Bone File #33DDP Elite USA Bone File #33 is ideally suit for use in neurosurgical and orthopedic surgeries that require manipulation of bone in and around delicate tissue structures. This type of instrument can be useful in filing down the skull in procedures like craniotomies or in reshaping the vertebral arch during laminectomies or hemi laminectomies. This gives added protection to the brain tissue or neurovascular bundles that can pass over these cut surfaces