Cervical spine rod-to-rod connector failure and pedicle screw malalignment with loosening
Citation, DOI & case data
Neck and back pain after multiple vertebral fusions
CT Cervical Spine
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There are devices present in the dorsal paraspinal hardware at the level of C6 likely intended to connect the bilateral cervical spinal rods to the ipsilateral thoracic paraspinal rods; however the paraspinal thoracic rods are subluxed posteromedially on the left and posteriorly on the right and are not secured in these devices.
CT Thoracic Spine
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There is a 4 mm of lucency adjacent to the right pedicle screw at T2 and 3 mm of lucency adjacent to the left pedicle screw at T2
The pedicle screw on the right at T3 and the pedicle screw on the left at T3 are about the lateral aspects of the T3 vertebral body and not fully contained within the T3 vertebral body.
The bilateral pedicle screws at the level of T4 are about the lateral aspects of the T4 vertebral body and are not fully contained within the T4 vertebral body
The right pedicle screws at the levels of T6 and T7 are lateral of the vertebral bodies
There is a spinal cord stimulator present with a wire entering the spinal canal
This is a case of a 55 year old female presenting with severe pain along her cervical and thoracic spine. She also had difficulty holding her head erect. Prior to the above scans, she most recently had a posterior C7 – T9 vertebral fusion 6 months ago. She returned multiple times for poor wound healing requiring multiple I&Ds, debridements, and wound vac placements. She also required an additional closure with a plastic surgeon. Her surgical history was complicated with over 10 previous surgeries over the course of a decade.
This case demonstrates multiple failures with orthopedic hardware.
These are domino connector devices used in revision and extension procedures which eliminate the need for hardware removal when doing an extended fusion or revision. When hardware fails, it can result in pseudoarthroses, non-union, and significant pain.
Pedicle screw loosening can be visualized by both X-ray and CT as lucency around the screw threads. Both modalities show low sensitivity but high specificity. One study showed that X-rays demonstrated 54.2% sensitivity and 83.5% specificity while CT demonstrated 64.8% sensitivity and 96.7% specificity 1.
Misplaced pedicle screws have an increased risk of non-union and morbidity. Back pain, spinal stenosis, radiculopathy, and neurogenic claudication are common post-surgical complaints. Spine surgery has a high burden of medical liability and malpractice litigation with misplaced pedicle screws being a common cause for claims 2.
This patient was taken for revision surgery after the above findings were reported. Intra-operatively, multiple non-unions were found. Revision was successful and the patient was pain-free at 1 month follow-up.
Case authors: Le J, Senti M, Huser M
- Sankey E, Mehta V, Wang T et al. The Medicolegal Impact of Misplaced Pedicle and Lateral Mass Screws on Spine Surgery in the United States. Neurosurg Focus. 2020;49(5):E20. doi:10.3171/2020.8.FOCUS20600 - Pubmed
- Spirig J, Sutter R, Götschi T, Farshad-Amacker N, Farshad M. Value of Standard Radiographs, Computed Tomography, and Magnetic Resonance Imaging of the Lumbar Spine in Detection of Intraoperatively Confirmed Pedicle Screw Loosening-A Prospective Clinical Trial. Spine J. 2019;19(3):461-8. doi:10.1016/j.spinee.2018.06.345 - Pubmed