Threaded washer and bone screw apparatus

摘要

A threaded washer with a central bore for use with a bone screw is disclosed. The washer is threaded into a counterbore extending below the bone surface and into cancellous bone material. The external washer threads are tapered to provide improved purchase. The bone screw is inserted through the central bore of the washer and threaded into the fragment beyond the fracture. The washer provides improved compressive forces while permitting the bone screw head to be located beneath the bone surface.