Skull closure

A method of reattaching a skull flap, removed during brain surgery and leaving an opening in a patient's skull, the flap having an area less than the area of the opening but substantially the same shape, and using a fastening system, comprising a fastener element made of bio-compatible radiolucent rigid plastic having a shank with ratchet teeth and a substantially disc shaped lock element with an opening defined at least in part by at least one locking tooth, and a plurality of ridges upstanding from the shank and extending substantially perpendicular to the ratchet teeth;

• said method comprising:
• (a) placing a plurality of fastener heads, with shanks facing outwardly, in the skull opening;
• (b) placing the skull flap in the skull opening so that a gap is provided between the outer periphery of the skill flap and the periphery of the skull opening, and the fastener shanks extend through the gap and the ridges engage at least one of the skull and the skull flap and provide a force holding the shank in operative engagement with the skull and skull flap;
• (c) placing the lock elements over the shanks;
• (d) for each fastener forcing the lock toward the head so that the ratchet teeth and at least one locking tooth move with respect to each other, until the head and lock element are locked together holding the skull flap in a position closing the skull opening;
• and
• (e) removing substantially all shank portions extending outwardly from the lock elements.

A fastener system comprising:

• a fastener element of bio-compatible radiolucent rigid plastic material comprising a substantially disc shaped head and a shank;
• said shank having a plurality of ratchet teeth thereon, and a thickness of about 7 mm or less;
• a substantially disc shaped lock of bio-compatible radiolucent plastic material having a through extending opening and at least one locking tooth defining at least part of said opening, said at least one locking tooth cooperating with said ratchet teeth to allow said shank to pass through said opening so that said head and lock can be forced toward each other, but not allowing movement away from each other;
• and
• wherein said lock element has first and second faces, and a plurality of force concentrating projections extending outwardly from said first face, toward said head in use and said head has a plurality of flexible, resilient outrigger leaves.

A fastener system comprising:

• a fastener element of bio-compatible radiolucent rigid plastic material comprising a substantially disc shaped head and a shank;
• said shank having a plurality of ratchet teeth thereon, and a thickness of about 7 mm or less;
• a substantially disc shaped lock of bio-compatible radiolucent plastic material having a through extending opening and at least one locking tooth defining at least part of said opening, said at least one locking tooth cooperating with said ratchet teeth to allow said shank to pass through said opening so that said head and lock can be forced toward each other, but not allowing movement away from each other;
• and
• wherein said head has a plurality of resilient outrigger leaves,
• said shank having a plurality of ridges substantially abutting said head and extending substantially perpendicular to said ratchet teeth a distance of about 3-7 mm from said head.

A fastener system comprising:

• a fastener element of bio-compatible radiolucent rigid plastic material comprising a substantially disc shaped head and a shank;
• said shank having a plurality of ratchet teeth thereon, and a thickness of about 7 mm or less;
• a substantially disc shaped lock of bio-compatible radiolucent plastic material having a through extending opening and at least one locking tooth defining at least part of said opening, said at least one locking tooth cooperating with said ratchet teeth to allow said shank to pass through said opening so that said head and lock can be forced toward each other, but not allowing movement away from each other;
• and
• wherein said lock element has first and second faces, and a plurality of force concentrating projections extending outwardly from said first face, toward said head in use,
• said shank having a plurality of ridges substantially abutting said head and extending substantially perpendicular to said ratchet teeth a distance of about 3-7 mm from said head.

A fastener system comprising:

• a fastener element of bio-compatible radiolucent rigid plastic material comprising a substantially disc shaped head and an elongated shank extending from said head;
• said shank having a plurality of ratchet teeth thereon, and a thickness of about 7 mm or less;
• a substantially disc shaped lock of bio-compatible radiolucent plastic material having a through extending opening and at least one locking tooth defining at least part of said opening, said at least one locking tooth cooperating with said ratchet teeth to allow said shank to pass through said opening so that said head and lock can be forced toward each other, but not allowing movement away from each other;
• and
• wherein said shank has first and second exterior side walls extending over a portion of the length thereof including past at least some of said ratchet teeth;
• each of said first and second exterior side walls having a height in a direction generally perpendicular to said shank greater than the thickness of said shank;
• and wherein said locking element opening has first and second side portions for receiving said side walls.