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Notes: Zusammenfassung Erfolgreiche Thrombendarteriektomien (TEA) der A. carotis interna führen zu einer verbesserten Perfusion im Stromgebiet dieser Arterie. Es ist jedoch schwierig, während der Operation Aussagen über die zerebrale und okuläre Durchblutung zu treffen. Methode. Bei 10 Patienten mit klinisch signifikanter A.-carotis-Stenose, die sich einer A.-carotis-TEA unterzogen erfolgte eine nichtinvasive intraoperative Messung der Pulsamplitude (PA) des intraokularen Drucks mit einem Pneumotonographen (OBF-Systems, U.K.). Aus der PA wurde der sog. Pulsatile okuläre Blutfluss (pOBF) errechnet. Der mittlere arterielle Blutdruck wurde während der gesamten Operation invasiv gemessen. Ergebnisse. Während der Abklemmphasen konnte keine PA gemessen werden. Postoperativ kam es zu einem Anstieg der PA (p=0,04) und des pOBF (p=0,028) auf der operierten Seite im Vergleich zu den präoperativen Werten. Es wurde kein Zusammenhang zwischen dem pOBF bzw. der PA und dem mittleren arteriellen Blutdruck festgestellt. Schlussfolgerung. Diese Methode kann eine veränderte pulsatile okuläre Perfusion nach einer erfolgreichen TEA nachweisen.

Notes: Résumé La scoliose lombaire dégénérative est un sujet d'actualité posant des problèmes fonctionnels à type de douleurs lombaires ou radiculaires. Par le passé, le traitement chirurgical n'était envisagé que dans des cas extrèmes en raison des risques et de la lourdeur de l'intervention. Le traitement par en arrière en un seul temps opératoire par rotation de la tige convexe restitue l'anatomie sans prendre de gros risque neurologiques. La solidité de l'ostéosynthèse permet un lever rapide sans contention externe. Les avantages de la technique autorisent le traitement des patients souffrant de leur scoliose sans que l'âge ne soit un frein à l'indication.

Notes: Résumé Ce travail basé sur 5 341 cas traités depuis 1982, analyse l'expérience de 2 102 prothèses SCL implantées par un groupe international d'étude de 1982 à 1986. Ces résultats à 5 ans ont été contrôlés de façon uniforme par le groupe. 1 964 cas ont pu être contrôlés. 8,74 % de complications ont été notées et 3,16 % de prothèses ont été changées (1,32 % sont à considérer comme échec de la prothèse et 1,84 % sont en rapport avec d'autres causes : infection, mauvaise indication ou mauvaise technique). Le total de l'expérience du groupe à ce jour repose sur 5 341 cas. Le taux d'échec global est de 1,81 % (97 prothèses enlevées à ce jour). La courbe de survivance d'après Kaplan Meier est de 98,4 % après 8 ans 1/2. Cette prothèse vissée avec ses nombreux avantages semble être une nouvelle et bonne alternative due certainement à la stabilisation primaire “press-fit” obtenue.

Notes: Summary The conservative treatment of scolioses has evolved in a spectacular way from the 60's onwards with the birth of glued plasters, the Cotrel frame and the lyonnais braces in plexidur. In the past “the disgrace of orthopaedics”, idiopathic scoliosis progressively saw its prognosis brighten up, at the cost nevertheless of a constraining and lengthy treatment. However, the treatment must be varied depending on several parameters: the importance of the scoliosis, the localization of the curvature, the bone age, the chronological age. The ideal case for the conservative treatment is that of a lumbar or thoracolumbar scoliosis with an initial Risser test inferior to 2. For thoracic curvatures, the conservative treatment is continued only if the angular gain remains superior to 30% during treatment, otherwise, it is better to stop the conservative treatment and recommend the surgery.

Notes: Abstract Lumbar stenosis has been well discussed recently, especially at the 64th French Orthopaedic Society (SOFCOT: July 1989). The results of different surgical treatments were considered as good, but the indications for surgical treatment were not clear cut. Laminectomy is not the only treatment of spinal stenosis. Laminectomy is an approach with its own rate of complications (dural tear, fibrosis, instability... ). Eight years ago, J. Sénégas described what he called the “recalibrage” (enlargement). His feeling was that, in the spinal canal, we can find two different AP diameters. The first one is a fixed constitutional AP diameter (FCAPD) at the cephalic part of the lamina. The second one is a mobile constitutional AP diameter (MCAPD) marked by the disc and the ligamentum flavum. This diameter is maximal in flexion, minimal in extension. The nerve root proceeds through the lateral part of the canal: first above, between the disc and the superior articular process, then below, in the lateral recess bordered by the pedicle, the vertebral body and the posterior articulation. With the degenerative change the disc space becomes shorter, the superior articular process is worn out with osteophytes. These degenerative events are complicated by inter vertebral instability increasing the stenosis. The idea of the “recalibrage” is to remove only the upper part of the lamina with the ligamentum flavum and to cut the hypertrophied anterior part of the articular process from inside. If needed the disc and other osteophytes are removed. The surgery is finished with a ligamentoplasty reducing the flexion and preventing the extension by a posterior wedge. Our experience in spine surgery especially in scoliosis surgery, showed us that it was possible to cure a radicular compression without opening the canal. The compression is then lifted by the 3D reduction and restoration of an anatomy as normal as possible. Lumbar stenosis is the consequence of a degenerative process. Indeed, hip flexion, obesity or quite simply overuse, involve an increase in the lumbar lordosis. The posterior articulations are worn out and the disc gets damaged by shear forces. The disc space becomes shorter with a bulging disc, and the inferior articular process of the superior vertebra goes down. This is responsible of a loss of lordosis. For restoring the sagittal balance the patient needs more extension of the spine. Above and below the considered level the degenerative disease carries on extending to the whole spine. At the level considered, because of local extension, the inferior facet moves forward, the disc bulges, the ligamentum flavum is shortened and the stenosis is increased. This situation is improved by local kyphosis: the inferior facet moves backward, the disc and the ligamentum flavum are stretched with a quite normal posterior disc height and most often there is no more stenosis. Myelograms show this very well with a quite normal appearance lying, clear compression standing, worse in extension and improved, indeed disappeared in flexion. CT scan and MRI don't show that because they are done lying. The expression of the clinical situation is the same, mute lying and maximum standing with restriction of walking. For us lumbar stenosis is operated with lumbar reconstruction without opening the canal. The patient is in moderate kyphosis on the operating table. Pedicle screws rotated to match a bent rod allow reduction of the spine. The posterior disc height is respected and not distracted, and the anterior part of the disc is stretched in lordosis. The inferior facet is cut for the arthrodesis and no longer compresses the dura. The canal is well enlarged and the lumbar segment in lordosis is the best protection of the adjacent levels at follow-up. This behaviour responds to the same analysis as the ≪recalibrage≫ (enlargement). The mobile segment is damaged by the degenerative disease, the stenosis is a consequence of this damage. It's logical to treat the instability and to restore the normal static anatomy; thus bone resection is not necessary. At the present time all the lumbar stenoses with reduction in flexion are instrumented with spinal reduction and arthrodesis without opening the canal. The laminoarthrectomy and the enlargement are done when there is a fixed arthrosis which is rare in our practice and found in an older population. The follow-up shows a loss of reduction in some cases after reduction-instrumentation-arthrodesis and poses the question of an interbody fusion. We don't open the canal only for fusion (PLIF) if this is not necessary for the treatment of the stenosis. We think that, in such a situation, the future is ALIF with endoscopical approach. The problem is to determine which disc demanding this anterior fusion, is able to regenerate or not.

Notes: Summary Single unit potentials can be recorded directly with wire electrodes during an operation in man. Since averaging is not necessary this recording method is a fast neuromonitoring tool. Using 2 pairs of platinum electrodes it was possible to record extracellular single unit potentials at 2 sites in nerve root filaments in the spinal canal and to determine conduction velocities. Afferent and efferent single unit potentials could be distinguished from each other by a reversed conduction time and a reversed potential change making a differentiation between dorsal and ventral root parts possible. An activity increase due to touching the skin could be recorded. Therefore dermatomes of nerve root filaments and root filaments of dermatomes can be identified during the operation.

Notes: Removability by shampoo and water is one of the criteria to be met by polymers used in hair sprays or setting lotions. To obtain quantitative measures for removabilities, ample laboratory testing is required. Gravimetry is one method which serves this purpose, with the disadvantage of being very time-consuming and depending on the individual handling of the materials. The new method to be presented in this paper is based on conductivity measurements of polymer-coated electrodes in electrolyte solutions. The effect of polymer blending and the degree of neutralization on removability can be assessed readily. Several polymers commonly used in hair sprays or setting lotions and polymer mixtures were tested. Comparison of the results shows good correlation between the two methods. The new method is especially useful in screening experiments. Changes in polymer properties as a function of composition can be detected rapidly.〈section xml:id="abs1-2"〉〈title type="main"〉RésuméElimination au lavage est l'un des critères que doivent posséder les polymères utilisés dans les laques capillaires et les lotions coiffantes. Pour obtenir des mesures quantitatives quant à ce critère, des tests approfondis sont nécessaires. La gravimétrie est une méthode qui permet d'atteindre cet objectif avec l'inconvénient d'être longue, fastidieuse et dépendant de la manière dont les individus manipulent les matériaux. La nouvelle méthode présentée dans cet article est basée sur les mesures de conductivité d'électrodes enduites de polymères dans des solutions d'électrolyte. Il est alors aisé d'analyser le degré de neutralisation et d'élimination des polymères. On a ainsi testé plusieurs polymères purs ou en mélange fréquemment utilisés dans les laques capillaires ou lotions coiffantes. La comparaison des résultats montre une bonne corrélation entre les deux méthodes. La nouvelle méthode est particulièrement utile dans les expériences de criblage. Les changements de propriétés des polymères peuvent être rapidement détectés.

Notes: A rapid method has been developed in order to compare the photostability of several sunscreen agents incorporated in the same type of emulsion. Thin films of the different preparations were spread on quartz plates and irradiated with a solar simulator. Differences in energy distribution according to wavelengths observed with solar simulator and sun radiation were taken into account. A kinetic study of absorption properties was carried out under solar simulator irradiation. A simple calculation gave the results which would be obtained under sunlight.This technique differentiated the reversible transformations of photoisomerizable compounds from an irreversible disappearance which resulted in a significant loss of protective power.Applied to benzylidene camphor derivatives, this technique showed the excellent photostability of these sunscreen agents.