Een kleine geschiedenis van het al

“Mijne dames en heren, mijn naam is Verbout, ik ben van de afdeling Orthopaedie en ga met u wat kennis delen over het Steun- en bewegingsstelsel”. Zo ben ik vanaf de jaren zeventig nogal wat colleges begonnen; de laatste jaren minder colleges en meer werkgroepen, maar toch. Dus vandaag ook maar zo aangevangen. * 1 Intro En dan weet u gelijk waar de titel ‘Een kleine geschiedenis van het al’ op slaat. Wel wat pretentieus, alsof de Orthopaedie ‘het al’ behelst. Maar toch minstens driekwart! En als ik de Anatomie, -vanuit mijn vorig leven, zoals ik dat wel placht te zeggen- erbij tel, is het wel geheel en al bepaald door het Steun- en bewegingsstelsel. Leden van de Raad van Bestuur van het Universitair Medisch Centrum Utrecht, geachte collegae, studenten, zeer gewaardeerde toehoorders, Niet alleen een pretentieuze, maar ook weinig originele titel. Ik zeg het maar gelijk, voordat ik door de plagiaatscanner van de Directie Onderwijs en Opleiding -gebruikt voor de werkstukken van studenten- eruit gezeefd zou worden. * 2 Boek Bryson Het is geleend van het terecht populaire boek van Bill Bryson. Met een aangepaste titel gebruik ik het in de omschrijving van van Dale: ‘het al’; ’alles wat van belang is, waar het op aan komt’ Welnu, dat gaat zeker op voor het Steun- en bewégingsstelsel. Want zonder ‘voort-bewéging’ zat u hier niet! En die vrijheid van bewéging is beslissend voor een menswaardig bestaan en is cruciaal voor de “kwaliteit van leven”. Zowel voor kind als oudere, voor werkende als rustende, voor ongeschondene als getraumatiseerde is mobiliteit onontbeerlijk. Daarom zijn stoornissen ervan maatschappelijk-economisch zeer ingrijpend. Ook weinig origineel is dat het college van vandaag over ‘het As-skelet’, de wervelkolom, gaat; dat is eveneens niet anders dan in de voorgaande 20 jaar

Design and fabrication of standardized hydroxyapatite scaffolds with a defined macro-architecture by rapid prototyping for bone-tissue-engineering research

This investigation describes the production and characterization of calcium phosphate scaffolds with defined and reproducible porous macro-architectures and their preliminary in vitro and in vivo bone-tissue-engineered response. Fugitive wax molds were designed and produced using a rapid prototyping technique. An aqueous hydroxyapatite slurry was cast in these molds. After sintering at 1250°C and then cleaning, dimensional and material characterizations of the scaffolds were performed. The resulting scaffolds represented the design, and their dimensions were remarkably consistent. A texture inherent to the layer-by-layer production of the mold was impressed onto the vertical surfaces of the scaffolds. The surface roughness (Ra) of the textured surfaces was significantly greater than that of the nontextured surfaces. Material analyses revealed a β-TCP phase in addition to hydroxyapatite for the molded ceramics. Non-molded control ceramics exhibited only hydroxyapatite. Thirty scaffolds were seeded with culture-expanded goat bone-marrow stromal cells (BMSCs) and implanted subcutaneously in nude mice for 4 or 6 weeks. Histology revealed mineralized bone formation in all the scaffolds for both implantation periods. After 4 weeks, bone was present primarily as a layer on scaffold surfaces. After 6 weeks, the surface bone formation was accompanied by bone budding from the surface and occasional bridging of pores. This budding and bridging bone formation almost always was associated with textured scaffold surfaces. However, the area percentage of bone in pores was similar for the 4- and 6-week implantation periods

Specificity of surface-EMG on the intrinsic lumbar back muscles

The cross-correlation coefficient functions (CCCFs) between twelve bipolar surface electrodes, placed symmetrically on the intrinsic lumbar back muscles (ILBM) were computed in order to estimate the amount of cross-talk. It was found that the CCCF values were mainly influenced by the distance between the electrodes. Other factors, such as static versus dynamic experimental conditions, the activity level, the angle between the dipole axis and the muscle fibres, the ECG, noise, power-line-induced-a.c.-components and resistance of biological material, have less influence, but nevertheless they do change the CCCF values. The absolute maximum in the CCCF can be used to validate EMG-signals. Absolute maxima in the CCCF within the range from 0 to 0.30 are considered as sufficient specific EMG-signals. The technique can be used to optimise the location of electrodes for the selective recording of localised muscle activity

Spine surgery research: on and beyond current strategies

Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

Effect of methodological quality measures in spinal surgery research: a metaepidemiological study

Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

Histologic changes after vertebroplasty.

Item does not contain fulltextBACKGROUND: Vertebroplasty with use of polymethylmethacrylate cement is gaining popularity in the treatment of some specific painful lesions of the spine. It remains unclear, however, what possible side effects this type of cement might have upon the vertebral body. We performed a histologic and radiographic analysis of the end plate and disc to determine whether there was a difference between vertebroplasty with polymethylmethacrylate cement and vertebroplasty with calcium phosphate cement in the surrounding tissue of the goat spine. Furthermore, we assessed whether a defect in the end plate, simulating end-plate fracture and allowing for direct contact of cement with disc tissue, had any effect on end-plate or disc degeneration. METHODS: Twenty-four mature goats were divided between two follow-up periods (six weeks and six months). All animals underwent a bilateral transpedicular vertebroplasty at two lumbar levels, where one of the following treatments was applied: vertebroplasty with calcium phosphate cement with or without an end-plate defect, and vertebroplasty with polymethylmethacrylate cement with or without an end-plate defect. The effect of the various treatments on the integrity of the intervertebral disc, end plate, and surrounding tissue was examined with semiquantitative histologic analysis and radiography. RESULTS: No sign of disc or end-plate degeneration was seen in any of the analyzed sections. The mean disc height did not decrease from the postoperative period to the time that the animals were killed in any group, thereby supporting the histologic findings. A mild inflammatory reaction was found in four vertebral bodies in the polymethylmethacrylate groups only. CONCLUSIONS: Calcium phosphate cement and polymethylmethacrylate cement both seem to be adequate bone-void fillers in terms of biological behavior in the vertebral body

No evidence for intervention-dependent influence of methodological features on treatment effect

Neurosurger