Complications in Thoracic and Lumbar Pedicle Screw Fixation
BY EDITOR, AUGUST 12, 2009
As part of our collaboration with ArgoSpine, we're republishing select content from the ArgoSpine News and Journal for our audience. The article below, written by Evalina Burger of the Spine Center at the University of Colorado Hospital, was first published in 2008 under the title "Thoracic and Lumbar Pedicle Screw Fixation."
Goal of the paper: To discuss the complications from inserting pedicle screws in the Thoracic
and Lumbar area. Historically we have gained much experience and became more proficient over the years as is clear by reading the literature of the first pedicle screw complications. Navigational surgery has further enhanced our ability to understand the 3D concept of the spine.
Complications can be divided in different categories:
- Surgeon error: pre-surgical planning and intra-operative events
- Anatomical anomalies
- Acute complications
- Long term complications
- Mechanical complication inherent to the implant
Most complications are a combination of poor judgment and planning combined with intra-operative fatigue and lack of concentration in long cases. Intra-operative events such as an unforeseen failure of equipment or a medical emergency necessitating immediate termination of the surgery can play a role in the misplacement of screws. As we are getting more proficient in the principles of pedicle screw placement, the surgeon should be aware of subtle anatomical variations. The sacrum is most frequently misjudged with big differences in the orientation of the foramina in position and size. Over distraction in a poor bone interface or aggressive in situ contouring or corrections of deformity can lead to fractures of the pedicles. Underestimation of the forces in correcting major deformities with under sizing of implants can contribute to failure with screw breakage and loosening.
Management: The best management is prevention; however misplaced screws should be removed or replaced if they pose a problem with fixation or neurological damage. The best methods of diagnosing these will be with a CT scan. It will be too costly to perform on every patient but in case of doubt; this is the only way to determine the position of the implant.
