Computer Assisted Orthopaedic Surgery: Current state and future prospects.

Imaging, sensing and computing technologies that are being introducedto aid in the planning and execution of surgical proceduresare providing orthopaedic surgeons with a powerful new set of toolsfor improving clinical accuracy, reliability and patient outcomeswhile reducing costs and operating times. Current computer assistedsurgery systems typically include four steps :1. A measurement process for collecting patient-specific medicaldata ; pre-operative images (CT, x-rays, MRI) ; intra-operativeimages (fluoroscopy, ultrasound images) ; intra-operative positionsof tools or bones obtained using 3D localizers.2. A registration process for aligning all images and data to thepatient coordinate system ; using anatomical landmarks ; usingbone surfaces digitized directly or with ultrasounds ; using x-rays3. A decision making process for generating a surgical plan onmulti-modality information ; interactive placement of tools or boneson images ; monitoring of criteria (angles, positions, impingement….)4. An action process for accurately achieving the goals specified inthe plan ; passive systems that display the position of tools or boneson images and data and active robots.In the future, it is expected that computer assisted surgery systemswill enable surgeons to measure the performances of surgical techniquesaccurately and consistently, which is a first step for optimizationof surgery.