Porous tantalum in spinal surgery: an overview.

Porous tantalum is an open-cell metal structure that approximates the appearance of human cancellous bone. It has a low modulus of elasticity, close to that of subchondral and cancellous bones, leading to better load transfer and minimizing the stress-shielding phenomenon. Its coefficient of friction is one of the highest among biomaterials, allowing for sufficient primary stabilization of implants, possibly even without screw fixation. Different fusion rates have been achieved in anterior cervical fusion, which lead to contradictory views among spine surgeons. However, in the lumbar spine, trabecular metal has been demonstrated to be effective in obtaining fusion and improving patient outcomes after anterior as well as posterior lumbar interbody fusion.