Bacteria utilize a quorum sensing (QS) system to coordinate gene expression by monitoring the concentration of molecules known as autoinducers (AI). In the present study, we confirmed the presence of a LuxS/AI-2 dependent QS system in vancomycin-resistant Enterococcus faecalis V583. Then, the cellular targets controlled by AI-2 were identified by comparative proteomics analysis in order to elucidate the possible role of AI-2 in E. faecalis. Results demonstrated 15 proteins that are differentially expressed upon the addition of AI-2, including proteins involved in metabolism, translation, energy production and/or conversion, and cell wall biogenesis. Glyceraldehyde-3-phosphate dehydrogenase and malate dehydrogenase associated with carbohydrate metabolism and energy production were up-regulated upon inducing by AI-2. In addition, externally added AI-2 could down-regulate acetyl-coenzyme A carboxylase and ornithine carbamoyltransferase, two key enzyme involved in metabolism. All these data suggest that AI-2 signaling may play a role in the regulation of a number of important metabolic properties of E. faecali. We further investigated the role of AI-2 in biofilm formation by E. faecalis, showing the addition of AI-2 to E. faecalis V583 cultures resulted in increased biofilm formation. Our results provide important clues to the role of a LuxS/AI-2 dependent QS system in vancomycin-resistant E. faecalis.

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Objectives The arthroscopic “lateral gutter drive‐through” (LGDT) sign is reported to diagnose popliteus tendon (PT) injury with high sensitivity and specificity. However, no study has provided a postoperative evaluation of combined posterior cruciate ligament (PCL) and posterolateral corner (PLC) injuries using the LGDT test. Methods From January 2012 to January 2015, a total of 80 consecutive patients who underwent combined PCL reconstruction and PLC surgeries were identified. Fifty eligible patients were included in this study for evaluation with subjective scoring systems, physical examinations, posterior and varus stress radiographs, and second‐look arthroscopic surgeries during hardware removal operation. Results Forty‐nine patients were available for a mean of 31.5 ± 9.3 months follow‐up (range, 24.0–81.0 months). In terms of PLC injury pattern, there were 27 type A, 10 type B, and 12 type C patients, with 21 acute cases and 28 chronic cases. At the final follow‐up, subjective scores were all significantly improved. The side‐to‐side difference (SSD) of posterior tibial translation (PTT) improved from 18.4 ± 9.2 mm (range, 12.9–25.6 mm) to 5.2 ± 5.0 mm (range, −5.0−18.5 mm, P < 0.001), and the SSD of tibial external rotation by dial test (ER) decreased from 18.0° ± 14.4° (range, 13.0°–22.0°) to 1.2° ± 7.5° (range, −9.0°–22.0°, P < 0.001). In patients with type C injury, the SSD of the lateral opening decreased from 14.2 ± 6.6 mm (range, 22–10.2 mm) to 0.9 ± 3.1 mm (range, −4.4‐6 mm, P < 0.001). In a comparison between patients with positive and negative LGDT signs, the LGDT‐negative patients had significant superiority in subjective scores, SSD of PTT, and SSD of ER. The sensitivity and specificity of the LGDT test in detecting postoperative posterolateral rotational instability (PLRI) were calculated as 100% and 88.4%, respectively. Conclusions In the series of surgically treated patients with PCL and PLC injury: (i) patients had improved subjective and objective clinical outcome after combined PCL reconstruction and PLC surgery at a minimum of 24‐months follow‐up; and (ii) second arthroscopic LGDT sign testing had high sensitivity and specificity in detecting postoperative PLRI, and a positive LGDT sign was related with inferior subjective and objective results.

Objective To evaluate the surgical security, feasibility, and clinical efficacy of the longitudinal outside‐in capsulotomy in hip arthroscopic treatment for cam‐type femoracetabular impingement (FAI). Methods We retrospectively reviewed patients with cam‐type FAI who underwent hip arthroscopy in our institute from January 2018 to June 2019. All hip arthroscopic procedures were performed by one experienced surgeon in the same manner, except the fashions of capsulotomy. Fifty six patients with mean age of 39.1 and mean body mass index (BMI) of 24.5 were categorized into two groups according to the fashions of capsulotomy. Twenty six cases with longitudinal outside‐in capsulotomy were categorized into Group L, and 30 cases with transversal interportal capsulotomy were categorized into Group T as the control group. The demographic parameters were retrieved from medical documents and compared between the two groups. Surgical outcome including overall surgical time, traction time, complications, visual analogue score (VAS), and intraoperative radiation exposure were compared to investigate the security and feasibility. Radiographic assessment, and functional outcome were compared between the two groups to determine the clinical efficacy of the longitudinal capsulotomy. Results There was no significant difference in the demography and duration of follow‐up between the two groups. The overall surgical time demonstrated no significant difference between Group L and Group T (130.8 ± 16.6 min and 134.0 ± 14.7 min, P = 0.490). Significantly decreased traction time was found in Group L (43.2 ± 8.4 min and 62.2 ± 8.6 min, P < 0.001) compared to Group T. The Median of the fluoroscopic shot was 1 and 3 (P < 0.001). No major complications and reoperation were reported in both groups. The case of intraoperative iatrogenic injure was 0 (0%) and 6 (20%) in Group L and Group T respectively (P = 0.035), and the case of postoperative neurapraxia was 0 (0%) and 8 (26.6%) in Group L and Group T respectively (P = 0.017). The Median of postoperative VAS was 2 and 3 in Group L Group T (P = 0.002). The postoperative α angle was 42.3° ± 3.4° and 44.4° ± 3.5° in group L and group T respectively (P = 0.001). The postoperative iHOT‐12 score at final follow‐up was 79.3 ± 6.7 and 77.0 ± 7.9 respectively (P = 0.141). Conclusion Longitudinal outside‐in capsulotomy with less radiation exposure, reduced traction time, and reduced complications could be a safe and feasible procedure in arthroscopic treatment for cam FAI. Its clinical efficacy was not worse compared with traditional interportal capsulotomy in short‐term follow‐up.

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