Orthopedic fastener method
An orthopedic structure includes a method for making a threaded fastener with thread geometry and leading edge geometry which provides greater precision during installation. Specifically, thread pitch and tooth profiles are independently variable. A leading portion of the fastener advances bone shards forward of the forward of the fastener to reduce insertion torque and prevent the shards from residing in the upstream tooth profile for better retention.
1. A process for forming an orthopedic fastener wherein the orthopedic fastener is adapted to be inserted into a skeletal structure, the steps including:
forming an interlocking thread on a substantially cylindrical stock of orthopedic grade substrate,
forming first ( 19 ) and second facets ( 23 ) of said interlocking thread on said substrate with a first cutting tool while inducing relative rotation between the substrate and the first cutting tool and providing clearance for a second cutting tool,
forming a third facet ( 20 ) on said substrate with a second cutting tool while still inducing rotation, and providing clearance for a third cutting tool,
forming fourth ( 21 ) and fifth facets ( 22 ) on said substrate with a third cutting tool while inducing counter rotation whereby counter rotation improves thread profile.
2. The process of claim 1 , further including counter rotating said substrate and forming a self-tapping cutting means on a distal end of said substrate thereby forming a fastener which advances bone fragments forward away from said interlocking threads.