Stable-L Lumbar Interbody System

The Stable-L Lumbar Interbody System is a spinal fusion device used in skeletally mature patients with symptomatic degenerative disc disease. It consists of titanium alloy interbody cages (additively manufactured) and bone screws inserted at one or two adjacent lumbar levels (L2–S1) alongside autogenous or allogenic bone graft. The device can feature integrated blade fixation or screw fixation, with supplemental posterior fixation required for hyperlordotic implants (>20° lordosis).

The subject device adds interbody cages with integrated blade fixation and expands size offerings compared to the predicate standalone system. Materials remain identical (Ti-6Al-4V ELI per ASTM F3001 for cages; titanium alloy per ASTM F136 for screws). Minor modifications to the Stable-L Cover Plate were also included, and shelf life for sterile devices was extended. Overall geometry is substantially the same with only slight differences.

ASTM F2077 (dynamic compression and dynamic shear testing), ASTM F3001 (titanium alloy for additive manufacturing), ASTM F136 (titanium alloy for fasteners). Additional testing included expulsion, blade compression/collapse, insertion, and screw pull-out testing on cover plates.

The subject device is substantially equivalent because it uses identical materials and falls within the indications for use of the predicate devices (Stable-L Standalone and supplemental predicates). Although geometry differs slightly to accommodate integrated blade fixation and expanded sizes, confirmatory performance testing demonstrates equivalent mechanical behavior to the predicate under compression and shear loads. The design modifications do not raise new safety or effectiveness concerns, and the device maintains the same intended clinical function.