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ABSTRACT This study was undertaken to screen periprosthetic tissues (PPTs) under specified conditions for a series of molecular components and describe them in bone remodeling processes within aseptic loosening. PPT samples were obtained from patients undergoing revision surgery of endoprostheses ( n = 24) and synovial tissues from patients with OA (control) ( n = 18), patients with any form of inflammatory arthritides were excluded. Tissue samples were examined via microbiology, histology (H&E, TRAP), immunohistochemistry (CD68/anti-S100a4), quantitative real-time PCR (ALP, COL1A1, cathepsin K, M-CSF, MMP13, OPG, RANK, RANKL, TNF-α, and TRAP) and an endotoxin-assay. PPT samples contained a variety of cellular components and stained positive for TRAP (56%), CD68 (100%), and S100a4 (100%). Wear debris were found in cells staining positive for CD68 and S100a4. In PPTs significantly higher ALP, COL1A1, MMP-13, RANK, RANKL, and TRAP expression were found along with a significantly higher RANKL/OPG ratio and a significantly lower OPG expression. No significant difference was observed for M-CSF, TNF-α, cathepsin K, and endotoxin levels. In conclusion we found osteogenic proteins (ALP, COL1A1), a proteolytic enzyme (MMP-13), markers for osteoclast differentiation (RANK, RANKL), and osteoclast activity (TRAP) to be increased in PPT, whereas OPG expression decreased significantly in comparison to control. We present data about a large series of molecular components in PPT and describe novel and key findings about their expression levels in regards to aseptic implant loosening. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:248-257, 2017. [ABSTRACT FROM AUTHOR]

Introduction: Rehabilitation protocols following anterior cruciate ligament (ACL) reconstruction often differ among orthopaedic surgeons. The primary aim of this study was to investigate which follow-up treatment is recommended by "AGA instructors" certified by the German-speaking Association for Arthroscopic and Open Joint Surgery (AGA). The secondary aim was to compare these findings with the current literature., Material and Methods: A structured anonymous online survey was performed with "AGA instructors" specialised in knee or ACL surgery. All participants were asked about their recommendations for rehabilitation following isolated ACL reconstruction using a questionnaire containing 23 items., Results: 117 out of 218 mail questionnaires were fully completed and analysed. 96.5 % of all surgeons allowed full weight-bearing after 4 weeks or earlier, 52.6 % put a limit on knee flexion, 9.7 % on knee extension after the operation. A brace was prescribed by 82.8 % of all participants. During the first six weeks, isometric training and closed-chain exercises were recommended by the majority of surgeons. Riding a bicycle or driving a car after 6 weeks or earlier was permitted by 78.5 % and 86.2 %, respectively. Jogging (65.5 %) or jumping activities (67.0 %) were allowed after 3 months or earlier. Skiing (53.0 %) or contact/team sport (55.2 % / 46.2 %) was often permitted after 12 months. 82.6 % of all surgeons would like to use return-to-sport test protocols., Conclusion: Rehabilitation protocols differ significantly even among experienced knee surgeons working as instructors. Their recommendations are often not evidence-based considering the current literature., Competing Interests: Die Autoren geben an, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background  Total knee replacement is the only surgical option to treat painful degenerative osteoarthritis, restore knee function, improve quality of life, and enable patients to return to sports activity. With an aging population expecting an active life after retirement, patients' expectations of improvement after surgery are increasing as well. In view of the growing demand for higher performance, exercise and athletic activity, clinicians have been increasingly forced to question how much athletic activity a patient may resume after total knee replacement, and what types of athletic activity seem to be acceptable. However, there is currently no consensus on the appropriate intensity of physical activity after total knee arthroplasty or how activity levels affect the rate of revision surgery. Patients, material and methods  In a retrospective study with a follow-up period of 12 years, 130 patients were asked about their sport activities 22 months before and after total knee replacement. Based on their answers, the patients were divided into one sports group (group A) and one group without any sports activity (group B). Seven years after surgery the same patients were asked about their sports activity again, and 12 years postoperatively they were additionally asked about whether or not they underwent revision surgery. Results  Twenty-two months after total knee replacement 88 (67.7 %) of the 130 patients practiced sports for a minimum of 3 times a week (group A), whereas 42 (32.3 %) patients reported that they practiced no sports (group B). In 2010 - 7 years postoperatively - 60 patients of group A and 27 patients of group B took part in the survey; their levels of sports activity had not changed over the previous 7 years. In 2015, 46 patients out of group A and 21 patients out of group B were questioned. We saw a revision rate of 15.2 % (7 out of 46 patients) in the group with continuous sports activity, whereas we found an increased revision rate of 23.8 % (5 out of 21 patients) in the group without any sports activity 12 years after total knee arthroplasty. Conclusion  Our study showed that sports activity after total knee replacement led to a reduced revision rate in the sports group compared with the non-sports group. Therefore, more liberal recommendations should be given to patients regarding athletic activity after total knee arthroplasty. We conclude that moderate sports activities have no negative influence on total knee arthroplasty and may even lead to improved osteointegration with a decrease in osteolytic changes and less prosthesis loosening., Competing Interests: Interessenkonflikt: Es besteht seitens der Autoren kein Interessenkonflikt., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: To develop and validate an all-purpose patient-reported outcome questionnaire for a patient-based follow-up examination regarding knee disorders., Methods: Each scale of the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, Lysholm knee score, Western Ontario Meniscal Evaluation Tool (WOMET) score, and Tegner score was analyzed, and after matching of the general topics, the dedicated items underwent a fusion to the final Munich Knee Questionnaire (MKQ) item and a score comprising 33 items was created. In a prospective clinical study, we evaluated validity, reliability, and responsiveness in 152 physical active patients (75 women and 77 men; mean age, 47 years) with traumatic as well as degenerative knee disorders., Results: Test-retest reliability was substantial, with intraclass correlation coefficients of at least 0.91. Construct validity and responsiveness were confirmed by correlation coefficients of 0.78 to 0.86 (P = .01) and 0.41 to 0.71, respectively. Correlation coefficients of the original scores (KOOS, IKDC, Lysholm, WOMET, and Tegner) and the scores calculated from the MKQ were between 0.80 and 0.91 (P = .01)., Conclusions: The MKQ is a reliable and valid patient-reported outcome questionnaire for assessing knee function. It seems to enable the calculation of the original items of the KOOS, IKDC score, Lysholm knee score, WOMET score, and Tegner score., Clinical Relevance: The MKQ facilitates the comparison of treatment results in knee disorders and allows the evaluation of treatment efficacy. Identified inadequate treatment concepts could be eliminated, leading to increased patient satisfaction and optimized quality of health care., (Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: Allogeneic bone transplantation is at risk of infection, and established disinfection methods typically compromise bone quality. High hydrostatic pressure (HHP) is well established for disinfection in food technology, and also it does protect biomechanical and biological properties of bone. This study is the first investigation of HHP regarding disinfection of bone biopsies., Materials and Methods: Bone biopsies of 34 patients with chronic infections were subjected to HHP and assessed for persisting bacterial growth. In series 1, bone biopsies were proceeded directly to HHP (10 min; maximal pressure Pmax 600 MPa). In series 2, HHP was applied after 5-day incubation in growth media (10 min or 2x30 min; Pmax 600 MPa). Furthermore, HHP-induced changes of bacterial morphology on artificially infected bone samples were evaluated by scanning electron microscopy (SEM)., Results: For series 1, 71% of the bone samples were sterilised by HHP (n=17), compared to 38% of the untreated control samples, which were obtained during the same surgery (n=8). For series 2, after prior incubation, HHP disinfected 7% of the bone specimens (n=55), all control samples showed bacterial growth (n=33). Destruction of cell wall integrity of Gram-negative strains was observed by SEM., Conclusion: The effectiveness of HHP for bone disinfection should be improved by optimising treatment parameters. Infections with barosensitive Gram-negative bacteria or yeast might represent possible clinical indications.

Purpose: Cationic liposomes have been shown to selectively target tumor endothelial cells. Therefore, the encapsulation of antineoplastic drugs into cationic liposomes is a promising tool to improve selective drug delivery by targeting tumor vasculature. It was the aim of our study to evaluate tumor selectivity and antitumoral efficacy of paclitaxel encapsulated in cationic liposomes in comparison with the free drug paclitaxel (Taxol(R)) in vivo., Experimental Design: Experiments evaluating tumor selectivity were carried out in male Syrian golden hamsters bearing the amelanotic hamster melanoma A-Mel-3 in dorsal skinfold preparations. Growth of tumor cells was observed after s.c. inoculation (day 0). On days 5, 7, 9, 12, 14, and 16, animals were treated by continuous i.v. infusion over 90 min with 5% glucose, Taxol(R), unloaded cationic liposomes, or paclitaxel encapsulated into cationic liposomes (LipoPac), respectively (lipid dose, 150 mg/kg body weight; paclitaxel dose, 5 mg/kg body weight). Tumor volumes and presence of regional lymph node metastases were quantified., Results: Vascular targeting of rhodamine-labeled cationic liposomes was maintained after encapsulation of paclitaxel as revealed by in vivo fluorescence microscopy (ratio of dye concentration, tumor:normal tissue = 3:1). The s.c. tumor growth revealed a remarkable retardation of tumor growth after treatment with LipoPac (1.7 +/- 0.3 cm(3)). In contrast, control tumors showed exponential tumor growth [tumor volume at the end of the observation period (mean +/- SE): 5% glucose, 17.7 +/- 1.9 cm(3); unloaded cationic liposomes, 10.0 +/- 1.6 cm(3); Taxol(R), 10.7 +/- 1.7 cm(3)]. In addition, the appearance of regional lymph node metastases was significantly delayed by treatment with paclitaxel encapsulated into cationic liposomes in comparison with all other groups., Conclusions: The data suggest that cationic liposomes are a powerful tool for selective and efficient drug delivery to tumor microvessels. This may serve as proof of the concept of neovascular tumor targeting therapy by cationic liposomes.