TY - JOUR A1 - Weißenberger, Manuel A1 - Wagenbrenner, Mike A1 - Schote, Fritz A1 - Horas, Konstantin A1 - Schäfer, Thomas A1 - Rudert, Maximilian A1 - Barthel, Thomas A1 - Heinz, Tizian A1 - Reppenhagen, Stephan T1 - The 3-triangle method preserves the posterior tibial slope during high tibial valgus osteotomy: first preliminary data using a mathematical model JF - Journal of Experimental Orthopaedics N2 - Purpose Despite much improved preoperative planning techniques accurate intraoperative assessment of the high tibial valgus osteotomy (HTO) remains challenging and often results in coronal over- and under-corrections as well as unintended changes of the posterior tibial slope. Noyes et al. reported a novel method for accurate intraoperative coronal and sagittal alignment correction based on a three-dimensional mathematical model. This is the first study examining preliminary data via the proposed Noyes approach for accurate intraoperative coronal and sagittal alignment correction during HTO. Methods From 2016 to 2020 a total of 24 patients (27 knees) underwent HTO applying the proposed Noyes method (Noyes-Group). Radiographic data was analyzed retrospectively and matched to patients that underwent HTO using the conventional method, i.e., gradual medial opening using a bone spreader under fluoroscopic control (Conventional-Group). All operative procedures were performed by an experienced surgeon at a single orthopaedic university center. Results From the preoperative to the postoperative visit no statistically significant changes of the posterior tibial slope were noted in the Noyes-Group compared to a significant increase in the Conventional-Group (p = 0.01). Regarding the axial alignment no significant differences between both groups were observed pre- and postoperatively. The number of over- and under-corrections did not differ significantly between both groups. Linear regression analysis showed a significant correlation of the postoperative medial proximal tibial angle (MPTA) with the position of the weightbearing line on the tibial plateau. Conclusion The 3-triangle method by Noyes seems to be a promising approach for preservation of the posterior tibial slope during HTO. KW - knee KW - high tibial valgus osteotomy KW - axial alignment KW - posterior tibial slope KW - weight bearing line KW - cartilage KW - triangle method KW - osteoarthritis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300806 SN - 2197-1153 VL - 9 ER - TY - JOUR A1 - Weissenberger, Manuel A1 - Weissenberger, Manuela H. A1 - Wagenbrenner, Mike A1 - Heinz, Tizian A1 - Reboredo, Jenny A1 - Holzapfel, Boris M. A1 - Rudert, Maximilian A1 - Groll, Jürgen A1 - Evans, Christopher H. A1 - Steinert, Andre F. T1 - Different types of cartilage neotissue fabricated from collagen hydrogels and mesenchymal stromal cells via SOX9, TGFB1 or BMP2 gene transfer JF - PLoS One N2 - 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. KW - stem cells KW - in vitro KW - chondrogenic differentiation KW - repair KW - chondrocytes KW - transplantation KW - stimulation KW - scaffolds KW - defects KW - therapy Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230494 VL - 15 IS - 8 ER - TY - JOUR A1 - Weissenberger, Manuel A1 - Heinz, Tizian A1 - Rueckl, Kilian A1 - Rudert, Maximilian A1 - Klug, Alexander A1 - Hoffmann, Reinhard A1 - Schmidt-Horlohé, Kay T1 - 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 JF - BMC Musculoskeletal Disorders N2 - 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. KW - Non-simultaneous bilateral distal biceps tendon rupture KW - Distal biceps tendon repair KW - Anatomic reattachment KW - Suture anchor KW - Case report Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229266 VL - 21 ER - TY - JOUR A1 - Wagenbrenner, Mike A1 - Poker, Konrad A1 - Heinz, Tizian A1 - Herrmann, Marietta A1 - Horas, Konstantin A1 - Ebert, Regina A1 - Mayer-Wagner, Susanne A1 - Holzapfel, Boris M. A1 - Rudert, Maximilian A1 - Steinert, Andre F. A1 - Weißenberger, Manuel T1 - Mesenchymal stromal cells (MSCs) isolated from various tissues of the human arthritic knee joint possess similar multipotent differentiation potential JF - Applied Sciences N2 - (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. KW - knee joint KW - MSCs KW - cellular origin KW - cartilage regeneration KW - tissue engineering KW - cell-based therapies KW - osteoarthritis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-262334 SN - 2076-3417 VL - 12 IS - 4 ER - TY - JOUR A1 - Wagenbrenner, Mike A1 - Mayer-Wagner, Susanne A1 - Rudert, Maximilian A1 - Holzapfel, Boris Michael A1 - Weissenberger, Manuel T1 - Combinations of hydrogels and mesenchymal stromal cells (MSCs) for cartilage tissue engineering — a review of the literature JF - Gels N2 - Cartilage offers limited regenerative capacity. Cell-based approaches have emerged as a promising alternative in the treatment of cartilage defects and osteoarthritis. Due to their easy accessibility, abundancy, and chondrogenic potential mesenchymal stromal cells (MSCs) offer an attractive cell source. MSCs are often combined with natural or synthetic hydrogels providing tunable biocompatibility, biodegradability, and enhanced cell functionality. In this review, we focused on the different advantages and disadvantages of various natural, synthetic, and modified hydrogels. We examined the different combinations of MSC-subpopulations and hydrogels used for cartilage engineering in preclinical and clinical studies and reviewed the effects of added growth factors or gene transfer on chondrogenesis in MSC-laden hydrogels. The aim of this review is to add to the understanding of the disadvantages and advantages of various combinations of MSC-subpopulations, growth factors, gene transfers, and hydrogels in cartilage engineering. KW - hydrogels KW - osteoarthritis KW - cartilage defects KW - MSCs KW - cartilage regeneration KW - tissue engineering Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250177 SN - 2310-2861 VL - 7 IS - 4 ER - TY - JOUR A1 - Wagenbrenner, Mike A1 - Heinz, Tizian A1 - Horas, Konstantin A1 - Jakuscheit, Axel A1 - Arnholdt, Jörg A1 - Hermann, Marietta A1 - Rudert, Maximilian A1 - Holzapfel, Boris M. A1 - Steinert, Andre F. A1 - Weißenberger, Manuel T1 - The human arthritic hip joint is a source of mesenchymal stromal cells (MSCs) with extensive multipotent differentiation potential JF - BMC Musculoskeletal Disorders N2 - Background While multiple in vitro studies examined mesenchymal stromal cells (MSCs) derived from bone marrow or hyaline cartilage, there is little to no data about the presence of MSCs in the joint capsule or the ligamentum capitis femoris (LCF) of the hip joint. Therefore, this in vitro study examined the presence and differentiation potential of MSCs isolated from the bone marrow, arthritic hyaline cartilage, the LCF and full-thickness samples of the anterior joint capsule of the hip joint. Methods MSCs were isolated and multiplied in adherent monolayer cell cultures. Osteogenesis and adipogenesis were induced in monolayer cell cultures for 21 days using a differentiation medium containing specific growth factors, while chondrogenesis in the presence of TGF-ss1 was performed using pellet-culture for 27 days. Control cultures were maintained for comparison over the same duration of time. The differentiation process was analyzed using histological and immunohistochemical stainings as well as semiquantitative RT-PCR for measuring the mean expression levels of tissue-specific genes. Results This in vitro research showed that the isolated cells from all four donor tissues grew plastic-adherent and showed similar adipogenic and osteogenic differentiation capacity as proven by the histological detection of lipid droplets or deposits of extracellular calcium and collagen type I. After 27 days of chondrogenesis proteoglycans accumulated in the differentiated MSC-pellets from all donor tissues. Immunohistochemical staining revealed vast amounts of collagen type II in all differentiated MSC-pellets, except for those from the LCF. Interestingly, all differentiated MSCs still showed a clear increase in mean expression of adipogenic, osteogenic and chondrogenic marker genes. In addition, the examination of an exemplary selected donor sample revealed that cells from all four donor tissues were clearly positive for the surface markers CD44, CD73, CD90 and CD105 by flow cytometric analysis. Conclusions This study proved the presence of MSC-like cells in all four examined donor tissues of the hip joint. No significant differences were observed during osteogenic or adipogenic differentiation depending on the source of MSCs used. Further research is necessary to fully determine the tripotent differentiation potential of cells isolated from the LCF and capsule tissue of the hip joint. KW - Hip joint KW - Osteoarthritis KW - MSCs KW - Cartilage regeneration KW - Tissue engineering KW - Ligamentum capitis femoris KW - Joint capsule KW - Bone marrow Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229497 VL - 21 IS - 1 ER - TY - JOUR A1 - Wagenbrenner, Mike A1 - Heinz, Tizian A1 - Horas, Konstantin A1 - Jakuscheit, Axel A1 - Arnholdt, Joerg A1 - Mayer-Wagner, Susanne A1 - Rudert, Maximilian A1 - Holzapfel, Boris M. A1 - Weißenberger, Manuel T1 - Impact of Tranexamic Acid on Chondrocytes and Osteogenically Differentiated Human Mesenchymal Stromal Cells (hMSCs) In Vitro JF - Journal of Clinical Medicine N2 - The topical application of tranexamic acid (TXA) helps to prevent post-operative blood loss in total joint replacements. Despite these findings, the effects on articular and periarticular tissues remain unclear. Therefore, this in vitro study examined the effects of varying exposure times and concentrations of TXA on proliferation rates, gene expression and differentiation capacity of chondrocytes and human mesenchymal stromal cells (hMSCs), which underwent osteogenic differentiation. Chondrocytes and hMSCs were isolated and multiplied in monolayer cell cultures. Osteogenic differentiation of hMSCs was induced for 21 days using a differentiation medium containing specific growth factors. Cell proliferation was analyzed using ATP assays. Effects of TXA on cell morphology were examined via light microscopy and histological staining, while expression levels of tissue-specific genes were measured using semiquantitative RT-PCR. After treatment with 50 mg/mL of TXA, a decrease in cell proliferation rates was observed. Furthermore, treatment with concentrations of 20 mg/mL of TXA for at least 48 h led to a visible detachment of chondrocytes. TXA treatment with 50 mg/mL for at least 24 h led to a decrease in the expression of specific marker genes in chondrocytes and osteogenically differentiated hMSCs. No significant effects were observed for concentrations beyond 20 mg/mL of TXA combined with exposure times of less than 24 h. This might therefore represent a safe limit for topical application in vivo. Further research regarding in vivo conditions and effects on hMSC functionality are necessary to fully determine the effects of TXA on articular and periarticular tissues. KW - tranexamic acid KW - hMSCs KW - chondrocytes KW - osteoarthritis KW - toxicity KW - differentiation capacity Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219410 SN - 2077-0383 VL - 9 IS - 12 ER - TY - JOUR A1 - von Hertzberg-Boelch, Sebastian Philipp A1 - Wagenbrenner, Mike A1 - Arnholdt, Jörg A1 - Frenzel, Stephan A1 - Holzapfel, Boris Michael A1 - Rudert, Maximilian T1 - Custom Made Monoflange Acetabular Components for the Treatment of Paprosky Type III Defects JF - Journal of Personalized Medicine N2 - 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. KW - patient specific implant KW - custom made implant KW - revision hip KW - Paprosky KW - pelvic discontinuity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236513 SN - 2075-4426 VL - 11 IS - 4 ER - TY - JOUR A1 - von Hertzberg-Boelch, Sebastian Philipp A1 - Luedemann, Martin A1 - Rudert, Maximilian A1 - Steinert, Andre F. T1 - PMMA bone cement: antibiotic elution and mechanical properties in the context of clinical use JF - Biomedicines N2 - This literature review discusses the use of antibiotic loaded polymethylmethacrylate bone cements in arthroplasty. The clinically relevant differences that have to be considered when antibiotic loaded bone cements (ALBC) are used either for long-term implant fixation or as spacers for the treatment of periprosthetic joint infections are outlined. In this context, in vitro findings for antibiotic elution and material properties are summarized and transferred to clinical use. KW - spacer KW - bone cement KW - PMMA KW - polymethylmethacrylate KW - periprosthetic infection KW - antibiotic elution Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281708 SN - 2227-9059 VL - 10 IS - 8 ER - TY - JOUR A1 - Trivanovic, Drenka A1 - Volkmann, Noah A1 - Stoeckl, Magdalena A1 - Tertel, Tobias A1 - Rudert, Maximilian A1 - Giebel, Bernd A1 - Herrmann, Marietta T1 - Enhancement of immunosuppressive activity of mesenchymal stromal cells by platelet-derived factors is accompanied by apoptotic priming JF - Stem Cell Reviews and Reports N2 - The pro-inflammatory phase of bone healing, initiated by platelet activation and eventually hematoma formation, impacts bone marrow mesenchymal stromal cells (MSCs) in unknown ways. Here, we created platelet-rich plasma (PRP) hydrogels to study how platelet-derived factors modulate functional properties of encapsulated MSCs in comparison to a non-inflammatory fibrin (FBR) hydrogel environment. MSCs were isolated from human bone marrow, while PRP was collected from pooled apheresis thrombocyte concentrates and used for hydrogel preparation. After their encapsulation in hydrogels for 72 h, retrieved MSCs were analyzed for immunomodulatory activities, apoptosis, stem cell properties, senescence, CD9\(^+\), CD63\(^+\) and CD81\(^+\) extracellular vesicle (EV) release, and metabolism-related changes. PRP-hydrogels stimulated immunosuppressive functions of MSCs, along with their upregulated susceptibility to cell death in communication with PBMCs and augmented caspase 3/7 activity. We found impaired clonal growth and cell cycle progression, and more pronounced β-galactosidase activity as well as accumulation of LC3-II-positive vacuoles in PRP-MSCs. Stimuli derived from PRP-hydrogels upregulated AKT and reduced mTOR phosphorylation in MSCs, which suggests an initiation of survival-related processes. Our results showed that PRP-hydrogels might represent a metabolically stressful environment, inducing acidification of MSCs, reducing polarization of the mitochondrial membrane and increasing lipid accumulation. These features were not detected in FBR-MSCs, which showed reduced CD63\(^+\) and CD81\(^+\) EV production and maintained clonogenicity. Our data revealed that PRP-derived hematoma components cause metabolic adaptation of MSCs followed by increased immune regulatory functions. For the first time, we showed that PRP stimuli represent a survival challenge and “apoptotic priming” that are detrimental for stem cell-like growth of MSCs and important for their therapeutic consideration. KW - hematoma KW - platelet-rich plasma KW - fibrin KW - mesenchymal stromal cells KW - immunomodulation KW - apoptosis KW - autophagy KW - senescence KW - extracellular vesicles KW - metabolism Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324669 VL - 19 IS - 3 ER -