Bioabsorbable surgical screw and washer system

• US 6,248,108 B1
• Filed: 09/30/1998
• Issued: 06/19/2001
• Est. Priority Date: 09/30/1998
• Status: Expired due to Term

• Current Assignee: Bionx Implants, Oy
• Original Assignee: Bionx Implants, Oy
• Inventors: Törmälä, Pertti, Tasto, James P.
• Primary Examiner(s): Recla, Henry J.
• Assistant Examiner(s): King, Anthony S.
• Application Number:
  US09/163,946
• Time in Patent Office: 993 Days
• Field of Search: 606/61, 606/72, 606/73, 606/75, 606/77, 411/533
• US Class Current: 606/318
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/8635 Tips of screws
• CPC Class Codes: A61B 17/866 Material or manufacture
• CPC Class Codes: A61B 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable, resorptive for implantable prostheses A61F2210/0004
• CPC Class Codes: A61F 2/0811 Fixation devices for tendons or ligaments
• CPC Class Codes: A61F 2002/0829 without deformation of anchor parts, e.g. fixation screws on bone surface, extending barbs, cams, butterflies, spring-loaded pins
• CPC Class Codes: A61F 2002/0858 Fixation of tendon or ligament between anchor and bone, e.g. interference screws, wedges
• CPC Class Codes: A61F 2002/0888 Anchor in or on a blind hole or on the bone surface without formation of a tunnel
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2210/0004 bioabsorbable

Abstract

An at least partially bioabsorbable surgical fastener or device formed in the shape of a screw and washer system and the methods for manufacturing and using the same. The surgical fastener is particularly but not solely intended to be used to attach rotator cuff tendons to bone.

Claims

1. A surgical fastener comprising:

an at least partially bioabsorbable screw made from a bioabsorbable material that is oriented or fibrillated comprising;

a distal end, a proximal end having a head having a first diameter and a height, a shank having a second diameter and connected to said head, and at least one thread having an outer diameter and an inner diameter, wherein at least a portion of said thread has a height of at least 1.5 mm;

an at least partially bioabsorbable annular washer having upper and lower sides and a opening therethrough, said upper side facing said head of said screw,

said shank of said screw passing through said opening in said washer, and

said opening having a third diameter that is;

larger than the second diameter of said shank;

smaller than the first diameter of said head; and

smaller than the outer diameter of said thread;

wherein the washer degrades faster in vivo than the screw.

2. The fastener of claim 1 wherein the at least partially bioabsorbable material is oriented or fibrillated.

3. The fastener of claim 1 wherein the washer comprises an at least partially bioabsorbable material that is biaxially oriented or fibrillated.

4. The fastener of claim 1 wherein the washer further comprises a plurality of protrusions protruding from the lower side of said washer.

5. The fastener of claim 4 wherein at least one of the protrusions is at least 0.6 mm in height.

6. The fastener of claim 5 wherein the upper side of said washer contains an indentation configured to removably receive at least a portion of said head of said screw.

7. The fastener of claim 6 wherein the indentation has a depth that is greater or equal to the height of the head of the screw.

8. The fastener of claim 1 wherein the pull out force of the fastener is at least 150 N.

9. The fastener of claim 1 wherein the distal end of the screw has a trocar tip.