Convertible threaded compression device and method of use

A device for connecting a bone fragment to an anchor bone for a healing duration and for extending out of the bone during the healing duration, the device having an elongated shaft extending about a shaft axis and comprising:

• a bone exterior section;
• and
• a bone penetration section extending distally from the bone exterior section, the bone penetration section comprising:
• a non-engaging fragment section;
• and
• a bone anchor section located distally to the non-engaging fragment section, the bone anchor section having threads for engagement with the anchor bone, with a major diameter of the threads being greater than a shaft diameter of the non-engaging fragment section;
• and
• a compression engagement on the bone exterior section, the compression engagement providing a shoulder extending at a substantial angle to the shaft axis for substantial contact with an exterior surface of the bone fragment, the compression engagement being axially movable on the bone exterior section.

A threaded compression device for placing a compression force on a fragment against an anchor substrate, comprising:

• a shaft running from a proximal end to a distal end about a shaft axis, the shaft comprising:
• an anchor section on the distal end of the shaft, the anchor section having threads with a major diameter and a minor diameter;
• a non-engaging fragment section proximal to the anchor section, the non-engaging fragment section having a diameter which is no greater than the minor diameter of the anchor section such that the non-engaging fragment section can fit within a profile drilled by the anchor section;
• and
• an exterior section proximal to the non-engaging fragment section, the exterior section having a length which makes up at least one third of the length of the shaft;
• and
• a compression shoulder adapted for mounting on a distal end of the exterior section of the shaft at a longitudinally adjustable position, the compression shoulder providing a contact surface which extends at an angle to the shaft axis for making contact with an exterior surface of the fragment.

A device for assisting in bone healing and growth, the device running from a proximal end to a distal end about a longitudinal axis, comprising:

• an anchor section on the distal end, the anchor section having threads with a major diameter and a minor diameter;
• a non-engaging fragment section proximal to the anchor section, the non-engaging fragment section having a smooth outer profile with a diameter which is no greater than the minor diameter of the threads of the anchor section;
• a compression engagement proximal to the non-engaging fragment section, the compression engagement having a shoulder which extends at an angle relative to the longitudinal axis, the shoulder being at a diameter greater than the major diameter of the threads of the anchor section;
• and
• a rotation section proximal to the compression engagement, the rotation section having a smooth outer diameter.

A threaded compression device for placing a compression force on a fragment against an anchor substrate, comprising:

• a shaft running from a proximal end to a distal end about a shaft axis, the shaft comprising:
• a distal drill tip for forward insertion;
• an anchor section on the distal end of the shaft next to the distal drill tip, the anchor section having threads with an anchor thread pitch;
• a proximal threaded shaft section proximal to the anchor section, the proximal threaded shaft section having threads with a compression thread pitch, the compression thread pitch being different than the anchor thread pitch;
• and
• a proximal drill tip for reverse insertion;
• and
• a compression shoulder adapted for mounting on the proximal threaded shaft section at an axially adjustable position, the compression shoulder providing a contact surface which extends at an angle to the shaft axis for making contact with an exterior surface of the fragment.

A reverse-taper threaded compression device for placing a compression force on a fragment against an anchor substrate, the compression device comprising:

• an elongated shaft running from a proximal end to a distal end about a shaft axis, the shaft comprising:
• an anchor section on the distal end of the shaft, the anchor section having external threads for engagement with the anchor substrate with an anchor major diameter and an anchor minor diameter;
• and
• a fragment exterior section proximal to the anchor section, the fragment exterior section having external threads with a fragment exterior major diameter and a fragment exterior minor diameter;
• wherein the fragment exterior major diameter is less than the anchor major diameter;
• and
• a compression engagement adapted for mounting on the fragment exterior section, the compression engagement providing a contact surface which extends at an angle to the shaft axis for making contact with an exterior surface of the fragment, the compression engagement having internal threads for mating with the external threads of the fragment exterior section enabling the compression engagement to be axially movable on the fragment exterior section.

A method of repairing a fractured bone, comprising:

• screwing a device through a bone fragment, the device comprising:
• an elongated shaft having a bone penetration section extending distally from a bone exterior section about a shaft axis, the bone penetration section being shorter than the bone exterior section, the bone penetration section including a fragment section and a bone anchor section located distally to the fragment section, the bone anchor section having threads with a major diameter of the threads being greater than a diameter of the fragment section;
• and
• a compression engagement on a distal end of the bone exterior section, the compression engagement providing a shoulder extending at a substantial angle to the shaft axis;
• and
• further screwing the device such that the bone anchor section advances into an anchor bone with the fragment section in the bone fragment.