Fracture of allograft interbody spacer resulting in post-operative radiculopathy: A case report

BACKGROUND: Allograft interbody spacers are utilized during transforaminal lumbar interbody fusion (TLIF) to reestablish anterior column support and disc height. While the TLIF technique offers many improvements over previous surgical methods, instrumentation and bone graft-related complications such as spacer misplacement or migration, screw fracture or misplacement, or rod breakage continue to be reported. The objective of this manuscript is to report on a fractured allograft interbody spacer that displaced into the neural foramen and resulted in impingement on the exiting nerve root that required revision. CASE SUMMARY: A 50-year-old male had two-level TLIF with immediate post-operative right L5 radiculopathy. Computed tomography scan demonstrated a fractured allograft interbody spacer that displaced into the right neural foramen and impinged on the exiting L5 nerve root. Revision surgery was performed to remove the broken allograft fragments from the right L5 foramen and the intact portion of the spacer was left in place. The right leg L5 radicular pain resolved. At the last follow up 12 mo after the index procedure, computed tomography scan confirmed sound interbody and posterolateral fusion. CONCLUSION: Displacement of broken allograft interbody spacer following TLIF procedures can result in neurological sequelae that require revision. To avoid such an occurrence, the authors recommend allowing sufficient time for the reconstitution of the graft in saline prior to use to decrease brittleness, to use an impactor size that is as close as possible to the spacer size and meticulous inspection of the cortical allograft spacer for any visible imperfection prior to insertion.