Surgical fastener with predetermined resorption rate

A resorbable screw fastener and instrument for inserting the resorbable screw fastener, comprising:

• an instrument having an outer tube on a distal end and a trigger mechanism on its proximal end;
• and
• a resorbable screw fastener having a body portion and a head portion disposed at the proximal end of the body portion, the body portion having a helical thread formed thereon, the fastener being inserted on the distal end of the instrument, the head of the resorbable screw fastener having a driver receiving configuration defining a slot formed in an outer radial side surface for transmitting both linear and rotational motion to the body portion, the head portion including a substantially flattened surface defined in an outermost diameter thereof, wherein the substantially flattened surface of the head portion is in radial registration with a substantially flattened surface formed in an outermost diameter of the helical thread without projecting into the body portion,
• wherein absorption of the resorbable screw fastener is nearly complete at approximately 12 months post implantation.

A resorbable screw fastener comprising:

• a body portion defining a longitudinal axis and having a proximal end and a distal end, the body portion having a helical thread formed thereon, the helical thread having a first distance and the body portion having a second distance;
• and
• a head portion disposed at the proximal end of the body portion, the head portion having a driver receiving structure defining a slot formed in an outer radial side surface for transmitting rotational motion to the body portion, the head portion having an outer diameter substantially equal to the first distance of the helical thread, the head portion including a substantially flattened surface defined in an outermost diameter thereof, wherein the substantially flattened surface of the head portion is in radial registration with a substantially flattened surface formed in an outermost diameter of the helical thread,
• wherein the substantially flattened surfaces of the head portion and the helical thread are disposed between the second distance of the body portion and the first distance of the helical thread without projecting into the body portion, and
• wherein absorption of the resorbable screw fastener is nearly complete at approximately 12 months post implantation.

A resorbable screw fastener comprising:

• a body portion defining a longitudinal axis and having a proximal end and a distal end, the body portion having a helical thread formed thereon, the helical thread having a first distance and the body portion having a second distance;
• and
• a head portion disposed at the proximal end of the body portion, the head portion having driver receiving structure defining a slot formed in an outer radial side surface for transmitting both linear and rotational motion to the body portion, the head portion having an outer diameter substantially equal to the first distance of the helical thread, the head portion including a substantially flattened surface defined in an outermost diameter thereof, wherein the substantially flattened surface of the head portion is in radial registration with a substantially flattened surface formed in an outermost diameter of the helical thread,
• wherein the substantially flattened surfaces of the head portion and the helical thread are disposed between the second distance of the body portion and the first distance of the helical thread without projecting into the body portion,
• wherein the resorbable screw fastener has a shear strength of about 3.5 pounds to about 5.5 pounds during a period of time ranging from the time of implantation in vivo to about one week after implantation, a shear strength ranging from about 0.5 pounds to about 4.2 pounds during a period of time ranging from about one week to about 1.5 weeks after implantation, and a shear strength of about 0 pounds about one year after implantation.