Auswirkungen hypobarer Hypoxie auf die Reaktionsfähigkeit im Alter

Einen großen Teil der Alpintouristen stellt heute die Gruppe der über 60-jährigen. Deshalb untersucht diese Arbeit erstmals standardisiert psychomotorische Beeinträchtigungen älterer Personen im Zusammenhang mit physiologischen Anpassungsreaktionen an die Höhe. Ziel ist es, durch ein besseres Verständnis des Unfallgeschehens die Primärprävention im Alpinsport zu optimieren. Methoden: Die 22 Probanden bildeten je eine Interventionsgruppe (IG) (sechs männlich, sechs weiblich, mittleres Alter: 64 Jahre) und eine Kontrollgruppe (KG) (fünf männlich, fünf weiblich, mittleres Alter: 64,4 Jahre). Beide Gruppen führten an zwei Untersuchungstagen je zwei computergesteuerte Wahlreaktionstests (Determinationstest, Typ: S1, Dauer: vier Minuten) mit dem Wiener Testsystem durch. Die IG absolvierte den ersten Untersuchungstag in 3100 m ü. NN und zwei Wochen später den zweiten Untersuchungstag auf 57 m ü. NN, die KG durchlief beide Untersuchungstage jeweils auf 57 m ü. NN. Der erste Test eines Tages wurde von beiden Gruppen in Ruhe durchgeführt. Vor dem direkt folgenden zweiten Test wurde die IG durch einen einminütigen Stepp-Test belastet. Die KG absolvierte beide Tests nacheinander mit 1 ½ Minuten Pause. Vor und nach jedem Test wurden zusätzlich die physiologischen Messwerte Herzfrequenz (HF) und arterielle Sauerstoffsättigung (SaO2) bestimmt. Ergebnisse: Auf 3100 m ü. NN lag in der IG die HF in Ruhe bei 85 Schlägen pro Minute und damit zehn Schläge pro Minute höher als auf 57 m ü. NN (paO2 in Ruhe fiel von 97,7 % auf 90 % in 3100 m ü. NN (paO2. Die besonders relevante Testvariable „falsche Reaktionen“ ergab, dass die IG am ersten Untersuchungstag (3100 m ü. NN) deutlich mehr „falsche Reaktionen“ (p0,05). Diskussion: Die sehr signifikant häufigeren „falschen Reaktionen“ der IG auf 3100 m ü. NN zeigen auf, dass die im Alter bereits reduzierten zentralnervösen Verarbeitungsprozesse unter Hypoxie noch langsamer ablaufen und es konsekutiv zu einer Handlungsüberforderung kommt. Somit kann gefolgert werden, dass sich eine hypobare Hypoxie negativ auf die komplexe Wahlreaktionsfähigkeit speziell von Älteren auswirkt. Daher sollte zur Risikominimierung im Bereich des Alpinsports mit Älteren auf geeignetes Gelände und Material, eine vorsichtige Höhenanpassung sowie eine moderate körperliche Beanspruchung geachtet werden

Growth factor release by vesicular phospholipid gels: in-vitro results and application for rotator cuff repair in a rat model

Background: Biological augmentation of rotator cuff repair is of growing interest to improve biomechanical properties and prevent re-tearing. But intraoperative single shot growth factor application appears not sufficient to provide healing support in the physiologic growth factor expression peaks. The purpose of this study was to establish a sustained release of granulocyte-colony stimulating factor (G-CSF) from injectable vesicular phospholipid gels (VPGs) in vitro and to examine biocompatibility and influence on histology and biomechanical behavior of G-CSF loaded VPGs in a chronic supraspinatus tear rat model. Methods: G-CSF loaded VPGs were produced by dual asymmetric centrifugation. In vitro the integrity, stability and release rate were analyzed. In vivo supraspinatus tendons of 60 rats were detached and after 3 weeks a transosseous refixation with G-CSF loaded VPGs augmentation (n = 15;control, placebo, 1 and 10 mu g G-CSF/d) was performed. 6 weeks postoperatively the healing site was analyzed histologically (n = 9;H&E by modified MOVIN score/Collagen I/III) and biomechanically (n = 6). Results: In vitro testing revealed stable proteins after centrifugation and a continuous G-CSF release of up to 4 weeks. Placebo VPGs showed histologically no negative side effects on the healing process. Histologically in vivo testing demonstrated significant advantages for G-CSF 1 mu g/d but not for G-CSF 10 mu g/d in Collagen III content (p = 0.035) and a higher Collagen I/III ratio compared to the other groups. Biomechanically G-CSF 1 mu g/d revealed a significant higher load to failure ratio (p = 0.020) compared to control but no significant differences in stiffness. Conclusions: By use of VPGs a continuous growth factor release could be obtained in vitro. The in vivo results demonstrate an improvement of immunohistology and biomechanical properties with a low dose G-CSF application via VPG. The VPG itself was well tolerated and had no negative influence on the healing behavior. Due to the favorable properties (highly adhesive, injectable, biocompatible) VPGs are a very interesting option for biologic augmentation. The study may serve as basis for further research in growth factor application models

Growth factor release by vesicular phospholipid gels: in-vitro results and application for rotator cuff repair in a rat model

Background: Biological augmentation of rotator cuff repair is of growing interest to improve biomechanical properties and prevent re-tearing. But intraoperative single shot growth factor application appears not sufficient to provide healing support in the physiologic growth factor expression peaks. The purpose of this study was to establish a sustained release of granulocyte-colony stimulating factor (G-CSF) from injectable vesicular phospholipid gels (VPGs) in vitro and to examine biocompatibility and influence on histology and biomechanical behavior of G-CSF loaded VPGs in a chronic supraspinatus tear rat model. Methods: G-CSF loaded VPGs were produced by dual asymmetric centrifugation. In vitro the integrity, stability and release rate were analyzed. In vivo supraspinatus tendons of 60 rats were detached and after 3 weeks a transosseous refixation with G-CSF loaded VPGs augmentation (n = 15;control, placebo, 1 and 10 mu g G-CSF/d) was performed. 6 weeks postoperatively the healing site was analyzed histologically (n = 9;H&E by modified MOVIN score/Collagen I/III) and biomechanically (n = 6). Results: In vitro testing revealed stable proteins after centrifugation and a continuous G-CSF release of up to 4 weeks. Placebo VPGs showed histologically no negative side effects on the healing process. Histologically in vivo testing demonstrated significant advantages for G-CSF 1 mu g/d but not for G-CSF 10 mu g/d in Collagen III content (p = 0.035) and a higher Collagen I/III ratio compared to the other groups. Biomechanically G-CSF 1 mu g/d revealed a significant higher load to failure ratio (p = 0.020) compared to control but no significant differences in stiffness. Conclusions: By use of VPGs a continuous growth factor release could be obtained in vitro. The in vivo results demonstrate an improvement of immunohistology and biomechanical properties with a low dose G-CSF application via VPG. The VPG itself was well tolerated and had no negative influence on the healing behavior. Due to the favorable properties (highly adhesive, injectable, biocompatible) VPGs are a very interesting option for biologic augmentation. The study may serve as basis for further research in growth factor application models

Significant Improvement in Shoulder Function and Pain in Patients Following Biologic Augmentation of Revision Arthroscopic Rotator Cuff Repair Using an Autologous Fibrin Scaffold and Bone Marrow Aspirate Derived From the Proximal Humerus

Purpose To clinically evaluate patients who underwent a biologic augmentation technique in revision arthroscopic rotator cuff repair using an autologous fibrin scaffold and concentrated stem cells isolated from bone marrow aspirate (BMA) obtained from the proximal humerus. Methods This is a retrospective review of prospectively collected data from patients who underwent biologic augmentation of revision arthroscopic rotator cuff repair using an autologous fibrin scaffold and BMA obtained from the proximal humerus between 2014 and 2015. Minimum follow-up was 12 months. Outcome measures were collected preoperatively and postoperatively including range of motion as well as American Shoulder and Elbow Surgeons Shoulder Form, Simple Shoulder Test, single assessment numeric evaluation, and visual analog score. In addition, BMA samples of each patient were assessed for the number of nucleated cells and colony-forming units. Regression analysis was performed to investigate whether the number of nucleated cells and colony-forming units had an influence on outcome and failure. Results Ten patients who underwent biologic augmentation of revision arthroscopic rotator cuff repair using an autologous fibrin scaffold and concentrated BMA obtained from the proximal humerus between 2014 and 2015 were included. The mean follow-up time was 30.7 (range: 12-49) months. Four patients were revised at final follow-up. Postoperative clinical scores improved significantly: American Shoulder and Elbow Surgeons (28.1 ± 5.4 to 60.9 ± 9.0; P < .01), single assessment numeric evaluation (6.6 ± 2.3 to 65.1 ± 10.9; P < .01), visual analog scale (7.2 ± 0.9 to 3.1 ± 0.9; P < .01), and Simple Shoulder Test (1.6 ± 0.5 to 10.3 ± 5.7; P < .01). Postoperative range of motion increased significantly with regard to flexion (97.0 ± 13.6 to 151.0 ± 12.2; P < .01) and abduction (88.0 ± 14.0 to 134.0 ± 15.1; P = .038) but not with external rotation (38.0 ± 5.7 to 50.5 ± 6.5; P = .16). Less pain was correlated to an increased number of nucleated cells (P = .026); however, there was no correlation between failure rate and number of nucleated cells (P = .430). Conclusions Patients who underwent biologic augmentation of revision arthroscopic rotator cuff repair using an autologous fibrin scaffold and concentrated BMA demonstrated a significant improvement in shoulder function along with reduction of pain. However, the overall revision rate for this procedure was 40%. Level of Evidence Level IV, therapeutic case series

Indirekte Zuggurtungsosteosynthese bei isolierter Tuberculum-majus-Fraktur

&lt;jats:title&gt;Zusammenfassung&lt;/jats:title&gt;&lt;jats:p&gt;Tuberculum-majus-Frakturen machen etwa 20 % der proximalen Humerusfrakturen aus und sind häufige Begleitverletzungen bei glenohumeralen Luxationen. Während isolierte, nichtdislozierte Frakturen konservativ behandelt werden können, sind dislozierte Frakturen durch ihre Auswirkung auf die Biomechanik des Schultergelenks, insbesondere aufgrund der Beeinträchtigung der Rotatorenmanschette, als Indikation zur operativen Versorgung anzusehen. Während die meisten operativen Ansätze eine direkte Zuggurtungs- oder Plattenosteosynthese der Fraktur fokussieren, ist in manchen Fällen auch eine indirekte Zuggurtungsosteosynthese mittels Knochenankerfixationstechnik möglich. Dieser Artikel soll einen solchen Fall beschreiben sowie die Vor- und Nachteile der indirekten Zuggurtung gegenüber anderen Versorgungstechniken diskutieren.&lt;/jats:p&gt

Learning about PRP using cell-based models

Studies using in vitro cell models enable evaluation of the effects of different PRP products under very controlled and standardized conditions. Therefore the results of such studies build the basis for understanding the variable results of clinical studies on the use of PRPs. The main lessons learned through the use of in vitro cell models are that many different PRP products exist and researchers have to report on component variation within each product. These different products may have distinctive effects on the various cells treated in musculoskeletal injuries; therefore, some products might be more beneficial in certain indication than others. In its utilization in cell models, PRP may generate a variety of positive effects on cell proliferation, recovery, and inflammatory response. There might also be a benefit to adding PRP to current pharmacological therapies (e.g. corticosteroids) to prevent their commonly known negative effects on e.g. tendon and cartilage tissu

Arthroscopically Assisted Treatment of Acute Dislocations of the Acromioclavicular Joint

Arthroscopically assisted treatments for dislocations of the acromioclavicular joint combine the advantages of exact and visually controlled coracoid tunnel placement with the possibility of simultaneous treatment of concomitant injuries. The clinical results of previous arthroscopically assisted techniques have been favorable at midterm and long-term follow-up. The presented surgical technique combines the advantages of arthroscopically positioned coracoclavicular stabilization with an additional suture cord cerclage of the acromioclavicular joint capsule for improved horizontal stability

Rotational range of motion of elliptical and spherical heads in shoulder arthroplasty: a dynamic biomechanical evaluation

INTRODUCTION: Elliptical shape humeral head prostheses have been proposed to reflect a more anatomic shoulder replacement. Its effect on the rotational range of motion (ROM) compared to a standard spherical head is still not understood. The purpose was to investigate if there would be a difference in rotational ROM when comparing elliptical and spherical prosthetic heads in a dynamic shoulder model. The authors hypothesized that the use of elliptical heads would result in significantly more rotational ROM compared to the spherical head design. MATERIALS AND METHODS: Six fresh-frozen, cadaveric shoulders were evaluated using a dynamic shoulder model. After being tested in the native condition, each specimen underwent 6 conditions in the hemiarthroplasty state: (1) matched-fit spherical head, (2) oversized spherical head, (3) undersized spherical head, (4) matched-fit elliptical head, (5) oversized elliptical head, and (6) undersized elliptical head. Following conversion to total shoulder arthroplasty (TSA), the 6 prior conditions were rerun. Each condition was tested at 0°, 30° and 60° of glenohumeral abduction. Rotational ROM was quantified using 3-dimensional tracking, while dynamically applying alternating forces for internal and external rotation via the rotator cuff tendons. RESULTS: Elliptical and spherical prosthetic heads showed no significant difference in the degree of the total, internal, and external rotational ROM for both the hemiarthroplasty and TSA state. Conversion from hemiarthroplasty to TSA resulted in less degree of total rotational ROM for both head designs in all abduction positions, without reaching statistical significance. There was a significant decrease in total, internal, and external rotational ROM for both elliptical and spherical heads in every replacement condition, when comparing 0° to 30° and 60° of abduction (P < 0.05, respectively). CONCLUSION: In a dynamic shoulder model, elliptical and spherical prosthetic head designs showed no significant difference in the degree of the total, internal, and external rotational ROM in both the hemiarthroplasty and TSA state. LEVEL OF EVIDENCE: Controlled laboratory study ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00402-020-03587-0) contains supplementary material, which is available to authorized users