Microplastics exhibit accumulation and horizontal transfer of antibiotic resistance genes.

Although the fates of microplastics (0.1-5 mm) in marine environments and freshwater are increasingly studied, little is known about their vector effect in wastewater treatment plants (WWTPs). Previous studies have evaluated the accumulation of antibiotic resistance genes (ARGs) on microplastics, but there is no direct evidence for the selection and horizontal transfer of ARGs on different microplastics in WWTPs. Here, we show biofilm formation as well as bacterial community and ARGs in these biofilms grown on four kinds of microplastics via incubation in the aerobic and anaerobic tanks of a WWTP. Microplastics showed differential capacities for bacteria and ARGs enrichment, differing from those of the culture environment. Furthermore, ARGs in microplastic biofilms were horizontally transferred at frequencies higher than those in water samples in both tanks. Therefore, microplastics in WWTPs can act as substrates for horizontal transfer of ARGs, potentially causing a great harm to the ecological environment and adversely affecting human health.

Complex Repair and Cruciate Ligament Reconstruction in KDs III and IV Multiligamentous Knee Injuries-Results of Mid-Term Follow-up.

The purpose of the present study was to describe the longitudinal outcomes of acute repair of extra-articular structure and anatomical reconstruction of cruciate ligament for knee dislocations (KDs) III and IV multiligamentous knee injuries. Forty-seven patients with an acute KD III or IV were treated with one-stage management within 9.2 days. Forty-five KDs III and IV with a follow-up at a mean of 53.2 months were evaluated. The mean International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score were 81.5 ± 0.7, 89.6 ± 1.2, and 6.8 ± 0.5, respectively. Comparing preoperative data with those at the latest follow-up, significant improvements in IKDC score (p < 0.01), Lysholm score (p < 0.01), and Tegner score (p < 0.01) were noted in all groups. Comparing contralateral knee stability, no statistical differences were found including the varus/valgus (0 degree/30 degrees) and Telos stress radiography. So, acute repair of extra-articular structure and anatomical reconstruction of cruciate ligament resulted in satisfactory outcomes for KDs III and IV multiligamentous knee injuries.

An Arthroscopic-Assisted Radial Meniscal Tear Repair Using Reinforced Suture Tape Rebars and Suture Tapes.

A radial tear of the meniscus can lead to significant loss of meniscus function, resulting in deleterious cartilage changes. Repair of radial meniscus tears has several challenges, including suture pull-out, which can reduce healing success. We present an arthroscopic repair technique in a complete radial lateral meniscus tear using vertical reinforced bars (rebar) of suture tapes to reduce suture pull-out and approximate the radial tear.

Application of Personalized Navigation Templates to Oxford Single Condylar Replacement in a Chinese Population.

The purpose of this study is to develop and validate a novel patient-specific navigational template for unicompartmental knee arthroplasty (UKA). A total of 120 patients who underwent UKA were randomized and divided into the conventional method and navigational template groups. In the navigational template group, patient-specific navigational templates were designed and used intraoperatively to assist 60 patients with UKA. Information on operation time and blood loss was recorded by an independent operating room nurse. After surgery, the positions of the prostheses were evaluated using X-rays. All navigation templates were found to fit its corresponding biomodel appropriately without any free movement. The navigational template exhibited significantly better accuracy than the conventional method. Statistically significant differences in the femoral prosthesis flip angle, femoral prosthesis flexion angle, and tibial plateau varus and valgus angle were observed between the two groups (p = 0.022, 0.042, 0.043, respectively). In addition, the mean operation time was statistically and significantly lower in the navigational template group than in the conventional group (p = 0.035). This study introduces a novel navigational template to UKA, the accuracy of which is proven by clinical operation. This is a Level III, therapeutic study.

Tension Band Wire Fixation Technique for Anterior Cruciate Ligament Tibial Avulsion Fracture: A New Fixation Technique.

This study evaluated clinical results of tension band wire fixation technique in the arthroscopic treatment of anterior cruciate ligament (ACL) tibial avulsion fracture. This study included 148 cases of ACL tibial avulsion fracture treated using arthroscopic tension band wire fixation technique. Patients were followed up for 25 to 36 months with an average of 27 months and evaluated in accordance with the International Knee Documentation Committee (IKDC) and Lysholm knee scoring scale. Fractures were united within 3 months after surgery in all cases. During the last follow-up, the anterior drawer, Lachman, and pivot shift tests showed negative, except for eight patients who had a 1-degree positive anterior drawer test. KT-1000 knee stability test showed no anterior instability exceeding 2 mm in 132 patients and 4 mm in 8 patients. In accordance with the IKDC scale, the knees of 132 patients were graded normal, whereas 8 other patients were nearly normal. Lysholm scores before surgery and during the last follow-up were 72.4 ± 3.2 and 97.5 ± 2.2, respectively. Statistically significant differences were observed among the Lysholm scores (p < 0.05). The Tegner scores were 6.5 ± 0.9 before injury and 6.4 ± 0.7 at the last follow-up (p > 0.05). No statistically significant differences between the preinjury and postoperative activity level were observed. All patients were satisfied with the outcomes of operation. Arthroscopic treatment of ACL tibial avulsion fracture by using tension band wire fixation technique ensures fracture healing and restores the stability and function of the joint in most patients. The level of evidence for this study is III.

Accuracy and efficacy of osteotomy in total knee arthroplasty with patient-specific navigational template.

This study develops and validates a novel patient-specific navigational template for total knee arthroplasty (TKA). A total of 70 patients who underwent TKA were randomized and divided into conventional method group and navigational template group. In the navigational template group, the patient-specific navigational templates were designed and used intraoperatively to assist 35 patients with knee arthroplasty. Information on operation time and blood loss was recorded. After surgery, the positions of the prosthesis were evaluated using CT scan and X-rays. Analysis showed significant differences in errors between the two techniques. In addition, mean operation time and mean blood loss were statistically and significantly lower in the navigational template group than in the conventional group. Overall, the navigational template method showed a high degree of accuracy and efficacy.

Tension band wire fixation for anterior cruciate ligament avulsion fracture: biomechanical comparison of four fixation techniques.

PURPOSE: The purpose of this study is to design a new fixation method to treat tibial eminence fractures and assess its stability compared with conventional fixation methods. METHODS: Eighty fresh porcine knees were stripped of all soft tissue, leaving intact only the femur-anterior cruciate ligament (ACL)-tibia complex. A standardized type III fracture was simulated at the anterior cruciate ligament attachment region using an osteotome. Then, the 80 specimens were randomly divided into 4 groups consisting of 20 knees each. The bony fragments were, respectively, fixed with sutures, steel wire, screws, and the newly designed tension band wire. All specimens were subsequently tested on a Material Testing Machine at a load rate of 60 mm/min. The statistically significant difference between the methods in terms of ultimate failure load, yield load, and displacement of the fragment under single-cycle loading and cyclic loading were analysed. RESULTS: Steel wire encircling K-wire fixation showed significantly higher maximum loads, yield loads, and less displacement than all the other fixation methods tested. Specimens fixed with steel wire had the second highest maximal load followed by fixation with the cannulated screw. The lowest maximal load was observed in the group using PDS II suture. CONCLUSIONS: The ultimate strength of tension band wire fixation of tibial eminence fractures in these specimens was significantly greater than those of the other three fixation methods. Tension band wire fixation of eminence fractures appears to provide biomechanical advantages over the other three fixation methods; hence, it is a practical alternative to conventional fixation techniques.

Novel patient-specific navigational template for total knee arthroplasty.

Current techniques for total knee arthroplasty have certain drawbacks, including violation of the intramedullary canals and limited accuracy. The aim of this research was to develop and validate the accuracy of a new computer-assisted preoperative planning concept for the creation of patient-specific navigational templates to replace conventional instruments. Volumetric computerized tomography (CT) scanning was performed on 30 cadaveric knees, and a three-dimensional reconstruction model of each knee was generated from the scan data. Using a reverse-engineering technique, optimal lower-limb alignment and rotational alignment were determined. A navigational template was also designed with a surface that matched the distal femur and proximal tibia. This template, with its corresponding femur and tibia, was manufactured using a rapid-prototyping technique and tested for violations. The navigational template was then used intraoperatively to assist with an arthroplasty in each of the 30 cadaveric knees. Following surgery, the positions of the prostheses were evaluated with X-rays and CT scans. The method showed a high degree of accuracy and reproducibility. In all cases, placing the template manually on the lamina of the femur and tibia was relatively easy. Twenty-eight prostheses were considered to be positioned entirely accurately, whereas two prostheses were considered to have a 1-2° malpositioning. This study thus introduces a novel navigational template for total knee arthroplasty. Preliminary cadaveric trials have demonstrated that this design can improve the accuracy of osteotomy in the surgical procedure.