Used for up-biting Kerrison decompression of the caudal edge of the lamina during cervical and lumbar microdiscectomy through a midline approach. The 40-degree footplate slides beneath the ligamentum flavum while the punch removes hypertrophic bone impinging on the dural sac. Neurosurgeons select this configuration when decompressing lateral recess stenosis at the L5–S1 segment.

Applied during posterior cervical foraminotomy to remove the medial facet and uncover the exiting C6 or C7 nerve root. This Kerrison variant provides a complementary cutting angle to the primary rongeur for complete foraminal decompression. Spine fellows use it to undercut the superior articular process without violating the pars interarticularis.