In September 2012, the U.S. Food and Drug Administration (FDA) convened a meeting of the Orthopaedic and Rehabilitation Devices Panel to consider whether a Class II device designation would be appropriate for posterior cervical screw fixation (including cervical pedicle and lateral mass screws).

These devices are components of rigid, posterior, spinal screw-and-rod systems generally intended as an adjunct to fusion for the treatment of degenerative disk disease (as defined by neck pain confirmed by radiographic studies), trauma, deformity, failed previous fusion, tumor, infection, and inflammatory disorders in the cervical spine.

The panel’s recommendations were based on evidence prepared by the FDA, material included in the classification petition submitted by the Orthopaedic Surgical Manufacturers Association (OSMA), and presentations from professional societies and the public.

AAOS members Paul A. Anderson, MD; Todd J. Albert, MD (representing the Scoliosis Research Society); and Lee H. Riley III, MD (representing the Cervical Spine Research Society), as well as surgeon representatives from the American Association of Neurological Surgeons and the North American Spine Society were among those who addressed the panel. John D. Kelly IV, MD, chaired the panel.

Subsequent to the presentations and deliberation, the panel made the following determinations:

Safety and effectiveness
Panel members agreed that available scientific evidence supports a reasonable assurance of safety and effectiveness for the use of cervical screw fixation systems in treating the proposed, indicated population. The panel did express concerns regarding future training of surgeons and collection of long-term data.

Proposed indications

• Panel members reached a general consensus supporting the FDA’s proposed indications for use, including the specific screw trajectories presented by the FDA.
• Reasonable evidence exists to support use of posterior cervical screws as an adjunct to fusion in the pediatric population. The FDA recognizes that this determination is based on a modest level of evidence and lack of long-term clinical data. Panel members emphasized that size of the osseous elements is more critical than the patients’ chronological age.
• The panel reached a general consensus supporting the nonfusion use of posterior cervical screws for a limited period in patients who have advanced stage tumors involving the cervical spine and whose life expectancy is of insufficient duration to permit achievement of fusion. Panel members emphasized that this consensus applies only to this narrow patient population and should not be extrapolated to other nonfusion applications or technology.

Risks

• Other than the risks associated with the presence of the vertebral arteries, the panel did not identify any other unique risks, as compared to other spinal implants, which may be present in the cervical spine.
• The panel confirmed the completeness of the FDA’s identified risks to health. In addition, the risk of iatrogenic foraminal stenosis associated with implant-related changes in spinal alignment resulting in neurologic injury was also raised.

Controls
The panel supported the adequacy of the proposed special controls. An additional recommendation was made with regard to the specific risks relating to C3–C6 pedicle screw placement. The panel supported the requirement that cross-sectional imaging be part of preoperative planning for procedures using posterior cervical screw fixation.

Summary
The use of internal cervical fixation dates back more than 75 years and has evolved to include placing screws into the lateral masses of the cervical spine. Although this practice is widespread, the use of posterior cervical screws in this application is not among the labeled indications. As such, rules governing the physician-directed use of devices prohibit manufacturers from teaching this technique in courses that they sponsor. The rules also complicate efforts to secure the hardware necessary to provide instruction in other venues, such as surgical skills courses sponsored by organizations like the AAOS. Concerns about these regulations further inhibit research and publication of clinical observations that would add to understanding of safety and effectiveness and enhance patient outcomes.

The FDA’s decision on posterior cervical screw systems is expected to be released later this year. Once the classification is finalized, the uses described above will become labeled indications, freeing surgeons and manufacturers from off-label constraints related to the teaching and promotion of those uses.

Katherine Sale is manager, biomedical research & regulation in the AAOS department of research & scientific affairs. She can be reached at sale@aaos.org

Background Information
In 1993 and 1994, the FDA held panel meetings to consider data related to all pedicle screw fixation systems, which were unclassified at the time. A 1998 final rule classified thoracolumbosacral pedicle screw systems as Class II devices for the following ­indications:

• degenerative spondylolisthesis with objective evidence of neurologic impairment
• fracture
• dislocation
• scoliosis
• kyphosis
• tumor
• failed previous fusion

Degenerative disk disease was specifically excluded due to a lack of conclusive clinical data; use of pedicle screw systems for this condition is still considered a Class III indication. The 1998 rule did not provide any classification for the use of pedicle screws in the cervical spine or in skeletally immature patients.

In 2009, the FDA requested safety and effectiveness information for several device types, including pedicle screw systems for use in the thoracic, lumbar, and sacral spine as an adjunct to fusion for treatment of degenerative disk disease and types of spondylolisthesis. Data regarding the use of posterior cervical screw fixation were submitted, necessitating a separate classification petition and, ultimately, a panel hearing to consider the classification.

Additional Information
Orthopaedic and Rehabilitation Devices Panel Meetings
September 21, 2012: Meeting Materials FDA Generated