External fixation connection rod for rapid and gradual adjustment

• US 8,574,232 B1
• Filed: 11/13/2012
• Issued: 11/05/2013
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: Texas Scottish Rite Hospital for Children
• Original Assignee: Texas Scottish Hospital For Children
• Inventors: Ross, John David, Samchukov, Mikhail L., Cherkashin, Alexander M., Birch, John G.
• Primary Examiner(s): Hoffman, Mary
• Assistant Examiner(s): NEGRELLIRODRIGUE, CHRISTINA
• Application Number:
  US13/675,961
• Time in Patent Office: 357 Days
• Field of Search: 606 53- 59, 606/246, 606250-253, 606/260, 606/278
• US Class Current: 606/57
• CPC Class Codes: A61B 17/62 Ring frames, i.e. devices extending around the bones to be positioned A61B17/6433 , A61B17/66 take precedence
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61F 5/042 for extension or stretching

Abstract

An external fixation connection rod that allows for rapid and gradual length adjustment. In some embodiments, the fixation connection rod includes an inner sleeve received within a telescopic rod to allow for rapid adjustment of an overall length of the fixation connection rod. In some embodiments, the fixation connection rod includes an adjustment mechanism to allow for gradual adjustment of the overall length of the fixation connection rod by lengthening or shortening a threaded elongated member within the inner sleeve, and the adjustment mechanism includes a first rotation member, a second rotation member, and a spring. Distal translation of the first rotation member relative to the second rotation member allows the adjustment mechanism to move from a first, locked position to a second, unlocked position, allowing the first rotation member and the second rotation member to rotate about the inner sleeve and the threaded elongated member during gradual adjustment.

Claims

1. A connecting rod for an external fixation device, the connecting rod defining a longitudinal axis and comprising:

a telescopic housing comprising a housing body having an axial bore defined therethrough;

an inner sleeve slidably disposed within the axial bore of the telescopic housing, the inner sleeve and the telescopic housing being releasably coupled by a fastener, the inner sleeve comprising;

a sleeve body having an axial bore defined therethrough;

an indexing flange coupled to a distal end of the sleeve body; and

a tip coupled to a distal surface of the indexing flange;

an adjustment mechanism disposed about the tip of the inner sleeve, the adjustment mechanism comprising;

a first rotating member having an axial bore defined therethrough, the axial bore comprising;

a polygonal recess in a distal end; and

an inner recess in a proximal end operable to receive the indexing flange of the inner sleeve;

a second rotating member having a threaded axial bore defined therethrough, the second rotating member comprising;

a polygonal head at a distal end operable to mate with the polygonal recess of the first rotating member; and

a proximal portion comprising an inner recess operable to receive the tip of the inner sleeve;

a biasing member placed adjacent to the proximal portion of the second rotating member; and

an externally threaded elongated member threadably coupled within the second rotating member of the adjustment mechanism;

wherein in a first, locked position, the inner recess of the proximal end of the first rotating member receives the indexing flange of the inner sleeve, thereby preventing the adjustment mechanism from rotating about the inner sleeve and the elongated member;

wherein in a second, unlocked position, the first rotating member is distally translated relative to the second rotating member and the inner recess of the proximal end of the first rotating member disengages from the indexing flange of the inner sleeve, thereby allowing the adjustment mechanism to rotate about the inner sleeve and the elongated member;

wherein when the adjustment mechanism is rotated about the inner sleeve and the elongated member, the elongated member is translated within the axial bore defined in the inner sleeve during gradual adjustment, thereby lengthening or shortening an overall length of the connecting rod; and

wherein when the adjustment mechanism is rotated about the inner sleeve and the elongated member, the adjustment mechanism is biased by the biasing member to return to the first, locked position when the inner recess of the proximal end of the first rotating member aligns with and receives the indexing flange of the inner sleeve.

2. The connecting rod of claim 1, wherein when the fastener is loosened, the inner sleeve can slidably translate within the axial bore of the telescopic housing during rapid adjustment, thereby lengthening or shortening the overall length of the connecting rod.

3. The connecting rod of claim 1, the telescopic housing comprising a first joint coupled to a proximal end portion of the housing body, and a first rotating member received in the first joint, wherein the first rotating member comprises a first connection mechanism operable to releasably couple the first rotating member to a first fixation ring.

4. The connecting rod of claim 1, the externally threaded elongated member comprising a second joint coupled to a distal end portion of the threaded rod, and a second rotating member received in the second joint, wherein the second rotating member comprises a second connection mechanism operable to releasably couple the second rotating member to a second fixation ring.

5. The connecting rod of claim 1, wherein the biasing member is a spring, a leaf spring, a clip, a coil spring, a wave spring, a linear rate spring, a progressive rate spring, a dual rate spring, a flat spring, a conical spring, or a compression spring.

6. The connecting rod of claim 1, wherein an outer circumference of the indexing flange is substantially similar in shape to an inner sidewall of the inner recess of the proximal end of the first rotating member, thereby allowing the inner recess to receive the indexing flange in the first, locked position.

7. The connecting rod of claim 6, wherein the outer circumference of the indexing flange comprises two opposing flat sides separated by two round portions.

8. The connecting rod of claim 7, wherein the inner sidewall of the inner recess of the proximal end of the first rotating member comprises two opposing flat sides separated by two round portions.

9. The connecting rod of claim 8, wherein when the adjustment mechanism is in its second, unlocked position, the first rotation member and the second rotation member are operable to rotate 180°

until the biased member returns the adjustment mechanism to the first, locked position, thereby lengthening or shortening the overall length of the connecting rod.

10. The connecting rod of claim 1, wherein the first rotation member further comprises an inwardly extending flange distal to the inner recess of the proximal end.

11. The connecting rod of claim 10, wherein the biasing member is placed between a distal side of the inwardly extending flange of the first rotation member and a proximal side of the polygonal head of the second rotation member when the first compression member is translated from the first, locked position to the second, unlocked position.

12. The connecting rod of claim 1, wherein the tip of the inner sleeve further comprises a plurality of mating barbs about an outer circumference of the tip.

13. The connecting rod of claim 12, where a sidewall of the inner recess of the second rotating member comprises mating barbs operable to mate with the mating barbs of the tip of the inner sleeve.

14. The connecting rod of claim 13, wherein the mating barbs of the inner sleeve and the mating barbs of the second rotating member prevent axial translation of the second rotating member relative to the inner sleeve.

15. The connecting rod of claim 1, wherein the externally threaded elongated member comprises a threaded portion at a distal end and a shoulder portion at a proximal end, wherein a diameter of the shoulder portion is greater than a diameter of the threaded portion.

16. The connecting rod of claim 15, wherein the shoulder portion of the externally threaded elongated member is operable to be received within an internal recess in a distal end of the tip of the inner sleeve.

17. The connecting rod of claim 2, further comprising a series of indicators on a surface of the inner sleeve operable to indicate a relative length of the connection rod during rapid and gradual adjustment.

18. The connecting rod of claim 17, further comprising a rapid adjustment mark located on the outer telescopic housing operable to indicate the overall length of the connection rod during rapid adjustment using the series of indicators on the surface of the inner sleeve.

19. The connecting rod of claim 18, further comprising a gradual adjustment mark located on the proximal end of the externally threaded elongated member operable to indicate an amount of gradual adjustment of the threaded elongated rod that is still available during gradual adjustment of the connection rod using the series of indicators on the surface of the inner sleeve.

20. The connecting rod of claim 19, further comprising an adjustment range midpoint mark located on the surface the inner sleeve operable to indicate at preset position an overall length of one half of the full extension of the connection rod.

21. A method of adjusting the position of first and second external fixation devices, comprising:

providing a connecting rod having a longitudinal axis and comprising;

a telescopic housing comprising a housing body having an axial bore defined therethrough;

an inner sleeve slidably disposed within the axial bore of the telescopic housing, the inner sleeve and the telescopic housing being releasably coupled by a fastener, the inner sleeve comprising;

a sleeve body having an axial bore defined therethrough;

an indexing flange coupled to a distal end of the sleeve body; and

a tip coupled to a distal surface of the indexing flange;

an adjustment mechanism disposed about the tip of the inner sleeve, the adjustment mechanism comprising;

a first rotating member having an axial bore defined therethrough, the axial bore comprising;

 

a polygonal recess in a distal end; and

 

an inner recess in a proximal end operable to receive the indexing flange of the inner sleeve;

a second rotating member having a threaded axial bore defined therethrough, the second rotating member comprising;

 

a polygonal head at a distal end operable to mate with the polygonal recess of the first rotating member; and

 

a proximal portion comprising an inner recess operable to receive the tip of the inner sleeve;

a biasing member placed adjacent to the proximal portion of the second rotating member; and

an externally threaded elongated member threadably coupled within the second rotating member of the adjustment mechanism;

receiving the indexing flange of the inner sleeve into the inner recess of the proximal end of the first rotating member, thereby preventing the adjustment mechanism from rotating about the inner sleeve and the elongated member in a first, locked position;

translating the first rotating member relative to the second rotating member and the inner recess of the proximal end of the first rotating member along the longitudinal axis of the connecting rode and rotating the first rotating member about the inner sleeve, thereby disengaging the first rotating member from the indexing flange of the inner sleeve and allowing the adjustment mechanism to rotate about the inner sleeve and the elongated member in a second, unlocked position;

rotating the adjustment mechanism about the inner sleeve and the elongated member, thereby translating the elongated member within the axial bore defined in the inner sleeve during gradual adjustment of an overall length of the connecting rod; and

biasing the biasing member to return to the first, locked position when the adjustment mechanism is rotated about the inner sleeve and the elongated member and when the inner recess of the proximal end of the first rotating member aligns with and receives the indexing flange of the inner sleeve.

22. The method of claim 21, wherein when the fastener is loosened, the inner sleeve can slidably translate within the axial bore of the telescopic housing during rapid adjustment, thereby adjusting the overall length of the connecting rod.

23. The method of claim 21, the telescopic housing comprising a first joint coupled to a proximal end portion of the housing body, and a first rotating member received in the first joint, wherein the first rotating member comprises a first connection mechanism operable to releasably couple the first rotating member to a first fixation ring.

24. The method of claim 21, wherein the externally threaded elongated member comprises a second joint coupled to a distal end portion of the threaded rod, and a second rotating member received in the second joint, wherein the second rotating member comprises a second connection mechanism operable to releasably couple the second rotating member to a second ring.

25. The method of claim 21, wherein the biasing member is a spring, a leaf spring, a clip, a coil spring, a wave spring, a linear rate spring, a progressive rate spring, a dual rate spring, a flat spring, a conical spring, or a compression spring.

26. The method of claim 21, wherein an outer circumference of the indexing flange is substantially similar in shape to an inner sidewall of the inner recess of the proximal end of the first rotating member, thereby allowing the inner recess to receive the indexing flange in the first, locked position.

27. The method of claim 26, wherein the outer circumference of the indexing flange comprises two opposing flat sides separated by two round portions.

28. The method of claim 27, wherein the inner sidewall of the inner recess of the proximal end of the first rotating member comprises two opposing flat sides separated by two round portions.

29. The method of claim 28, wherein when the adjustment mechanism is in its second, unlocked position, the first rotation member and the second rotation member are operable to rotate 180°

until the biasing member returns the adjustment mechanism to the first, locked position, thereby adjusting the overall length of the connecting rod.

30. The method of claim 21, wherein the first rotation member further comprises an inwardly extending flange distal to the inner recess of the proximal end.

31. The method of claim 30, wherein the biasing member is biased between a distal side of the inwardly extending flange of the first rotation member and a proximal side of the hex-shaped head of the second rotation member when the first compression member is translated from the first, locked position to the second, unlocked position.

32. The method of claim 21, wherein the tip of the inner sleeve further comprises a plurality of mating barbs disposed on an outer circumference of the tip.

33. The method of claim 32, where a sidewall of the inner recess of the second rotating member comprises mating barbs operable to mate with the mating barbs of the tip of the inner sleeve.

34. The method of claim 33, wherein the mating barbs of the inner sleeve and the mating barbs of the second rotating member prevent translation of the second rotating member relative to the inner sleeve.

35. The method of claim 21, wherein the externally threaded elongated member comprises a threaded portion at a distal end and a shoulder portion at a proximal end, wherein a diameter of the shoulder portion is greater than a diameter of the threaded portion.

36. The method of claim 35, wherein the shoulder portion of the externally threaded elongated member is operable to be received within an internal recess in a distal end of the tip of the inner sleeve.

37. The method of claim 22, further comprising a series of indicators on a surface of the inner sleeve operable to indicate a relative length of the connection rod during rapid and gradual adjustment.

38. The method of claim 37, further comprising a rapid adjustment mark located on the outer telescopic housing operable to indicate the overall length of the connection rod during rapid adjustment using the series of indicators on the surface of the inner sleeve.

39. The method of claim 38, further comprising a gradual adjustment mark located on the proximal end of the externally threaded elongated member operable to indicate an amount of gradual adjustment of the threaded elongated rod that is still available during gradual adjustment of the connection rod using the series of indicators on the surface of the inner sleeve.

40. The method of claim 39, further comprising an adjustment range midpoint mark located on the surface the inner sleeve operable to indicate at preset position an overall length of one half of the full extension of the connection rod.