The incidence of DVT was 3.869-fold higher in the highest-risk group and 2.676-fold higher in the high-risk group compared to the low-risk group (p = 0.013 and p = 0.014, respectively). Combining the revised Caprini risk stratification with D-dimer level demonstrated an improved AUC of 0.792, compared to D-dimer level alone (AUC 0.774) and the revised Caprini model alone (AUC 0.598). Furthermore, applying specific D-dimer thresholds across the four Caprini risk stratifications outperformed the combination of the revised Caprini model and D-dimer level in terms of AUC, specificity, and reduction in unnecessary ultrasonography. Using the Youden index, the AUC for the threshold-based method was slightly higher (0.775 vs 0.754, p = 0.310), with significantly better specificity (76.8% vs 63.6%, p < 0.001) and a greater reduction in ultrasound use (74.1% vs 61.4%). At a sensitivity of 85.5%, the differences were modest but still favored the threshold-based approach. At a sensitivity of 100%, the specificity (36.0% vs 24.7%, p < 0.001) and ultrasound reduction (34.8% vs 23.9%) were significantly better. Conclusion The revised Caprini risk stratification improves preoperative DVT prediction in patients with knee osteoarthritis. Incorporating specific D-dimer thresholds into the four-level Caprini risk model enhances specificity and reduces unnecessary ultrasonography, outperforming both the use of individual indicators and the combination of the revised Caprini model with D-dimer level.

PURPOSE:The aims of this study were to generalise the distribution and sex differences in functional knee phenotypes in a Chinese osteoarthritis (OA) population and to compare the distributions of functional knee phenotypes across geographic regions. METHODS:Knee phenotypes were evaluated according to Hirschmann's classification in 908 knees with OA, and the correlations among the hip-knee-ankle angle (HKA), femoral mechanical angle (FMA) and tibial mechanical angle (TMA) and their differences between the sexes were described. Studies reporting the distributions of functional knee phenotypes for arthritic knees were included to compare the variability in geographic distribution. RESULTS:The average values (males, females) of the HKA (173.1 ± 5.4°, 174.0 ± 6.9°), FMA (90.5 ± 2.9°, 91.6 ± 3.5°), and TMA (85.7 ± 3.1°, 85.7 ± 3.6°) demonstrated that the Chinese OA population tended towards femoral and tibial varus deformities in both males and females. A total of 145 functional knee phenotypes were identified in all 908 knees, comprising 68 types in males and 136 types in females. The most common phenotypes were VARHKA6° + VARFMA3° + NEUTMA0° (5.7%) for all knees, VARHKA3° + NEUFMA0° + NEUTMA0° (7.4%) for males and VARHKA6° + VARFMA3° + NEUTMA0° (5.4%) for females. The incidence of femoral varus deformity was greater than that of tibial varus deformity in 48.4% of males and 36.5% of females, and the incidence of tibial varus deformity was greater than that of femoral varus deformity in 24.7% of males and 35.2% of females. Seven studies including 16,395 knees were identified. The main femoral and tibial phenotypes in different geographic regions were VARFMA3° and NEUTMA0°, but their proportional distributions differed significantly. CONCLUSIONS:Sex differences in the functional knee phenotypes of OA patients in China were identified. Femoral varus deformity was more common than tibial varus deformity in males, whereas the difference was minimal in females. Moreover, functional knee phenotypes varied significantly across geographic regions. LEVEL OF EVIDENCE:Level IV.

Deep vein thrombosis (DVT) is a common and serious risk in elderly patients with knee osteoarthritis (OA), making preoperative detection crucial. Despite this, identifying OA patients at high risk for preoperative DVT and appropriately targeting them for venous ultrasound screening remains a challenge. There is limited research-based evidence on the risk factors for preoperative DVT in elderly patients with end-stage OA. We examined the incidence of and risk factors for preoperative DVT in elderly patients with end-stage OA scheduled for total knee arthroplasty. We retrospectively analyzed the demographic data (age, sex, body mass index, current smoking, alcohol consumption, walking status, and Barthel index score), medical history, and laboratory test indices of 1411 patients with end-stage OA aged ≥ 60 years scheduled for total knee arthroplasty from January 2015 to December 2018. Risk factors for preoperative DVT were evaluated by univariate and multivariate logistic analyses. Receiver operating characteristic analysis was performed to determine optimal cut-off values. The incidence of preoperative DVT was 4.5

BACKGROUND:This study aimed to develop a novel deep convolutional neural network called Dual-path Double Attention Transformer (DDA-Transformer) designed to achieve precise and fast knee joint CT image segmentation and to validate it in robotic-assisted total knee arthroplasty (TKA). METHODS:The femoral, tibial, patellar, and fibular segmentation performance and speed were evaluated and the accuracy of component sizing, bone resection and alignment of the robotic-assisted TKA system constructed using this deep learning network was clinically validated. RESULTS:Overall, DDA-Transformer outperformed six other networks in terms of the Dice coefficient, intersection over union, average surface distance, and Hausdorff distance. DDA-Transformer exhibited significantly faster segmentation speeds than nnUnet, TransUnet and 3D-Unet (p < 0.01). Furthermore, the robotic-assisted TKA system outperforms the manual group in surgical accuracy. CONCLUSIONS:DDA-Transformer exhibited significantly improved accuracy and robustness in knee joint segmentation, and this convenient and stable knee joint CT image segmentation network significantly improved the accuracy of the TKA procedure.