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Regeneration of large bone defects is a major objective in trauma surgery. Bone marrow mononuclear cell (BMC)-supported bone healing was shown to be efficient after immobilization on a scaffold. We hypothesized that fibrous demineralized bone matrix (DBM) in various forms with BMCs is superior to granular DBM. A total of 65 male SD rats were assigned to five treatment groups: syngenic cancellous bone (SCB), fibrous demineralized bone matrix (f-DBM), fibrous demineralized bone matrix densely packed (f-DBM 120%), DBM granules (GDBM) and DBM granules 5% calcium phosphate (GDBM5%Ca2+). BMCs from donor rats were combined with different scaffolds and placed into 5 mm femoral bone defects. After 8 weeks, bone mineral density (BMD), biomechanical stability and histology were assessed. Similar biomechanical properties of f-DBM and SCB defects were observed. Similar bone and cartilage formation was found in all groups, but a significantly bigger residual defect size was found in GDBM. High bone healing scores were found in f-DBM (25) and SCB (25). The application of DBM in fiber form combined with the application of BMCs shows promising results comparable to the gold standard, syngenic cancellous bone. Denser packing of fibers or higher amount of calcium phosphate has no positive effect.
Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma), demineralized bone matrix (DBM), and bovine cancellous bone (BS) were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo.
Bei Knochendefekten kritischer Größe ist es notwendig, den Knochen bei der Heilung zu unterstützen. Der derzeitige Goldstandard bei der Behandlung von critical size defects ist die Entnahme von autologem Knochen aus dem Beckenkamm, dies ist jedoch mit Nachteilen wie Entnahmemorbidität und Limitierung der entnehmbaren Menge vergesellschaftet. Das Knochen tissue engineering, bei welchem regenerative Zellen mit einem Knochenersatzmaterial kombiniert werden, könnte eine vielversprechende Alternative sein. Stromale Knochenmarkzellen, die Osteoblasten differenzieren können, und endotheliale Vorläuferzellen, die die Vaskularisierung der Defektzone unterstützen, zeigten sich effektiv in tierexperimentellen Studien; jedoch müssen diese Zellen vor Verwendung über einen längeren Zeitraum in Kultur expandiert werden. Dies kann jedoch zu einer Akkumulation genetischer Schäden und möglicherweise zu einer Entartung der transplantierten Zellen führen. Bone marrow mononuclear cells (BMC) stellen eine interessante Alternative dar, sie können innerhalb weniger Stunden isoliert und dem Patienten zurückgegeben werden. Ziel dieser Arbeit war daher, die Adhäsion und funktionelle Aspekte von BMC auf drei verschiedenen Knochenersatzmaterialien zu analysieren.
Im ersten Versuchsteil wurde untersucht, ob es möglich ist, BMC auf einem β-Tricalciumphosphat (β-TCP)-Scaffold auszusäen, und ob eine Beschichtung des Scaffolds eine positive Auswirkung auf die BMC-Adhäsion und Aktivität hat. Hierbei wurde eine Beschichtung mit humanem Plasma (FFP) und Fibronektin gegen eine Kontrolle verglichen. Es konnte gezeigt werden, dass BMC auf unbeschichtetem β-TCP adhärieren und dass eine Vorbeschichtung des Scaffolds mit Fibronektin oder mit FFP zu keiner weiteren Verbesserung der initialen Adhäsion führt. FACS-Analysen zeigten, dass der Prozentsatz der auf dem Material adhärierenden Fraktionen regenerativer Zellen dem Prozentsatz der in der Kontrolle enthaltenen regenerativen Zellen entspricht. Überdies konnte eine endotheliale Differenzierung der ausgesäten BMC beobachtet werden. Die Anzahl adhärierender BMC war zum ersten Messpunkt an Tag zwei unabhängig von der Vorbeschichtung am höchsten. Interessanterweise war die Zahl der adhärierenden BMC auf unbeschichtetem Material signifikant gegenüber den beschichteten Materialien erhöht.
Basierend auf der Beobachtung, dass eine Vorbeschichtung der Trägersubstanz nicht zu einer Verbesserung der BMC-Adhäsion auf dem Gerüststoff führt, wurden im zweiten Versuchsteil unbeschichtete Gerüststoffe miteinander verglichen. Für diese Arbeit wurden drei aus verschiedenen Klassen der Knochenersatzmaterialien stammende Scaffolds gewählt. ChronOs® als Vertreter der β-TCPs, Cerabone®, eine verarbeitete bovine Knochenmatrix, und Demineralized Bone Matrix (DBM), ein sterilisiertes humanes Knochentransplantat. Die Untersuchungen ergaben signifikante Unterschiede in der Aussaateffizienz der Zellen auf den Materialien und der Zellaktivität im Verlauf über 21 Tage. DBM zeigte hier im Materialvergleich die besten Ergebnisse. In unserem Versuch zeigte sich die Menge der absorbierten Flüssigkeit im Verhältnis zur Materialmenge bei DBM signifikant erhöht gegenüber den beiden anderen Materialien. Zudem konnte mittels HE- und Kern-Färbung (DAPI) der Nachweis erbracht werden, dass sich Zellen tief im Inneren des Materials anlagern. MTT-Tests zeigten an Tag 14 eine signifikant erhöhte metabolische Aktivität auf DBM gegenüber Cerabone® und an Tag 21 gegenüber beiden Vergleichsmatrices. Wir konnten auf allen Materialien an Tag 2 eine signifikant erhöhte VEGF-Produktion feststellen. Mittels Real-Time-PCR ließ sich eine VEGF-Genexpression in BMC auf allen Materialien bis Tag 14 und auf DBM über die kompletten 21 Tage nachweisen. Die Genexpression von vWF konnte ebenfalls auf allen Materialien über den gesamten Zeitraum nachgewiesen werden.
Zusammengefasst konnte durch diese Studie belegt werden, dass die initiale Adhärenz von BMC auf unbeschichtete Knochenersatzmaterialien generell hoch ist, aber signifikante materialspezifische Unterschiede in der Aussaateffizienz und nachfolgend der metabolischen Aktivität und der VEGFSynthese der BMC existieren. Humanes Knochenersatzmaterial zeigte sich in unserer Studie als überlegen. Daher sollte die Art des Knochenersatzmaterials für den künftigen klinischen Einsatz von BMC Berücksichtigung finden.
Purpose: Every physician must be able to sufficiently master medical emergencies, especially in medical areas where emergencies occur frequently such as in the emergency room or emergency surgery. This contrasts with the observation that medical students and young residents often feel insufficiently prepared to handle medical emergencies. It is therefore necessary to train them in the treatment of emergency patients. The aim of this study is to analyze the influence of the assignment of manikin versus simulated patients during a training for undergraduate medical students on learning outcomes and the perceived realism.
Methods: The study had a prospective cross-over design and took place in a 3-day emergency medicine training for undergraduate medical students. Students completed three teaching units (‘chest pain’, ‘impaired consciousness’, ‘dyspnea’), either with manikin or simulated patient. Using a questionnaire after each unit, overall impression, didactics, content, the quality of practical exercises, and the learning success were evaluated. The gained competences were measured in a 6-station objective structured clinical examination (OSCE) at the end of training.
Results: 126 students participated. Students rated simulated patients as significantly more realistic than manikins regarding the possibility to carry out examination techniques and taking medical history. 54.92% of the students would prefer to train with simulated patients in the future. Regarding the gained competences for ‘chest pain’ and ‘impaired consciousness’, students who trained with a manikin scored less in the OSCE station than the simulated patients-group.
Conclusion: Simulated patients are rated more realistic than manikins and seem to be superior to manikins regarding gained competence.
Hintergrund: Aufgrund des Nachwuchsmangels muss die Chirurgie vermehrt für die Weiterbildung zum Chirurgen begeistern. Studierende bemängeln, dass ihr Unterricht nachrangig zur Patientenversorgung und durch die Faktoren Zeit und ärztliches Personal limitiert ist. Obwohl es viele Arbeiten mit Fokus auf die Studierenden gibt, fehlen Arbeiten mit dem Fokus auf die Sicht der Lehrenden. Ziel der Arbeit: Die Lehre im Fach Chirurgie im Stationsalltag und Ursachen von Problemen hierbei sollen aus Sicht der Lehrenden analysiert werden. Material und Methoden: Im Rahmen der prospektiven Studie wurde ein Leitfaden für semistrukturierte Interviews mit ausformulierten, offenen Fragen erstellt, die mit weiteren Spezifizierungsfragen versehen wurden. Alle Interviews wurden anhand des Leitfadens geführt und aufgezeichnet. Die Anzahl der Interviews ergab sich aus dem Prinzip der inhaltlichen Sättigung. Ergebnisse: Alle der 22 befragten Ärzte messen der Lehre im klinischen Alltag einen hohen Stellenwert bei. Dennoch beschreiben sie, dass die Lernziele im klinischen Alltag nicht immer erreicht werden. Als Hauptgrund hierfür wird die mangelnde Zeit genannt. Mit zunehmender klinischer Erfahrung kommen jedoch weitere Faktoren hinzu: Ober- und Chefärzte beklagen die zu geringen Vorkenntnisse und die zu geringe Motivation einiger Studierender. Die meisten Befragten beschreiben, keine Anerkennung für ihre Lehre zu erhalten. Insgesamt wird die studentische Lehre als zusätzliche Belastung wahrgenommen, die aber alle Befragten für lohnenswert halten. Diskussion: Neben Personalmangel ist die fehlende Anerkennung das wichtigste Hemmnis für eine effektive Lehre. Es ist daher wichtig, die Wertigkeit der Lehre durch die Belohnung guter Lehrleistungen und Schaffung einer dahingehenden Transparenz zu erhöhen.
Purpose: Every physician must be able to sufficiently master medical emergencies, especially in medical areas where emergencies occur frequently such as in the emergency room or emergency surgery. This contrasts with the observation that medical students and young residents often feel insufficiently prepared to handle medical emergencies. It is therefore necessary to train them in the treatment of emergency patients. The aim of this study is to analyze the influence of the assignment of manikin versus simulated patients during a training for undergraduate medical students on learning outcomes and the perceived realism.
Methods: The study had a prospective cross-over design and took place in a 3-day emergency medicine training for undergraduate medical students. Students completed three teaching units (‘chest pain’, ‘impaired consciousness’, ‘dyspnea’), either with manikin or simulated patient. Using a questionnaire after each unit, overall impression, didactics, content, the quality of practical exercises, and the learning success were evaluated. The gained competences were measured in a 6-station objective structured clinical examination (OSCE) at the end of training.
Results: 126 students participated. Students rated simulated patients as significantly more realistic than manikins regarding the possibility to carry out examination techniques and taking medical history. 54.92% of the students would prefer to train with simulated patients in the future. Regarding the gained competences for ‘chest pain’ and ‘impaired consciousness’, students who trained with a manikin scored less in the OSCE station than the simulated patients-group.
Conclusion: Simulated patients are rated more realistic than manikins and seem to be superior to manikins regarding gained competence.
Background: Surgical complications are associated with a significant burden to patients and hospitals and are increasingly discussed in recent literature. This cohort study reviewed surgery-related complications in a Level I trauma center. The effect of a complication avoidance care bundle on the rate of surgical complications was analyzed. Methods: All complications (surgical and nonsurgical) that occur in our trauma department are prospectively captured using a standardized documentation form and are discussed and analyzed in a weekly trauma Morbidity and Mortality (M&M) conference. Surgical complication rates are calculated using the annual surgical procedure numbers. Based on discussions in the M&M conference, a complication avoidance care bundle consisting of five measures was established: (1) Improving team situational awareness; (2) reducing operating room traffic by staff members and limiting door-opening events; (3) preoperative screening for infectious foci; (4) adapted preoperative antibiotic prophylaxis in anatomic regions with a high risk of infectious complications; and (5) use of iodine-impregnated adhesive drape. Results: The number of surgical procedures steadily increased over the study years, from 3587 in 2015 to 3962 in 2019 (an increase of 10.5%). Within this 5-year study period, the overall rate of surgical complications was 0.8%. Surgical site infections were the most frequently found complications (n = 40, 24.8% of all surgical complications), followed by screw malposition (n = 20, 12.4%), postoperative dislocations of arthroplasties (n = 18, 11.2%), and suboptimal fracture reduction (n = 18, 11.2%). Following implementation of the complication avoidance care bundle, the overall rate of surgical complications significantly decreased, from 1.14% in the year 2016 to 0.56% in the study year 2019, which represents a reduction of 51% within a 3-year time period. Conclusions: A multimodal strategy targeted at reducing the surgical complication rate can be successfully established based on a transparent discussion of adverse surgical outcomes. The combination of the different preventive measures was associated with reducing the overall complication rate by half within a 3-year time period.
The rapid detection of pathogens in infected wounds can significantly improve the clinical outcome. Wound exudate, which can be collected in a non-invasive way, offers an attractive sample material for the detection of pathogens at the point-of-care (POC). Here, we report the development of a nucleic acid lateral flow immunoassay for direct detection of isothermally amplified DNA combined with fast sample preparation. The streamlined protocol was evaluated using human wound exudate spiked with the opportunistic pathogen Pseudomonas aeruginosa that cause severe health issues upon wound colonization. A detection limit of 2.1 × 105 CFU per mL of wound fluid was achieved, and no cross-reaction with other pathogens was observed. Furthermore, we integrated an internal amplification control that excludes false negative results and, in combination with the flow control, ensures the validity of the test result. The paper-based approach with only three simple hands-on steps has a turn-around time of less than 30 min and covers the complete analytical process chain from sample to answer. This newly developed workflow for wound fluid diagnostics has tremendous potential for reliable pathogen POC testing and subsequent target-oriented therapy.
Falls from a height are a common cause of polytrauma care in Level I Trauma Centers worldwide. The expected injury consequences depend on the height of the fall and the associated acceleration, as well as the condition of the ground. In addition, we further hypothesize a correlation between the cause of the fall, the age of the patient, and the patient’s outcome. A total of 178 trauma patients without age restriction who were treated in our hospital after a fall >3 m within a 5-year period were retrospectively analyzed. The primary objective was a clinically and radiologically quantifiable increase in the severity of injuries after falls from different relevant heights (>3 m, >6 m, and >9 m). The cause of the fall, either accidental or suicidal; age and duration of intensive care unit stay, including duration of ventilation; and total hospital stay were analyzed. Additionally, the frequency of urgent operations, such as, external fixation of fractures or hemi-craniectomies, laboratory parameters; and clinical outcomes were also among the secondary objectives. Sustaining a thoracic trauma or pelvis fractures increases significantly with height, and vital parameters are significantly compromised. We also found significant differences in urgent pre- and in-hospital emergency interventions, as well as organ complications and outcome parameters depending on the fall’s height.
Objectives: Reconstruction of long segmental bone defects is demanding for patients and surgeons, and associated with long-term treatment periods and substantial complication rates in addition to high costs. While defects up to 4–5 cm length might be filled up with autologous bone graft, heterologous bone from cadavers, or artificial bone graft substitutes, current options to reconstruct bone defects greater than 5 cm consist of either vascularized free bone transfers, the Masquelet technique or the Ilizarov distraction osteogenesis. Alternatively, autologous cell transplantation is an encouraging treatment option for large bone defects as it eliminates problems such as limited autologous bone availability, allogenic bone immunogenicity, and donor-site morbidity, and might be used for stabilizing loose alloplastic implants.
Methods: The authors show different cell therapies without expansion in culture, with ex vivo expansion and cell therapy in local bone defects, bone healing and osteonecrosis. Different kinds of cells and scaffolds investigated in our group as well as in vivo transfer studies and BMC used in clinical phase I and IIa clinical trials of our group are shown.
Results: Our research history demonstrated the great potential of various stem cell species to support bone defect healing. It was clearly shown that the combination of different cell types is superior to approaches using single cell types. We further demonstrate that it is feasible to translate preclinically developed protocols from in vitro to in vivo experiments and follow positive convincing results into a clinical setting to use autologous stem cells to support bone healing.
In Bone Tissue Engineering (BTE), autologous bone-regenerative cells are combined with a scaffold for large bone defect treatment (LBDT). Microporous, polylactic acid (PLA) scaffolds showed good healing results in small animals. However, transfer to large animal models is not easily achieved simply by upscaling the design. Increasing diffusion distances have a negative impact on cell survival and nutrition supply, leading to cell death and ultimately implant failure. Here, a novel scaffold architecture was designed to meet all requirements for an advanced bone substitute. Biofunctional, porous subunits in a load-bearing, compression-resistant frame structure characterize this approach. An open, macro- and microporous internal architecture (100 µm–2 mm pores) optimizes conditions for oxygen and nutrient supply to the implant’s inner areas by diffusion. A prototype was 3D-printed applying Fused Filament Fabrication using PLA. After incubation with Saos-2 (Sarcoma osteogenic) cells for 14 days, cell morphology, cell distribution, cell survival (fluorescence microscopy and LDH-based cytotoxicity assay), metabolic activity (MTT test), and osteogenic gene expression were determined. The adherent cells showed colonization properties, proliferation potential, and osteogenic differentiation. The innovative design, with its porous structure, is a promising matrix for cell settlement and proliferation. The modular design allows easy upscaling and offers a solution for LBDT.
Treatment of large bone defects is one of the great challenges in contemporary orthopedic and traumatic surgery. Grafts are necessary to support bone healing. A well-established allograft is demineralized bone matrix (DBM) prepared from donated human bone tissue. In this study, a fibrous demineralized bone matrix (f-DBM) with a high surface-to-volume ratio has been analyzed for toxicity and immunogenicity. f-DBM was transplanted to a 5-mm, plate-stabilized, femoral critical-size-bone-defect in Sprague-Dawley (SD)-rats. Healthy animals were used as controls. After two months histology, hematological analyses, immunogenicity as well as serum biochemistry were performed. Evaluation of free radical release and hematological and biochemical analyses showed no significant differences between the control group and recipients of f-DBM. Histologically, there was no evidence of damage to liver and kidney and good bone healing was observed in the f-DBM group. Reactivity against human HLA class I and class II antigens was detected with mostly low fluorescence values both in the serum of untreated and treated animals, reflecting rather a background reaction. Taken together, these results provide evidence for no systemic toxicity and the first proof of no basic immunogenic reaction to bone allograft and no sensitization of the recipient.
Objective: The aim of this study was to retrospectively review the midface and orbital floor fractures treated at our institution with regard to epidemiological aspects, surgical treatment options and postoperative complications and discuss this data with the current literature. Study design: One thousand five hundred and ninety-four patients with midface and orbital fractures treated at the Department of Oral, Cranio-Maxillofacial and Facial Plastic Surgery of the Goethe University Hospital in Frankfurt (Germany) between 2007 and 2017 were retrospectively reviewed. The patients were evaluated by age, gender, etiology, fracture pattern, defect size, surgical treatment and complications. Results: The average patient age was 46.2 (± 20.8). Most fractures (37.5%) occurred in the age between 16 and 35. Seventy-two percent of patients were male while 28% were female. The most common cause of injury was physical assault (32.0%) followed by falls (30.8%) and traffic accidents (17.0%). The average orbital wall defect size was 297.9 mm2 (± 190.8 mm2). For orbital floor reconstruction polydioxanone sheets (0.15 mm 38.3%, 0.25 mm 36.2%, 0.5 mm 2.8%) were mainly used, followed by titanium meshes (11.5%). Reconstructions with the 0.15 mm polydioxanone sheets showed the least complications (p < 0.01, r = 0.15). Eighteen percent of patients who showed persistent symptoms and post-operative complications: 12.9% suffered from persistent hypoesthesia, 4.4% suffered from post-operative diplopia and 3.9% showed intra-orbital hematoma. Conclusion: Results of the clinical outcome in our patients show that 0.15 mm resorbable polydioxanone sheets leads to significantly less post-operative complications for orbital floor defects even for defects beyond the recommended 200 mm2.
Background: The treatment of severely injured patients, especially in older age, is complex, and based on strict guidelines. Methods: We conducted a retrospective study by analyzing our internal registry for mortality risk factors in deceased trauma patients. All patients that were admitted to the trauma bay of our level-1-trauma center from 2014 to 2018, and that died during the in-hospital treatment, were included. The aim of this study was to carry out a quality assurance concerning the initial care of severely injured patients. Results: In the 5-year period, 135 trauma patients died. The median (IQR) age was 69 (38–83) years, 71% were male, and the median (IQR) Injury Severity Score (ISS) was 25 (17–34) points. Overall, 41% of the patients suffered from severe traumatic brain injuries (TBI) (AIShead ≥ 4 points). For 12.7%, therapy was finally limited owing to an existing patient’s decree; in 64.9% with an uncertain prognosis, a ‘therapia minima’ was established in consensus with the relatives. Conclusion: Although the mortality rate was primarily related to the severity of the injury, a significant number of deaths were not exclusively due to medical reasons, but also to a self-determined limitation of therapy for severely injured geriatric patients. The conscientious documentation concerning the will of the patient is increasingly important in supporting medical decisions.
Purpose: Fractures of the humerus account for 5%–8% of all fractures. Nonunion is found with an incidence of up to 15%, depending on the location of the fracture. In case of a manifest nonunion the surgeon faces a challenging problem and has to conceive a therapy based on the underlying pathology. The aim of this study was to describe our treatment concepts for this entity and present our results of the last five years.
Methods: Twenty-six patients were treated for nonunion of the humerus between January 2013 and December 2017. Their charts were reviewed retrospectively and demographic data, pathology, surgical treatment and outcome were assessed.
Results: The most frequent location for a nonunion was the humeral shaft, with the most common trauma mechanism being multiple falls. Most often atrophic nonunion (n = 14), followed by hypertrophic and infection-caused nonunion (each n = 4), were found. Our treatment concept could be applied in 19 patients, of which in 90% of those who were available for follow-up consolidation could be achieved.
Conclusion: Humeral nonunion is a heterogeneous entity that has to be analyzed precisely and be treated correspondingly. We therefore present a treatment concept based on the underlying pathology.
The detection of multiple biomolecule classes in one go is highly desirable for a wide variety of areas, and in particular for point-of-care diagnostics. For example, wound infections are a major problem for patient’s health and cause huge efforts in our healthcare system. In this regard, monitoring infected wounds through simultaneous detection of pathogens via nucleic acid analysis and detection of local inflammation biomarkers is key in order to enable a personalized therapy, improve the clinical outcome and thus, leading to a reduction of overall healthcare costs. In this regard, wound exudate offers an attractive sample material which can be collected in a non-invasive manner. Here, we report the development of a Multianalyte-Assay detecting inflammation biomarkers and pathogen DNA simultaneously from one sample within 35 min. Protein-compatible amplification and labeling transforms nucleic acid information into the measurement principle for protein detection. The combination with rapid detection via lateral flow immunoassay enables a fast and straightforward analysis of multiple biomolecule classes using identical assay conditions. To demonstrate the feasibility of the Multianalyte-Assay, the proinflammatory cytokine interleukin-6 (IL-6) and gDNA of the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa) are used. The detection limits of 4 ng/mL IL-6 and 70 copies/reaction P. aeruginosa gDNA meet the clinically relevant range and thus, having tremendous potential to improve the wound management at the point-of-care.
Introduction: The induced membrane technique for the treatment of large bone defects is a two-step procedure. In the first operation, a foreign body membrane is induced around a spacer, then, in the second step, several weeks or months later, the spacer is removed and the Membrane pocket is filled with autologous bone material. Induction of a functional biological membrane might be avoided by initially using a biological membrane. In this study, the effect of a human acellular dermis (hADM, Epiflex, DIZG gGmbH) was evaluated for the treatment of a large (5 mm), plate-stabilised femoral bone defect.
Material and Methods: In an established rat model, hADM was compared to the two-stage induced membrane technique and a bone defect without membrane cover. Syngeneous spongiosa from donor animals was used for defect filling in all groups. The group size in each case was n = 5, the induction time of the membrane was 3–4 weeks and the healing time after filling of the defect was 8 weeks.
Results: The ultimate loads were increased to levels comparable with native bone in both membrane groups (hADM: 63.2% ± 29.6% of the reference bone, p < 0.05 vs. no membrane, induced membrane: 52.1% ± 25.8% of the reference bone, p < 0.05 vs. no membrane) and were significantly higher than the control group without membrane (21.5%). The membrane groups were radiologically and histologically almost completely bridged by new bone formation, in contrast to the control Group where no closed osseous bridging could be observed.
Conclusion: The use of the human acellular dermis leads to equivalent healing results in comparison to the two-stage induced membrane technique. This could lead to a shortened therapy duration of large bone defects.
Determination of the effective dose of bone marrow mononuclear cell therapy for bone healing in vivo
(2020)
Introduction: Cell-based therapy by bone marrow mononuclear cells (BMC) in a large-sized bone defect has already shown improved vascularization and new bone formation. First clinical trials are already being conducted. BMC were isolated from bone marrow aspirate and given back to patients in combination with a scaffold within some hours. However, the optimal concentration of BMC has not yet been determined for bone healing. With this study, we want to determine the optimal dosage of the BMC in the bone defect to support bone healing.
Material and methods: Scaffolds with increasing BMC concentrations were inserted into a 5 mm femoral defect, cell concentrations of 2 × 106 BMC/mL, 1 × 107 BMC/mL and 2 × 107 BMC/mL were used. Based on the initial cell number used to colonize the scaffolds, the groups are designated 1 × 106, 5 × 106 and 1 × 107 group. Bone healing was assessed biomechanically, radiologically (µCT), and histologically after 8 weeks healing time.
Results: Improved bone healing parameters were noted in the 1 × 106 and 5 × 106 BMC groups. A significantly higher BMD was observed in the 1 × 106 BMC group compared to the other groups. Histologically, a significantly increased bone growth in the defect area was observed in group 5 × 106 BMC. This finding could be supported radiologically.
Conclusion: It was shown that the effective dose of BMC for bone defect healing ranges from 2 × 106 BMC/mL to 1 × 107 BMC/mL. This concentration range seems to be the therapeutic window for BMC-supported therapy of large bone defects. However, further studies are necessary to clarify the exact BMC-dose dependent mechanisms of bone defect healing and to determine the therapeutically effective range more precisely.
Introduction: The aim of this article is to show a new concept of indication and application of the MUTARS® RS Cup System in primary and revision hip arthroplasty. This integrated system is applicable for different acetabular cup replacements in patients with acetabular fractures or instable defects, as well as periprosthetic acetabular fractures. The MUTARS® RS Cup System is a cementless revision cup for insertion into the acetabulum with an integrated polyethylene cup, which fits to a regular or bipolar head. This system replaces the conventional approach for acetabular revision with a Burch-Schneider ring, in which a normal polyethylene cup is cemented. This interface with its complications is avoided with this system of a titanium revision cup with integrated polyethylene cup. Steps of preoperative planning and the intraoperative implementation will be highlighted in this article.
Material and methods: This system was applied in 49 patients with 52 MUTARS® RS Cup Implantations in 30 males, 22 females, with an average age of 76,1 years (36,9–94,4 years).
Results and discussion: The system shows a good operative feasibility, as well as a reliable handling and safe method for stable treatment of non-reconstructable acetabular fractures or acetabular incongruencies and instabilities.