Trocar-tipped drill bit

Abstract

A drill bit for drilling through bone may include a fluted portion and a trocar tip disposed at an end of the fluted portion. The trocar tip may include an outer lateral surface that is tapered at an angle ranging from about 5 degrees to about 15 degrees relative to a longitudinal axis of the drill bit.

What is claimed is: 
     
         1 . A drill bit for drilling through bone, the drill bit comprising:
 a fluted portion; and   a trocar tip disposed at an end of the fluted portion, wherein the trocar tip comprises an outer lateral surface that is tapered at an angle ranging from about 5 degrees to about 15 degrees relative to a longitudinal axis of the drill bit.   
     
     
         2 . The drill bit of  claim 1 , wherein the lateral outer surface of the trocar tip comprises a plurality of sides that are curved or planar. 
     
     
         3 . The drill bit of  claim 1 , wherein the trocar tip comprises from 3 to 8 lateral sides. 
     
     
         4 . The drill bit of  claim 1 , wherein the fluted portion comprises a plurality of flutes. 
     
     
         5 . The drill bit of  claim 4 , wherein each of the plurality of flutes comprises a primary cutting edge between the trocar tip and a remainder of the fluted portion. 
     
     
         6 . The drill bit of  claim 5 , wherein the plurality of cutting edges are in a plane substantially perpendicular to a longitudinal axis of the drill bit. 
     
     
         7 . The drill bit of  claim 5 , wherein each of the plurality of cutting edges has a cutting angle ranging from about 5° to about 20° with respect to a plane perpendicular to a longitudinal axis of the drill bit. 
     
     
         8 . The drill bit of  claim 5 , further comprising additional cutting edges positioned between the plurality of primary cutting edges and the remainder of the fluted portion. 
     
     
         9 . The drill bit of  claim 8 , wherein each of the additional cutting edges has a cutting angle ranging from about 25° to about 50° with respect to a plane perpendicular to the longitudinal axis of the drill bit. 
     
     
         10 . The drill bit of  claim 1 , further comprising a countersink portion disposed at an end of the fluted portion opposite the trocar tip. 
     
     
         11 . The drill bit of  claim 10 , wherein the countersink portion is tapered at an angle ranging from about 18° to about 80° relative to the longitudinal axis of the drill bit. 
     
     
         12 . The drill bit of  claim 1 , wherein the trocar tip is configured to drill through relatively hard bone and the fluted portion is configured to drill through relatively soft bone. 
     
     
         13 . The drill bit of  claim 1 , wherein the trocar tip is configured to drill through cortical bone and the fluted portion is configured to drill through cancellous bone. 
     
     
         14 . The drill bit of  claim 1 , wherein a cross-sectional area of the fluted portion taken in a plane perpendicular to a longitudinal axis of the fluted portion is greater than the largest cross-sectional area of the trocar tip taken in any plane perpendicular to the longitudinal axis. 
     
     
         15 . A drill bit for drilling through bone, the drill bit comprising:
 a fluted portion terminating in an end face; and   a trocar tip disposed on the end face, wherein a perimeter of the end face extends radially beyond the trocar tip, wherein the trocar tip comprises an outer tapered surface that tapers at an angle ranging from about 5 degrees to about 15 degrees relative to a longitudinal axis of the drill bit.   
     
     
         16 . The drill bit of  claim 15 , wherein the outer surface of the trocar tip comprises a plurality of sides that are curved or planar. 
     
     
         17 . The drill bit of  claim 15 , wherein the trocar tip comprises from 3 to 8 lateral sides. 
     
     
         18 . The drill bit of  claim 15 , further comprising a plurality of primary cutting edges disposed along the end face of the fluted portion. 
     
     
         19 . The drill bit of  claim 18 , further comprising additional cutting edges positioned between the plurality of primary cutting edges and the remainder of the fluted portion. 
     
     
         20 . A system for drilling through bone, the system comprising:
 a drill bit comprising:
 a fluted portion comprising a plurality of flutes, and 
 a trocar tip disposed at an end of the fluted portion, wherein the trocar tip comprises a tapered, non-fluted lateral outer surface; and 
   a sleeve configured to be disposed relative to the drill bit to limit a penetration depth of the drill bit during drilling.   
     
     
         21 . The system of  claim 20 , wherein each of the plurality of flutes of the drill bit comprises a primary cutting edge between the trocar tip and a remainder of the fluted portion. 
     
     
         22 . The system of  claim 21 , further comprising additional cutting edges positioned between the plurality of primary cutting edges and the remainder of the fluted portion. 
     
     
         23 . The system of  claim 20 , wherein the sleeve is fitted over at least a portion of the drill bit. 
     
     
         24 . The system of  claim 20 , wherein the sleeve is permanently attached to the drill bit. 
     
     
         25 . The system of  claim 20 , wherein the sleeve is configured to be removeably positioned relative to the drill bit.