Alexander Olk

Evaluation of Cartilage Repair Tissue After Matrix-Associated Autologous Chondrocyte Transplantation Using a Hyaluronic-Based or a Collagen-Based Scaffold With Morphological MOCART Scoring and Biochemical T2 Mapping Preliminary Results

Background In cartilage repair, bioregenerative approaches using tissue engineering techniques have tried to achieve a close resemblance to hyaline cartilage, which might be visualized using advanced magnetic resonance imaging. Purpose To compare cartilage repair tissue at the femoral condyle noninvasively after matrix-associated autologous chondrocyte transplantation using Hyalograft C, a hyaluronic-based scaffold, to cartilage repair tissue after transplantation using CaReS, a collagen-based scaffold, with magnetic resonance imaging using morphologic scoring and T2 mapping. Study Design Cohort study; Level of evidence, 3. Methods Twenty patients after matrix-associated autologous chondrocyte transplantation (Hyalograft C, n = 10; CaReS, n = 10) underwent 3-T magnetic resonance imaging 24 months after surgery. Groups were matched by age and defect size/localization. For clinical outcome, the Brittberg score was assessed. Morphologic analysis was applied using the magnetic resonance observation of cartilage repair tissue score, and global and zonal biochemical T2 mapping was performed to reflect biomechanical properties with regard to collagen matrix/content and hydration. Results The clinical outcome was comparable in each group. The magnetic resonance observation of cartilage repair tissue score showed slightly but not significantly (P = .210) better results in the CaReS group (76.5) compared to the Hyalograft C group (70.0), with significantly better (P = .004) constitution of the surface of the repair tissue in the CaReS group. Global T2 relaxation times (milliseconds) for healthy surrounding cartilage were comparable in both groups (Hyalograft C, 49.9; CaReS, 51.9; P = .398), whereas cartilage repair tissue showed significantly higher results in the CaReS group (Hyalograft C, 48.2; CaReS, 55.5; P = .011). Zonal evaluation showed no significant differences (P ≥ .05). Conclusion Most morphologic parameters provided comparable results for both repair tissues. However, differences in the surface and higher T2 values for the cartilage repair tissue that was based on a collagen scaffold (CaReS), compared to the hyaluronic-based scaffold, indicated differences in the composition of the repair tissue even 2 years postimplantation. Clinical Relevance In the follow-up of cartilage repair procedures using matrix-associated autologous chondrocyte transplantation, differences due to scaffolds have to be taken into account.

Paracrine effect of transplanted rib chondrocyte spheroids supports formation of secondary cartilage repair tissue

The studys objective was to investigate if transplanted chondrocyte or periosteal cell spheroids have influence on ingrowing bone marrow‐derived cells in a novel cartilage repair approach in miniature pigs. Autologous rib chondrocytes or periosteal cells were cultured as spheroids and press‐fitted into cavities that were milled into large, superficial chondral lesions of the patellar joint surface. Within the milled cavities, the subchondral bone plate was either penetrated or left intact (full‐thickness or partial‐thickness cavities). The transplantation of chondrocyte spheroids into full‐thickness cavities induced the formation of additional secondary repair cartilage that exceeded the original volume of the transplanted spheroids. The resulting continuous tissue was rich in proteoglycans and stained positive for type II collagen. Cell labeling revealed that secondarily invading repair cells did not originate from transplanted spheroids, but rather from arroded bone marrow. However, secondary invasion of repair cells was less pronounced following transplantation of periosteal cells and absent in partial‐thickness cavities. According to in vitro analyses, these observations could be ascribed to the ability of chondrocyte spheroids to secrete relevant amounts of bone morphogenetic protein‐2, which was not detected for periosteal cells. Transplanted chondrocyte spheroids exert a dual function: they provide cells for the repair tissue and have a stimulatory paracrine activity, which promotes ingrowth and chondrogenesis of bone marrow‐derived cells.

[The vacuum-assisted closure (V.A.C.) and instillation dressing: limb salvage after 3 degrees open fracture with massive bone and soft tissue defect and superinfection].

We report the case of a 17-year-old boy who was hit by a high velocity train. The polytraumatized patient suffered a 3 degrees open femur defect fracture with a substantial loss of the lateral femoral muscles and significant disruption of the soft tissue of the lower leg. The enormous wound areas on the thigh and the lower leg were infected by Pseudomonas aeruginosa, Enterobacter cloacae, and Stenotrophomonas maltophilia. The enormous tissue defects and the superinfection did not leave any hope for saving the limb from amputation. After rapid aggressive debridement and pulsatile lavage, we covered the wounds as a last resort with a new technique of vacuum-assisted closure (V.A.C) and instillation (V.A.C. Instill(R)) dressings. In sequences of 1 min we instilled Lavasept, kept it for 20 min on the wound surface, and exhausted the liquid. We repeated this for 6 consecutive days and then changed the dressing. In the follow-up examinations the number of germs was significantly reduced. During follow-up care we used the V.A.C. treatment without instillation and finally we transplanted skin onto the clean wound surface and were able to save the leg of this young patient. We discharged him with a good function of his lower leg. This technique of V.A.C. Instill seems to offer great possibilities in critically infected wound situations.

Der „Vacuum-assisted closure and instillation-“ (VAC™-Instill-)Verband

We report the case of a 17-year-old boy who was hit by a high velocity train. The polytraumatized patient suffered a 3 degrees open femur defect fracture with a substantial loss of the lateral femoral muscles and significant disruption of the soft tissue of the lower leg. The enormous wound areas on the thigh and the lower leg were infected by Pseudomonas aeruginosa, Enterobacter cloacae, and Stenotrophomonas maltophilia. The enormous tissue defects and the superinfection did not leave any hope for saving the limb from amputation. After rapid aggressive debridement and pulsatile lavage, we covered the wounds as a last resort with a new technique of vacuum-assisted closure (V.A.C) and instillation (V.A.C. Instill(R)) dressings. In sequences of 1 min we instilled Lavasept, kept it for 20 min on the wound surface, and exhausted the liquid. We repeated this for 6 consecutive days and then changed the dressing. In the follow-up examinations the number of germs was significantly reduced. During follow-up care we used the V.A.C. treatment without instillation and finally we transplanted skin onto the clean wound surface and were able to save the leg of this young patient. We discharged him with a good function of his lower leg. This technique of V.A.C. Instill seems to offer great possibilities in critically infected wound situations.

Das generalisierte Kompartmentsyndrom nach exzessivem Trinken: Seltene Komplikation psychischer Erkrankungen?

ZusammenfassungDas Kompartmentsyndrom in Folge sturzförmigen Trinkens großer Mengen hypotoner Flüssigkeit, ist eine bei psychiatrischen Erkrankungen in der Häufigkeit unterschätzte Komplikation. Wird das Erkrankungsbild vom klinisch führenden Hirnödem überlagert, besteht die Gefahr, synchron auftretende Kompartmentsyndrome an den Extremitäten nicht oder verspätet zu diagnostizieren. Anhand einer Literaturstudie und Fallbeschreibung werden mögliche weitere Einflüsse dargestellt und die spezifische Diagnostik und Therapie beschrieben.SummaryPsychogenic polydipsia can lead to compartment syndromes, which is too infrequently considered in psychiatric patients who binge-drink on hypotonic fluids. If masked by the leading clinical presentation of cerebral edema, compartment syndromes of the extremities may be diagnosed too late or remain undetected. Based on a literature review and case report, we discuss additional factors and the specific features of diagnosis and treatment.

Das generalisierte Kompartmentsyndrom nach exzessivem Trinken

ZusammenfassungDas Kompartmentsyndrom in Folge sturzförmigen Trinkens großer Mengen hypotoner Flüssigkeit, ist eine bei psychiatrischen Erkrankungen in der Häufigkeit unterschätzte Komplikation. Wird das Erkrankungsbild vom klinisch führenden Hirnödem überlagert, besteht die Gefahr, synchron auftretende Kompartmentsyndrome an den Extremitäten nicht oder verspätet zu diagnostizieren. Anhand einer Literaturstudie und Fallbeschreibung werden mögliche weitere Einflüsse dargestellt und die spezifische Diagnostik und Therapie beschrieben.SummaryPsychogenic polydipsia can lead to compartment syndromes, which is too infrequently considered in psychiatric patients who binge-drink on hypotonic fluids. If masked by the leading clinical presentation of cerebral edema, compartment syndromes of the extremities may be diagnosed too late or remain undetected. Based on a literature review and case report, we discuss additional factors and the specific features of diagnosis and treatment.

Stand und Perspektiven der Robotronik in der Unfall- und Wiederherstellungschirurgie

ZusammenfassungRobotik und Elektronik bestimmen die Arbeitsabläufe unseres heutigen Lebens. Es stellt sich sowohl für unsere Patienten, die überwiegend in diesen Arbeitsabläufen tätig sind, als auch im besonderen Maß für die Mediziner die Frage, inwieweit diese hoch spezialisierten Technologien zum Nutzen des Patienten eingesetzt werden können. Die Entscheidung hierüber darf weder von der Angst des Operateurs durch Maschinen in Frage gestellt noch durch ein nostalgisches Festhalten am vermeintlich hochwertigen Ideal handwerklicher Arbeit bestimmt werden. Ganz sicher sollten Marketing und Werbeaspekte bei dieser Entscheidung keinen Platz finden. Unabdingbare Forderungen, die bei der Einführung neuer Technologien immer gestellt werden müssen, sind, ob der bisherig erreichte Goldstandard gewährleistet ist, ob sich die Methode sinnvoll in bewährten Praktiken integriert und ob die ¶wissenschaftlich fundierten Kenntnisse weiterentwickelt und nicht umgestoßen werden.AbstractThe sequences of operations in our daily life are determined by robotics and electronics. We are now confronted with the questions of how these modern and useful technologies can be used to improve the medical care of our patients and, in particular, how we can use robotics to get a better outcome. There is no room for fear of the new machines; nor is it justifiable to hold on to the old ideals of traditional craftsmanship from fear of new processes that are accomplished robotically. Marketing and publicity should most certainly not affect decisions on buying and developing new high-tech equipment. Absolute requirements that should always be demanded of all technologies before they are introduced into research work are that they are equal to the current „gold standard“ in the results they yield and that they can be conveniently integrated into daily clinical practice.

Der „Vacuum-assisted closure and instillation-“ (VAC™-Instill-)Verband@@@The vacuum-assisted closure (V.A.C.) and instillation dressing: Extremitätenerhalt bei drittgradig offener superinfizierter Femurfraktur mit massivem Knochen- und Weichteildefekt@@@Limb salvage after 3° open fracture with massive bone and soft tissue defect and superinfection

We report the case of a 17-year-old boy who was hit by a high velocity train. The polytraumatized patient suffered a 3 degrees open femur defect fracture with a substantial loss of the lateral femoral muscles and significant disruption of the soft tissue of the lower leg. The enormous wound areas on the thigh and the lower leg were infected by Pseudomonas aeruginosa, Enterobacter cloacae, and Stenotrophomonas maltophilia. The enormous tissue defects and the superinfection did not leave any hope for saving the limb from amputation. After rapid aggressive debridement and pulsatile lavage, we covered the wounds as a last resort with a new technique of vacuum-assisted closure (V.A.C) and instillation (V.A.C. Instill(R)) dressings. In sequences of 1 min we instilled Lavasept, kept it for 20 min on the wound surface, and exhausted the liquid. We repeated this for 6 consecutive days and then changed the dressing. In the follow-up examinations the number of germs was significantly reduced. During follow-up care we used the V.A.C. treatment without instillation and finally we transplanted skin onto the clean wound surface and were able to save the leg of this young patient. We discharged him with a good function of his lower leg. This technique of V.A.C. Instill seems to offer great possibilities in critically infected wound situations.

Navigation und Robotronik in der Knieendoprothetik

ZusammenfassungDer breite Einsatz von Robotern und Elektronik in der Fertigung nahezu sämtlicher Gegenstände des Alltagslebens legt die Frage nahe, ob diese Technologien nicht auch im Rahmen operativer Eingriffe zum Nutzen der Patienten eingesetzt werden können. Dieser Einsatz sollte nicht als Konkurrenz für den Operateur, sondern eng begrenzt auf genau beschriebene Operationsabschnitte,im Sinn eines Helfers, in der Hand eines erfahrenen Operateurs gesehen werden.Nach erfolgreicher Einführung der roboterassistierten und navigierten Operation Mitte der 1990er Jahre werden diese Verfahren nun zunehmend auch in der Knieendoprothetik eingesetzt.AbstractThe wide application of robotics and electronics in the manufacture of virtually everything we use in everyday life leads us to ask whether it would not benefit our patients if these technologies were also applied in the setting of operative interventions.Such applications should certainly not be seen as attempts to replace the surgeon, but should be strictly restricted to precisely defined steps in the operations concerned and can thus be seen as an aid to an experienced surgeon. Following the successful introduction of robot-assisted navigation systems and surgery in the mid-1990s, these procedures and systems are now being applied more and more frequently in knee replacement operations.

Anatomische Voraussetzungen der Patellaluxation

ZusammenfassungUm eine genaue Begutachtung der Kniegelenkfunktion erstellen zu können, ist eine dezidierte Untersuchung unter Einbeziehung der Achsverhältnisse des gesamten Beins erforderlich. Bereits dabei sind die häufigsten Anlagevariationen, die die Patellainstabilität begünstigen, zu erkennen. Die radiologische Untersuchung liefert durch ergänzende Längen- und Winkelbestimmungen zusätzliche Fakten. Aus der Zusammenschau dieser anatomischen Befunde wird das Luxationsrisiko abschätzbar, sodass eine zuverlässige Unterscheidung zwischen traumatischer und habitueller Verrenkung möglich wird. Im folgenden Artikel werden die anatomischen Parameter dargestellt und die dynamischen und statischen Stabilisatoren, die Form der Patella, das Retinaculum sowie biomechanische Eigenschaften dargestellt und Zusammenhänge zu etwaigen Krankheitsbildern erläutert.AbstractA precise assessment of the knee function with preparation of an expert report requires a purposeful examination including consideration of the axis of the entire leg. Even at this stage the most common anlage variations that foster patellar instability should be recognized. The radiological examination provides additional information in terms of supplementary lengths and angles that can be measured. Taken together, these findings allow reliable estimation of the risk of luxation, making it possible to differentiate reliably between traumatic and habitual dislocation. This paper presents the anatomical parameters. In particular, dynamic and static stabilizers, the form of the patella, the retinaculum and biomechanical properties are presented, and links with possible clinical pictures are explained.