The US Food and Drug Administration (FDA) has cleared Medtronic’s CD Horizon fenestrated screw set. This marks the first US clearance for cement-augmented pedicle screws.
The product can be used for patients diagnosed with advanced stage tumours involving the thoracic and lumbar spine. The fenestrated screws are designed for use with Medtronic’s HV-R fenestrated screw cement, a polymethylmethacrylate (PMMA) cement, and are intended for use at spinal levels where the structural integrity of the spine is not severely compromised.
“Current cancer treatments can weaken a patient’s bones and primary malignancies often spread to the spine, which cause considerable pain and are complex to manage,” says Francis H Shen, an orthopaedic surgeon from Charlottesville, USA. “When placed into compromised bone, traditional screws run the risk of loosening over time. The ability to utilise cement augmentation directly through a fenestrated screw…allows me to achieve immediate implant stability, which would not be possible with traditional non-augmented screws. More importantly this allows me to help to mobilise my patients more quickly.”
The fenestrated screw set features cannulated pedicle screws designed with six holes located near the end of the screw, intended to allow controlled cement injection into the targeted vertebral body after having placed all of the screws. The self-curing PMMA cement should provide immediate screw fixation in the patient’s spine. According to a press release, it significantly increases the screw pull-out strength compared to standard screws. The cement is injected through a continuous tract in the adapter and into the screw cannula. This continuous tract delivery system is designed to have a completely secure channel that can be visually verified outside the patient, to help reduce the likelihood of cement leakage at the adapter/screw interface, while being compatible for minimally invasive surgery (MIS) and open procedures.
