Bone screw with multiple thread profiles for far cortical locking and flexible engagement to a bone
AssigneeZimmer, Inc.
InventorsMichael Bottlang, Michael K. Keith, Josef Doornink, Anthony Lee Koser
Life of this patent
Estimating the term…
Abstract
Osteosynthesis constructs for treating bone fractures and bone screws for use in such systems are disclosed. The bone screws include a threaded front section configured for engagement with cortical bone, a threaded mid-section and an unthreaded neck section configured for limited movement within the near cortex of the bone. Osteosynthesis constructs of the type disclosed promote secondary healing by allowing for substantially parallel motion at the near and far cortex within the effective motion range for callus formation.
Claims20
A bone screw comprising:
- a head portion;
- and
- a shaft portion, the shaft portion including:
- an unthreaded neck section;
- a threaded mid-section extending from a first end to a second end, the threaded mid-section having a first thread profile that extends from the first end to the second end and a first core diameter;
- a threaded front section distal to the threaded mid-section, the threaded front section having a second thread profile different from the first thread profile and a second core diameter greater than the first core diameter;
- and
- an expanded core section positioned distal to the unthreaded neck section, the expanded core section having a third core diameter that is greater than the first core diameter and the second core diameter.
A bone screw comprising:
- a head portion;
- and
- a shaft portion, including:
- an unthreaded neck section having a neck diameter;
- a threaded mid-section extending from a first end to a second end, the threaded mid-section having a first thread profile that extends from the first end to the second end and a first core diameter;
- a threaded front section distal to the threaded mid-section, the threaded front section having a second thread profile different from the first thread profile and a second core diameter greater than the first core diameter;
- and
- an expanded core portion positioned between the threaded mid-section and the unthreaded neck section, the expanded core portion having a third core diameter, the third core diameter greater than the first core diameter of the threaded mid-section, the second core diameter of the threaded front section, and the neck diameter of the unthreaded neck section.
A bone screw comprising:
- a head portion having a plurality of threads;
- and
- a shaft portion, including:
- an unthreaded neck section having a neck diameter and an unthreaded neck length;
- a threaded mid-section extending from a first end to a second end, the threaded mid-section having a first thread profile that extends from the first end to the second end, a first core diameter, and a first major diameter;
- a threaded front section distal to the threaded mid-section, the threaded front section having a second thread profile, a second core diameter, and a second major diameter;
- an expanded core portion positioned between the threaded mid-section and the unthreaded neck section, the expanded core portion having a third core diameter and an expanded core portion length,
- wherein the third core diameter is greater than the first core diameter, the second core diameter, and the neck diameter,
- wherein the first thread profile has a first thread angle equal to a second thread angle of the second thread profile, and the first thread profile has a first thread root that is greater than a second thread root of the second thread profile, and
- wherein the expanded core portion length is less than the unthreaded neck length.
Dependencies are inferred from the claim text.