Frameless Stereotaxic Surgery Can Go Off Course, FDA Warns

June 15, 2017

Surgeons who use frameless stereotaxic navigation systems need to address accuracy problems with this technology that have led to serious injuries and death, the US Food and Drug Administration (FDA) announced today.

The FDA emphasized that the benefits of these navigation systems still outweigh their risks. In addition, the agency has not determined that some systems are riskier than others.

In stereotaxic procedures, a computer system uses computed tomography or magnetic resonance images of the patient's anatomy — typically the head — to guide a surgeon in the placement of surgical instruments. Framed-based navigation systems involve fastening a rigid frame to the head with pins and screws as part of establishing 3-dimensional coordinates of anatomical landmarks, registering them on patient imagery, and tracking surgical instruments. Frameless systems, more commonly deployed, rely on other technologies to keep patient imagery and patient anatomy in sync as the surgeon works.

However, some surgeons have gone off course in stereotaxic procedures because of accuracy errors with frameless navigation systems, the FDA said in a news release. The errors can arise from a laundry list of factors:

  • Damaged hardware and software glitches

  • Human errors in setting up the system, entering data, and performing surgery, which can arise from the technology's complexity

  • The use of accessory instruments that are incompatible with a particular navigation system

  • Anatomical complexity, which includes brain shift and spinal movement

  • Poor registration and tracking

  • Poor image quality

To reduce the potential of mishaps, surgeons should continually assess the accuracy of the navigation system they're using throughout the surgery, the FDA advised. With electromagnetic-based navigation systems, one problem to look out for is interference from other emitters or metallic objects that can create errors.

Among other FDA recommendations, surgical teams should inspect frameless stereotaxic navigation systems before every procedure and install software updates recommended by the manufacturer.

The agency said that much of this advice applies to frame-based systems as well.

Working with manufacturers, the FDA will revise the labels of frameless stereotaxic navigation systems to include clear instructions on how to minimize accuracy errors.

More information on today's announcement is available on the FDA's website.

To report any problems with frameless stereotaxic navigation systems, contact MedWatch, the FDA's Safety Information and Adverse Event Reporting Program, by telephone at 1-800-FDA-1088; by fax at 1-800-FDA-0178; online at; with postage-paid FDA form 3500, available at; or by mail to MedWatch, 5600 Fishers Lane, Rockville, Maryland 20852-9787.

Follow Robert Lowes on Twitter @LowesRobert


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