PEEK Spinal Cage: Uses, Properties, and Patient Questions

PEEK means polyether ether ketone, a strong medical-grade polymer used in some spinal implants. A spinal cage is shaped to fit between vertebrae after a damaged disc is removed or prepared. It helps maintain space and alignment while bone grows across the treated segment.

The cage may be used with bone graft material and additional fixation, such as plates, rods, or screws. It is not a replacement for the entire spine or a guarantee that fusion will occur.

PEEK is relatively light and radiolucent, meaning it creates less obstruction on many X-rays than metal. This can help clinicians assess the surrounding bone and the progress of fusion. Its stiffness and surface design are engineered to work with the surrounding vertebral structures, while the implant’s exact behaviour depends on its design and placement.

PEEK cages are used in selected spinal fusion operations in the neck or lower back. In cervical fusion, a cage may be placed between neck vertebrae after disc removal to help restore disc height and support fusion. Read about [Cervical Fusion](/treatments/spine-care/cervical-fusion/) and [Spinal Fusion](/treatments/spine-care/spinal-fusion/).

Other choices include cages made from titanium or different polymers, bone graft without a cage in selected situations, or a non-fusion procedure when the diagnosis allows it. The surgeon weighs anatomy, bone quality, alignment, the level treated, and the need for additional fixation when selecting an implant.

The cage is an internal support used while the treated vertebrae heal together. Recovery instructions may include wound care, movement limits, physiotherapy, and follow-up imaging. Ask what material and graft are planned, whether a plate or screws will be added, and how the team will check healing.

A cage is generally intended to remain in place after a successful fusion. Possible problems include infection, movement or sinking into bone, nerve symptoms, swallowing difficulty after some neck operations, or failure of the bones to join. Fever, wound drainage, new weakness, severe pain, or difficulty breathing or swallowing should receive prompt medical attention.