Dynamic compression implant

Inventors

Gregersen, Colin S. • Fallin, T. Wade • Saltzman, Charles L. • HAGMAN, Chase

Assignees

University of Utah • University of Utah Research Foundation Inc

Abstract

A dynamic compression implant may be insertable into a bone, and may have a distal member with distal bone-engaging threads, a proximal member that slidably engages the distal member, and a tension member with a proximal end coupled to the proximal member, and a distal end coupled to the distal member such that, in response to motion of the distal member distally away from the proximal member, the tension member elongates and urges the distal member to move proximally toward the proximal member. The bone screw may further have an interpositional member, formed separately from the proximal member and the distal member, that cooperates with the proximal member and the distal member to form a torque transmission feature that transmits torque between the proximal member and the distal member. The dynamic compression implant may be a bone screw, intramedullary implant, or other implant that applies compression across two bone portions.

Core Innovation

The dynamic compression implant is insertable into a bone and includes a distal member comprising distal bone-engaging threads and a proximal member configured to slidably engage the distal member. A tension member has a proximal end coupled to the proximal member and a distal end coupled to the distal member such that, in response to motion of the distal member distally away from the proximal member, the tension member elongates and urges the distal member to move proximally toward the proximal member. The implant thereby provides dynamic compression based on relative motion between the distal and proximal members.

The implant further includes an interpositional member formed separately from the proximal member and the distal member. The interpositional member cooperates with the proximal member and the distal member to form a torque transmission feature that transmits torque between the proximal member and the distal member.

In described embodiments, the interpositional member cooperates with the proximal member and the distal member to form a length limiting mechanism that prevents motion of the distal member distally away from the proximal member beyond a maximum length of the dynamic compression implant. The length limiting mechanism also prevents motion of the distal member proximally toward the proximal member when the implant length would fall below a specified minimum length.

Claims Coverage

The independent claims are directed to 3 main inventive features: the elongating tension member that urges the distal member proximally, the separately formed interpositional member that forms a torque transmission feature, and the separately formed interpositional member that forms a length limiting mechanism.

Claim coverage centers on the elongation-driven urging of the distal member proximally, together with a separately formed interpositional member that either transmits torque or limits implant length.

Stated Advantages

Documented Applications

No documented applications found