Intraspinal metalloma causing lumbar stenosis after interbody fusion with cylindrical titanium cages.

Intraspinal metallomas are rare. The authors present a case after implantation of two titanium threaded interbody cages at the L4L5 level, without posterior instrumentation. To their knowledge this is the first case due to intervertebral cages. The lack of additional instrumentation had probably allowed the cages to make contact. Subsequently, friction generated wear debris, which led to the formation of a granuloma, responsible for compression of the dural sac. Intraspinal metallosis should be kept in mind as an infrequent cause of delayed neurological symptoms after spinal surgery with metallic instrumentation.