초록 ▼

A self-drilling, self-tapping screw for use in repairing broken bones. The screw is made of a high strength material selected from the group consisting of titanium alloys, chrome cobalt, and high strength resinous polymer. The screw has threw segments: a tip region, a body region and a head region.

A self-drilling, self-tapping screw for use in repairing broken bones. The screw is made of a high strength material selected from the group consisting of titanium alloys, chrome cobalt, and high strength resinous polymer. The screw has threw segments: a tip region, a body region and a head region. The tip and body regions have a retention thread formed over substantially their entire lengths. The tip has an included angle .alpha. in the range between 45.degree. and 50.degree.. The head region is specifically designed to maximize the torque it can withstand and minimize the amount of material removed in formation of the recess. The head has a generally frusto-conical shape with an included angle of between 90.degree. and 120.degree. to prevent pull through while minimizing the head's profile. The retention threads on the tip region and the body region have similar shapes and pitches with the pitch on the tip region being slightly smaller than the pitch on the body region. Each of the retention threads has a lead angle between 48.degree. and 52.degree., and a trailing angle between 98.degree. and 102.degree., as measured from the centerline of the screw.

대표청구항 ▼

[ We claim:] [1.] A self-drilling, self-tapping screw used in repairing broken bones by reattaching at least a first and a second bone section, said screw having an overall length and comprising:a tip region for penetrating the bone sections and initiating thread formation therein, said tip region h

[ We claim:] [1.] A self-drilling, self-tapping screw used in repairing broken bones by reattaching at least a first and a second bone section, said screw having an overall length and comprising:a tip region for penetrating the bone sections and initiating thread formation therein, said tip region having a point with an included angle of between about 45.degree. and about 50.degree. to provide a necessary strength and, yet, penetrate the bone, said tip region having a retention thread formed through substantially its entire length;b) a body region having a substantially uniform diameter and having a retention thread formed substantially throughout its entire length;c) a round head region includingi) a head which has a maximum diameter and a drive recess, andii) a portion underlying said head which is without any thread, said drive recess being cruciform in shape, said cruciform being formed by two ortho-gonal slots which each extend from between 70% and 95% of said maximum diameter to provide a required level of torque, said drive recess having retention means so said screw can be attached to a driver and inserted by a single hand of a user;d) a cutting flute extending over at least a portion of said overall length for cutting and removing bone fragments to permit penetration and thread formation by said screw in at least one of said bone sections which are being reattached by said screw; reby a configuration of said head region including said drive recess provides said adequate level of torque required to permit said screw to be driven into said bone and adequate strength to resist deformation and twisting of said head off said body region of said screw during installation.