166 research outputs found
Computer-Assisted Resection and Reconstruction of Pelvic Tumor Sarcoma
Pelvic sarcoma is associated with a relatively poor prognosis, due to the difficulty in obtaining an adequate surgical margin given the complex pelvic anatomy. Magnetic resonance imaging and computerized tomography allow valuable surgical resection planning, but intraoperative localization remains hazardous. Surgical navigation systems could be of great benefit in surgical oncology, especially in difficult tumor location; however, no commercial surgical oncology software is currently available. A customized navigation software was developed and used to perform a synovial sarcoma resection and allograft reconstruction. The software permitted preoperative planning with defined target planes and intraoperative navigation with a free-hand saw blade. The allograft was cut according to the same planes. Histological examination revealed tumor-free resection margins. Allograft fitting to the pelvis of the patient was excellent and allowed stable osteosynthesis. We believe this to be the first case of combined computer-assisted tumor resection and reconstruction with an allograft
Selection of massive bone allografts using shape-matching 3-dimensional registration
Background and purpose Massive bone allografts are used when surgery causes large segmental defects. Shape-matching is the primary criterion for selection of an allograft. The current selection method, based on 2-dimensional template comparison, is inefficient for 3-dimensional complex bones. We have analyzed a 3-dimensional (3-D) registration method to match the anatomy of the allograft with that of the recipient
When density fails to predict bone strength
This review is the report of a single experimental protocol on the nature, structure and mechanical strength of 136 bones samples from the vertebral body of 9 subjects. On these samples, we combined mechanical testing with density measurements (Part I), a study of some microarchitectural parameters (part II) and a biochemical analysis of bone collagen (part III). As multiple samples were studied in each subject we explored whether a given parameter was characteristic of that subject. The parameters ware also systematically screened as potential indicators of the bone quality. The association of biochemical and microarchitectural data offered a unique opportunity to compare both sets of data (part IV). Finally, in a technical addendum, we report the comparison of histology vs pQCT (a small scanner) as investigation tools for the bone density and microarchitectureThÚse de doctorat en sciences biomédicales (SBIM 3)--UCL, 200
When density fails to predict bone strength
This review is the report of a single experimental protocol on the nature, structure and mechanical strength of 136 bones samples from the vertebral body of 9 subjects. On these samples, we combined mechanical testing with density measurements (Part I), a study of some microarchitectural parameters (part II) and a biochemical analysis of bone collagen (part III). As multiple samples were studied in each subject we explored whether a given parameter was characteristic of that subject. The parameters ware also systematically screened as potential indicators of the bone quality. The association of biochemical and microarchitectural data offered a unique opportunity to compare both sets of data (part IV). Finally, in a technical addendum, we report the comparison of histology vs pQCT (a small scanner) as investigation tools for the bone density and microarchitectureThÚse de doctorat en sciences biomédicales (SBIM 3)--UCL, 200
Quarante ans dâhistoires et de croisements. Entretien avec Xavier Rousseaux
Xavier Rousseaux est nĂ© Ă Bruxelles en 1957. Il est licenciĂ©-agrĂ©gĂ© en histoire (1982), bachelier en philosophie (1983), licenciĂ© en communication et maĂźtre en sociologie en 1987, docteur en histoire trois ans plus tard. Directeur de recherche du FNRS et professeur extraordinaire Ă lâUCLouvain, Xavier Rousseaux a Ă©tĂ© enseignant dans le secondaire (1982-1984), aspirant FNRS (1985-1989), assistant en sociologie aux FUSL de 1989 Ă 1995. Enfin, aprĂšs un mandat de chargĂ© de recherche (1990) il devient chercheur qualifiĂ© au FNRS Ă lâUCLouvain (1992), puis professeur invitĂ© aux UniversitĂ©s de Bruxelles, du Luxembourg et dâAngers. ChargĂ© de recherche invitĂ© au CNRS (1992-1993), Research Fellow du NIAS Wassenaar (1998-1999) et de lâIEA (2015-2016), il est Ă©galement directeur dâĂ©tudes invitĂ© Ă lâEHESS Ă Paris (2020)
Canal lombaire Ă©troit
Ce chapitre couvre les situations oĂč les racines lombaires (dites de la queue de cheval) sont mises Ă lâĂ©troit dans le canal mĂ©dullaire. Il sâagit de toutes les situations, en grande majoritĂ© dĂ©gĂ©nĂ©ratives et chroniques, oĂč il existe une compression extrinsĂšque du sac dural et des racines quâil contient. Cette compression est dynamique ou statique, caractĂ©risĂ©e par un effacement des espaces sous-arachnoĂŻdiens et une disparition du liquide cĂ©phalo-rachidien (LCR) qui entoure et protĂšge naturellement les racines. On parle alors de canal lombaire Ă©troit (synonyme de stĂ©nose du canal mĂ©dullaire lombaire, angl. : Lumbar Spinal Stenosis, LSS). Le canal lombaire Ă©troit est parfois associĂ© Ă un spondylolisthĂ©sis dĂ©gĂ©nĂ©ratif qui fait lâobjet dâun chapitre Ă part car la prise en charge est particuliĂšre. Les compressions liĂ©es Ă une pathologie tumorale extradurale (mĂ©tastase, myĂ©lome, etc.), Ă un abcĂšs pĂ©ridural ou Ă des fractures sont couvertes dans dâautres chapitres. Les lĂ©sions liĂ©es Ă un processus tumoral intrathĂ©cal (dans le sac dural) ne sont pas couvertes. Le processus de dĂ©gĂ©nĂ©rescence de la colonne peut sâexprimer de façon relativement aiguĂ« quand il est provoquĂ© par une hernie discale ou un kyste arthrosynovial intracanalaire. Les stĂ©noses congĂ©nitales ou constitutionnelles, et les rĂ©trĂ©cissements causĂ©s par la lipomatose pĂ©ridurale sont des variantes relativement rares, simplement Ă©voquĂ©es dans ce chapitre
Time spent per patient in lumbar spinal stenosis surgery
Purpose: To examine the time needed from a surgeon's viewpoint to treat a patient operated for lumbar spinal stenosis. We firstly aimed to give evidence of the wide ranging duration of standardized procedure. Secondly, we investigated factors affecting the time allocated to each patient. Methods: 438 medical records of patients operated on for lumbar decompression without fusion (2005-2011) were retrospectively examined. Primary data were operative time (OT, min), length of stay (LoS, days) and number of postoperative visits. A fourth parameter was calculated, the time spent per patient (TSPP, min) by summing the time spent in surgery, during inpatient and outpatient follow-up visits. Factors that influenced these medical resources were examined. Results: Median (5th-95th percentile) LoS was 5 days (2-15), OT 106 min (60-194), number of medical visits 5 (2-11) and TSPP 329 min (206-533). In descending order, factors predicting LoS were age, no. of levels, sex, operative technique, cardiovascular risk index, dural tear and haematoma. Factors predicting OT were number of levels, dural tear, foraminotomy, synovial cyst and body mass index. The statistical model could predict 36 % of the TSPP variance. We recommend that surgeons add 35 min for each level, 29 min for patients over 65 years, 30 min for women, 132 min for dural tear and 108 min for epidural haematoma. Conclusion: TSPP treated for lumbar spinal stenosis is highly variable, yet partially predictable. These data may help individual surgeons or heads of departments to plan their activities. © 2013 Springer-Verlag Berlin Heidelberg
Spondylolisthésis dégénératif lombaire
Le spondylolisthĂ©sis dĂ©gĂ©nĂ©ratif est une forme dâarthrose lombaire oĂč sâassocient un dĂ©calage des vertĂšbres de profil et une stĂ©nose du canal mĂ©dullaire. Le traitement chirurgical par laminotomie (dĂ©compression simple) ou arthrodĂšse est efficace. Le choix entre les deux techniques se fait en fonction dâune sĂ©rie de particularitĂ©s Ă lâimagerie mĂ©dicale
Considérations générales sur le rachis dégénératif
La colonne vertĂ©brale peut ĂȘtre affectĂ©e par un trouble de croissance (comme une scoliose idiopathique), par une pathologie tumorale (comme une mĂ©tastase de cancer du sein) ou une pathologie septique (comme une spondylodiscite). La colonne peut aussi ĂȘtre le siĂšge dâune lĂ©sion traumatique (comme une burst fracture de L1). NĂ©anmoins la toute grande majoritĂ© des pathologies de la colonne vertĂ©brale est dĂ©gĂ©nĂ©rative. Cela signifie quâil sâagit dâanomalies liĂ©es au vieillissement naturel ou prĂ©maturĂ© des articulations de la colonne. La pathologie dĂ©gĂ©nĂ©rative de la colonne concerne essentiellement les disques (hernie discale, discarthrose), les facettes vertĂ©brales (arthrose zygapophysaire) ou les articulations uncovertĂ©brales (uncodiscarthrose cervicale). Les hernies discales ne sont quâun Ă©vĂ©nement, un incident, dans le cycle de vieillissement du disque intervertĂ©bral. Câest donc une pathologie articulaire, comme la coxarthrose, mais la proximitĂ© de la moelle et des racines fait que sa prĂ©sentation clinique va au-delĂ dâune douleur locale et dâun enraidissement. Il y a souvent des signes neurologiques. Nous verrons dans ce chapitre et dans les suivants quelles pathologies rentrent dans ce groupe et surtout comment elles peuvent se manifester
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