I'm an orthopaedic surgeon, and I doubt it's anything more than just a typical spacer that is commonly used.
OK found the article, and I'm corect.
The title is misleading - it's just a 3D printed version of spacers that are commonly used - it really doesn't look, nor function any differently than the ones currently being used. The patient had a non-ossifying fibroma - rare in the spine, but benign, and will turn into regular bone eventually. This could have been treated with some bone graft and a plate and screws, which is basically what they did.
Nothing really new here.