0000000000022128
AUTHOR
M. Schwitalle
Vergleich radiologischer Verfahren zur präoperativen Beurteilung der Verankerungsfestigkeit von Wirbelsäulenimplantaten
PURPOSE To compare three techniques with regards to their ability to estimate pull out strength of spinal fusion hardware. MATERIAL AND METHODS VDS-screw fixation strength in 50 human cadaveric vertebral bodies was approximated by means of pull out force measurement. Bone quality was assessed by Dual X-ray Absorptiometry (DXA). Quantitative Computed Tomography (QCT) and T2*-relaxation time. For each of these techniques, correlation with axial pull out force strength was investigated. RESULTS Highest correlation was found for cancellous bone density measured by QCT (r = 0.72; p < 0.001). Immediately followed by DXA (r = 0.70; p < 0.001), which involves all bone components. Inverted T2*-relax…
Vergleich der prognostischen Aussagefähigkeit der Catterall- und Herring-Klassifikation bei Patienten mit Morbus Perthes
QUESTION Investigation of the predictive value of the Catterall- as compared to the Herring-classification in patients with Perthes disease. METHOD A radiological follow-up study including 53 patients with a total of 59 affected hips was carried out. In the initial diagnosis the Catterall-, Waldenstrom- and Herring-stages were assessed. The epiphyseal ratio, the head-neck ratio and the lateral subluxation were measured and compared at the time of diagnosis, fragmentation stage and in a follow-up examination, which was carried out 4, 9 years after diagnosis on the average. The results of the follow-up examination were assessed using the Mose-classification and compared as well. In addition t…
Bestimmung der Knochenqualität vor Wirbelsäuleninstrumentation - Stellenwert verschiedener in vivo-Methoden
OBJECTIVE: The present investigation should elucidate which assessment technique for bone quality is most appropriate to estimate preoperatively fixation strength of instrumental spine fusions. METHODS: VDS-screw fixation strength in 50 human cadaveric vertebral bodies was approximated by means of pullout force assessment. Bone quality was assessed by Dual Energy X-ray Absorptiometry (DEXA), Quantitative Computed Tomography (QCT), MRT and histomorphometry. For each of these techniques, correlation with axial pull out force strength was investigated. RESULTS: Highest correlation was found for cancellous bone density (QCT) (r = 0.72; p < 0.001) and DEXA (r = 0.70; p < 0.001). MRT, cortical bo…
Messung der Pfannenwanderung bei zementfreien Hüftimplantaten
PURPOSE Migration measurements of acetabular components using a special computer aided method (EBRA = abbreviation for the German term "Ein-Bild-Rontgenanalyse") were performed to evaluate early results of the implants and predict aseptic loosening. METHODS Standard ap-radiographs of the pelvis were marked, specific points were digitised. Simulating the spatial situation the programme computes longitudinal and vertical migration of the cup. 74 acetabular components in 71 patients could be studied by migration measurements. RESULTS 14 patients showed migration of more than 1 mm, which is the confidence limit of this method. Each of these patients showed diverse reasons for the migration, i.e…
Radiologische Veränderungen nach Implantation zweier unterschiedlicher zementfreier Hüftschaftsysteme
PURPOSE: Of the study was to evaluate radiological alterations of the femoral bone after implantation of two different prostheses. METHODS: 81 patients with 87 hips underwent total hip arthroplasty by using the Zweymuller-stem fixating in the medullary canal, and 175 patients with 182 ABG-stems with a proximally fixating, anatomical design were followed up clinically and radiologically. RESULTS: Adaptive bone remodelling in Zweymuller-stems showed in some patients thickening of the cortex of the femur and proximal bone-stock loss; reactive lines were seen in the proximal areas surrounding the prosthesis. Radiographs of patients with ABG-stems showed these lines in the distal, smooth part of…
Überprüfung der Läsionsgefahr des N. ischiadicus des Kaninchens durch die Applikation niedrig- und mittelenergetischer extrakorporaler Stoßwellen
Aim The aim of the study was to evaluate the likeliness for peripheral nerve lesions following extracorporeal shock wave application. Material and method 82 rabbit sciatic nerves were randomized to undergo low-energetic (0.08 mJ/mm2), middle-energetic (0.28 mJ/mm2) or no (controls) shock wave therapy. After 1 to 28 days an independent neuropathologist checked the specimen for signs of neural lesions. Results Only after 14 and 28 days vacuolic swelling of the axons was noted, somewhat pronounced in the middle-energetic group. In no case was there any disruption of the nerve's continuity. We did not observe any neurapraxia. Conclusion Shock wave application does not threaten peripheral nerve …