Cage Migration of Lumbar Interbody Fusion Cage

  Just heard a buzz from a representative of German Spine company that titanium lumbar cage is revived in Europe instead of PEEK cage. That, titanium cage has less incidence of migration than PEEK cage.

Cage protruded posteriorly. L5-S1 PLIF Ti Cage + pedicle screw,

  Talking about pull out force of both materials , it is understandable from this paper: "The titanium cage pull out force was significantly (P=0.0002) higher compared to both radiolucent cage constructs."
 No wonder, the hearsay may be true of higher incidence of PEEK cage migration.
  Even you make a bigger footprint of PEEK cage, migration is still likely :"The larger footprint radiolucent cage did not increase stability as compared to the standard footprint."

PEEK stand-alone cage at L3-4 level; the cage migrated persistently inside the space  eroding the vertebrae and resulted in a big defect (red arrow). The 58 y/o male was disabled then cured by other method.

  Supplemental posterior instrumentation is not even a safeguard to prevent migration of PEEK cage.
  Fortunately, this case report used lateral access, and the cage migrated to lateral side, no sequel occurred. The authors are thinking about solution of putting a lateral plate with screws to prevent the cage slip away.

  Posterior migration may result in disaster, either titanium or PEEK are alike.