External fixation assembly and method of use

• US 7,931,651 B2
• Filed: 03/30/2007
• Issued: 04/26/2011
• Est. Priority Date: 11/17/2006
• Status: Expired due to Fees

• Current Assignee: Wake Forest University Health Sciences
• Original Assignee: Wake Forest University Health Sciences
• Inventors: Morykwas, Michael J., Webb, Lawrence X., Argenta, Louis C.
• Primary Examiner(s): Robert; Eduardo C
• Assistant Examiner(s): Schneider; Lynnsy
• Application Number:
  US11/694,395
• Publication Number:
  US 20080281324A1
• Time in Patent Office: 1,488 Days
• Field of Search: 606 53- 59, 606/92, 606300-329, 600/571, 604/176, 604/541, 604/543
• US Class Current: 606/59
• CPC Class Codes: A61B 17/60 for external osteosynthesis, e.g. distractors, contractors
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/866 Material or manufacture
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61B 2017/00544 pneumatically

Abstract

An external fixation assembly includes a plurality of hollow pins that are inserted into a patient'"'"'s bone. Each pin has an interior bore and a plurality of apertures extending through the pin wall from the bore. The pin may be coupled to a source of vacuum pressure operable to create reduced pressure in the tissue surrounding the pin. A cover is placed around the pin and sealed to provide a fluid-tight enclosure that maintains reduced pressure around the pin. A method for applying external fixation using the fixator pins described above includes the steps of inserting each pin through a skin opening, positioning the pin apertures near selected tissue, covering the skin opening with a sealed enclosure, connecting the pins to a source of vacuum pressure, and activating the source of vacuum pressure to create reduced pressure in the patient'"'"'s tissue at or near the bone.

Claims

1. A method for applying external fixation to a bone defect comprising the steps of:

A. inserting a fixator pin through a skin opening and into bone, the pin comprising

i. a hollow shaft having an insertion end for insertion into the bone and an attachment end for positioning externally to the bone for communication with a vacuum source, said shaft forming a bore that extends along a longitudinal axis of the shaft and having a port in communication with the bore;

ii. a threaded section of the shaft for securing the pin in the bone; and

iii. a plurality of apertures that extend through a wall of the shaft in fluid communication with the bore, said apertures located proximate a region of the attachment end and external to the insertion end to provide a plurality of apertures for communication with a location external to the bone;

B. connecting the pin to a fixator device;

C. positioning a porous reduced-pressure distribution element around the pin, said porous reduced-pressure distribution element adapted to distribute negative pressure;

D. covering the skin opening and the porous reduced-pressure distribution element with a removable cover to create a sealed enclosure around the pin, the cover disposed at a location relative to the apertures of the pin such that the enclosure communicates with the apertures to provide negative pressure to the enclosure through the apertures;

E. connecting a vacuum source with the hollow shaft of the pin via a flexible tube removably connectable with the port on the pin to supply negative pressure to the pin; and

F. activating the vacuum source to apply a reduced pressure to the sealed enclosure through the pin apertures.

2. The method of claim 1, wherein the plurality apertures are formed proximate a region of both the insertion end and attachment end to provide apertures for communication with regions internal and external to the bone.

3. The method of claim 1, wherein the port extends through the attachment end of the shaft.

4. The method of claim 1, wherein the port is formed through a sidewall of the shaft.

5. The method of claim 4, wherein the port comprises a cylindrical hub that extends radially outwardly from the shaft.

6. The method of claim 1, wherein the cover comprises an O-ring seal and the shaft comprises a pair of circumferential ridges separated by a groove adapted to form a seat to receive the O-ring seal.

7. The method of claim 1, wherein the reduced-pressure distribution element comprises an open cell foam.

8. The method of claim 1, comprising a detachable shaft section to provide an implant that may be left in the bone.

9. The method of claim 8, wherein the detachable shaft section comprises a bone substitute material.

10. The method of claim 9, wherein the detachable shaft section comprises an osteoconductive material, an osteoinductive material, or combinations thereof.

11. The method of claim 9, wherein the detachable shaft section comprises a bioglass, a ceramic material, calcium sulphate, calcium phosphate, hydroxyapatite, fluorapatite, tri-calcium phosphate, bioglass ceramics, or combinations thereof.

12. The method of claim 1, wherein the pin comprises a bone substitute material.

13. The method of claim 12, wherein the pin comprises an osteoconductive material, an osteoinductive material, or combinations thereof.

14. The method of claim 12, wherein the pin comprises a bioglass, a ceramic material, calcium sulphate, calcium phosphate, hydroxyapatite, fluorapatite, tri-calcium phosphate, bioglass ceramics, or combinations thereof.

15. The method of claim 1, comprising a guide pin for insertion into the bone, and wherein the bore of the fixation pin is dimensioned to permit the guide pin to be inserted therein.

16. The method of claim 1, wherein the step of inserting the pin comprises placing the apertures adjacent to epidermis.

17. The method of claim 1, wherein the step of inserting the pin comprises placing the apertures within dermis.

18. The method of claim 1, wherein the step of inserting the pin comprises positioning at least one of the apertures in the bone.

19. The method of claim 1, wherein the reduced pressure is applied to promote bone formation at the bone defect.

20. The method of claim 19, wherein the step of positioning the porous reduced pressure distribution element comprises placing the porous reduced pressure distribution element between the skin opening and the cover.

21. The method of claim 19, comprising introducing a medication to the hollow shaft and delivering the medication through the apertures to the selected tissue.

22. The method of claim 15, comprising inserting a guide pin into the bone and wherein the step of inserting the hollow fixator pin comprises placing the fixator pin over the guide pin so that at least a portion of the guide pin is disposed within the hollow shaft of the fixator pin.