# US 2014/0194886 A1 · Fenestrated bone screw and method of injecting bone cement into bone structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0194886 A1 - Document ID: US20140194886A1 - Status: Published application - Kind: A1 - Application number: 14/148,270 - Filed: 2014-01-06 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Inventors: Nicholas Poulos - Web page: https://patentgrep.com/patent/US20140194886A1 ## CPC - A61B 17/7098: {wherein the implant is permeable or has openings, e.g. fenestrated screw (hollow surgical screws A61B17/864)} - A61B 17/864: {hollow, e.g. with socket or cannulated} - A61B 17/8822: {characterised by means facilitating expulsion of fluid from the introducer, e.g. a screw pump plunger, hydraulic force transmissions, application of vibrations or a vacuum} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A fenestrated bone screw and method of use is disclosed in which a bone cement injection tube may be readily and sealably connected to the head of the bone screw by means of a bayonet connector so that bone cement from a cement pump may be forced into a cannula of the bone screw and into the bone structure proximate the fenestrations of the bone screw. Upon completion of the injection of the bone cement, the cement tube may be readily disconnected from the bone screw in such manner that leakage of bone cement is minimized. A surgical method of injecting bone cement into bone structure using such a cannulated, fenestrated bone screw is also disclosed. ## Claims ### Claim 1 A bone screw having a shank, a tip, and a head, at least a portion of said shank having threads thereon configured to be threaded into bone structure, said shank having a longitudinal cannula therein, at least one fenestration extending outwardly from said cannula to the exterior of said screw, a central opening in the outer end of the head configured to form a socket for receiving a driving tool for driving the screw into bone structure, said opening being configured to form a connector inwardly of said socket and adapted to be sealably connected to a source of bone cement to said screw so that bone cement may be delivered to said cannula of said screw and forced out of said at least one fenestration and into bone structure proximate said fenestrations. ### Claim 2 (depends on 1) A bone screw as set forth in claim 1 wherein said cannula stops short of the distal end of the screw such that the screw is a blind end cannulated screw. ### Claim 3 (depends on 1) A bone screw as set forth in claim 1 wherein said cannula extends through the tip of the bone screw so that upon said injection of said cement into said cannula, said cement is forced out of the end of the cannula and into bone structure proximate the tip of the screw. ### Claim 4 (depends on 1) A bone screw as set forth in claim 1 wherein said threads each have a crest and a root, and wherein the outer end of said at least one of said fenestration is substantially centered on a thread crest. ### Claim 5 (depends on 1) A bone screw as set forth in claim 1 wherein a cement injection tube is configured to be coupled to a suitable bone cement pump and to be coupled to said connector in the head of said bone screw for the delivery of bone cement into said cannula of said bone screw. ### Claim 6 (depends on 5) A bone screw as set forth in claim 5 wherein said cement injection tube has a male connector on its distal end, and wherein said connector in the head of said bone screw has a female opening for receiving said male connector thereby to couple said tube to said screw. ### Claim 7 (depends on 6) A bone screw as set forth in claim 6 wherein said connector in the head of said bone screw has a pair of substantially diametrically opposed connection slots with each connection slot comprising an axial slot and a circumferential slot. ### Claim 8 (depends on 7) A bone screw as set forth in claim 7 wherein said male connector has a pair of substantially diametrically opposed tangs with each said tang being configured to be received in a respective one of said connection slots in said connector so that upon said tangs being aligned with said connection slots and upon said tube being moved axially toward said screw, said tangs move along said axial slots in said connector until the tangs are in register with said circumferential slots whereupon upon rotation of said tube in one direction moves said tangs into said circumferential slots thereby to connect said tube to said screw. ### Claim 9 (depends on 8) A bone screw as set forth in claim 8 further comprising a seal disposed between said male connector and said connector so that when said tangs are received within said circumferential slots said cement injection tube is sealably connected to said screw. ### Claim 10 (depends on 9) A bone screw as set forth in claim 9 wherein said seal is an O-ring. ### Claim 11 (depends on 9) A bone screw as set forth in claim 9 wherein said seal is carried by said male connector. ### Claim 12 (depends on 9) A bone screw as set forth in claim 9 wherein each of said circumferential slots has a blind end and a detent proximate said blind end for receiving a respective tang thereby to releasably secure said male connector to said connector with said seal being at least partially compressed such that the seal resiliently maintains said male connector and said connector in a mechanically coupled, sealed relation. ### Claim 13 (depends on 12) A bone screw as set forth in claim 12 wherein the end of said detent toward said axial slot has a sloped cam surface thereon. ### Claim 14 (depends on 13) A bone screw as set forth in claim 13 where when it is desired to uncouple said tube from said screw, said tube is and rotated in the opposite direction thus causing each said tang to encounter its respective said sloped cam surface thereby to guide each said tang into its respective said circumferential slot upon continued rotation of said tube in said opposite direction. ### Claim 15 (depends on 14) A bone screw as set forth in claim 14 whereupon further rotation of said tube in said opposite direction causes said tangs to move through said circumferential slots into register with said axial slots at which point said tube is axially removable from said screw. ### Claim 16 (depends on 4) A bone screw as set forth in claim 4 wherein said thread crest upon which said fenestration is substantially centered has one edge constituting a leading edge and another edge constituting a trailing edge such that upon rotation of said screw into said bone structure said leading and trailing edges minimize the entry of bone material into said fenestration. ### Claim 17 A bone screw having a shank, a tip, and a head, at least a portion of said shank having bone threads thereon for being threaded into bone structure, said shank having a central longitudinal cannula, a plurality of fenestrations extending outwardly from said cannula to the exterior of said screw, a central opening in the outer end of the head configured to form a socket for receiving a driving tool for driving the screw into bone structure, said opening having a connector inwardly of said socket configured to sealably receive a male connector, the latter being in communication with a source of bone cement so that bone cement is delivered to said cannula and injected into said bone structure adjacent said fenestrations. ### Claim 18 (depends on 17) A bone screw as set forth in claim 17 wherein said connector is tubular member having a central opening therethrough with a pair of substantially diametrically opposed axial blind slots, each of said blind slots have a circumferential slot extending circumferentially from said axial blind slot, said male connector having a pair of substantially diametrically opposed tangs each of which is adapted to be received in a respective said axial slot of said connector so that with said tangs in register with said axial slots said male connector may move axially with respect to said screw until said tangs are in register with said circumferential slots at which point said male connector is configured to be rotated such that said tangs move into said circumferential slots thereby to sealably and mechanically couple said male connector to said screw. ### Claim 19 (depends on 18) A bone screw as set forth in claim 18 further comprising a seal between said male connector and said connector. ### Claim 20 (depends on 19) A bone screw as set forth in claim 19 wherein said seal is an O-ring. ### Claim 21 (depends on 17) A bone screw as set forth in claim 17 wherein said male connector is carried on a cement delivery tube with the latter being adapted to be connected to a bone cement pump for delivery of bone cement to said cannula of said screw and to be injected into said bone structure adjacent said fenestrations. ### Claim 22 A bone screw and bone screw driving tool, wherein said bone screw has a shank, a tip and a head, at least a portion of said shank having threads thereon, said shank having a cannula extending along the central axis of the screw, a plurality of fenestrations extending outwardly from said cannula to the exterior of said screw, said head having a central opening with the outer end of the opening being configured to constitute a socket adapted to receive a driving head for driving the screw into bone structure and with the inner end of the opening being in communication with said cannula, and wherein said driving tool has a driving head adapted to be received in said socket, said driving tool further having an elongate rod extending axially from said driving head for being received within said cannula of said screw when said driving head is received in said socket, said rod being of a length sufficient to extend axially within said cannula so as to minimize bone material entering said cannula as the screw is driven into bone structure. ### Claim 23 (depends on 22) A bone screw and bone screw installation tool as set forth in claim 22 wherein said bone screw is a fully cannulated bone screw such that the cannula extends through the tip of the screw, and wherein said rod is of a length so as to extend beyond the most distal of said fenestrations but to terminate short of said tip. ### Claim 24 A method of injecting bone cement into surrounding bone structure, said method comprising the steps of: Installing a bone screw into bone structure, said bone screw having a shank, a tip, and a head, at least a portion of said shank have threads thereon, said shank having a cannula extending from said head, a plurality of fenestrations extending outwardly from said cannula, said head having a central opening with the inner portion of said central opening being in communication with said cannula and with the outer portion of said central opening being configured to receive a driving tool for driving the screw into bone structure, said inner portion of said central opening being configured to be sealably coupled to and uncoupled from a supply of bone cement so that bone cement may be delivered to said cannula and forced out of said fenestrations into said bone structure adjacent said fenestrations; Sealably connecting said supply of bone cement to said screw; and Injecting bone cement into said cannula of said bone screw and into said bone structure proximate said fenestrations. ### Claim 25 (depends on 24) The method of claim 24 wherein said bone screw is a fully cannulated bone screw with said cannula extending from said head through said tip of said bone screw, and wherein said step of injecting bone cement includes injecting bone cement into said bone structure proximate the tip of said bone screw. ### Claim 26 (depends on 24) The method of claim 24 further comprising the step of disconnecting said supply of bone cement from said bone screw. ### Claim 27 (depends on 24) The method of claim 24 wherein said supply of bone cement includes a cement delivery tube having a male connector on its distal end configured to be received in said central opening and a seal between said male connector and said head of said screw. ### Claim 28 (depends on 27) The method of claim 27 wherein, after injecting bone cement into said bone structure, said method further comprising inserting a plunger through said cement delivery tube and into the cannula of said screw thereby to substantially prevent cement within said cannula form leaking from said screw upon disconnecting said cement injection tube from said screw. ### Claim 29 (depends on 24) The method of claim 24 wherein said central opening in the head of said screw is configured to be a female connector installed in the inner portion of said central opening and further configured to receive a male connector carried on the end of a cement delivery tube, and wherein said female and male connectors are bayonet connectors and have a seal disposed between them, said method further comprising inserting said male connector in said female connector and twisting said tube thereby to lock said male and female connectors and to compress said seal so as to seal said tube to said screw. ### Claim 30 A method of injecting bone cement into surrounding bone structure, said method comprising the steps of: a. Installing a plurality of bone screws into adjacent bone structure, each said bone screw having a shank, a tip, and a head, at least a portion of said shank having threads thereon, said shank having a cannula extending lengthwise of the screw, a plurality of fenestrations extending outwardly from said cannula, said head having a central opening with the outer portion of the opening configured to receive a driving tool for driving the screw into bone structure, said central opening in said head having an inner portion configured to sealably receive a cement delivery tube so that a suitable bone cement may be injected into said cannula of said screw and forced out of said fenestrations and into the surrounding bone structure; b. Sealably connecting one of said cement delivery tubes to each said screw; c. Connecting a cement pump to a first one of said cement injection tubes; d. Injecting cement into said cannula of a first one said bone screw and into said bone structure proximate said first screw; e. Removing said cement pump from said first cement injection tube substantially without leakage of cement adjacent the head of said first screw; f. Connecting said cement pump to a second cement injection tube; g. Injecting cement into the cannula of a second of said bone screws; and h. Removing said cement injection tube from its respective said second screw substantially without leakage of cement adjacent the head of said second screw. ### Claim 31 (depends on 30) The method of claim 30 further comprising repeating steps (e) through (h) until all of said plurality of bone screws have had cement injected into the bone structure proximate each of said bone screws.