Various embodiments of the spinal fusion involve methods and apparatuses for securing an interbody graft between adjacent vertebrae after a direct lateral interbody fusion (DLIF) or anterior lumbar interbody fusion (ALIF) procedure.

Key Features

• Unique Fastener Assembly
  The invention includes a fastener assembly with an asymmetric washer, featuring a major and minor lobe, and a screw designed to secure the major lobe near the interbody region, effectively retaining the graft in place after a DLIF procedure.

• Locking Screw Assembly
  A locking screw assembly with a washer and a screw having mating locking features allows surgeons to adjust the washer’s angular position relative to the interbody region for precise placement.

• Graft Retention Methods
  The method for replacing disc material involves inserting a washer and screw through a guide sleeve adjacent to the interbody space, then attaching the screw to the vertebral bodies to hold the graft in place during bony growth.

• Enhanced DLIF Graft Retention Assemblies
  Additional embodiments feature a dog bone washer secured by fasteners, a screw locking mechanism for precise washer positioning, and designs that facilitate angled screw insertion while keeping the screw head aligned with the vertebral body surface. Other designs include washers with angled threaded holes for angled screw insertion and washers that resiliently deform as screws are driven into the vertebral body.