Anchorage of pedicle screw rod instrumentation in the elderly spine with poor bone quality remains challenging. Our study aims to evaluate how the screw bone anchorage is affected by screw design, bone quality, loading conditions, and cementing techniques. Micro-finite element (µFE) models were created from micro-CT (μCT) scans of vertebrae implanted with two types of pedicle screws (L: Ennovate and R: S4). Simulations were conducted for a 10 mm radius region of interest (ROI) around each screw and for a full vertebra (FV) where different cementing scenarios were simulated around the screw tips. Stiffness was calculated in pull-out and anterior bending loads.Aims
Methods
Rates of mortality as high as 25% to 30% have been described
following fractures of the odontoid in the elderly population. The
aim of this study was to examine whether easily identifiable variables
present on admission are associated with mortality. A consecutive series of 83 elderly patients with a fracture of
the odontoid following a low-impact injury was identified retrospectively.
Data that were collected included demographics, past medical history
and the results of blood tests on admission. Radiological investigations
were used to assess the Anderson and D’Alonzo classification and
displacement of the fracture. The mean age was 82.9 years (65 to
101). Most patients (66; 79.5%) had a type 2 fracture. An associated
neurological deficit was present in 11 (13.3%). All were treated
conservatively; 80 (96.4%) with a hard collar and three (3.6%) with
halo vest immobilisation.Aims
Patients and Methods
