Cell-Laden and Cell-Free Matrix-Induced Chondrogenesis versus Microfracture for the Treatment of Articular Cartilage Defects: A Histological and Biomechanical Study in Sheep.

OBJECTIVE: The aim of this study was to evaluate the regenerative potential of cell-laden and cell-free collagen matrices in comparison to microfracture treatment applied to full-thickness chondral defects in an ovine model. METHODS: Animals (n = 30) were randomized into 5 treatment groups, and 7-mm full-cartilage-thickness defects were set at the trochlea and medial condyle of both knee joints and treated as follows: 2 scaffolds in comparison (collagen I/III, Chondro-Gide(®); collagen II, Chondrocell(®)) for covering microfractured defects (autologous matrix-induced chondrogenesis), both scaffolds colonized in vitro with autologous chondrocytes (matrix-associated chondrocyte transplantation), or scaffold-free microfracture technique. One year after surgery, cartilage lesions were biomechanically (indentation test), histologically (O'Driscoll score), and immunohistochemically (collagen type I and II staining) evaluated. RESULTS: All treatment groups of the animal model induced more repair tissue and showed better histological scores and biomechanical properties compared to controls. The average thickness of the repair tissue was significantly greater when a scaffold was used, especially the collagen I/III membrane. However, none of the index procedures surpassed the others from a biomechanical point of view or based on the histological scoring. Collagen type II expression was better in condylar defects compared to the trochlea, especially in those treated with collagen I/III membranes. CONCLUSION: Covering of defects with suitable matrices promotes repair tissue formation and is suggested to be a promising treatment option for cartilage defects. However, it failed to improve the biomechanical and histological properties of regenerated articular cartilage compared to microfracture alone in an ovine model under the given circumstances.

The intraindividual agreement of the bone density of the human proximal tibia.

The interindividual variability in the biomechanical properties of cadaver bones has remained an unsolved problem in biomechanical investigation procedures. For this reason, it is postulated to use matched bone pairs from the same individual for comparative biomechanical tests. The rationale behind this procedure is based on the assumption that biomechanically similar behaviour is to be expected in an intraindividual rather than an interindividual comparison. Systematic studies confirming this thesis were performed on the human femur. However, investigations regarding the intraindividual properties of the proximal tibial metaphysis with respect to the underlying bone densities, have not yet been performed. In order to verify the hypothesis that matched proximal tibial metaphyses from the same donor imply corresponding bone density values, densitometric measurements (pQCT) were performed in 14 matched cadaver tibias (average age 61 years, 9 men, 5 women) which were fresh-frozen at -40 degrees C after removal. After statistical analysis of the bone density values, five tibial pairs were identified as differing on the basis of missing correlations and the existence of systematic differences within the pairwise data. In other words, only about 2/3 of the data in the random sample available was classified as comparable. As the bone density measured by pQCT technique significantly correlates with the biomechanical properties of the bone, it can be concluded from the test result available that matched human tibiae show no concurring bone density values in 1/3 of cases. Thus the pairing of corpse tibiae does not necessarily imply suitability for comparative biomechanical experiments.

[Designing a surgical device for harvesting autologous fascia lata grafts as a minimal invasive procedure]. / Entwicklung eines Operationsgerätes zur minimal-invasiven Fascia lata-Entnahme.

AIMS: Fascia lata is used in different shapes and sizes as a graft material in surgical procedures. The conventional method of harvesting a fascia lata graft is through a long skin incision on the lateral aspect of the thigh. Minimal invasive procedures have been established to reduce the disadvantages of an extensive surgical approach for obtaining the autotransplant. However, they do not facilitate to suture the remaining fascia after harvesting the transplant and therefore bear the risk of a symptomatic herniation of the muscle belly. The aim of this study was to design a surgical device to harvest a fascia lata graft and close the resulting fascia defect as a minimal invasive procedure. MATERIALS AND METHODS: The prototype was tested in 11 human cadaver specimens. It was introduced subcutanously via two small skin incisions. The device contained a special fixation- and working mechanism which enabled the fascial closure using a continuous suture. After the harvest procedure, both the transplant and the sutured fascia lata were examined. RESULTS: The experiments demonstrated the suitability of this method for minimal invasive harvesting of fascia lata. The removed transplants complied in all experiments with the expected dimensions. The continuous suture of the femoral fascia ran with accurate gaps between the sutures and constant tension without dehiscence. Neither the transplant nor the tissue in the region of harvest have shown unduly macroscopic damage due to the use of the device. CONCLUSION: The designed prototype can be used for harvesting a fascia lata graft and repairing the resulting defect minimal invasively. Clinical implementation seems possible. However, improvements could be made mainly concerning the handling of the device.

Economic burden of illness imposed by severe sepsis in Austria.

INTRODUCTION: Sepsis is a life-threatening disease, requiring instant treatment in an intensive care unit (ICU). The aim of this study was to determine the direct and indirect costs occurring in Austria due to this disease. PATIENTS AND METHODS: Direct costs were calculated based on a retrospective chart analysis in four adult Austrian ICUs, evaluating 74 patient records from the years 2000/2001. Patients were identified to have suffered from severe sepsis using ACCP-definitions. Assessed resource use (medication, laboratory analysis, microbiology analysis, consumer-goods, diagnostic procedures, staff costs, and basic bed costs) was linked with related center specific costs to determine direct costs per patient. Indirect costs due to productivity losses were calculated using official statistical material. RESULTS: The mean length of ICU stay (LOS ICU) of a severely septic patient was 18.1 days. Overall ICU mortality was found to be 43.2% and showed no gender difference. The mean daily direct ICU costs of care for severely septic patients were [symbol: see text] 1,617 and the mean total direct ICU costs per septic patient were [symbol: see text] 28,582. In total costs, survivors were equally expensive as non-survivors ([symbol: see text] 28,699 vs. 28,463) although their length of study was considerably longer (21.9 vs. 13.2 days). Considering a range of patients with severe sepsis in Austria from 6,700 to 9,500 per year, total direct costs in Austria range from [symbol: see text] 192 million to [symbol: see text] 272 million. Indirect costs determined by productivity losses due to unfitness for work (temporary and permanent) and premature death amount to [symbol: see text] 484 million to [symbol: see text] 686 million in Austria per year (same incidence range). Total costs, i.e. burden of illness, combining direct costs with indirect costs, range from [symbol: see text] 676 million to [symbol: see text] 958 million. CONCLUSION: Patients with severe sepsis have a high mortality rate, spend prolonged periods of time in the ICU, and are expensive to treat. Indirect costs of severe sepsis due to productivity losses, particularly by premature death, are considerable.