@article{BoelchWeissenbergerSpohnetal.2018, author = {Boelch, Sebastian Philipp and Weissenberger, Manuel and Spohn, Frederik and Rudert, Maximilian and Luedemann, Martin}, title = {Insufficient sensitivity of joint aspiration during the two-stage exchange of the hip with spacers}, series = {Journal of Orthopedic Surgery and Research}, volume = {13}, journal = {Journal of Orthopedic Surgery and Research}, number = {7}, doi = {10.1186/s13018-017-0703-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175576}, year = {2018}, abstract = {Background: Evaluation of infection persistence during the two-stage exchange of the hip is challenging. Joint aspiration before reconstruction is supposed to rule out infection persistence. Sensitivity and specificity of synovial fluid culture and synovial leucocyte count for detecting infection persistence during the two-stage exchange of the hip were evaluated. Methods: Ninety-two aspirations before planned joint reconstruction during the two-stage exchange with spacers of the hip were retrospectively analyzed. Results: The sensitivity and specificity of synovial fluid culture was 4.6 and 94.3\%. The sensitivity and specificity of synovial leucocyte count at a cut-off value of 2000 cells/μl was 25.0 and 96.9\%. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values were significantly higher before prosthesis removal and reconstruction or spacer exchange (p = 0.00; p = 0.013 and p = 0.039; p = 0.002) in the infection persistence group. Receiver operating characteristic area under the curve values before prosthesis removal and reconstruction or spacer exchange for ESR were lower (0.516 and 0.635) than for CRP (0.720 and 0.671). Conclusions: Synovial fluid culture and leucocyte count cannot rule out infection persistence during the two-stage exchange of the hip.}, language = {en} } @article{LiedtkeHofmannJakobetal.2020, author = {Liedtke, Daniel and Hofmann, Christine and Jakob, Franz and Klopocki, Eva and Graser, Stephanie}, title = {Tissue-Nonspecific Alkaline Phosphatase—A Gatekeeper of Physiological Conditions in Health and a Modulator of Biological Environments in Disease}, series = {Biomolecules}, volume = {10}, journal = {Biomolecules}, number = {12}, publisher = {MDPI}, issn = {2218-273X}, doi = {10.3390/biom10121648}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220096}, year = {2020}, abstract = {Tissue-nonspecific alkaline phosphatase (TNAP) is a ubiquitously expressed enzyme that is best known for its role during mineralization processes in bones and skeleton. The enzyme metabolizes phosphate compounds like inorganic pyrophosphate and pyridoxal-5′-phosphate to provide, among others, inorganic phosphate for the mineralization and transportable vitamin B6 molecules. Patients with inherited loss of function mutations in the ALPL gene and consequently altered TNAP activity are suffering from the rare metabolic disease hypophosphatasia (HPP). This systemic disease is mainly characterized by impaired bone and dental mineralization but may also be accompanied by neurological symptoms, like anxiety disorders, seizures, and depression. HPP characteristically affects all ages and shows a wide range of clinical symptoms and disease severity, which results in the classification into different clinical subtypes. This review describes the molecular function of TNAP during the mineralization of bones and teeth, further discusses the current knowledge on the enzyme's role in the nervous system and in sensory perception. An additional focus is set on the molecular role of TNAP in health and on functional observations reported in common laboratory vertebrate disease models, like rodents and zebrafish.}, language = {en} } @article{SchmalzlPlumhoffGilbertetal.2019, author = {Schmalzl, Jonas and Plumhoff, Piet and Gilbert, Fabian and Gohlke, Frank and Konrads, Christian and Brunner, Ulrich and Jakob, Franz and Ebert, Regina and Steinert, Andre F.}, title = {Tendon-derived stem cells from the long head of the biceps tendon}, series = {Bone \& Joint Research}, volume = {8}, journal = {Bone \& Joint Research}, number = {9}, doi = {10.1302/2046-3758.89.BJR-2018-0214.R2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200370}, pages = {414-424}, year = {2019}, abstract = {Objectives The long head of the biceps (LHB) is often resected in shoulder surgery and could therefore serve as a cell source for tissue engineering approaches in the shoulder. However, whether it represents a suitable cell source for regenerative approaches, both in the inflamed and non-inflamed states, remains unclear. In the present study, inflamed and native human LHBs were comparatively characterized for features of regeneration. Methods In total, 22 resected LHB tendons were classified into inflamed samples (n = 11) and non-inflamed samples (n = 11). Proliferation potential and specific marker gene expression of primary LHB-derived cell cultures were analyzed. Multipotentiality, including osteogenic, adipogenic, chondrogenic, and tenogenic differentiation potential of both groups were compared under respective lineage-specific culture conditions. Results Inflammation does not seem to affect the proliferation rate of the isolated tendon-derived stem cells (TDSCs) and the tenogenic marker gene expression. Cells from both groups showed an equivalent osteogenic, adipogenic, chondrogenic and tenogenic differentiation potential in histology and real-time polymerase chain reaction (RT-PCR) analysis. Conclusion These results suggest that the LHB tendon might be a suitable cell source for regenerative approaches, both in inflamed and non-inflamed states. The LHB with and without tendinitis has been characterized as a novel source of TDSCs, which might facilitate treatment of degeneration and induction of regeneration in shoulder surgery.}, language = {en} } @article{MeyerHessenauerReicheletal.2020, author = {Meyer, Julian S. and Hessenauer, Florian M. and Reichel, Thomas and Pham, Mirko and Plumhoff, Piet and Rueckl, Kilian}, title = {Isolated mononeuropathy of the suprascapular nerve: traumatic traction injury as an important differential diagnosis to the entrapment syndrome}, series = {JSES International}, volume = {4}, journal = {JSES International}, number = {3}, doi = {10.1016/j.jseint.2020.04.008}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229322}, pages = {499-502}, year = {2020}, abstract = {No abstract available.}, language = {en} } @article{PrasseStratosNiehoffetal.2022, author = {Prasse, Tobias and Stratos, Ioannis and Niehoff, Anja and Christ, Hildegard and Heck, Vincent and Meyer, Carolin and Mittlmeier, Thomas}, title = {Bisphenol A-related effects on bone morphology and biomechanical properties in an animal model}, series = {Toxics}, volume = {10}, journal = {Toxics}, number = {2}, issn = {2305-6304}, doi = {10.3390/toxics10020086}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262216}, year = {2022}, abstract = {Bisphenol A (BPA), which is contained in numerous plastic products, is known to act as an endocrine-disruptive, toxic, and carcinogenic chemical. This experimental series sought to determine the influence of BPA exposure on the femoral bone architecture and biomechanical properties of male and female Wistar rats. BPA was applied subcutaneously by using osmotic pumps. After 12 weeks, the bones were analyzed by micro-computed tomography (micro-CT) and a three-point bending test. Comparing the female low- and high-dose groups, a significantly greater marrow area (p = 0.047) was identified in the group exposed to a higher BPA concentration. In addition, the trabecular number tended to be higher in the female high-dose group when compared to the low-dose group (p > 0.05). The area moment of inertia also tended to be higher in the male high-dose group when compared to the male low-dose group (p > 0.05). Considering our results, BPA-related effects on the bone morphology in female Wistar rats are osteoanabolic after high-dose exposure, while, in male rats, a tendency toward negative effects on the bone morphology in terms of a reduced cross-sectional cortical area and total area could be demonstrated.}, language = {en} } @article{SeefriedGenestBaumannetal.2022, author = {Seefried, Lothar and Genest, Franca and Baumann, Jasmin and Heidemeier, Anke and Meffert, Rainer and Jakob, Franz}, title = {Efficacy of Zoledronic Acid in the Treatment of Nonmalignant Painful Bone Marrow Lesions: A Triple-Blind, Randomized, Placebo-Controlled Phase III Clinical Trial (ZoMARS)}, series = {Journal of Bone and Mineral Research}, volume = {37}, journal = {Journal of Bone and Mineral Research}, number = {3}, doi = {10.1002/jbmr.4493}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276368}, pages = {420 -- 427}, year = {2022}, abstract = {Bone marrow lesions (BML) represent areas of deteriorated bone structure and metabolism characterized by pronounced water-equivalent signaling within the trabecular bone on magnetic resonance imaging (MRI). BML are associated with repair mechanisms subsequent to various clinical conditions associated with inflammatory and non-inflammatory injury to the bone. There is no approved treatment for this condition. Bisphosphonates are known to improve bone stability in osteoporosis and other bone disorders and have been used off-label to treat BML. A randomized, triple-blind, placebo-controlled phase III trial was conducted to assess efficacy and safety of single-dose zoledronic acid (ZOL) 5 mg iv with vitamin D 1000 IU/d as opposed to placebo with vitamin D 1000 IU/d in 48 patients (randomized 2:1) with BML. Primary efficacy endpoint was reduction of edema volume 6 weeks after treatment as assessed by MRI. After treatment, mean BML volume decreased by 64.53\% (±41.92\%) in patients receiving zoledronic acid and increased by 14.43\% (±150.46\%) in the placebo group (p = 0.007). A decrease in BML volume was observed in 76.5\% of patients receiving ZOL and in 50\% of the patients receiving placebo. Pain level (visual analogue scale [VAS]) and all categories of the pain disability index (PDI) improved with ZOL versus placebo after 6 weeks but reconciled after 6 additional weeks of follow-up. Six serious adverse events occurred in 5 patients, none of which were classified as related to the study drug. No cases of osteonecrosis or fractures occurred. Therefore, single-dose zoledronic acid 5 mg iv together with vitamin D may enhance resolution of bone marrow lesions over 6 weeks along with reduction of pain compared with vitamin D supplementation only.}, language = {en} } @article{WeiderSchlagenhaufSeefried2022, author = {Weider, Margareta and Schlagenhauf, Ulrich and Seefried, Lothar}, title = {Oral health status of adult hypophosphatasia patients: A cross-sectional study}, series = {Journal of Clinical Periodontology}, volume = {49}, journal = {Journal of Clinical Periodontology}, number = {12}, doi = {10.1111/jcpe.13718}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-293777}, pages = {1253 -- 1261}, year = {2022}, abstract = {Aim This study evaluated the oral health status of adult patients with hypophosphatasia (HPP). Materials and Methods Parameters of oral health assessment comprised decayed/missing/filled teeth (DMFT) index, probing pocket depth and clinical attachment level (CAL) as well as documentation of tooth loss and periodontal health status according to CCD/AAP criteria. Findings were compared with national reference data (DMS V survey) reporting oral health status in age-related controls. Within-group comparisons were made between the HPP patients harbouring one versus two alkaline phosphatase liver/bone/kidney type (ALPL) gene variants. Results Of 80 HPP patients (64 female) with a mean age of 46.4 years (range 24-78) and one (n = 55) or two (n = 18) variants (n = 7 lacking testing) within the ALPL gene, those with two variants displayed substantially higher tooth loss rate (14.0 ± 9.3) than those affected by only one ALPL variant (4.1 ± 5.4), who did not differ substantially from healthy DMS V controls. While DMFT score and severe periodontal diseases (PDs) of HPP patients with one variant only increased with progressing age, the two-variant sub-cohort age independently exhibited increased DMFT scores and a higher rate of severe PDs. Conclusions HPP patients affected by two variants of the ALPL gene exhibited a higher risk of periodontitis and tooth loss than the general population, while patients with one variant developed clinically relevant oral disease symptoms with progressing ageing.}, language = {en} } @article{ArnholdtKamawalHorasetal.2020, author = {Arnholdt, J{\"o}rg and Kamawal, Yama and Horas, Konstantin and Holzapfel, Boris M. and Gilbert, Fabian and Ripp, Axel and Rudert, Maximilian and Steinert, Andre F.}, title = {Accurate implant fit and leg alignment after cruciate-retaining patient-specific total knee arthroplasty}, series = {BMC Musculoskeletal Disorders}, volume = {21}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-020-03707-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230012}, year = {2020}, abstract = {Background For improved outcomes in total knee arthroplasty (TKA) correct implant fitting and positioning are crucial. In order to facilitate a best possible implant fitting and positioning patient-specific systems have been developed. However, whether or not these systems allow for better implant fitting and positioning has yet to be elucidated. For this reason, the aim was to analyse the novel patient-specific cruciate retaining knee replacement system iTotal (TM) CR G2 that utilizes custom-made implants and instruments for its ability to facilitate accurate implant fitting and positioning including correction of the hip-knee-ankle angle (HKA). Methods We assessed radiographic results of 106 patients who were treated with the second generation of a patient-specific cruciate retaining knee arthroplasty using iTotal\(^{TM}\) CR G2 (ConforMIS Inc.) for tricompartmental knee osteoarthritis (OA) using custom-made implants and instruments. The implant fit and positioning as well as the correction of the mechanical axis (hip-knee-ankle angle, HKA) and restoration of the joint line were determined using pre- and postoperative radiographic analyses. Results On average, HKA was corrected from 174.4 degrees +/- 4.6 degrees preoperatively to 178.8 degrees +/- 2.2 degrees postoperatively and the coronal femoro-tibial angle was adjusted on average 4.4 degrees. The measured preoperative tibial slope was 5.3 degrees +/- 2.2 degrees (mean +/- SD) and the average postoperative tibial slope was 4.7 degrees +/- 1.1 degrees on lateral views. The joint line was well preserved with an average modified Insall-Salvati index of 1.66 +/- 0.16 pre- and 1.67 +/- 0.16 postoperatively. The overall accuracy of fit of implant components was decent with a measured medial overhang of more than 1 mm (1.33 mm +/- 0.32 mm) in 4 cases only. Further, a lateral overhang of more than 1 mm (1.8 mm +/- 0.63) (measured in the anterior-posterior radiographs) was observed in 11 cases, with none of the 106 patients showing femoral notching. Conclusion The patient-specific iTotal\(^{TM}\) CR G2 total knee replacement system facilitated a proper fitting and positioning of the implant components. Moreover, a good restoration of the leg axis towards neutral alignment was achieved as planned. Nonetheless, further clinical follow-up studies are necessary to validate our findings and to determine the long-term impact of using this patient- specific system.}, language = {en} } @article{FuchsHeiligMcDonoghetal.2020, author = {Fuchs, Konrad F. and Heilig, Philipp and McDonogh, Miriam and Boelch, Sebastian and Gbureck, Uwe and Meffert, Rainer H. and Hoelscher-Doht, Stefanie and Jordan, Martin C.}, title = {Cement-augmented screw fixation for calcaneal fracture treatment: a biomechanical study comparing two injectable bone substitutes}, series = {Journal of Orthopaedic Surgery and Research}, volume = {15}, journal = {Journal of Orthopaedic Surgery and Research}, doi = {10.1186/s13018-020-02009-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230336}, year = {2020}, abstract = {Background The role of cement-augmented screw fixation for calcaneal fracture treatment remains unclear. Therefore, this study was performed to biomechanically analyze screw osteosynthesis by reinforcement with either a calcium phosphate (CP)-based or polymethylmethacrylate (PMMA)-based injectable bone cement. Methods A calcaneal fracture (Sanders type IIA) including a central cancellous bone defect was generated in 27 synthetic bones, and the specimens were assigned to 3 groups. The first group was fixed with four screws (3.5 mm and 6.5 mm), the second group with screws and CP-based cement (Graftys (R) QuickSet; Graftys, Aix-en-Provence, France), and the third group with screws and PMMA-based cement (Traumacem (TM) V+; DePuy Synthes, Warsaw, IN, USA). Biomechanical testing was conducted to analyze peak-to-peak displacement, total displacement, and stiffness in following a standardized protocol. Results The peak-to-peak displacement under a 200-N load was not significantly different among the groups; however, peak-to-peak displacement under a 600- and 1000-N load as well as total displacement exhibited better stability in PMMA-augmented screw osteosynthesis compared to screw fixation without augmentation. The stiffness of the construct was increased by both CP- and PMMA-based cements. Conclusion Addition of an injectable bone cement to screw osteosynthesis is able to increase fixation strength in a biomechanical calcaneal fracture model with synthetic bones. In such cases, PMMA-based cements are more effective than CP-based cements because of their inherently higher compressive strength. However, whether this high strength is required in the clinical setting for early weight-bearing remains controversial, and the non-degradable properties of PMMA might cause difficulties during subsequent interventions in younger patients.}, language = {en} } @article{JakubietzSchmidtHolzapfeletal.2020, author = {Jakubietz, Rafael G. and Schmidt, Karsten and Holzapfel, Boris M. and Meffert, Rainer H. and Jakubietz, Michael G.}, title = {Pedicled perforator flaps for mid-tibial soft tissue reconstruction in medically compromised patients}, series = {JPRAS Open}, volume = {24}, journal = {JPRAS Open}, doi = {10.1016/j.jpra.2020.02.002}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229473}, pages = {47-55}, year = {2020}, abstract = {Background: The soft tissue of the central pretibial area is difficult to reconstruct often requiring free tissue transfer. Especially medi- cally compromised patients are not ideal candidates for free tissue transfer and may benefit from expeditiously harvested local flaps with limited donor site morbidity. As muscle flaps are rare, pedi- cled flaps based on lateral perforators represent an alternative as the arc of rotation can often be limited to 90 °. Material and Methods: A retrospective analysis of patient data was conducted to identify patients over the age of 60 years with comor- bidities that underwent pretibial soft tissue reconstruction with a single-pedicle perforator flap. Patient demographics, size and cause of the defect, flap dimension, arc of rotation and complications were recorded. Results: Five patients with an average age of 71.4 years were in- cluded. The arc of rotation was 69 °, all flaps healed. There were two recurrences of osteomyelitis. Conclusion: Lateral perforators originating from the anterior tib- ial artery or peroneal artery are adequate source vessels for single pedicled perforator flaps even in medically compromised patients. A perforator located proximal to the defect allows limiting the arcof rotation to less than 90 °, which increases the safety of the flap. Patients benefit from a simple procedure without a microvascular anastomosis and a donor site confined to one extremity}, language = {en} } @article{LuedemannJakuscheitEwaldetal.2021, author = {L{\"u}demann, Martin and Jakuscheit, Axel and Ewald, Andrea and Fr{\"u}hmann, Leena and H{\"o}lscher-Doht, Stefanie and Rudert, Maximilian and von Hertzberg-Boelch, Sebastian Philipp}, title = {Influence of Tranexamic Acid on Elution Characteristics and Compressive Strength of Antibiotic-Loaded PMMA-Bone Cement with Gentamicin}, series = {Materials}, volume = {14}, journal = {Materials}, number = {19}, issn = {1996-1944}, doi = {10.3390/ma14195639}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246236}, year = {2021}, abstract = {Purpose: The topical application of tranexamic acid (TXA) into the joint space during total joint arthroplasty (TJA) with no increase of complications, has been widely reported. We investigated the influence of TXA on antibiotic release, activity of the released antibiotic against a clinical isolate of S. aureus, and compressive strength of a widely used commercially prepared gentamicin-loaded cement brand (PALACOS R + G). Method: 12 bone cement cylinders (diameter and height = 6 and 12 mm, respectively) were molded. After curing in air for at least 1 h, six of the cylinders were completely immersed in 5 mL of fetal calf serum (FCS) and the other six were completely immersed in a solution consisting of 4.9 mL of FCS and 0.1 mL (10 mg) of TXA. Gentamicin elution tests were performed over 7 d. Four hundred µL of the gentamicin eluate were taken every 24 h for the first 7 d without renewing the immersion fluid. The gentamicin concentration was determined in a clinical analyzer using a homogeny enzyme immuno-assay. The antimicrobial activity of the eluate, obtained after day 7, was tested. An agar diffusion test regime was used with Staphylococcus aureus. Bacteria were grown in a LB medium and plated on LB agar plates to get a bacterial lawn. Fifty µL of each eluate were pipetted on 12-mm diameter filter discs, which were placed in the middle of the agar gel. After 24 h of cultivation at 37 °C, the zone of inhibition (ZOI) for each specimen was measured. The compressive strength of the cements was determined per ISO 5833. Results: At each time point in the gentamicin release test, the difference in gentamicin concentration, obtained from specimens immersed in the FCS solution only and those immersed in the FCS + TXA solution was not significant (p = 0.055-0.522). The same trend was seen in each of the following parameters, after 7 d of immersion: (1) Cumulative gentamicin concentration (p < 0.297); (2) gentamicin activity against S. aureus (strongly visible); (3) ZOI size (mostly > 20 mm) (p = 0.631); and (4) compressive strength (p = 0.262). Conclusions: For the PALACOS R + G specimens, the addition of TXA to FCS does not produce significant decreases in gentamicin concentration, in the activity of the gentamicin eluate against a clinical isolate of S. aureus, the zone of inhibition of S. aureus, and in the compressive strength of the cement, after 7 d of immersion in the test solution.}, language = {en} } @article{ArnholdtGilbertBlanketal.2017, author = {Arnholdt, J{\"o}rg and Gilbert, Fabian and Blank, Marc and Papazoglou, Jannis and Rudert, Maximilian and N{\"o}th, Ulrich and Steinert, Andre F.}, title = {The Mayo conservative hip: complication analysis and management of the first 41 cases performed at a University level 1 department}, series = {BMC Muskoskeletal Disorders}, volume = {18}, journal = {BMC Muskoskeletal Disorders}, number = {250}, doi = {10.1186/s12891-017-1613-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157812}, year = {2017}, abstract = {Background: To prevent bone loss in hip arthroplasty, several short stem systems have been developed, including the Mayo conservative hip system. While there is a plethora of data confirming inherent advantages of these systems, only little is known about potential complications, especially when surgeons start to use these systems. Methods: In this study, we present a retrospective analysis of the patients' outcome, complications and the complication management of the first 41 Mayo conservative hips performed in 37 patients. For this reason, functional scores, radiographic analyses, peri- and postoperative complications were assessed at an average follow-up of 35 months. Results: The overall HHS improved from 61.2 pre-operatively to 85.6 post-operatively. The German Extra Short Musculoskeletal Function Assessment Questionnaire (XSFMA-D) improved from 30.3 pre-operatively to 12.2 post-operatively. The most common complication was an intraoperative non-displaced fracture of the proximal femur observed in 5 cases (12.1\%). Diabetes, higher BMI and older ages were shown to be risk factors for these intra-operative periprosthetic fractures (p < 0.01). Radiographic analysis revealed a good offset reconstruction in all cases. Conclusion: In our series, a high complication rate with 12.1\% of non-displaced proximal femoral fractures was observed using the Mayo conservative hip. This may be attributed to the flat learning curve of the system or the inherent patient characteristics of the presented cohort."}, language = {en} } @article{BoelchRuecklFuchsetal.2018, author = {Boelch, Sebastian P. and Rueckl, Kilian and Fuchs, Clara and Jordan, Martin and Knauer, Markus and Steinert, Andre and Rudert, Maximilian and Luedemann, Martin}, title = {Comparison of elution characteristics and compressive strength of biantibiotic-loaded PMMA bone cement for spacers: Copal\(^®\) spacem with gentamicin and vancomycin versus Palacos\(^®\) R+G with vancomycin}, series = {BioMed Research International}, volume = {2018}, journal = {BioMed Research International}, number = {4323518}, doi = {10.1155/2018/4323518}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177435}, year = {2018}, abstract = {Purpose. Copal\(^®\) spacem is a new PMMA bone cement for fabricating spacers. This study compares elution of gentamicin, elution of vancomycin, and compressive strength of Copal\(^®\) spacem and of Palacos\(^®\) R+G at different vancomycin loadings in the powder of the cements. We hypothesized that antibiotic elution of Copal\(^®\) spacem is superior at comparable compressive strength. Methods. Compression test specimens were fabricated using Copal\(^®\) spacem manually loaded with 0.5 g gentamicin and additionally 2 g, 4 g, and 6 g of vancomycin per 40 g of cement powder (COP specimens) and using 0.5 g gentamicin premixed Palacos\(^®\) R+G manually loaded with 2 g, 4 g, and 6 g of vancomycin per 40 g of cement powder (PAL specimens). These specimens were used for determination of gentamicin and vancomycin elution (in fetal calf serum, at 22°C) and for determination of compressive strength both prior and following the elution tests. Results. Cumulative gentamicin concentrations (p < 0.005) and gentamicin concentration after 28 days (p ≤ 0.043) were significantly lower for COP specimens compared to PAL specimens. Cumulative vancomycin concentrations were significantly higher (p ≤ 0.043) for COP specimens after the second day. Vancomycin concentrations after 28 days were not significantly higher for the Copal specimens loaded with 2 g and 4 g of vancomycin. Compressive strength was not significantly different between COP specimens and PAL specimens before elution tests. Compressive strength after the elution tests was significantly lower (p = 0.005) for COP specimens loaded with 2 g of vancomycin. Conclusion. We could not demonstrate consistent superior antibiotic elution from Copal\(^®\) spacem compared to Palacos\(^®\) R+G for fabricating gentamicin and vancomycin loaded spacers. The results do not favor Copal\(^®\) spacem over Palacos\(^®\) R+G for the use as a gentamicin and vancomycin biantibiotic-loaded spacer.}, language = {en} } @article{JakuscheitSchaeferRoedigetal.2021, author = {Jakuscheit, Axel and Schaefer, Nina and Roedig, Johannes and Luedemann, Martin and Hertzberg-Boelch, Sebastian Philipp von and Weissenberger, Manuel and Schmidt, Karsten and Holzapfel, Boris Michael and Rudert, Maximilian}, title = {Modifiable individual risks of perioperative blood transfusions and acute postoperative complications in total hip and knee arthroplasty}, series = {Journal of Personalized Medicine}, volume = {11}, journal = {Journal of Personalized Medicine}, number = {11}, issn = {2075-4426}, doi = {10.3390/jpm11111223}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250290}, year = {2021}, abstract = {Background: The primary aim of this study was to identify modifiable patient-related predictors of blood transfusions and perioperative complications in total hip and knee arthroplasty. Individual predictor-adjusted risks can be used to define preoperative treatment thresholds. Methods: We performed this retrospective monocentric study in orthopaedic patients who underwent primary total knee or hip arthroplasty. Multivariate logistic regression models were used to assess the predictive value of patient-related characteristics. Predictor-adjusted individual risks of blood transfusions and the occurrence of any perioperative adverse event were calculated for potentially modifiable risk factors. Results: 3754 patients were included in this study. The overall blood transfusion and complication rates were 4.8\% and 6.4\%, respectively. Haemoglobin concentration (Hb, p < 0.001), low body mass index (BMI, p < 0.001) and estimated glomerular filtration rate (eGFR, p = 0.004) were the strongest potentially modifiable predictors of a blood transfusion. EGFR (p = 0.001) was the strongest potentially modifiable predictor of a complication. Predictor-adjusted risks of blood transfusions and acute postoperative complications were calculated for Hb and eGFR. Hb = 12.5 g/dL, BMI = 17.6 kg/m\(^2\), and eGFR = 54 min/mL were associated, respectively, with a 10\% risk of a blood transfusion, eGFR = 59 mL/min was associated with a 10\% risk of a complication. Conclusion: The individual risks for blood transfusions and acute postoperative complications are strongly increased in patients with a low preoperative Hb, low BMI or low eGFR. We recommend aiming at a preoperative Hb ≥ 13g/dL, an eGFR ≥ 60 mL/min and to avoid a low BMI. Future studies must show if a preoperative increase of eGFR and BMI is feasible and truly beneficial.}, language = {en} } @article{HerrmannDiederichsMelniketal.2021, author = {Herrmann, Marietta and Diederichs, Solvig and Melnik, Svitlana and Riegger, Jana and Trivanović, Drenka and Li, Shushan and Jenei-Lanzl, Zsuzsa and Brenner, Rolf E. and Huber-Lang, Markus and Zaucke, Frank and Schildberg, Frank A. and Gr{\"a}ssel, Susanne}, title = {Extracellular Vesicles in Musculoskeletal Pathologies and Regeneration}, series = {Frontiers in Bioengineering and Biotechnology}, volume = {8}, journal = {Frontiers in Bioengineering and Biotechnology}, issn = {2296-4185}, doi = {10.3389/fbioe.2020.624096}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222882}, year = {2021}, abstract = {The incidence of musculoskeletal diseases is steadily increasing with aging of the population. In the past years, extracellular vesicles (EVs) have gained attention in musculoskeletal research. EVs have been associated with various musculoskeletal pathologies as well as suggested as treatment option. EVs play a pivotal role in communication between cells and their environment. Thereby, the EV cargo is highly dependent on their cellular origin. In this review, we summarize putative mechanisms by which EVs can contribute to musculoskeletal tissue homeostasis, regeneration and disease, in particular matrix remodeling and mineralization, pro-angiogenic effects and immunomodulatory activities. Mesenchymal stromal cells (MSCs) present the most frequently used cell source for EV generation for musculoskeletal applications, and herein we discuss how the MSC phenotype can influence the cargo and thus the regenerative potential of EVs. Induced pluripotent stem cell-derived mesenchymal progenitor cells (iMPs) may overcome current limitations of MSCs, and iMP-derived EVs are discussed as an alternative strategy. In the last part of the article, we focus on therapeutic applications of EVs and discuss both practical considerations for EV production and the current state of EV-based therapies.}, language = {en} } @article{BoelchJakuscheitDoerriesetal.2018, author = {Boelch, S. P. and Jakuscheit, A. and Doerries, S. and Fraissler, L. and Hoberg, M. and Arnholdt, J. and Rudert, M.}, title = {Periprosthetic infection is the major indication for TKA revision - experiences from a university referral arthroplasty center}, series = {BMC Musculoskeletal Disorders}, volume = {19}, journal = {BMC Musculoskeletal Disorders}, number = {395}, doi = {10.1186/s12891-018-2314-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176983}, year = {2018}, abstract = {Background: We hypothesized, that periprosthetic joint infection (PJI) accounts for the major proportion of first (primary) and repeated (secondary) Total Knee Arthroplasty revisions at our university referral arthroplasty center. Methods: One thousand one hundred forty-three revisions, performed between 2008 and 2016 were grouped into primary (55\%) and secondary (45\%) revisions. The rate of revision indications was calculated and indications were categorized by time after index operation. The odds ratios of the indications for primary versus secondary revision were calculated. Results: In the primary revision group PJI accounted for 22.3\%, instability for 20.0\%, aseptic loosening for 14.9\% and retropatellar arthrosis for 14.2\%. PJI (25.6\%) was the most common indication up to 1 year after implantation, retropatellar arthrosis (26.8\%) 1-3 years and aseptic loosening (25.6\%) more than 3 years after implantation. In the secondary revision group PJI accounted for 39.7\%, aseptic loosening for 16.2\% and instability for 13.2\%. PJI was the most common indication at any time of revision with 43.8\% up to one, 35.4\% 1-3 years and 39.4\% more the 3 years after index operation. The odds ratios in repeated revision were 2.32 times higher (p = 0.000) for PJI. For instability and retropatellar arthrosis the odds ratios were 0.60 times (p = 0.006) and 0.22 times (p = 0.000) lower. Conclusions: PJI is the most common indication for secondary TKA revision and within one year after primary TKA. Aseptical failures such as instability, retropatellar arthrosis and aseptical loosening are the predominant reasons for revision more than one year after primary TKA.}, language = {en} } @article{AchenbachLeHanneurCamenzindetal.2022, author = {Achenbach, Leonard and Le Hanneur, Malo and Camenzind, Roland S. and Bouyer, Michael and Pottecher, Pierre and Lafosse, Thibault}, title = {Systematic bifocal decompression for isolated long thoracic nerve paresis: A case series of 12 patients}, series = {Interdisciplinary Neurosurgery}, volume = {27}, journal = {Interdisciplinary Neurosurgery}, doi = {10.1016/j.inat.2021.101384}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265085}, year = {2022}, abstract = {To date, no consensus exists regarding the best surgical management of isolated, micro-traumatic long thoracic nerve (LTN) paresis. Our hypothesis was that a combined decompression of the LTN at two potential locations for entrapment would be effective in the management of dynamic LTN paresis. We report on twelve patients with isolated LTN parersis, with tenderness at two entrapment sites, who underwent bifocal LTN decompression after undergoing unsuccessful conservative treatment for at least 6 months; all patients had preoperative electrodiagnostic studies that confirmed the paresis and ruled out peripheral neuritis. Clinical and electrical improvements were observed in eight patients (67\%) regarding shoulder flexion, shoulder abduction, and Quick-DASH scores. Four patients (33\%) did not improve after surgery. The results corroborate our hypothesis that a bifocal LTN decompression can be an effective and reliable therapeutic option in more than half of a very selective patient population suffering from serratus anterior muscle deficiency.}, language = {en} } @article{HerrmannHildebrandMenzeletal.2019, author = {Herrmann, Marietta and Hildebrand, Maria and Menzel, Ursula and Fahy, Niamh and Alini, Mauro and Lang, Siegmund and Benneker, Lorin and Verrier, Sophie and Stoddart, Martin J. and Bara, Jennifer J.}, title = {Phenotypic characterization of bone marrow mononuclear cells and derived stromal cell populations from human iliac crest, vertebral body and femoral head}, series = {International Journal of Molecular Sciences}, volume = {20}, journal = {International Journal of Molecular Sciences}, number = {14}, issn = {1422-0067}, doi = {10.3390/ijms20143454}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285054}, year = {2019}, abstract = {(1) In vitro, bone marrow-derived stromal cells (BMSCs) demonstrate inter-donor phenotypic variability, which presents challenges for the development of regenerative therapies. Here, we investigated whether the frequency of putative BMSC sub-populations within the freshly isolated mononuclear cell fraction of bone marrow is phenotypically predictive for the in vitro derived stromal cell culture. (2) Vertebral body, iliac crest, and femoral head bone marrow were acquired from 33 patients (10 female and 23 male, age range 14-91). BMSC sub-populations were identified within freshly isolated mononuclear cell fractions based on cell-surface marker profiles. Stromal cells were expanded in monolayer on tissue culture plastic. Phenotypic assessment of in vitro derived cell cultures was performed by examining growth kinetics, chondrogenic, osteogenic, and adipogenic differentiation. (3) Gender, donor age, and anatomical site were neither predictive for the total yield nor the population doubling time of in vitro derived BMSC cultures. The abundance of freshly isolated progenitor sub-populations (CD45-CD34-CD73+, CD45-CD34-CD146+, NG2+CD146+) was not phenotypically predictive of derived stromal cell cultures in terms of growth kinetics nor plasticity. BMSCs derived from iliac crest and vertebral body bone marrow were more responsive to chondrogenic induction, forming superior cartilaginous tissue in vitro, compared to those isolated from femoral head. (4) The identification of discrete progenitor populations in bone marrow by current cell-surface marker profiling is not predictive for subsequently derived in vitro BMSC cultures. Overall, the iliac crest and the vertebral body offer a more reliable tissue source of stromal progenitor cells for cartilage repair strategies compared to femoral head.}, language = {en} } @article{RuecklRunerBechleretal.2019, author = {Rueckl, Kilian and Runer, Armin and Bechler, Ulrich and Faschingbauer, Martin and Boelch, Sebastian Philipp and Keyes Sculco, Peter and Boettner, Friedrich}, title = {The posterior-anterior-flexed view is essential for the evaluation of valgus osteoarthritis. A prospective study on 134 valgus knees}, series = {BMC Muscoskeletal Disorders}, volume = {20}, journal = {BMC Muscoskeletal Disorders}, doi = {10.1186/s12891-019-3012-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200536}, pages = {636}, year = {2019}, abstract = {Background Radiographic imaging is an important tool to assess osteoarthritis (OA). Lateral compartment osteoarthritis (valgus OA) usually starts with cartilage degeneration along the posterior aspect of the lateral femoral condyle. There is evidence that the posterior-anterior (PA)-flexed view is more sensitive when diagnosing early stages of valgus OA compared to the anterior-posterior (AP) view. The current paper analyzes the value of the PA-flexed view for patients scheduled for total knee arthroplasty (TKA). Methods Radiographs of 134 valgus knees were assessed prior to TKA. The minimal joint space width (minJSW) was measured on AP and PA-flexed views. The extent of mechanical deformity was measured on hip to ankle standing films. Results 49 (36.6\%) AP views showed Kellgren and Lawrence (K/L)-grade 4 osteoarthritis in the lateral compartment, 82 (63.4\%) showed grade 3 or less. The PA-flexed view resulted in an increased K/L-grading to grade 4 for 53 knees (62.4\%) that were considered grade 3 or less on standard AP-radiographs. There was a significant differences between lateral minJSW on AP and PA-flexed view for patients with up to 10 degrees of mechanical valgus deformity (p < 0.001), as well as 11 to 15 degrees of mechanical deformity (p = 0.021). Only knees with severe deformity of more than 15 degrees did not show a difference in minJSW between PA-flexed view and AP view (p = 0.345). Conclusions The PA-flexed view is superior to the standard AP view in quantifying the extent of valgus OA in patients with zero to fifteen degrees of valgus deformity. It is recommended for the initial assessment of patients with valgus osteoarthritis and better documents the extent of osteoarthritis prior to TKA.}, language = {en} } @article{KemmlerKohlFroehlichetal.2020, author = {Kemmler, Wolfgang and Kohl, Matthias and Fr{\"o}hlich, Michael and Jakob, Franz and Engelke, Klaus and von Stengel, Simon and Schoene, Daniel}, title = {Effects of High-Intensity Resistance Training on Osteopenia and Sarcopenia Parameters in Older Men with Osteosarcopenia—One-Year Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)}, series = {Journal of Bone and Mineral Research}, volume = {35}, journal = {Journal of Bone and Mineral Research}, number = {9}, doi = {10.1002/jbmr.4027}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214609}, pages = {1634 -- 1644}, year = {2020}, abstract = {Dynamic resistance exercise (DRT) might be the most promising agent for fighting sarcopenia in older people. However, the positive effect of DRT on osteopenia/osteoporosis in men has still to be confirmed. To evaluate the effect of low-volume/high-intensity (HIT)-DRT on bone mineral density (BMD) and skeletal muscle mass index (SMI) in men with osteosarcopenia, we initiated the Franconian Osteopenia and Sarcopenia Trial (FrOST). Forty-three sedentary community-dwelling older men (aged 73 to 91 years) with osteopenia/osteoporosis and SMI-based sarcopenia were randomly assigned to a HIT-RT exercise group (EG; n = 21) or a control group (CG; n = 22). HIT-RT provided a progressive, periodized single-set DRT on machines with high intensity, effort, and velocity twice a week, while CG maintained their lifestyle. Both groups were adequately supplemented with whey protein, vitamin D, and calcium. Primary study endpoint was integral lumbar spine (LS) BMD as determined by quantitative computed tomography. Core secondary study endpoint was SMI as determined by dual-energy X-ray absorptiometry. Additional study endpoints were BMD at the total hip and maximum isokinetic hip-/leg-extensor strength (leg press). After 12 months of exercise, LS-BMD was maintained in the EG and decreased significantly in the CG, resulting in significant between-group differences (p < 0.001; standardized mean difference [SMD] = 0.90). In parallel, SMI increased significantly in the EG and decreased significantly in the CG (p < 0.001; SMD = 1.95). Total hip BMD changes did not differ significantly between the groups (p = 0.064; SMD = 0.65), whereas changes in maximum hip-/leg-extensor strength were much more prominent (p < 0.001; SMD = 1.92) in the EG. Considering dropout (n = 2), attendance rate (95\%), and unintended side effects/injuries (n = 0), we believe our HIT-RT protocol to be feasible, attractive, and safe. In summary, we conclude that our combined low-threshold HIT-RT/protein/vitamin D/calcium intervention was feasible, safe, and effective for tackling sarcopenia and osteopenia/osteoporosis in older men with osteosarcopenia.}, language = {en} } @article{HeinzMellerLuetkensetal.2022, author = {Heinz, Tizian and Meller, Felix and Luetkens, Karsten Sebastian and Horas, Konstantin and Sch{\"a}fer, Thomas and Rudert, Maximilian and Reppenhagen, Stephan and Weißenberger, Manuel}, title = {Can the MRI based AMADEUS score accurately assess pre-surgery chondral defect severity according to the ICRS arthroscopic classification system?}, series = {Journal of Experimental Orthopaedics}, volume = {9}, journal = {Journal of Experimental Orthopaedics}, number = {1}, issn = {2197-1153}, doi = {10.1186/s40634-022-00511-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300781}, year = {2022}, abstract = {Purpose The AMADEUS (Area Measurement And DEpth and Underlying Structures) scoring and grading system has been proposed for the MRI based evaluation of untreated focal chondral defects around the knee. The clinical practicability, its correlation with arthroscopically assessed grading systems (ICRS - International Cartilage Repair Society) and thereby its clinical value in terms of decision making and guiding prognosis was yet to determine. Methods From 2008 to 2019 a total of 89 individuals were indicated for high tibial valgus osteotomy (HTO) due to tibial varus deformity and concomitant chondral defects of the medial compartment of the knee. All patients received a preoperative MRI (1.5 Tesla or 3.0 Tesla) and pre-osteotomy diagnostic arthroscopy. Chondral defects of the medial compartment were scored and graded with the MRI based AMADEUS by three independent raters and compared to arthroscopic defect grading by the ICRS system. Interrater and intrarater reliability as well as correlation analysis with the ICRS classification system were assessed. Results Intraclass correlation coefficients for the various subscores of the AMADEUS showed an overall good to excellent interrater agreement (min: 0.26, max: 0.80). Intrarater agreement turned out to be substantially inferior (min: 0.08, max: 0.53). Spearman correlation revealed an overall moderate correlative association of the AMADEUS subscores with the ICRS classification system, apart from the defect area subscore. Sensitivity of the AMADEUS to accurately identify defect severity according to the ICRS was 0.7 (0.69 for 3.0 Tesla MRI, 0.67 for 1.5 Tesla MRI). The mean AMADEUS grade was 2.60 ± 0.81 and the mean ICRS score 2.90 ± 0.63. Conclusions Overall, the AMADEUS with all its subscores shows moderate correlation with the arthroscopic chondral grading system according to ICRS. This suggests that chondral defect grading by means of the MRI based AMADEUS is well capable of influencing and guiding treatment decisions. Interrater reliability shows overall good agreement.}, language = {en} } @article{GenestRakPetryketal.2020, author = {Genest, Franca and Rak, Dominik and Petryk, Anna and Seefried, Lothar}, title = {Physical Function and Health-Related Quality of Life in Adults Treated With Asfotase Alfa for Pediatric-Onset Hypophosphatasia}, series = {JBMR Plus}, volume = {4}, journal = {JBMR Plus}, number = {9}, doi = {10.1002/jbm4.10395}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218410}, year = {2020}, abstract = {Hypophosphatasia (HPP) is a rare, inherited, metabolic disease characterized by tissue-nonspecific alkaline phosphatase deficiency resulting in musculoskeletal and systemic clinical manifestations. This observational study evaluated the effectiveness of enzyme replacement therapy with asfotase alfa on physical function and health-related quality of life (HRQoL) among adults with pediatric-onset HPP who received asfotase alfa for 12 months at a single center (ClinicalTrial.gov no.: NCT03418389). Primary outcomes evaluated physical function with the 6-minute walk test (6MWT), timed up-and-go (TUG) test, Short Physical Performance Battery (SPPB), and handheld dynamometry (HHD). Secondary outcome measures included the Lower Extremity Functional Scale (LEFS), pain prevalence/intensity, and pain medication use; HRQoL was evaluated using the 36-Item Short-Form Health Survey version 2 (SF-36v2). Safety data were collected throughout the study. All 14 patients (11 women) had compound heterozygous ALPL gene mutations and ≥1 HPP bone manifestation, including history of ≥1 fracture. Mean (min, max) age was 51 (19 to 78) years. From baseline to 12 months of treatment, median 6MWT distance increased from 267 m to 320 m (n = 13; p = 0.023); median TUG test time improved from 14.4 s to 11.3 s (n = 9; p = 0.008). Specific components of the SPPB also improved significantly: median 4-m gait speed increased from 0.8 m/s to 1.1 m/s (n = 10; p = 0.007) and median repeated chair-rise time improved from 22 s to 13 s (n = 9; p = 0.008). LEFS score improved from 24 points to 53 points (n = 10; p = 0.002). Improvements in HHD were not clinically significant. SF-36v2 Physical Component Score (PCS) improved after 12 months of treatment (n = 9; p = 0.010). Pain level did not change significantly from baseline to 12 months of treatment. There were significant improvements on chair-rise time and SF-36v2 PCS by 3 months, and on TUG test time after 6 months. No new safety signals were identified. These results show the real-world effectiveness of asfotase alfa in improving physical functioning and HRQoL in adults with pediatric-onset HPP. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.}, language = {en} } @article{KaiserBrambrinkBenditzetal.2022, author = {Kaiser, Moritz and Brambrink, Sara and Benditz, Achim and Achenbach, Leonard and Gehentges, Matthias and K{\"o}nig, Matthias Alexander}, title = {Increase in lower limb strength after multimodal pain management in patients with low back pain}, series = {Medicina}, volume = {58}, journal = {Medicina}, number = {7}, issn = {1648-9144}, doi = {10.3390/medicina58070837}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284264}, year = {2022}, abstract = {Background and Objectives: The aim of the present study was to evaluate the efficacy of a multimodal pain therapy (MPM) regarding the objective parameter muscle strength of segment-dependent lower limb muscle groups before and after such a treatment. Materials and Methods: 52 patients with a history of low back pain and/or leg pain received standardized multimodal pain management. Strength of segment indicating lower limb muscles were assessed for each patient before and after ten days of treatment by handheld dynamometry. Results: Overall strength increased significantly from 23.6 kg ± 6.6 prior to treatment to 25.4 ± 7.3 after treatment, p ≤ 0.001. All muscle groups significantly increased in strength with exception of great toe extensors. Conclusions: Despite lower basic strength values at the beginning of treatment, all investigated muscle groups, except for the great toe extensors, showed a significant increase of overall strength after completion of the multimodal pain management concept. Increased overall strength could help with avoiding further need of medical care by supporting patients' autonomy in daily life activities, as well as maintaining working abilities. Thus, our study is the first to show a significant positive influence on lower limb strength in patients with low back pain after a conservative MPM program.}, language = {en} } @article{ChaudryGrimmFriedbergeretal.2020, author = {Chaudry, Oliver and Grimm, Alexandra and Friedberger, Andreas and Kemmler, Wolfgang and Uder, Michael and Jakob, Franz and Quick, Harald H. and von Stengel, Simon and Engelke, Klaus}, title = {Magnetic Resonance Imaging and Bioelectrical Impedance Analysis to Assess Visceral and Abdominal Adipose Tissue}, series = {Obesity}, volume = {28}, journal = {Obesity}, number = {2}, doi = {10.1002/oby.22712}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213591}, pages = {277 -- 283}, year = {2020}, abstract = {Objective This study aimed to compare a state-of-the-art bioelectrical impedance analysis (BIA) device with two-point Dixon magnetic resonance imaging (MRI) for the quantification of visceral adipose tissue (VAT) as a health-related risk factor. Methods A total of 63 male participants were measured using a 3-T MRI scanner and a segmental, multifrequency BIA device. MRI generated fat fraction (FF) maps, in which VAT volume, total abdominal adipose tissue volume, and FF of visceral and total abdominal compartments were quantified. BIA estimated body fat mass and VAT area. Results Coefficients of determination between abdominal (r\(^{2}\) = 0.75) and visceral compartments (r\(^{2}\) = 0.78) were similar for both groups, but slopes differed by a factor of two. The ratio of visceral to total abdominal FF was increased in older men compared with younger men. This difference was not detected with BIA. MRI and BIA measurements of the total abdominal volume correlated moderately (r\(^{2}\) = 0.31-0.56), and visceral measurements correlated poorly (r\(^{2}\) = 0.13-0.44). Conclusions Visceral BIA measurements agreed better with MRI measurements of the total abdomen than of the visceral compartment, indicating that BIA visceral fat area assessment cannot differentiate adipose tissue between visceral and abdominal compartments in young and older participants.}, language = {en} } @article{vonHertzbergBoelchWagenbrennerArnholdtetal.2021, author = {von Hertzberg-Boelch, Sebastian Philipp and Wagenbrenner, Mike and Arnholdt, J{\"o}rg and Frenzel, Stephan and Holzapfel, Boris Michael and Rudert, Maximilian}, title = {Custom Made Monoflange Acetabular Components for the Treatment of Paprosky Type III Defects}, series = {Journal of Personalized Medicine}, volume = {11}, journal = {Journal of Personalized Medicine}, number = {4}, issn = {2075-4426}, doi = {10.3390/jpm11040283}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236513}, year = {2021}, abstract = {Purpose: Patient-specific, flanged acetabular components are used for the treatment of Paprosky type III defects during revision total hip arthroplasty (THA). This monocentric retrospective cohort study analyzes the outcome of patients treated with custom made monoflanged acetabular components (CMACs) with intra- and extramedullary iliac fixation. Methods: 14 patients were included who underwent revision THA with CMACs for the treatment of Paprosky type III defects. Mechanism of THA failure was infection in 4 and aseptic loosening in 10 patients. Seven patients underwent no previous revision, the other seven patients underwent three or more previous revisions. Results: At a mean follow-up of 35.4 months (14-94), the revision rate of the implant was 28.3\%. Additionally, one perioperative dislocation and one superficial wound infection occurred. At one year postoperatively, we found a significant improvement of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score (p = 0.015). Postoperative radiographic analysis revealed good hip joint reconstruction with a mean leg length discrepancy of 3 mm (-8-20), a mean lateralization of the horizontal hip center of rotation of 8 mm (-8-35), and a mean proximalization of the vertical hip center of rotation of 6 mm (13-26). Radiolucency lines were present in 30\%. Conclusion: CMACs can be considered an option for the treatment of acetabular bone loss in revision THA. Iliac intra- and extramedullary fixation allows soft tissue-adjusted hip joint reconstruction and improves hip function. However, failure rates are high, with periprosthetic infection being the main threat to successful outcome.}, language = {en} } @article{Trivanović2022, author = {Trivanović, Drenka}, title = {Adult stem cells in aging}, series = {Journal of Personalized Medicine}, volume = {12}, journal = {Journal of Personalized Medicine}, number = {5}, issn = {2075-4426}, doi = {10.3390/jpm12050795}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275226}, year = {2022}, abstract = {No abstract available}, language = {en} } @article{WagenbrennerPokerHeinzetal.2022, author = {Wagenbrenner, Mike and Poker, Konrad and Heinz, Tizian and Herrmann, Marietta and Horas, Konstantin and Ebert, Regina and Mayer-Wagner, Susanne and Holzapfel, Boris M. and Rudert, Maximilian and Steinert, Andre F. and Weißenberger, Manuel}, title = {Mesenchymal stromal cells (MSCs) isolated from various tissues of the human arthritic knee joint possess similar multipotent differentiation potential}, series = {Applied Sciences}, volume = {12}, journal = {Applied Sciences}, number = {4}, issn = {2076-3417}, doi = {10.3390/app12042239}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262334}, year = {2022}, abstract = {(1) Background: The mesenchymal stromal cells (MSCs) of different tissue origins are applied in cell-based chondrogenic regeneration. However, there is a lack of comparability determining the most suitable cell source for the tissue engineering (TE) of cartilage. The purpose of this study was to compare the in vitro chondrogenic potential of MSC-like cells from different tissue sources (bone marrow, meniscus, anterior cruciate ligament, synovial membrane, and the infrapatellar fat pad removed during total knee arthroplasty (TKA)) and define which cell source is best suited for cartilage regeneration. (2) Methods: MSC-like cells were isolated from five donors and expanded using adherent monolayer cultures. Differentiation was induced by culture media containing specific growth factors. Transforming growth factor (TGF)-ß1 was used as the growth factor for chondrogenic differentiation. Osteogenesis and adipogenesis were induced in monolayer cultures for 27 days, while pellet cell cultures were used for chondrogenesis for 21 days. Control cultures were maintained under the same conditions. After, the differentiation period samples were analyzed, using histological and immunohistochemical staining, as well as molecularbiological analysis by RT-PCR, to assess the expression of specific marker genes. (3) Results: Plastic-adherent growth and in vitro trilineage differentiation capacity of all isolated cells were proven. Flow cytometry revealed the clear co-expression of surface markers CD44, CD73, CD90, and CD105 on all isolated cells. Adipogenesis was validated through the formation of lipid droplets, while osteogenesis was proven by the formation of calcium deposits within differentiated cell cultures. The formation of proteoglycans was observed during chondrogenesis in pellet cultures, with immunohistochemical staining revealing an increased relative gene expression of collagen type II. RT-PCR proved an elevated expression of specific marker genes after successful differentiation, with no significant differences regarding different cell source of native tissue. (4) Conclusions: Irrespective of the cell source of native tissue, all MSC-like cells showed multipotent differentiation potential in vitro. The multipotent differentiation capacity did not differ significantly, and chondrogenic differentiation was proven in all pellet cultures. Therefore, cell suitability for cell-based cartilage therapies and tissue engineering is given for various tissue origins that are routinely removed during total knee arthroplasty (TKA). This study might provide essential information for the clinical tool of cell harvesting, leading to more flexibility in cell availability.}, language = {en} } @article{StreckForstervonHertzbergBoelchetal.2022, author = {Streck, Laura Elisa and Forster, Johannes and von Hertzberg-Boelch, Sebastian Philipp and Reichel, Thomas and Rudert, Maximilian and Rueckl, Kilian}, title = {The role of synovial fluid aspiration in shoulder joint infections}, series = {BMC Musculoskeletal Disorders}, volume = {23}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-022-05285-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300795}, year = {2022}, abstract = {Background Joint aspiration with analysis of synovial fluid white blood cell count (WBC) and microbiological culture is a widely established aspect in the diagnosis of shoulder joint infections (SJI). In case of a two stage revision for SJI, joint aspiration before re-/implantation of a total shoulder arthroplasty (TSA) was used to rule out persistent infection for years but its value is under debate. Shoulder specific data on all aspects is rare. The current study aims to answer the following research questions: Does joint aspiration have an insufficient predictive value in the diagnosis of SJI in (1) initial workup and (2) before definite arthroplasty with polymethylmethacrylate (PMMA)-Spacer in place? Methods This retrospective evaluation investigates 35 patients that were treated for SJI with a two staged implantation of a TSA after debridement and implantation of an PMMA-Spacer. Joint aspirations were performed preoperatively (PA) and before re-/implantation of the prosthesis while spacer was in place (interstage aspiration, IA). Samples were taken for microbiological culture and analysis of WBC. Sensitivity and specificity were calculated with reference to intraoperative microbiological samples. Receiver Operating Characteristic (ROC), Area-Under-Curve analysis (AUC) and calculation of the Youden index were performed to find optimum cut-off for WBC. Results The sensitivity of microbiological cultures from PA was 58.3\% and the specificity was 88.9\%. The mean WBC was 27,800 leucocytes/mm3 (range 400-96,300). The maximum Youden index (0.857) was a cut-off of 2600 leucocytes/mm3 with a sensitivity of 85.7\% and a specificity of 100.0\%. The sensitivity and specificity of IA were 0.0\% and 88.5\%, respectively. Conclusions Preoperative aspiration is likely to miss Cutibacteria spp. and CoNS and cannot rule out infection for sure. However, we recommend it for its advantages of targeted antibiotic therapy in case of germ identification. Empiric antibiotic therapy should cover Cutibacteria and CoNS even if aspiration showed negative microbiological cultures. In contrast, the diagnostic value of interstage aspiration does not qualify for its routine use.}, language = {en} } @article{BoelchStreckPlumhoffetal.2020, author = {Boelch, Sebastian Philipp and Streck, Laura Elisa and Plumhoff, Piet and Konrads, Christian and Gohlke, Frank and Rueckl, Kilian}, title = {Infection control and outcome of staged reverse shoulder arthroplasty for the management of shoulder infections}, series = {JSES International}, volume = {4}, journal = {JSES International}, doi = {10.1016/j.jseint.2020.08.012}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230620}, pages = {959-963}, year = {2020}, abstract = {Background The treatment of septic arthritis, caused by either hematogenous seeding, injections, or surgery, can be challenging. Staged reverse shoulder arthroplasty (RSA) with temporary implantation of an antibiotic-loaded spacer is widely accepted but still discussed controversially. This study investigated the shoulder-specific bacterial spectrum, infection control rate, functional outcome, and infection-free survival rate after staged RSA in the mid- to long-term follow-up. It was hypothesized that staged RSA would show a high infection-free survival rate. Methods A total of 39 patients treated with staged RSA for primary septic arthritis (n = 8), secondary infection (n = 8), or periprosthetic infection (n = 23) were retrospectively included. The infection control rate was calculated based on cultures taken intraoperatively at spacer removal and RSA implantation. Infection-free survival was defined as no revision due to infection. The minimum follow-up period for functional outcome assessment was 2 years (n = 14; mean, 76 months; range, 31-128 months). Results Cutibacterium (26\%) and coagulase-negative staphylococci (23\%) were the predominant pathogens. The infection control rate was 90\%. The cumulative infection-free survival rate was 91\% after 128 months. Follow-up examinations showed a mean Constant score of 48 (range, 7-85), a mean QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) score of 40.0 (range, 11.4-93.3), and a mean pain score of 1.6 (range, 0-7). Conclusion Staged RSA implantation was confirmed to be a reliable treatment option for primary, secondary, and periprosthetic infections of the shoulder. The infection control rate and infection-free survival rate are satisfactory. However, patients and surgeons must be aware of functional impairment even after successful treatment of infections.}, language = {en} } @article{WeissenbergerWeissenbergerWagenbrenneretal.2020, author = {Weissenberger, Manuel and Weissenberger, Manuela H. and Wagenbrenner, Mike and Heinz, Tizian and Reboredo, Jenny and Holzapfel, Boris M. and Rudert, Maximilian and Groll, J{\"u}rgen and Evans, Christopher H. and Steinert, Andre F.}, title = {Different types of cartilage neotissue fabricated from collagen hydrogels and mesenchymal stromal cells via SOX9, TGFB1 or BMP2 gene transfer}, series = {PLoS One}, volume = {15}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0237479}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230494}, year = {2020}, abstract = {Objective As native cartilage consists of different phenotypical zones, this study aims to fabricate different types of neocartilage constructs from collagen hydrogels and human mesenchymal stromal cells (MSCs) genetically modified to express different chondrogenic factors. Design Human MSCs derived from bone-marrow of osteoarthritis (OA) hips were genetically modified using adenoviral vectors encoding sex-determining region Y-type high-mobility-group-box (SOX)9,transforming growth factor beta (TGFB) 1or bone morphogenetic protein (BMP) 2cDNA, placed in type I collagen hydrogels and maintained in serum-free chondrogenic media for three weeks. Control constructs contained unmodified MSCs or MSCs expressing GFP. The respective constructs were analyzed histologically, immunohistochemically, biochemically, and by qRT-PCR for chondrogenesis and hypertrophy. Results Chondrogenesis in MSCs was consistently and strongly induced in collagen I hydrogels by the transgenesSOX9,TGFB1andBMP2as evidenced by positive staining for proteoglycans, chondroitin-4-sulfate (CS4) and collagen (COL) type II, increased levels of glycosaminoglycan (GAG) synthesis, and expression of mRNAs associated with chondrogenesis. The control groups were entirely non-chondrogenic. The levels of hypertrophy, as judged by expression of alkaline phosphatase (ALP) and COL X on both the protein and mRNA levels revealed different stages of hypertrophy within the chondrogenic groups (BMP2>TGFB1>SOX9). Conclusions Different types of neocartilage with varying levels of hypertrophy could be generated from human MSCs in collagen hydrogels by transfer of genes encoding the chondrogenic factorsSOX9,TGFB1andBMP2. This technology may be harnessed for regeneration of specific zones of native cartilage upon damage.}, language = {en} } @article{BoelchRueecklStrecketal.2021, author = {Boelch, Sebastian Philipp and R{\"u}eckl, Kilian and Streck, Laura Elisa and Szewczykowski, Viktoria and Weißenberger, Manuel and Jakuscheit, Axel and Rudert, Maximilian}, title = {Diagnosis of chronic infection at total hip arthroplasty revision is a question of definition}, series = {Biomed Research International}, volume = {2021}, journal = {Biomed Research International}, doi = {10.1155/2021/8442435}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265762}, year = {2021}, abstract = {Purpose. Contradicting definitions of periprosthetic joint infection (PJI) are in use. Joint aspiration is performed before total hip arthroplasty (THA) revision. This study investigated the influence of PJI definition on PJI prevalence at THA revision. Test quality of prerevision aspiration was evaluated for the different PJI definitions. Methods. 256 THA revisions were retrospectively classified to be infected or not infected. Classification was performed according to the 4 different definitions proposed by the Musculoskeletal Infection Society (MSIS), the Infectious Diseases Society of America (IDSA), the International Consensus Meeting (ICM), and the European Bone and Joint Infection Society (EBJIS). Only chronic PJIs were included. Results. PJI prevalence at revision significantly correlated with the applied PJI definition (p=0.01, Cramer's V=0.093). PJI prevalence was 20.7\% for the MSIS, 25.4\% for the ICM, 28.1\% for the IDSA, and 32.0\% for the EBJIS definition. For synovial fluid white blood cell count, the best ROC-AUC for predicting PJI was 0.953 in combination with the MSIS definition. Conclusion. PJI definition significantly influences the rate of diagnosed PJIs at THA revision. Synovial fluid white blood cell count is a reliable means to rule out PJI. In cases with a borderline high synovial white blood cell count before THA revision as the only sign of chronic PJI, an extended diagnostic work-up should be considered.}, language = {en} } @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{PereiraTrivanovićHerrmann2019, author = {Pereira, A. R. and Trivanović, D. and Herrmann, M.}, title = {Approaches to mimic the complexity of the skeletal mesenchymal stem/stromal cell niche in vitro}, series = {European Cells and Materials}, volume = {37}, journal = {European Cells and Materials}, issn = {1473-2262}, doi = {10.22203/eCM.v037a07}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268823}, pages = {88-112}, year = {2019}, abstract = {Mesenchymal stem/stromal cells (MSCs) are an essential element of most modern tissue engineering and regenerative medicine approaches due to their multipotency and immunoregulatory functions. Despite the prospective value of MSCs for the clinics, the stem cells community is questioning their developmental origin, in vivo localization, identification, and regenerative potential after several years of far-reaching research in the field. Although several major progresses have been made in mimicking the complexity of the MSC niche in vitro, there is need for comprehensive studies of fundamental mechanisms triggered by microenvironmental cues before moving to regenerative medicine cell therapy applications. The present comprehensive review extensively discusses the microenvironmental cues that influence MSC phenotype and function in health and disease - including cellular, chemical and physical interactions. The most recent and relevant illustrative examples of novel bioengineering approaches to mimic biological, chemical, and mechanical microenvironmental signals present in the native MSC niche are summarized, with special emphasis on the forefront techniques to achieve bio-chemical complexity and dynamic cultures. In particular, the skeletal MSC niche and applications focusing on the bone regenerative potential of MSC are addressed. The aim of the review was to recognize the limitations of the current MSC niche in vitro models and to identify potential opportunities to fill the bridge between fundamental science and clinical application of MSCs.}, language = {en} } @article{SteinertSchroederSefrinetal.2022, author = {Steinert, Andre F. and Schr{\"o}der, Lennart and Sefrin, Lukas and Janßen, Bj{\"o}rn and Arnholdt, J{\"o}rg and Rudert, Maximilian}, title = {The impact of total knee replacement with a customized cruciate-retaining implant design on patient-reported and functional outcomes}, series = {Journal of Personalized Medicine}, volume = {12}, journal = {Journal of Personalized Medicine}, number = {2}, issn = {2075-4426}, doi = {10.3390/jpm12020194}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312746}, year = {2022}, abstract = {Purpose: To treat patients with tricompartimental knee osteoarthritis (OA), a customized cruciate-retaining total knee arthroplasty (CCR-TKA) system can be used, including both individualized instrumentation and implants. The objective of this monocentric cohort study was to analyze patient-reported and functional outcomes in a series of patients implanted with the second generation of this customized implant. Methods: At our arthroplasty center, we prospectively recruited a cohort of patients with tricompartmental gonarthrosis to be treated with total knee replacement (TKA) using a customized cruciate-retaining (CCR) implant design. Inclusion criteria for patients comprised the presence of intact posterior cruciate and collateral ligaments and a knee deformity that was restricted to <15° varus, valgus, or flexion contracture. Patients were assessed for their range of motion (ROM), Knee Society Score (KSS), Western Ontario and McMaster University osteoarthritis index (WOMAC), and short form (SF)-12 physical and mental scores, preoperatively, at 3 and 6 months, as well as at 1, 2, 3, and 5 years of follow-up (FU) postoperatively. Results: The average age of the patient population was 64 years (range: 40-81), the average BMI was 31 (range: 23-42), and in total, 28 female and 45 male patients were included. Implant survivorship was 97.5\% (one septic loosening) at an average follow-up of 2.5 years. The KSS knee and function scores improved significantly (p < 0.001) from, respectively, 41 and 53 at the pre-operative visit, to 92 and 86, respectively, at the 5-year post-operative time point. The SF-12 Physical and Mental scores significantly (p < 0.001) improved from the pre-operative values of 28 and 50, to 50 and 53 at the 5-year FU, respectively. Patients experienced significant improvements in their overall knee range of motion, from 106° at the preoperative visit to 122°, on average, 5 years postoperatively. The total WOMAC score significantly (p < 0.001) improved from 49.1 preoperatively to 11.4 postoperatively at 5-year FU. Conclusions: Although there was no comparison to other implants within this study, patients reported high overall satisfaction and improvement in functional outcomes within the first year from surgery, which continued over the following years. These mid-term results are excellent compared with those reported in the current literature. Comparative long-term studies with this device are needed. Level of evidence 3b (individual case-control study).}, 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{WeissenbergerHeinzRueckletal.2020, author = {Weissenberger, Manuel and Heinz, Tizian and Rueckl, Kilian and Rudert, Maximilian and Klug, Alexander and Hoffmann, Reinhard and Schmidt-Horloh{\´e}, Kay}, title = {No functional differences in anatomic reconstruction with one vs. two suture anchors after non-simultaneous bilateral distal biceps brachii tendon rupture: a case report and review of the literature}, series = {BMC Musculoskeletal Disorders}, volume = {21}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-020-03304-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229266}, year = {2020}, abstract = {Background Surgical reattachment of the tendon is still the gold standard for ruptures of the distal biceps brachii tendon. Several fixation techniques have been described in the literature, with suture anchors being one of the most common fixation techniques. Currently, there is no data available on how many anchors are required for a safe and stable refixation. In this case report clinical data of a patient with non-simultaneous bilateral distal biceps tendon ruptures treated with a different number of suture anchors for each side (one vs. two) are demonstrated. Case presentation A 47-year-old factory worker suffered a rupture of the distal biceps tendon on both arms following two different occasions. The left side was fixed using a single suture anchor, while refixation on the right side was performed with two anchors. The patient was prospectively followed for one year. Functional outcome was assessed using the Andrews Carson Score (ACS), the Oxford Elbow Score (OES), and the Disabilities of Arm, Shoulder and Hand (DASH) Score after six, twelve, 24 and 48 weeks. Furthermore, an isokinetic strength measurement for flexion strength was performed after 24 and 48 weeks. After 48 weeks the patient presented with excellent functional outcome scores and no follow-up complications. During the follow-up period, no differences in the functional scores nor in the isokinetic flexion strength measurement could be detected. Furthermore, no radiological complications (like heterotopic ossifications) could be detected in the postoperative radiographs after one year. Conclusions Anatomic reattachment of the distal biceps tendon is a successful operative treatment option for distal biceps tendon ruptures. Suture anchor fixation remains one of the most common techniques, as it allows fast surgery and provides good results with respect to range of motion (ROM) and functional scoring according to the current literature. However, the number of anchors required for a stable fixation remains unclear. As indicated by our presented case, we hypothesize, that there are no significant differences between a one-point or a two-point fixation. In the presented case report, no intraindividual differences between the usage of one versus two suture anchors were evident in the short-term follow-up.}, 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{ArmbrusterKriegWeissenbergeretal.2017, author = {Armbruster, Nicole and Krieg, Jennifer and Weißenberger, Manuel and Scheller, Carsten and Steinert, Andre F.}, title = {Rescued Chondrogenesis of Mesenchymal Stem Cells under Interleukin 1 Challenge by Foamyviral Interleukin 1 Receptor Antagonist Gene Transfer}, series = {Frontiers in Pharmacology}, volume = {8}, journal = {Frontiers in Pharmacology}, number = {255}, doi = {10.3389/fphar.2017.00255}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170919}, year = {2017}, abstract = {Background: Mesenchymal stem cells (MSCs) and their chondrogenic differentiation have been extensively investigated in vitro as MSCs provide an attractive source besides chondrocytes for cartilage repair therapies. Here we established prototype foamyviral vectors (FVV) that are derived from apathogenic parent viruses and are characterized by a broad host range and a favorable integration pattern into the cellular genome. As the inflammatory cytokine interleukin 1 beta (IL1β) is frequently present in diseased joints, the protective effects of FVV expressing the human interleukin 1 receptor antagonist protein (IL1RA) were studied in an established in vitro model (aggregate culture system) of chondrogenesis in the presence of IL1β. Materials and Methods: We generated different recombinant FVVs encoding enhanced green fluorescent protein (EGFP) or IL1RA and examined their transduction efficiencies and transgene expression profiles using different cell lines and human primary MSCs derived from bone marrow-aspirates. Transgene expression was evaluated by fluorescence microscopy (EGFP), flow cytometry (EGFP), and ELISA (IL1RA). For evaluation of the functionality of the IL1RA transgene to block the inhibitory effects of IL1β on chondrogenesis of primary MSCs and an immortalized MSC cell line (TERT4 cells), the cells were maintained following transduction as aggregate cultures in standard chondrogenic media in the presence or absence of IL1β. After 3 weeks of culture, pellets were harvested and analyzed by histology and immunohistochemistry for chondrogenic phenotypes. Results: The different FVV efficiently transduced cell lines as well as primary MSCs, thereby reaching high transgene expression levels in 6-well plates with levels of around 100 ng/ml IL1RA. MSC aggregate cultures which were maintained in chondrogenic media without IL1β supplementation revealed a chondrogenic phenotype by means of strong positive staining for collagen type II and matrix proteoglycan (Alcian blue). Addition of IL1β was inhibitory to chondrogenesis in untreated control pellets. In contrast, foamyviral mediated IL1RA expression rescued the chondrogenesis in pellets cultured in the presence of IL1β. Transduced MSC pellets reached thereby very high IL1RA transgene expression levels with a peak of 1087 ng/ml after day 7, followed by a decrease to 194 ng/ml after day 21, while IL1RA concentrations of controls were permanently below 200 pg/ml. Conclusion: Our results indicate that FVV are capable of efficient gene transfer to MSCs, while reaching IL1RA transgene expression levels, that were able to efficiently block the impacts of IL1β in vitro. FVV merit further investigation as a means to study the potential as a gene transfer tool for MSC based therapies for cartilage repair.}, language = {en} } @article{MuellerDeubertSeefriedKrugetal.2017, author = {M{\"u}ller-Deubert, Sigrid and Seefried, Lothar and Krug, Melanie and Jakob, Franz and Ebert, Regina}, title = {Epidermal growth factor as a mechanosensitizer in human bone marrow stromal cells}, series = {Stem Cell Research}, volume = {24}, journal = {Stem Cell Research}, doi = {10.1016/j.scr.2017.08.012}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170247}, pages = {69-76}, year = {2017}, abstract = {Epidermal growth factors (EGFs) e.g. EGF, heparin-binding EGF and transforming growth factor alpha and their receptors e.g. EGFR and ErbB2 control proinflammatory signaling and modulate proliferation in bone marrow stromal cells (BMSC). Interleukin-6 and interleukin-8 are EGF targets and participate in the inflammatory phase of bone regeneration via non-canonical wnt signaling. BMSC differentiation is also influenced by mechanical strain-related activation of ERK1/2 and AP-1, but the role of EGFR signaling in mechanotransduction is unclear. We investigated the effects of EGFR signaling in telomerase-immortalized BMSC, transfected with a luciferase reporter, comprising a mechanoresponsive AP1 element, using ligands, neutralizing antibodies and EGFR inhibitors on mechanotransduction and we found that EGF via EGFR increased the response to mechanical strain. Results were confirmed by qPCR analysis of mechanoresponsive genes. EGF-responsive interleukin-6 and interleukin-8 were synergistically enhanced by EGF stimulation and mechanical strain. We show here in immortalized and primary BMSC that EGFR signaling enhances mechanotransduction, indicating that the EGF system is a mechanosensitizer in BMSC. Alterations in mechanosensitivity and -adaptation are contributors to age-related diseases like osteoporosis and the identification of a suitable mechanosensitizer could be beneficial. The role of the synergism of these signaling cascades in physiology and disease remains to be unraveled.}, language = {en} } @article{ReichertvonRottkayRothetal.2018, author = {Reichert, Johannes C. and von Rottkay, Eberhard and Roth, Franz and Renz, Tim and Hausmann, Johannes and Kranz, Julius and Rackwitz, Lars and N{\"o}th, Ulrich and Rudert, Maximilian}, title = {A prospective randomized comparison of the minimally invasive direct anterior and the transgluteal approach for primary total hip arthroplasty}, series = {BMC Musculoskeletal Disorders}, volume = {19}, journal = {BMC Musculoskeletal Disorders}, number = {241}, doi = {10.1186/s12891-018-2133-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176072}, year = {2018}, abstract = {Background: The presented prospective randomized controlled single-centre study compares the clinical outcome up to 12 months after total hip arthroplasty using a minimally invasive single-incision direct anterior (DAA) and a direct transgluteal lateral approach. Methods: A total of 123 arthroplasties were evaluated utilizing the Harris Hip Score (HHS), the extra short musculoskeletal functional assessment questionnaire (XSFMA), the Short Form 36 (SF-36) health survey, a Stepwatch™ Activity Monitor (SAM), and a timed 25 m foot walk (T25-FW). Postoperative x-ray images after THA were reviewed to determine inclination and stem positioning. Results: At final follow-up, the XSFMA functional index scores were 10.3 (anterior) and 15.08 (lateral) while the bother index summed up to a score of 15.8 (anterior) and 21.66 (lateral) respectively, thus only differing significantly for the functional index (p = 0.040 and p = 0.056). The SF-36 physical component score (PCS) was 47.49 (anterior) and 42.91 (lateral) while the mental component score (MCS) summed up to 55.0 (anterior) and 56.23 (lateral) with a significant difference evident for the PCS (p = 0.017; p = 0.714). Patients undergoing THA through a DAA undertook a mean of 6402 cycles per day while those who had undergone THA through a transgluteal approach undertook a mean of 5340 cycles per day (p = 0.012). Furthermore, the obtained outcome for the T25-FW with 18.4 s (anterior) and 19.75 s (lateral) and the maximum walking distance (5932 m and 5125 m) differed significantly (p = 0.046 and p = 0.045). The average HHS showed no significant difference equaling 92.4 points in the anterior group and 91.43 in the lateral group (p = 0.477). The radiographic analysis revealed an average cup inclination of 38.6° (anterior) and 40.28° (lateral) without signs of migration. Conclusion: In summary, our outcomes show that after 1 year THA through the direct anterior approach results in a higher patient activity compared to THA utilizing a transgluteal lateral approach while no differences regarding hip function are evident.}, language = {en} } @article{BoelchRothArnholdtetal.2018, author = {Boelch, Sebastian P. and Roth, Magnus and Arnholdt, Joerg and Rudert, Maximilian and Luedemann, Martin}, title = {Synovial fluid aspiration should not be routinely performed during the two-stage exchange of the knee}, series = {BioMed Research International}, volume = {2018}, journal = {BioMed Research International}, number = {6720712}, doi = {10.1155/2018/6720712}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176800}, year = {2018}, abstract = {Purpose. Detection of infection persistence during the two-stage exchange of the knee for periprosthetic joint infection is challenging. Synovial fluid culture (SFC) and synovial white blood cell count (SWBCC) before joint reimplantation are widespread diagnostic means for this indication. The sensitivity and specificity of SFC and of SWBCC for infection persistence before planned reimplantation were evaluated. Methods. 94 two-stage exchanges of the knee with synovial fluid aspiration performed after a drug holiday of at least 14 days and before reimplantation or spacer exchange (planned reimplantation) were retrospectively analyzed. Only cases with at least 3 intraoperative samples at planned reimplantation were included. SFC and SWBCC were compared to pathogen detection (SFC\(_{(culture)}\)/SWBCC\(_{(culture)}\) and to histopathological signs of infection persistence (SFC\(_{(histo)}\)/SWBCC\(_{(histo)}\) from intraoperative samples at planned reimplantation. For SFC, the sensitivity and specificity were calculated. For SWBCC, the optimal cut-off value with its sensitivity and specificity was calculated with the Youden-Index. Results. Sensitivity and specificity of SFC\(_{(culture)}\) were 0.0\% and 98.9\%. Sensitivity and specificity of SFC\(_{(histo)}\) were 3.4\% and 100\%. The optimal cut-off value for SWBCC\(_{(culture)}\) was 4450 cells/μl with a sensitivity of 50.0\% and a specificity of 86.5\%. The optimal cut-off value for SWBCC\(_{(histo)}\) was 3250 cells/μl with a sensitivity of 35.7\% and a specificity of 92.9\%. Conclusion. The detection of infection persistence remains challenging and a consented approach is lacking. The results do not warrant the routine performance of SFC during the two-stage exchange at the knee. SWBCC can be used to confirm infection persistence at high cut-offs, but they only occur in few patients and are therefore inappropriate for the routine use.}, 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{LiedertNemitzHaffnerLuntzeretal.2020, author = {Liedert, Astrid and Nemitz, Claudia and Haffner-Luntzer, Melanie and Schick, Fabian and Jakob, Franz and Ignatius, Anita}, title = {Effects of estrogen receptor and Wnt signaling activation on mechanically induced bone formation in a mouse model of postmenopausal bone loss}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {21}, issn = {1422-0067}, doi = {10.3390/ijms21218301}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285487}, year = {2020}, abstract = {In the adult skeleton, bone remodeling is required to replace damaged bone and functionally adapt bone mass and structure according to the mechanical requirements. It is regulated by multiple endocrine and paracrine factors, including hormones and growth factors, which interact in a coordinated manner. Because the response of bone to mechanical signals is dependent on functional estrogen receptor (ER) and Wnt/β-catenin signaling and is impaired in postmenopausal osteoporosis by estrogen deficiency, it is of paramount importance to elucidate the underlying mechanisms as a basis for the development of new strategies in the treatment of osteoporosis. The present study aimed to investigate the effectiveness of the activation of the ligand-dependent ER and the Wnt/β-catenin signal transduction pathways on mechanically induced bone formation using ovariectomized mice as a model of postmenopausal bone loss. We demonstrated that both pathways interact in the regulation of bone mass adaption in response to mechanical loading and that the activation of Wnt/β-catenin signaling considerably increased mechanically induced bone formation, whereas the effects of estrogen treatment strictly depended on the estrogen status in the mice.}, language = {en} } @article{NedopilDhaliwalHowelletal.2022, author = {Nedopil, Alexander J. and Dhaliwal, Anand and Howell, Stephen M. and Hull, Maury L.}, title = {A surgeon that switched to unrestricted kinematic alignment with manual instruments has a short learning curve and comparable resection accuracy and outcomes to those of an experienced surgeon}, series = {Journal of Personalized Medicine}, volume = {12}, journal = {Journal of Personalized Medicine}, number = {7}, issn = {2075-4426}, doi = {10.3390/jpm12071152}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281842}, year = {2022}, abstract = {After starting an orthopedic practice, a surgeon with a fellowship in mechanically aligned (MA) TKA initiated this study to characterize their learning curve after they switched to unrestricted kinematic alignment (KA) TKA using manual instruments. Accordingly, the present study determined for the inexperienced (IE) surgeon the number of cases required to achieve consistent femoral resections and operating times, and whether the femoral resection accuracy, patient-reported outcome measures (PROMs), and component alignment were different from an experienced (E) surgeon. This prospective cohort study analyzed the IE surgeon's first 30 TKAs, all performed with KA, and 30 consecutive KA TKAs performed by an E surgeon. The resection accuracy or deviation was the calipered thickness of the distal and posterior medial and lateral femoral resections minus the planned resection thickness, which was the thickness of the corresponding condyle of the femoral component, minus 2 mm for cartilage wear, and 1 mm for the kerf of the blade. Independent observers recorded the femoral resection thickness, operative times, PROMs, and alignment. For each femoral resection, the deviation between three groups of patients containing ten consecutive KA TKAs, was either insignificant (p = 0.695 to 1.000) or within the 0.5 mm resolution of the caliper, which indicated no learning curve. More than three groups were needed to determine the learning curve for the operative time; however, the IE surgeon's procedure dropped to 77 min for the last 10 patients, which was 20 min longer than the E surgeon. The resection deviations of the IE and E surgeon were comparable, except for the posterolateral femoral resection, which the IE surgeon under-resected by a mean of -0.8 mm (p < 0.0001). At a mean follow-up of 9 and 17 months, the Forgotten Joint Score, Oxford Knee Score, KOOS, and the alignment of the components and limbs were not different between the IE and E surgeon (p ≥ 0.6994). A surgeon that switches to unrestricted KA with manual instruments can determine their learning curve by computing the deviation of the distal and posterior femoral resections from the planned resection. Based on the present study, an IE surgeon could have resection accuracy, post-operative patient outcomes, and component alignment comparable to an E surgeon.}, language = {en} } @article{HorasvanHerckMaieretal.2020, author = {Horas, Konstantin and van Herck, Ulrike and Maier, Gerrit S. and Maus, Uwe and Harrasser, Norbert and Jakob, Franz and Weissenberger, Manuel and Arnholdt, J{\"o}rg and Holzapfel, Boris M. and Rudert, Maximilian}, title = {Does vitamin D deficiency predict tumour malignancy in patients with bone tumours? Data from a multi-center cohort analysis}, series = {Journal of Bone Oncology}, volume = {25}, journal = {Journal of Bone Oncology}, doi = {10.1016/j.jbo.2020.100329}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230314}, year = {2020}, abstract = {Vitamin D deficiency is a global health concern that is estimated to afflict over one billion people globally. The major role of vitamin D is that of a regulator of calcium and phosphate metabolism, thus, being essential for proper bone mineralisation. Concomitantly, vitamin D is known to exert numerous extra-skeletal actions. For example, it has become evident that vitamin D has direct anti-proliferative, pro-differentiation and pro-apoptotic actions on cancer cells. Hence, vitamin D deficiency has been associated with increased cancer risk and worse prognosis in several malignancies. We have recently demonstrated that vitamin D deficiency promotes secondary cancer growth in bone. These findings were partly attributable to an increase in bone remodelling but also through direct effects of vitamin D on cancer cells. To date, very little is known about vitamin D status of patients with bone tumours in general. Thus, the objective of this study was to assess vitamin D status of patients with diverse bone tumours. Moreover, the aim was to elucidate whether or not there is an association between pre-diagnostic vitamin D status and tumour malignancy in patients with bone tumours. In a multi-center analysis, 25(OH)D, PTH and calcium levels of 225 patients that presented with various bone tumours between 2017 and 2018 were assessed. Collectively, 76\% of all patients had insufficient vitamin D levels with a total mean 25(OH)D level of 21.43 ng/ml (53.58 nmol/L). In particular, 52\% (117/225) of patients were identified as vitamin D deficient and further 24\% of patients (55/225) were vitamin D insufficient. Notably, patients diagnosed with malignant bone tumours had significantly lower 25(OH)D levels than patients diagnosed with benign bone tumours [19.3 vs. 22.75 ng/ml (48.25 vs. 56.86 nmol/L); p = 0.04). In conclusion, we found a widespread and distressing rate of vitamin D deficiency and insufficiency in patients with bone tumours. However, especially for patients with bone tumours sufficient vitamin D levels seem to be of great importance. Thus, we believe that 25(OH)D status should routinely be monitored in these patients. Collectively, there should be an increased awareness for physicians to assess and if necessary correct vitamin D status of patients with bone tumours in general or of those at great risk of developing bone tumours.}, language = {en} } @article{OhlebuschBorstFrankenbachetal.2020, author = {Ohlebusch, Barbara and Borst, Angela and Frankenbach, Tina and Klopocki, Eva and Jakob, Franz and Liedtke, Daniel and Graser, Stephanie}, title = {Investigation of alpl expression and Tnap-activity in zebrafish implies conserved functions during skeletal and neuronal development}, series = {Scientific Reports}, volume = {10}, journal = {Scientific Reports}, doi = {10.1038/s41598-020-70152-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230024}, year = {2020}, abstract = {Hypophosphatasia (HPP) is a rare genetic disease with diverse symptoms and a heterogeneous severity of onset with underlying mutations in the ALPL gene encoding the ectoenzyme Tissue-nonspecific alkaline phosphatase (TNAP). Considering the establishment of zebrafish (Danio rerio) as a new model organism for HPP, the aim of the study was the spatial and temporal analysis of alpl expression in embryos and adult brains. Additionally, we determined functional consequences of Tnap inhibition on neural and skeletal development in zebrafish. We show that expression of alpl is present during embryonic stages and in adult neuronal tissues. Analyses of enzyme function reveal zones of pronounced Tnap-activity within the telencephalon and the mesencephalon. Treatment of zebrafish embryos with chemical Tnap inhibitors followed by axonal and cartilage/mineralized tissue staining imply functional consequences of Tnap deficiency on neuronal and skeletal development. Based on the results from neuronal and skeletal tissue analyses, which demonstrate an evolutionary conserved role of this enzyme, we consider zebrafish as a promising species for modeling HPP in order to discover new potential therapy strategies in the long-term.}, language = {en} } @article{ReichelRuecklFenwicketal.2019, author = {Reichel, Thomas and Rueckl, Kilian and Fenwick, Annabel and Vogt, Niklas and Rudert, Maximilian and Plumhoff, Piet}, title = {Hibernoma of the upper extremity: complete case of a rare but benign soft tissue tumor}, series = {Case Reports in Orthopedics}, volume = {2019}, journal = {Case Reports in Orthopedics}, doi = {10.1155/2019/6840693}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201669}, pages = {6840693}, year = {2019}, abstract = {Hibernoma is a rare benign lipomatous tumor showing differentiation of brown fatty tissue. To the author's best knowledge, there is no known case of malignant transformation or metastasis. Due to their slow, noninfiltrating growth hibernomas are often an incidental finding in the third or fourth decade of life. The vast majority are located in the thigh, neck, and periscapular region. A diagnostic workup includes ultrasound and contrast-enhanced MRI. Differential diagnosis is benign lipoma, well-differentiated liposarcoma, and rhabdomyoma. An incisional biopsy followed by marginal resection of the tumor is the standard of care, and recurrence after complete resection is not reported. The current paper presents diagnostic and intraoperative findings of a hibernoma of the upper arm and reviews similar reports in the current literature.}, 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} }