Background: The search for potential markers for a timely and accurate diagnosis of periprosthetic joint infection (PJI) is ongoing. Previous studies have focused on inflammatory markers and have rarely examined coagulation-related indicators. The purpose of this study was to evaluate the values of plasma fibrinogen, D-dimer, and other blood markers for the diagnosis of PJI through a multicenter retrospective study. Methods: A total of 565 revision total hip and knee arthroplasty cases were enrolled in this study from January 2016 through December 2017, 126 of which had coagulation-related comorbidities and were analyzed separately. The remaining 439 cases included 76 PJI and 363 non-PJI patients. The definition of PJI was based on the International Consensus Meeting (ICM) on Periprosthetic Infection criteria. The diagnostic values of D-dimer, plasma fibrinogen, the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and white blood-cell (WBC) count were analyzed using receiver operating characteristic (ROC) curves. Results: ROC curves showed that plasma fibrinogen had the highest area under the curve (AUC), 0.852, followed by 2 classical markers, the CRP level and ESR, which had an AUC of 0.810 and 0.808, respectively. D-dimer had an AUC of 0.657, which was the second lowest value and only slightly higher than that of the WBC count, 0.590. The optimal threshold for plasma D-dimer was 1.25 μg/mL, with a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 0.645, 0.650, 0.278, and 0.897, respectively. The optimal threshold for plasma fibrinogen was 4.01 g/L, which showed good sensitivity, specificity, PPV, and NPV, with values of 0.763, 0.862, 0.537, and 0.946, respectively. Conclusions: Plasma D-dimer may have a very limited diagnostic value for PJI, while plasma fibrinogen, another coagulation-related indicator, exhibits promising performance. Plasma fibrinogen has good sensitivity and specificity for diagnosing PJI, with values similar to those of classical markers, including CRP level and ESR. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Inaccurate placement of an acetabular cup can cause impingement, dislocation, and accelerated wear. However, there is no universally agreed-on approach to measuring cup position using plain radiographs. Our goal was to evaluate the reliability and validity of measuring the orientation of acetabular components on plain anteroposterior (AP) radiographs. We obtained plain AP radiographs and CT scans for 60 patients who underwent 60 primary total hip arthroplasties (THAs). The method devised by Lewinnek et al. was used to measure the orientation of acetabular components on plain AP radiographs, and three-dimensional (3-D) CT scans were used to measure both the radiographic anteversion angle and the inclination angle. Reliability was evaluated by analysis of the agreement between inter- and intraobserver measurements using plain AP radiographs. Measurements on 3-D CT scans were regarded as the reference standard; validity was assessed by comparing radiographic measurements with the CT scans. Inter- and intraobserver reliability for measuring component orientation on plain AP radiographs was nearly perfect with intraclass correlation coefficients of 0.896 and 0.969 for anteversion and 0.984 and 0.993 for inclination. Measurement of cup inclination angles differed between plain radiographs and CT scans, but the difference was small, and the difference, although statistically significant, probably was not clinically important (2.3° ± 1.8°, p < 0.001). There was no significant difference between the anteversion as measured on CT scan versus that measured on plain radiographs (p = 0.19). Measurement of the orientation of acetabular components on plain AP radiographs is reliable and accurate compared with measurement on CT. Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Background: Venous thromboembolism (VTE) is an important complication after major orthopedic surgery. Pharmaceutical methods represent the main strategy of VTE prevention. The use of aspirin in VTE prevention is still controversial worldwide, especially in China. The purpose of this study was to evaluate the role of aspirin combined with mechanical measures in the prevention of VTE after total knee arthroplasty (TKA). Methods: Between January 2012 and May 2013 and in accordance with the inclusion criteria, 120 patients undergoing TKA were randomly allocated to two groups. To prevent VTE, patients in group A received aspirin combined with mechanical measures postoperatively, while patients in group B received low-molecular-weight heparin (LMWH) sodium and rivaroxaban sequentially in combination with mechanical measures postoperatively. All surgeries were performed by one surgeon using a posterior-stabilized cemented prosthesis. The two groups were followed up and compared for the incidence of deep vein thrombosis (DVT) by duplex ultrasound scan and clinical VTE events. The adverse events, the blood loss index, and the cost of VTE prevention were also compared. Results: DVT was detected in 10 of 60 patients in group A (16.7%, 95% CI: 7.3%-26.1%) compared with 11 of 60 in group B (18.3%, 95% CI: 8.5%-27.8%) (P=0.500). There is no statistical evidence supporting the inferior effect of aspirin in preventing DVT as compared with the other medications. There were no cases of symptomatic VTE or death during the follow-up period. Area of ecchymosis was lower in group A than in group B, and the differences were statistically significant. Patients in group A had the lower blood loss index as compared with patients in group B. No transfusion cases were found in both groups. The differences were statistically significant. The cost of VTE prevention analysis indicated a cost reduction using aspirin in group A compared with using LMWH and rivaroxaban in group B. Conclusion: Aspirin combined with mechanical measures had a good effect on prevention of VTE after TKA and resulted in lower cost, less blood loss, and less subcutaneous ecchymosis.

Tissue engineering provides a promising avenue for treating cartilage defects. However, great challenges remain in the development of structurally and functionally optimized scaffolds for cartilage repair and regeneration. In this study, decellularized cartilage extracellular matrix (ECM) and waterborne polyurethane (WPU) were employed to construct WPU and WPU-ECM scaffolds by water-based 3D printing using low-temperature deposition manufacturing (LDM) system, which combines rapid deposition manufacturing with phase separation techniques. The scaffolds successfully achieved hierarchical macro‐microporous structures. After adding ECM, WPU scaffolds were markedly optimized in terms of porosity, hydrophilia and bioactive components. Moreover, the optimized WPU-ECM scaffolds were found to be more suitable for cell distribution, adhesion, and proliferation than the WPU scaffolds. Most importantly, the WPU-ECM scaffold could facilitate the production of glycosaminoglycan (GAG) and collagen and the upregulation of cartilage-specific genes. These results indicated that the WPU-ECM scaffold with hierarchical macro‐microporous structures could recreate a favorable microenvironment for cell adhesion, proliferation, differentiation, and ECM production. In vivo studies further revealed that the hierarchical macro‐microporous WPU-ECM scaffold combined with the microfracture procedure successfully regenerated hyaline cartilage in a rabbit model. Six months after implantation, the repaired cartilage showed a similar histological structure and mechanical performance to that of normal cartilage. In conclusion, the hierarchical macro‐microporous WPU-ECM scaffold may be a promising candidate for cartilage tissue engineering applications in the future.

Teau in Chinese people. Methods: We included knees from fifty Chinese individuals (twenty-five females and twenty-five males) in this study. On magnetic resonance imaging scans of the tibial plateau and the proximal part of the tibial shaft of each lower limb, the distance between the axis of the tibial shaft and the center of the tibial plateau was measured and was defined as the offset of the tibial shaft from the tibial plateau at three resection levels: the first just distal to the subchondral bone of the medial tibial plateau, the second 5 mm distal to it, and the third 10 mm distal to it. The dimensions of the tibial plateau were measured as well. Results: At the first, second, and third resection levels, the mean tibial shaft offsets (and standard deviations) from the center of the tibial plateau were, respectively, 7.23 ± 2.44 mm (3.40 ± 1.94 mm of mediolateral offset and 6.22 ± 2.05 mm of anteroposterior offset), 6.33 ± 2.26 mm (3.14 ± 2.04 mm of mediolateral offset and 5.24 ± 1.96 mm of anteroposterior offset), and 4.75 ± 2.07 mm (2.68 ± 1.91 mm of mediolateral offset and 3.46 ± 2.03 mm of anteroposterior offset). At each resection level, the mean offset in the male group was significantly larger than that in the female group. Conclusions: There is a large variation in the offset of the tibial shaft from the tibial plateau in Chinese people. The axis of the tibial shaft is located anterolateral to the center of the tibial plateau in this population. Clinical Relevance: The use of an anterolaterally offset tibial keel or stem seems more suitable for Chinese patients undergoing primary or revision total knee arthroplasty....