Compressive intramedullary nail

• US 5,057,103 A
• Filed: 05/01/1990
• Issued: 10/15/1991
• Est. Priority Date: 05/01/1990
• Status: Expired due to Fees

• Current Assignee: Emsley A. Davis
• Original Assignee: Emsley A. Davis
• Inventors: Davis, Emsley A.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Owens, Kerry
• Application Number:
  US07/517,583
• Time in Patent Office: 532 Days
• Field of Search: 606/60-63, 606/66-68
• US Class Current: 606/63
• CPC Class Codes: A61B 17/7225 for bone compression
• CPC Class Codes: A61B 17/7233 with special means of locking the nail to the bone
• CPC Class Codes: A61B 17/7266 with fingers moving radially outwardly
• CPC Class Codes: A61B 17/921 for intramedullary devices
• CPC Class Codes: A61B 2017/922 Devices for impaction, impact element

Abstract

A nail is inserted into the medullary canal of a fractured bone to fixate the bone segments in order to promote healing. The nail provides compressive force to close the fracture and further promote healing. The nail has an outer member and an inner member that is slidable within the outer member. The inner member has at one end arms for engaging the interior of the bone cortex in the distal bone segment and at the other end a holding member for engaging the cortex in the proximal bone segment. The arms are movable between stowed positions, for allowing the insertion of the nail into the bone, and deployed positions, for engaging the bone cortex. The force exerted by the arms and the holding member on the bone is adjustable.

Claims

1. A device for use in promoting healing of a fractured bone in a human or animal, said bone having a cortex, a medullary canal and a fracture site, comprising:

a) an elongated insertable member having a longitudinal axis, a first end portion, and a second end portion, and having an exterior surface, said insertable member having a transverse dimension which is small enough to allow the insertion of said insertable member into the medullary canal of said bone;

(b) first holding means located at said insertable member first end portion, said first holding means being adapted for engaging said bone cortex and for holding said first end portion in position relative to said bone cortex when so engaged;

(c) said first holding means being expandable into an engagement position from a stowed position in said insertable member, wherein said insertable member first end portion can be inserted into the medullary canal of said bone when said first holding means is in said stowed position;

(d) second holding means coupled with said insertable member second end portion, said second holding means being adapted for engaging said bone cortex and for holding said second end portion in position relative to said bone cortex when so engaged;

(e) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said fist and second holding means;

(f) said first holding means comprising plural arms that are pivotable between said stowed position and said engagement position;

(g) said second holding means comprising a flanged cap member that is adapted to engage an outer surface of said bone cortex;

(h) said pivotable arms of aid first holding means have free ends that are adapted for engaging said bone cortex, said pivotable arms comprising snag means for snagging said cortex and for providing that said pivotable arms securely engage said bone cortex, said snag means being located at the free ends of said pivotable arms.

2. The device of claim 1 wherein each of said snag means comprises a projection extending from said free end of each pivotable arm, each of said projections having a sharp edge that is adapted to engage an interior surface of said bone cortex.

3. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer ember;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with aid first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) deploying surfaces on said outer ember at said first end portion openings, said deploying surfaces being adapted to outwardly deploy said arms when said inner member is moved toward said outer member first end portion;

(i) said second holding means comprises a flanged cap member that is adapted to engage an outer surface of said bone cortex;

(i) said pivotable arms of said first holding means have free end that are adapted for engaging said bone cortex, said pivotable arms comprising snag means for snagging said cortex and for providing that said pivotable arms securely engage said bone cortex, said snag means being located at the free ends of said pivotable arms.

4. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with aid exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) deploying surfaces on said outer member at said first end portion openings, said deploying surfaces being adapted to outwardly deploy said arms when said inner member is moved toward said outer member first end portion;

(i) said second holding means comprises a flanged cap member that is adapted to engage an outer surface of said bone cortex;

(j) said retaining means comprises a retaining cap that is coupled to aid outer member second end portion, said retaining cap having an opening that is aligned with said outer member second end portion opening, said retaining cap opening being of a smaller diameter than said inner member second end, wherein said cap opening limits the movement of said inner member towards said outer member second end portion when said arms are in said deployed position.

5. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) said inner member has a passage therein extending between said inner member first and second ends, said passage being adapted for receiving a guide wire for use in inserting said device into said medullary canal.

6. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means in the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) said pivotable arms of said first holding means have free ends that are adapted for engaging said bone cortex, said pivotable arms comprising snag means for snagging said cortex and for providing that said pivotable arms securely engage said bone cortex, said snag means being located at the free ends of said pivotable arms.

7. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) said retaining means comprises a retaining cap that is coupled to said outer member second end portion, said retaining cap having an opening that is aligned with said outer member second end portion opening, said retaining cap opening being of a smaller diameter than said inner member second end, wherein said cap opening limits the movement of said inner member towards said outer member second end portion when said arms are in said deployed position.

8. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) said exterior surface of said outer member is polygonal in transverse cross-section.

9. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said first holding means comprises plural arms that are pivotally coupled to said inner member;

(h) insertion mean for inserting and removing said outer and inner members from said bone, said insertion means comprising a rod having a fixed end and a free end, said fixed end being adapted to be removably coupled to said inner member second end, said rod having stop members thereon, said rod having throw weight means thereon, said throw weight means being movable along said rod between said stop members.

10. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an elongated outer member having first and second end portions and a longitudinal axis extending therebetween, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings communicating with the exterior of said outer member, said openings being located at said first and second end portions, said outer member having an exterior surface that is polygonal in transverse cross-section;

(b) an elongated inner member having first and second ends, said inner member being located within said outer member passage such that said inner member first and second end are adjacent to said outer member first and second end portions respectively;

(c) first arm means adapted to engage said bone cortex, said first arm means comprising plural first arms that are pivotally coupled to said inner member first end with hinge means, said first arms being pivotable between stowed and deployed positions, wherein when said first arms are in said stowed position said first arms are located within said outer member such that said outer member can be inserted into said medullary canal and when said first arms are in said deployed position said first arms extend out from said outer member through said outer member first end portion openings, said first arms being moved between said stowed and deployed positions by sliding said inner member in said outer member, said first arms having snag means to engage said bone cortex;

(d) said outer member first end portion openings having inclined surfaces wherein when said inner member is slid in said outer member to deploy said first arms said inclined surfaces force said first arms outward;

(e) bolt means coupled to said inner member second end, said bolt means extending through said outer member second end portion opening;

(f) second arm means adapted to engage said bone cortex, said second arm means slidingly coupled to said bolt means, said second arm means comprising projections that extend radially outward from aid bolt means, wherein said bolt means can adjust the distance between said first and second arm means;

(g) a retaining cap adapted to be removably coupled to said outer member, said retaining cap having an opening for receiving said bolt means, said retaining cap having stop surfaces for preventing movement of said inner member away from said outer member first end portion when said first arms are in said deployed position in order to retain said first arms in said deployed position.

11. The device of claim 10 wherein aid inner member has a passage therein extending between said inner member first and second ends, said passage being adapted for receiving a guide wire for use in inserting said device into said medullary canal.

12. The device of claim 10 further comprising insertion means for inserting and removing said outer and inner members from said bone, said insertion means comprising a rod having a fixed end and a free end, said fixed end being adapted to be removably coupled to said inner member second end, said rod having stop members thereon, said rod having trow weight means thereon, said throw weight means being movable along said rod between said stop members.

13. The device of claim 10, further comprising:

(a) insertion means for inserting and removing said outer and inner members from said bone, said insertion means comprising a rod having a fixed end and a free end, said fixed end being adapted to be removably coupled to said inner member second end, said rod having stop members thereon, said rod having throw weight means thereon, said throw weight means being movable along said rod between said stop members;

(b) said inner member has a passage therein extending between said inner member first and second ends, said passage being adapted for receiving a guide wire for use in inserting said device into said medullary canal.

14. A method for promoting healing of a fractured long bone in a human or animal, said bone having a cortex, a medullary canal and a fracture site, said fracture site separating said bone into a proximal segment and a distal segment, comprising the steps of:

(a) entering said medullary canal from the end of said proximal segment;

(b) removing tissue from said medullary canal so as to form a passage, said passage spanning said fracture site from said proximal segment to said distal segment;

(c) providing nail means which is adapted to be inserted into said medullary canal, said nail means having first and second holding means adapted to engage said cortex, said first holding means being deployable from a stowed position, providing insertion means for inserting and removing said nail means from said bone, said insertion means having a throw weight that is movable between two stop members, said insertion means being removably coupled to said nail means;

(d) inserting said nail means into said medullary canal from said proximal segment, then inserting said nail means through said fracture site and into said distal segment such that said nail means extends from said proximal segment to said distal segment, said insertion of said nail means into said medullary canal being assisted by said insertion means, wherein said throw weight is thrown against one of said stop members so as to drive said nail means into said bone;

(e) deploying said first holding means so that said first holding means engages an interior surface of the cortex of said distal segment;

(f) coupling said second holding means onto said nail means in said proximal segment;

(g) engaging said second holding means with the cortex of said proximal segment;

(h) adjusting the distance between said first and second holding means to close the fracture site and to bring the proximal and distal segments into compressive contact with each other across the fracture site;

(i) exiting said medullary canal while leaving said nail means in place.

15. The method of claim 14 further comprising the step of inserting guide wire means into said medullary canal from said proximal segment through said fracture site and into said distal segment, then inserting said nail means into said medullary canal along said guide wire means and then removing said guide wire means after said nail means has been inserted into said bone.

16. The method of claim 15 wherein said second holding means engages an outside surface of the cortex of said proximal segment.

17. The method of claim 16 wherein said nail means is chosen so as to have a transverse diameter that will produce an interference fit with the narrowest portion of said medullary canal.

18. The method of claim 14 wherein said second holding means engages an outside surface of the cortex of said proximal segment.

19. The method of claim 14 wherein said nail means is chosen so as to have a transverse diameter that will produce an interference fit with the narrowest portion of said medullary canal.

20. The method of claim 14 further comprising the step of removing said nail means from said bone by coupling said insertion means to said nail means and throwing said throw weight against the other of said stop members so as to drive said nail means out of said bone.

21. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second holding means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) insertion means for inserting and removing said outer and inner members from said bone, said insertion means comprising a rod having a fixed end and a free end, said fixed end being adapted to be removably coupled to said inner member second end, said rod having stop members thereon, said rod having throw weight means thereon, said throw weight means being movable along said rod between said stop members.

22. A device for insertion into a bone, said bone having a medullary canal, a cortex and a fracture site, comprising:

(a) an outer member having a longitudinal axis extending between first and second end portions, said outer member having an exterior surface and a transverse dimension which is small enough to allow the insertion of said outer member into the medullary canal of said bone, said outer member having a passage therein which passage extends between said first and second end portions, said passage having openings to communicate with said exterior surface, said openings being located at said first and second end portions;

(b) an inner member located in said passage, said inner member extending between said first and second end portions of said outer member, said inner member having first and second ends that are oriented so as to be adjacent to said first and second end portions of said outer member respectively, said inner member being movable longitudinally within said passage;

(c) first holding means coupled to said inner member first end, said first holding means being adapted to engage said bone cortex, said first holding means being expandable into a deployed position from a stowed position, wherein said first holding means protrudes out from said outer member and through said outer member first end opening when said first holding means is in the deployed position and wherein when said first holding means is in the stowed position said first holding means is located in said outer member such that said outer member can be inserted into said medullary canal, said inner member moving longitudinally in said outer member to manipulate said first holding means between said deployed and stowed positions;

(d) second holding means coupled to said inner member second end, said second holding means being adapted to engage said bone cortex;

(e) retaining means for retaining said inner member in a position whereby said first holding means is in said deployed position, said retaining means being coupled to said inner and outer member;

(f) means for adjusting the force exerted by said first and second holding means on said bone along said longitudinal axis, said force adjustment means being coupled with said first and second holding means, wherein said device is adapted to be inserted into the medullary canal of said bone so as to span the site of said bone fracture with said first holding means on one side of said fracture site and said second means on the other side of said fracture site, said device being adapted to exert compressive force onto said bone across said fracture site with said first and second holding means;

(g) said retaining means comprising a retaining cap that is coupled to said outer member second end portion, said retaining cap having an opening that is aligned with said outer member second end portion opening, said retaining cap opening being of a smaller diameter than said inner member second end, wherein said cap opening limits the movement of said inner member towards said outer member second end portion when said arms are in said deployed position.