External fixation connection rod for rapid and gradual adjustment

• US 9,381,042 B2
• Filed: 11/04/2013
• Issued: 07/05/2016
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: Texas Scottish Rite Hospital for Children
• Original Assignee: Texas Scottish Rite Hospital for Children
• Inventors: Ross, John David, Samchukov, Mikhail L., Cherkashin, Alexander M., Birch, John G.
• Primary Examiner(s): Hammond, Ellen C
• Assistant Examiner(s): Negrellirodrigue, Christina
• Application Number:
  US14/071,333
• Publication Number:
  US 20140135764A1
• Time in Patent Office: 974 Days
• Field of Search: 606 53- 59, 606/246, 606250-253, 606/260, 606/278
• US Class Current: 1/1
• 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, wherein a surface of the inner sleeve further comprises a series of indicators operable to indicate a relative value associated with a state of the connecting rod during rapid and gradual adjustment;

an adjustment mechanism rotatably coupled with the inner sleeve;

wherein the adjustment mechanism is operable to be placed in one or more locked positions at fixed intervals or an unlocked position;

wherein the adjustment mechanism has a threaded bore defined therethrough; and

wherein the adjustment mechanism is operable to be rotated about the inner sleeve by the fixed intervals between the locked positions; and

an externally threaded elongated member threadably coupled with the adjustment mechanism; and

wherein when the adjustment mechanism is rotated about the inner sleeve during gradual adjustment, the elongated member is translated relative to the adjustment mechanism along the longitudinal axis, thereby lengthening or shortening an overall length of the connecting rod;

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.

2. The connecting rod of claim 1, wherein the inner sleeve comprises:

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.

3. The connecting rod of claim 2, wherein the adjustment mechanism is disposed about the tip of the inner sleeve and comprises:

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 the threaded 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.

4. The connecting rod of claim 3, wherein in the one or more locked positions, 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 wherein in the 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.

5. The connecting rod of claim 4, further comprising:

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

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

6. The connecting rod of claim 3, wherein the tip of the inner sleeve further comprises a plurality of mating barbs about an outer circumference of the tip.

7. The connecting rod of claim 6, 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.

8. The connecting rod of claim 7, 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.

9. The connecting rod of claim 8, wherein the adjustment mechanism of the connecting rod is operable to be adjusted by a patient.

10. The connecting rod of claim 2, 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 and is operable to be received within an internal recess in a distal end of the tip of the inner sleeve.

11. 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 third rotating member received in the first joint, wherein the third rotating member comprises a first connection mechanism operable to releasably couple the third rotating member to a first fixation ring.

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

13. The connecting rod of claim 1, wherein the relative value is a relative length of the connecting rod.

14. A method of adjusting a relative 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, wherein a surface of the inner sleeve further comprises a series of indicators operable to indicate a relative value associated with a state of the connecting rod during rapid and gradual adjustment;

an adjustment mechanism rotatably coupled with the inner sleeve;

wherein the adjustment mechanism is operable to be placed in one or more locked positions at fixed intervals or an unlocked position; and

wherein the adjustment mechanism has a threaded bore defined therethrough; and

an externally threaded elongated member threadably coupled with the adjustment mechanism; and

loosening the fastener and rotating the adjustment mechanism about the inner sleeve by the fixed intervals between the locked positions, thereby translating the elongated member relative to the adjustment mechanism along the longitudinal axis, thereby lengthening or shortening an overall length of the connecting rod.

15. The method of claim 14, wherein the inner sleeve comprises:

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.

16. The method of claim 15, wherein the adjustment mechanism is disposed about the tip of the inner sleeve and further comprises:

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 the threaded 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.

17. The method of claim 16, further comprising:

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 in the one or more locked positions; and

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

18. The method of claim 17, further comprising:

biasing the adjustment mechanism to return to the one or more locked positions with a biasing member that is placed adjacent to the proximal portion of the second rotating member when the adjustment mechanism is rotated about the inner sleeve 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.