45 research outputs found
Construction of a statistical shape model of lumbar vertebrae and its application in reconstructing a 3D model from a single lateral fluoroscopic image
No full textValidation of statistical shape model based reconstruction of the proximal femur: a morphometric study
No full textSeventeen bones (sixteen cadaveric bones and one plastic bone) were used to validate a method for reconstructing a surface model of the proximal femur from 2D X-ray radiographs and a statistical shape model that was constructed from thirty training surface models. Unlike previously introduced validation studies, where surface-based distance errors were used to evaluate the reconstruction accuracy, here we propose to use errors measured based on clinically relevant morphometric parameters. For this purpose, a program was developed to robustly extract those morphometric parameters from the thirty training surface models (training population), from the seventeen surface models reconstructed from X-ray radiographs, and from the seventeen ground truth surface models obtained either by a CT-scan reconstruction method or by a laser-scan reconstruction method. A statistical analysis was then performed to classify the seventeen test bones into two categories: normal cases and outliers. This classification step depends on the measured parameters of the particular test bone. In case all parameters of a test bone were covered by the training population's parameter ranges, this bone is classified as normal bone, otherwise as outlier bone. Our experimental results showed that statistically there was no significant difference between the morphometric parameters extracted from the reconstructed surface models of the normal cases and those extracted from the reconstructed surface models of the outliers. Therefore, our statistical shape model based reconstruction technique can be used to reconstruct not only the surface model of a normal bone but also that of an outlier bone
A comprehensive computer-assisted application for diagnosis, planning, and conduction of navigated joint preserving surgery in patients with femoroacetabular impingement
No full textAccurate and reliable navigation of a surgical reaming device for femoral head-neck offset improvement
No full textOptimization of perioperative management of proximal femoral fracture in the elderly
No full textInternational audienceProximal femoral fracture in elderly subjects is a major event that is life-threatening in the medium-to-long term. Advanced age, male gender and number of comorbidities largely account for high mortality and require geriatric expertise. Protein-energy malnutrition and bone demineralization increase mortality. Mortality can, on the other hand, be reduced by acting on two variables accessible to medical intervention: daily activities and nutritional status. Functional and neurocognitive assessment allow the risk of dependency to be evaluated, and global geriatric work-up can prevent sudden breakdown of homeostasis. In the emergency setting, pain is to be alleviated, polymedication and anticoagulation therapy checked, and instability (notably cardiac and pulmonary) and confusion syndrome screened for on geriatric and anesthesiologic opinions. Surgery should be implemented without delay, within 48hours of admission, preferably using multimodal anesthesia. The technique should be geared to allow early weight-bearing and mobilization. The most comprehensive care plan involves team-work between emergency physicians, surgeons, orthopedic specialists, anesthesiologists, geriatricians, pharmacists, rehabilitation specialists and nursing staff, to reduce mortality and readmission and improve functional results. Post-fracture coordination seeks to prevent falls and further fractures and to treat bone demineralization
Analysis of anatomic positioning in computer-assisted and conventional anterior cruciate ligament reconstruction
No full textSummaryIntroductionAnterior cruciate ligament (ACL) reconstruction should be anatomic while achieving favorable anisometric behavior to avoid impingement with the femoral notch. Computerization enables these biomechanical conditions to be optimally fulfilled; but what of anatomic positioning? The present study compared the positioning of tibial and femoral tunnels, drilled using either a conventional ACL guide or a navigation system, using the anatomic foot-print areas of the native ACL.Material and methodsThis cadaver study used computerized recording to compare tibial and femoral ACL attachment areas to the positioning of tunnels created either conventionally or under computer-guided navigation.ResultsComputer guidance enabled the tibial and femoral tunnels to be systematically positioned within the anatomic area and, as regards the tibial area, within the anterior third near to the medial tibial spine, without femoral notch impingement. Anisometry was in all cases favorable, at a mean 3.3±0.7mm; using a conventional guide, anisometry was favorable in only 50% of cases, at a mean 5.4±1.2mm.ConclusionComputer-guided navigation ensured implant positioning within the so-called anatomometric area of the native ACL attachment, avoiding impingement with the femoral notch.Level of evidenceLevel 2
