I agree with Stryker that radiolucent cages allow post-operative visualization of fusion- in the lumbar spine- but in the cervical spine, there is so little surface area for fusion that any waste of surface area reduces the opportunity for fusion,
The other problem is that the amount of space in the center of the peek cage is so small that fusion bone is not easily visualized. Again, the edge of the PEEK cage will not fuse with the edge of the vertebra so a continuous visual line will persist even in the place of solid fusion.
The ease and speed of placing the PEEK cage is valuable to a number of surgeons but there is some cost to it.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.