Lumbar Column Surgery with Radiography

A new pedicular screw method, which is based on research with intra-operative anatomic references, has recently been applied in a study to 44 patients.

The insertion of pedicular screws into the lumbar vertebral column is suitable for the treatment of fractures and problems of instability caused by tumors or degenerative disorders. It involves a common method in orthopedics and bone surgery. However, lesions of the nerve roots can occur as a complication, a risk that can affect up to 3% of patients.

The imaging method is based on intraoperative x-rays; using the anteroposterior and lateral views and aided by oblique projections and the Steinmann projection for the sacrum. Investigators at the University Hospital of Navarra (Pamplona, Spain) have assessed a technique to validate the pedicular screw system in a practical way, avoiding the neurologic complications. This system clusters together a series of x-ray projections by means of which the borders of the vertebrae can be seen, thereby enabling the path of the screws to be established with precision. The results of this method are similar to those produced by computer-assisted surgery. An additional benefit is that it is a much simpler method that has no need for neuronavigators, thereby significantly reducing health costs.

Another finding of the study related to the shape of the vertebrae and location of the injury. The x-ray images were used to preoperatively assess the shape and size of the vertebrae and enabled the scientists to determine the width and length of the screws that were used and in which direction they should go.

Ultimately, this study has shown the usefulness of imaging in accurately determining the position of the screws once introduced and at the end of the procedure. After assessing the appearance of the inside of the vertebra, the researchers noted that the 5.5 mm width screws appear as measuring up to 8 mm on the scans. Computed tomography (CT) images were also obtained and showed that part of the screws appear to be outside the vertebra when, in actuality, this was not the case.




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University Hospital of Navarra