To incorporate magnetic resonance (MR) image data in a finite element (FE) model to estimate intervertebral disc stress as a function of posture. Determining the stresses on the intervertebral discs is important for understanding disc degeneration and developing treatment strategies. The effect of different postures on disc stress has previously been investigated through disc pressure measurements and through computational modelling. Kinematic data derived from MR images and used in an FE model may provide a non-invasive way of assessing a wide range of subjects and postures.Purpose of the study
Background
Proximal fifth metatarsal fractures distal to the tuberosity, also known as Jones’ fractures, are troublesome fractures to manage with a high incidence of delayed union and nonunion. We conducted a retrospective study of 32 patients with fractures of the fifth metatarsal distal to the tuberosity over a three year period. The aim was to assess healing with non-weight bearing and variations of weight bearing mobilization including minimal, partial and full weight bearing. This is one of the largest reported series of such fractures. These fractures were classified as acute fractures (14 fractures), fractures with features of delayed union (15 fractures) and fractures with features of nonunion (three fractures) at presentation according to the radiological classification used by Torg in 1984. These patients were treated in a plaster cast and mobilised either non-weight bearing or with variations of weight bearing. These patients were followed up for a mean of 16 months. Our findings correspond with those observed by Torg and we describe a correlation between the radiological appearance of the fracture at presentation and the clinical course. Prevailing guidelines for the management of these fractures are ambiguous. A standardized classification is important because there is great variability in the types of fractures and appropriate treatment. It is important that radiological features are correlated with clinical features and appropriate treatment instituted. The treatment of choice for acute fractures is immobilization of the limb in a below-knee non-weight bearing plaster for 6 to 8 weeks. Fractures with delayed union may eventually heal if treated non-operatively, although this may take up to 20 weeks. An active athlete will benefit from early surgery. Fractures with symptomatic nonunion require surgery.
