Fracture fixation systems

• US 8,546,456 B2
• Filed: 07/24/2009
• Issued: 10/01/2013
• Est. Priority Date: 07/25/2008
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: Rose, John, Martin, Charles C.
• Primary Examiner(s): Seidleck, James J
• Assistant Examiner(s): Salamon, Peter A
• Application Number:
  US13/055,922
• Publication Number:
  US 20120029102A1
• Time in Patent Office: 1,530 Days
• Field of Search: 521/88, 521/170, 521/137, 521/134, 521/82
• US Class Current: 521/88
• CPC Class Codes: A61B 17/64 Devices extending alongside the bones to be positioned
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/82 for bone cerclage apparatus for manipulating wires or straps A61B17/8861; wires, bands or straps other than cerclage A61B17/842
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61F 2/2846 Support means for bone substitute or for bone graft implants, e.g. membranes or plates for covering bone defects nets or sleeves applied to surface of endoprostheses A61F2/30907; bone plates A61B17/80; bone regeneration in dental surgery A61C8/0006
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0066 shrinkable
• CPC Class Codes: A61F 2210/0085 hardenable in situ, e.g. epoxy resins
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/001 for adjusting a diameter
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61L 24/0084 containing fillers of phosphorus-containing inorganic compounds, e.g. apatite
• CPC Class Codes: A61L 2400/06 Flowable or injectable implant compositions
• CPC Class Codes: A61L 27/46 with phosphorus-containing inorganic fillers
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 27/58 : Materials at least partially resorbable by the body
• CPC Class Codes: C08L 75/04 : Polyurethanes

Abstract

Systems for bone fracture repair are disclosed. One system includes a biocompatible putty that may be packed about a bone fracture to provide full loadbearing capabilities within days. The disclosed putties create an osteoconductive scaffold for bone regeneration and degrade over time to harmless 5 resorbable byproducts. Fixation devices for contacting an endosteal wall of an intramedullary (IM) canal of a fractured bone are also disclosed. One such fixation device includes a woven elongated structure fabricated from resorbable polymer filaments. The woven elongated structure has resilient properties that allow the woven 10 structure to be radially compressed and delivered to the IM canal using an insertion tube. When the insertion tube is removed, the woven structure expands towards its relaxed cross-sectional width to engage the endosteal wall. The woven elongated structure is impregnated with a resorbable polymer resin that cures in situ, or in the IM canal.

Claims

1. A hardenable and moldable material for orthopedic implantation and reconstruction, the material comprising:

a resorbable polymer resin;

a first filler having a first mean particle diameter ranging from about 5 to about 15 μ

m; and

at least one additional filler selected from the group consisting of a second filler having a mean particle diameter ranging from about 400 to about 1800 μ

m and a third filler having a mean particle size ranging from about 1800 to about 4000 μ

m, wherein the at least one additional filler provides porosity within the material after hardening and is present in an amount greater than the first filler.

2. The material of claim 1 wherein:

the resin is present in an amount ranging from about 15 to about 40 wt %;

the first filler is present in an amount ranging from about 10 to about 25 wt %;

the additional filler is present in an amount greater than the first filler and ranging from about 20 to about 75 wt %.

3. The material of claim 2 wherein the additional filler comprises both second and third fillers.

4. The material of claim 3 wherein the first filler has a mean particle diameter ranging from about 8 to about 12 μ

m, the second filler has a mean particle diameter ranging from about 800 to about 1800 μ

m and the third filler has a mean particle diameter ranging from greater than 1800 to about 2800 μ

m.

5. The material of claim 4 wherein:

the resin is present in an amount ranging from about 20 to about 30 wt %;

the first filler is present in an amount ranging from about 10 to about 20 wt %;

the second filler is present in an amount ranging from about 25 to about 35 wt %;

the third filler is present in an amount ranging from about 20 to about 30 wt %.

6. The material of claim 4 wherein

the resin is present in an amount ranging from about 15 to about 40 wt %;

the first filler is present in an amount ranging from about 10 to about 25 wt %;

the second filler is present in an amount ranging from about 20 to about 40 wt %;

the third filler is present in an amount ranging from about 15 to about 35 wt %.

7. The material of claim 6 wherein the first filler is present in a first amount, the second filler is present and a second amount and the third filler is present in a third amount, and a ratio of the second to third amounts ranges from about 1:

1 to about 1.5;

1.

8. The material of claim 7 wherein a ratio of the second and third amounts combined to the first amount ranges from about 3.5:

1 to about 4.5;

1.

9. The material of claim 1 further comprising a porogen comprising water soluble crystals.

10. The material of claim 9 wherein the porogen comprises mannitol.

11. The material of claim 1 further comprising water as a blowing agent.

12. The material of claim 1 wherein the first, and additional fillers are selected from the group consisting of degradable polymer PU, PLA, PGA, PCL, or co-polymers thereof, hydroxyapatite (HA), calcium phosphates, orthophosphates, monocalcium phosphates, dicalcium phosphates, tricalcium phsosphates, whitlockite, tetracalcium phosphates, amorphous calcium phosphates, magnesium and magnesium alloys.

13. The material of claim 12 comprising at least two different fillers from the group.

14. The material of claim 12 wherein the first filler is hydroxyapatite (HA) having a mean particle diameter of 10 μ

m.

15. The material of claim 1 comprising at least two different materials selected from the group consisting of degradable polymers PU, PLA, PGA, PCL, or co-polymers thereof, hydroxyapatite (HA), calcium phosphates, orthophosphates, monocalcium phosphates, dicalcium phosphates, tricalcium phosphates, whitlockite, tetracalcium phosphates and amorphous calcium phosphates, magnesium, magnesium alloys and calcium sulfate.

16. The material of claim 1, wherein upon combination with the resorbable polymer resin, the at least one additional filler creates voids that increase the porosity of the material.

17. A kit for an orthopedic implant comprising:

a resorbable polymer resin;

a first filler having a mean particle diameter ranging from about 5 to about 15 μ

m; and

at least one additional filler selected from a second filler having a mean particle diameter ranging from about 400 to about 1800 μ

m and a third filler having a mean particle size ranging from about 1800 to about 4000 μ

m;

wherein mixing the fillers with the resorbable polymer resin forms a hardenable and moldable putty.

18. The kit of claim 17 wherein:

the resin is present in an amount ranging from about 15 to about 40 wt %;

the first filler is present in an amount ranging from about 10 to about 25 wt %;

the additional filler is present in an amount greater than the first filler and ranging from about 20 to about 75 wt %.

19. The kit of claim 17 wherein the additional filler comprises both second and third fillers.

20. The kit of claim 17 wherein the first filler is present in a first amount, the second filler is present and a second amount and the third filler is present in a third amount, and a ratio of the second to third amounts ranges from about 1:

1 to about 1.5;

1.

21. A hardenable and moldable material for orthopedic implantation and reconstruction, the material comprising:

a resorbable polymer resin;

at least one filler selected from the group consisting of first filler particles having a mean particle diameter ranging from about 400 to about 1800 μ

m and second filler particles having a mean particle size ranging from about 1800 to about 4000 μ

m, wherein the filler provides porosity within the material after hardening; and

an additional filler comprising particles having a mean particle diameter of about 5 μ

m to about 15 μ

m.

22. The material of claim 21 wherein the first filler particles are present in a first amount and the second filler particles are present in a second amount, and a ratio of the first to second amounts ranges from about 1:

1 to about 1.5;

1.

23. The material of claim 21 wherein the at least one filler comprises the second filler particles having a mean particle diameter of about 1800 μ

m to about 4000 μ

m.