@article{StratosScarlatRudert2021, author = {Stratos, Ioannis and Scarlat, Marius M. and Rudert, Maximilian}, title = {Bibliometrics of orthopaedic articles published by authors of Germanophone countries}, series = {International Orthopaedics}, volume = {45}, journal = {International Orthopaedics}, number = {5}, doi = {10.1007/s00264-021-05052-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266343}, pages = {1121-1124}, year = {2021}, abstract = {No abstract available.}, language = {en} } @article{MagesShojaaKohletal.2021, author = {Mages, Michelle and Shojaa, Mahdieh and Kohl, Matthias and Stengel, Simon von and Becker, Clemens and Gosch, Markus and Jakob, Franz and Kerschan-Schindl, Katharina and Kladny, Bernd and Kl{\"o}ckner, Nicole and Lange, Uwe and Middeldorf, Stefan and Peters, Stefan and Schoene, Daniel and Sieber, Cornel C. and Tholen, Reina and Thomasius, Friederike E. and Uder, Michael and Kemmler, Wolfgang}, title = {Exercise effects on Bone Mineral Density in men}, series = {Nutrients}, volume = {13}, journal = {Nutrients}, number = {12}, issn = {2072-6643}, doi = {10.3390/nu13124244}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250247}, year = {2021}, abstract = {In contrast to postmenopausal women, evidence for a favorable effect of exercise on Bone Mineral Density (BMD) is still limited for men. This might be due to the paucity of studies, but also to the great variety of participants and study characteristics that may dilute study results. The aim of the present systematic review and meta-analysis was to evaluate the effect of exercise on BMD changes with rational eligibility criteria. A comprehensive search of six electronic databases up to 15 March 2021 was conducted. Briefly, controlled trials ≥6 months that determined changes in areal BMD in men >18 years old, with no apparent diseases or pharmacological therapy that relevantly affect bone metabolism, were included. BMD changes (standardized mean differences: SMD) of the lumbar spine (LS) and femoral neck (FN) were considered as outcomes. Twelve studies with 16 exercise and 12 control groups were identified. The pooled estimate of random-effect analysis was SMD = 0.38, 95\%-CI: 0.14-0.61 and SMD = 0.25, 95\%-CI: 0.00-0.49, for LS and FN, respectively. Heterogeneity between the trials was low-moderate. Funnel plots and rank and regression correlation tests indicate evidence for small study publication bias for LS but not FN-BMD. Subgroup analyses that focus on study length, type of exercise and methodologic quality revealed no significant difference between each of the three categories. In summary, we provided further evidence for a low but significant effect of exercise on BMD in men. However, we are currently unable to give even rough exercise recommendations for male cohorts.}, language = {en} } @article{EidmannEwaldBoelchetal.2021, author = {Eidmann, Annette and Ewald, Andrea and Boelch, Sebastian P. and Rudert, Maximilian and Holzapfel, Boris M. and Stratos, Ioannis}, title = {In vitro evaluation of antibacterial efficacy of vancomycin-loaded suture tapes and cerclage wires}, series = {Journal of Materials Science: Materials in Medicine}, volume = {32}, journal = {Journal of Materials Science: Materials in Medicine}, number = {4}, doi = {10.1007/s10856-021-06513-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260089}, pages = {42}, year = {2021}, abstract = {Usage of implants containing antibiotic agents has been a common strategy to prevent implant related infections in orthopedic surgery. Unfortunately, most implants with microbial repellent properties are characterized by accessibility limitations during daily clinical practice. Aim of this in vitro study was to investigate whether suture tapes and cerclage wires, which were treated with vancomycin, show a sustainable antibacterial activity. For this purpose, we used 24 stainless steel wire cerclages and 24 ultra-high molecular weight polyethylene and polyester suture tape test bodies. The test bodies were incubated for 30 min. in 100 mg/ml vancomycin solution or equivalent volumes of 0.9\% NaCl. After measuring the initial solution uptake of the test bodies, antibacterial efficacy via agar diffusion test with Staphylococcus aureus and vancomycin elution tests were performed 1, 2, 3, and 6 days after incubation. Vancomycin-loaded tapes as well as vancomycin-loaded cerclage wires demonstrated increased bacterial growth inhibition when compared to NaCl-treated controls. Vancomycin-loaded tapes showed an additional twofold and eightfold increase of bacterial growth inhibition compared to vancomycin-loaded wires at day 1 and 2, respectively. Elution tests at day 1 revealed high levels of vancomycin concentration in vancomycin loaded tapes and wires. Additionally, the concentration in vancomycin loaded tapes was 14-fold higher when compared to vancomycin loaded wires. Incubating suture tapes and cerclage wires in vancomycin solution showed a good short-term antibacterial activity compared to controls. Considering the ease of vancomycin application on suture tapes or wires, our method could represent an attractive therapeutic strategy in biofilm prevention in orthopedic surgery.}, language = {en} } @article{GraserLiedtkeJakob2021, author = {Graser, Stephanie and Liedtke, Daniel and Jakob, Franz}, title = {TNAP as a new player in chronic inflammatory conditions and metabolism}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {2}, issn = {1422-0067}, doi = {10.3390/ijms22020919}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258888}, year = {2021}, abstract = {This review summarizes important information on the ectoenzyme tissue-nonspecific alkaline phosphatase (TNAP) and gives a brief insight into the symptoms, diagnostics, and treatment of the rare disease Hypophosphatasia (HPP), which is resulting from mutations in the TNAP encoding ALPL gene. We emphasize the role of TNAP beyond its well-known contribution to mineralization processes. Therefore, above all, the impact of the enzyme on central molecular processes in the nervous system and on inflammation is presented here.}, language = {en} } @article{BoelchGurokGilbertetal.2021, author = {Boelch, Sebastian P. and Gurok, Anna and Gilbert, Fabian and Weißenberger, Manuel and Rudert, Maximilian and Barthel, Thomas and Reppenhagen, Stephan}, title = {Why compromise the patella? Five-year follow-up results of medial patellofemoral ligament reconstruction with soft tissue patellar fixation}, series = {International Orthopaedics}, volume = {45}, journal = {International Orthopaedics}, issn = {0341-2695}, doi = {10.1007/s00264-020-04922-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235751}, pages = {1493-1500}, year = {2021}, abstract = {Purpose This study investigates the redislocation rate and functional outcome at a minimum follow-up of five years after medial patellofemoral ligament (MPFL) reconstruction with soft tissue patellar fixation for patella instability. Methods Patients were retrospectively identified and knees were evaluated for trochlea dysplasia according to Dejour, for presence of patella alta and for presence of cartilage lesion at surgery. At a minimum follow-up of five years, information about an incident of redislocation was obtained. Kujala, Lysholm, and Tegner questionnaires as well as range of motion were used to measure functional outcome. Results Eighty-nine knees were included. Follow-up rate for redislocation was 79.8\% and for functional outcome 58.4\%. After a mean follow-up of 5.8 years, the redislocation rate was 5.6\%. There was significant improvement of the Kujala score (68.8 to 88.2, p = 0.000) and of the Lysholm score (71.3 to 88.4, p = 0.000). Range of motion at follow-up was 149.0° (115-165). 77.5\% of the knees had patella alta and 52.9\% trochlear dysplasia types B, C, or D. Patellar cartilage legions were present in 54.2\%. Redislocations occurred in knees with trochlear dysplasia type C in combination with patella alta. Conclusion MPFL reconstruction with soft tissue patellar fixation leads to significant improvement of knee function and low midterm redislocation rate. Patients with high-grade trochlear dysplasia should be considered for additional osseous correction.}, language = {en} } @article{GenestRakBaetzetal.2021, author = {Genest, Franca and Rak, Dominik and B{\"a}tz, Elisa and Ott, Kerstin and Seefried, Lothar}, title = {Sarcopenia and Malnutrition Screening in Female Osteoporosis Patients — A Cross-Sectional Study}, series = {Journal of Clinical Medicine}, volume = {10}, journal = {Journal of Clinical Medicine}, number = {11}, issn = {2077-0383}, doi = {10.3390/jcm10112344}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239658}, year = {2021}, abstract = {Sarcopenia and malnutrition are important determinants of increased fracture risk in osteoporosis. SARC-F and MNA-SF are well-established questionnaires for identifying patients at risk for these conditions. We sought to evaluate the feasibility and potential added benefit of such assessments as well as the actual prevalence of these conditions in osteoporosis patients. We conducted a cross-sectional, single-center study in female osteoporosis patients ≥ 65 years (SaNSiBaR-study). Results of the sarcopenia (SARC-F) and malnutrition (MNA-SF) screening questionnaires were matched with a functional assessment for sarcopenia and data from patients' medical records. Out of 107 patients included in the analysis, a risk for sarcopenia (SARC-F ≥ 4 points) and a risk for malnutrition (MNA-SF ≤ 11 points) was found in 33 (30.8\%) and 38 (35.5\%) patients, respectively. Diagnostic overlap with coincident indicative findings in both questionnaires was observed in 17 patients (16\%). As compared to the respective not-at-risk groups, the mean short physical performance battery (SPPB) score was significantly reduced in both patients at risk for sarcopenia (7.0 vs. 10.9 points, p < 0.001) and patients at risk for malnutrition (8.7 vs. 10.5 points, p = 0.005). Still, confirmed sarcopenia according to EWGSOP2 criteria was present in only 6 (6\%) of all 107 patients, with only 3 of them having an indicative SARC-F score. Bone mineral density was not significantly different in any of the at-risk groups at any site. In summary, applying SARC-F and MNA-SF in osteoporosis patients appears to be a complementary approach to identify individuals with functional deficits.}, language = {en} } @article{PereiraLipphausErginetal.2021, author = {Pereira, Ana Rita and Lipphaus, Andreas and Ergin, Mert and Salehi, Sahar and Gehweiler, Dominic and Rudert, Maximilian and Hansmann, Jan and Herrmann, Marietta}, title = {Modeling of the Human Bone Environment: Mechanical Stimuli Guide Mesenchymal Stem Cell-Extracellular Matrix Interactions}, series = {Materials}, volume = {14}, journal = {Materials}, number = {16}, issn = {1996-1944}, doi = {10.3390/ma14164431}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245012}, year = {2021}, abstract = {In bone tissue engineering, the design of in vitro models able to recreate both the chemical composition, the structural architecture, and the overall mechanical environment of the native tissue is still often neglected. In this study, we apply a bioreactor system where human bone-marrow hMSCs are seeded in human femoral head-derived decellularized bone scaffolds and subjected to dynamic culture, i.e., shear stress induced by continuous cell culture medium perfusion at 1.7 mL/min flow rate and compressive stress by 10\% uniaxial load at 1 Hz for 1 h per day. In silico modeling revealed that continuous medium flow generates a mean shear stress of 8.5 mPa sensed by hMSCs seeded on 3D bone scaffolds. Experimentally, both dynamic conditions improved cell repopulation within the scaffold and boosted ECM production compared with static controls. Early response of hMSCs to mechanical stimuli comprises evident cell shape changes and stronger integrin-mediated adhesion to the matrix. Stress-induced Col6 and SPP1 gene expression suggests an early hMSC commitment towards osteogenic lineage independent of Runx2 signaling. This study provides a foundation for exploring the early effects of external mechanical stimuli on hMSC behavior in a biologically meaningful in vitro environment, opening new opportunities to study bone development, remodeling, and pathologies.}, language = {en} } @article{SeefriedRakPetryketal.2021, author = {Seefried, L. and Rak, D. and Petryk, A. and Genest, F.}, title = {Bone turnover and mineral metabolism in adult patients with hypophosphatasia treated with asfotase alfa}, series = {Osteoporosis International}, volume = {32}, journal = {Osteoporosis International}, number = {12}, doi = {10.1007/s00198-021-06025-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265310}, pages = {2505-2513}, year = {2021}, abstract = {Summary There is limited understanding of how asfotase alfa affects mineral metabolism and bone turnover in adults with pediatric-onset hypophosphatasia. This study showed that adults with hypophosphatasia treated with asfotase alfa experienced significant changes in biochemical markers of bone and mineral metabolism, possibly reflecting enhanced bone remodeling of previously osteomalacic bone. Introduction Hypophosphatasia (HPP), due to a tissue nonspecific alkaline phosphatase (TNSALP) deficiency, can cause impaired bone mineralization and turnover. Although HPP may be treated with asfotase alfa, an enzyme replacement therapy, limited data are available on how treatment with asfotase alfa affects mineral metabolism and bone turnover in adults with HPP. Methods ALP substrates, bone turnover and mineral metabolism markers, and bone mineral density (BMD) data from EmPATHY, a single-center, observational study of adults (≥ 18 years) with pediatric-onset HPP treated with asfotase alfa (NCT03418389), were collected during routine clinical care and analyzed from baseline through 24 months of treatment. Results Data from 21 patients showed significantly increased ALP activity and reduced urine phosphoethanolamine (PEA)/creatinine (Cr) ratios after baseline through 24 months of asfotase alfa treatment. There were significant transient increases in parathyroid hormone 1-84 (PTH), osteocalcin, and procollagen type 1 N-propeptide (P1NP) levels at 3 and 6 months and in tartrate-resistant acid phosphatase 5b (TRAP5b) levels at 3 months, with a significant decrease in N-terminal telopeptide of type 1 collagen (NTX) levels at 24 months. Lumbar spine BMD T scores continuously increased during treatment. Conclusion Significant changes in bone turnover and mineral metabolism markers after asfotase alfa treatment suggest that treatment-mediated mineralization may enable remodeling and bone turnover on previously unmineralized surfaces. Urine PEA/Cr ratios may be a useful parameter in monitoring treatment during routine care.}, language = {en} } @article{GenestClaussenRaketal.2021, author = {Genest, F. and Claußen, L. and Rak, D. and Seefried, L.}, title = {Bone mineral density and fracture risk in adult patients with hypophosphatasia}, series = {Osteoporosis International}, volume = {32}, journal = {Osteoporosis International}, issn = {0937-941X}, doi = {10.1007/s00198-020-05612-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235793}, pages = {377-385}, year = {2021}, abstract = {Summary In adult hypophosphatasia (HPP) patients, elevated lumbar spine dual X-ray absorptiometry (DXA) values are associated with markers of disease severity and disease-specific fracture risk while femoral bone mineral density (BMD), being largely unaffected by the disease severity, may still be useful to monitor other causes of increased fracture risk due to low BMD. Introduction Hypophosphatasia (HPP) is a rare inherited metabolic disorder due to deficient activity of the tissue-nonspecific alkaline phosphatase (TNAP). Clinical manifestation in adult HPP patients is manifold including an increased risk for fractures, but data regarding clinical significance of DXA measurement and associations with fracture risk and disease severity is scarce. Methods Retrospective single-center analysis of DXA scans in patients with confirmed HPP (documented mutation, clinical symptoms, low alkaline phosphatase activity). Further data evaluation included disease-related fractures, laboratory results (alkaline phosphatase, pyridoxalphosphate, phosphoethanolamine), and medical history. Results Analysis included 110 patients (84 female, mean age of 46.2 years) of whom 37.3\% (n = 41) were harboring two mutations. Average T-Score level at the lumbar spine was - 0.1 (SD 1.9), and mean total hip T-Score was - 1.07 (SD 0.15). Both lower ALP activity and higher substrate levels (pyridoxalphosphate and phosphoethanolamine) were significantly correlated with increased lumbar spine T-Score levels (p < 0.001) while BMD at the hip was not affected by indicators of disease severity. Increased lumbar spine BMD was significantly associated with an increased risk for HPP-related fractures, prevalent in 22 (20\%) patients (p < 0.001) with 21 of them having biallelic mutations. Conclusion BMD in adult HPP patients is not systematically reduced. Conversely, increased lumbar spine BMD appears to be associated with severely compromised mineralization and increased risk for HPP-related fractures while BMD at the hip appears unaffected by indicators of disease severity, suggesting suitability of this anatomic location for assessing and discerning disorders with increased fracture risk owing to reduced BMD like osteoporosis. Trial registration number German register for clinical studies (DRKS00014022) Date of registration 02/10/2018 - retrospectively registered}, language = {en} }