Portable desktop computer-aided digitiser system for the analysis of spinal deformities

Prophylactic orthopaedic management of spinal deformities in non-ambulatory children with the Duchenne-type muscular dystrophy has been enhanced by a computer-aided digitiser system. Routine standardised spine radiographs are analysed using a microprocessor-controlled digitiser interfaced to a desktop computer with a refreshing type c.r.t. display and full graphics capabilities. Analysis includes computation of conventional two-dimensional orthopaedic parameters as well as spatial (three-dimensional) quantities describing the actual geometry of the spine curvatures. Three views of the spine, antero-posterior (a-p), lateral and apical, are plotted on the c.r.t. Other graphical presentations include rotation of the a-p view about the vertical axis into the lateral view as well as perspective views of the three-dimensional geometry of the spine curves. Digitising and analysis of a particular patient's spine radiographs take place in the clinic while the patient is being examined. Comparison with previous examinations of spine deformities may be done by superimposing graphic representations of the spine curves. Optional routines include a comprehensive review of previously stored data for that patient, review of current data for selected patient groups and statistical analysis of variables from any of the available data files. Additional data files include neurology, pulmonary function and orthotics service. 332 patients are currently being followed with documentation generated using the system described in this article.