Expandable intramedullary nail for the fixation of bone fractures

• US 4,453,539 A
• Filed: 03/01/1982
• Issued: 06/12/1984
• Est. Priority Date: 03/01/1982
• Status: Expired due to Fees

• Current Assignee: University of Toledo
• Original Assignee: University of Toledo
• Inventors: Baril, James D., Raftopoulos, Demetrios D., Reimer, Glenn
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US06/353,511
• Time in Patent Office: 834 Days
• Field of Search: 128/92 BC, 128/92 B, 128/92 BA
• US Class Current: 606/63
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone

Abstract

The present invention relates to an improved expandable intramedullary nail for the fixation of bone fractures. The nail includes an elongate sleeve having one end adapted to be inserted within the medullary cavity of the bone. The one end of the sleeve is formed of a predetermined maximum retracted diameter to permit the insertion of the one end within the bone cavity. A plurality of circumferentially spaced, radially expandable elements are carried by the one end of the sleeve. The elements are radially movable from a first, retracted position wherein the elements define a first diameter to a second, expanded position wherein the elements define a second diameter greater than the predetermined maximum retracted diameter and the first diameter. In accordance with the present invention, when the elements are in the expanded position, the elements provide at least two support points at the second diameter and axially spaced along the sleeve for engagement with the inner wall of the bone cavity. A camming member is carried by the one end of the elongate sleeve for moving the elements from the retracted position to the expanded position. An actuator is located at the other end of the sleeve and is coupled to operate the camming member for controlling the radial position of the elements.

Claims

1. A fixation device for insertion into a medullary cavity of a bone comprising:

an elongate member defining a longitudinal axis and having one end adapted to be inserted within the medullary cavity of the bone, said one end having a predetermined maximum diameter to permit insertion of said one end within the bone cavity;

a plurality of circumferentially spaced, radially expandable elements carried by said one end of said member, said elements being radially movable from a first, retracted position wherein said elements define a first diameter to a second, expanded position wherein said elements define a second diameter greater than said predetermined maximum diameter and said first diameter, each of said elements including a radially outermost portion adapted to engage the inner wall of the bone cavity, said radially outermost portions of said elements in said second position providing at least two spaced apart support points at said second diameter and located along an axis generally parallel to the longitudinal axis of said elongate member, said radially outermost portions of said elements providing said support points being maintained at a generally equal spacing from the longitudinal axis of said elongate members as said elements are moved from said first position to said second position;

means carried by said elongate member for moving said elements from said first position to said second position; and

actuator means located at the other end of said elongate member and coupled to operate said moving means for controlling the radial position of said elements.

2. The fixation device according to claim 1 wherein said elongate member is a sleeve provided with a plurality of circumferentially spaced openings for receiving said radially expandable elements.

3. The fixation device according to claim 2 including means for maintaining said elements within said openings.

4. The fixation device according to claim 2 wherein said radially expandable elements are each provided with an axially extending outer surface for engagement with the inner wall of the bone cavity, said outer surface providing said axially spaced apart support points when said elements are in said second position.

5. The fixation device according to claim 4 wherein said moving means includes cam means engagable with said elements for positioning said outer surface of said elements at a selected position defining a diameter between said first and second diameters.

6. The fixation device according to claim 5 wherein said actuator means is an elongate shaft extending axially through said sleeve and mounted for selective rotational movement within said sleeve, said cam means being responsive to the rotational movement of said shaft for controlling the radial position of said elements.