At the Second Annual Meeting of Computer Assisted Orthopaedic Surgery, which took place in Pittsburgh from June 18th till 20th latest, Dr. David Kahler, surgeon and associate professor from the University of Virginia Health Sciences Centre, demonstrated a new computer guided surgical technique, in order to treat pelvic and hip socket fractures in a more efficient way. A virtual computer model of the patient's pelvis serves as a guide for the accurate introduction of surgical instruments and screws at the exact location of the fracture. In contrast with conventional surgery, the method only requires minimal invasion and allows the patient to leave the hospital far more quickly.
Car accidents due to high speed constitute the major cause for hip socket and pelvis fractures. Typically, this kind of injuries is quite difficult to treat by means of traditional techniques because of the huge danger for infection, the slow or even bad wound healing, the enormous loss of blood, and possible nerve damage. Large incisions of nearly two feet are necessary to search for and reach the fracture spot. After the intervention, patients are forced to stay at least another week in the hospital in order to properly recover. Up to this point, the newly developed computer assisted technique has been tried out on twenty patients by Dr. Kahler and the results appear to be very hopeful.
Dr. Kahler uses an integrated hardware system, which is referred to as "StealthStation", designed by Sofamor Danek, a Memphis-based manufacturer. The UNIX-based Silicon Graphics workstation is connected to an optical digitizer. The special software is provided by Surgical Navigation Technologies, a subsidiary of Sofamor Danek. To start with, Dr. Kahler loads the system with a Computed Tomography (CT) scan of the patient's pelvis in order to construct a virtual three-dimensional model of the visual data. By rotating the model, the surgeon can view the cross sections from different angles to discover the ideal pathway for insertion of the screws. In this way, a pre-operative plan is being prepared.
In the operating theatre, the computer displays the patient's pelvis by means of a sophisticated camera, following the coded registration points, which have been attached to the patient's body. The surgical instruments are equipped with LEd's so that the surgeon can locate them at any time. He performs a small incision at the pre-determined entry point of the pathway to introduce the screws, carefully respecting the guidelines, as previously set out on the computer model. Each screw takes twenty minutes to be fixed. According to Dr. Kahler, the screws can be inserted in directions and angles that are inconceivable in traditional surgery. One stitch suffices to close the wound.
At present, the University Hospital of Virginia is the only facility in the United States where this type of computer guided surgical intervention is being executed for pelvic and hip socket fractures. Over the past ten years, the same technique has frequently been used for neurosurgery but the orthopaedic specialists have long been hesitating to adopt the method, Dr. Kahler claims. Still, the Biomedical Imaging Resource (BIR) at the Mayo Clinic in Rochester, has developed a great activity in this field. It is still too early for decisive positive outcome measurements but Dr. Kahler believes that computer assisted orthopaedic surgery has a beautiful future in store. More news is to be found on the Conference Web site of the Computer Assisted Orthopaedic Surgery's annual meeting.