Orthopedic implants and methods
Inventors
Harmon, Jon A. • Marinescu Tanasoca, Ruxandra C. • Landon, Ryan • Housman, Mark • Haddock, Sean
Assignees
Publication Number
US-12336911-B2
Publication Date
2025-06-24
Expiration Date
2038-10-26
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Abstract
There is provided a tibial component comprising a tibial tray having a superior side and an inferior side, and a support member connected to the inferior side of the tibial tray, the support member having a stem portion, the stem portion including one or more fins and a first arm angled relative to a second arm. In one form, the fins have a curvature that extends away from the stem portion. In another form, the first arm defines an opening sized to receive an anchor wherein the anchor is configured to penetrate a portion of bone and the opening in the first arm. Optionally, the stem portion includes a first portion having a first cross sectional area and a second portion having a second cross sectional area wherein the first cross sectional area is larger than the second cross sectional area. The fins and arms can include rail protrusions.
Core Innovation
The invention provides a tibial component designed for orthopedic implantation, specifically comprising a tibial tray with superior and inferior sides, and a support member connected to the inferior side. The support member features a stem portion that includes one or more fins and arms, with the fins possessing specific configurations such as different lengths, curvatures, openings for placement of anchors, and rail protrusions. Some embodiments include arms angled relative to each other, and the fins and arms are designed to optimize engagement with the bone.
The problem addressed is the limited immediate postoperative fixation of cementless tibial trays, where stability relies on bone ingrowth that takes several months, exposing patients to risk of implant loosening or failure. Existing cemented solutions have drawbacks related to the use of bone cement, prompting a need for improved cementless fixation methods that offer both immediate stability and promote secure long-term bone integration.
The core innovation lies in the specialized configuration and arrangement of the support member’s fins and arms, with variable geometries, rail protrusions, and openings for anchors. These features are designed to enhance rotational stability, liftoff resistance, and secure fixation of the tibial component to bone, optionally allowing for intraoperative use of anchors for additional stability, especially in challenging bone conditions. Some variants include pegs, notches for ligament preservation, and surfaces prepared for various articular inserts, making the component adaptable for different clinical situations.
Claims Coverage
The patent includes one independent claim covering the tibial component with several inventive features.
Tibial component with differentiated fin configurations
The tibial component comprises: - A tibial tray having superior and inferior sides, an anterior side, posterior side, and rim. - A support member attached to the inferior side, including a stem portion. - The stem portion has a plurality of fins, including fins of a first configuration (first and second fins) and a second configuration (third and fourth fins). - The fins of the first configuration (first and second) are longer (as measured along the inferior side) than those of the second configuration (third and fourth). - The first fin extends from the stem portion toward the rim, posteriorly and toward a first side, with a curved profile; the second fin extends posteriorly and toward the second side, similarly with curvature. - The third and fourth fins extend anteriorly and toward respective first and second sides, with the fourth fin longer than the third. - The fins’ curved profiles bend about an axis perpendicular to the superior side.
The claims cover a tibial component with a support member comprising multiple fins of varying configurations and lengths, designed and positioned to improve fixation and rotational stability. The features include particularly shaped, oriented, and dimensioned fins, as well as arrangements enhancing engagement with bone.
Stated Advantages
The configuration of fins, arms, and support member enhances rotational resistance and strength of the tibial component after implantation.
The unique arrangement of fins and arms improves fixation between the tibial tray and bone post-operatively, providing increased immediate stability.
Specific cross-sectional shapes of the stem portion enhance the fit and fixation surface area, particularly benefiting patients with varying anatomic features or high BMI.
Rail protrusions or ridges on the fins increase bone compression and fixation strength.
Curved fins reduce risk of bone fracture during implantation, especially in hard bone.
Pegs can provide added stability by entering denser bone near the tibial plateau.
Optional anchors provide flexibility for intraoperative decisions based on bone quality or desired initial fixation levels.
The arrangement allows preservation of cruciate ligaments due to specific notches in the tibial tray.
Documented Applications
Orthopedic implantation as a tibial component for knee replacement, including use in both cruciate sacrificing and cruciate preserving procedures.
Use with cementless fixation in patients where immediate postoperative stability and long-term fixation without bone cement are desirable.
Application in patients with osteoporosis or compromised bone quality, where anchors and drug-carrier polymers may be used for stability and enhanced healing.
Use in both mobile bearing and fixed bearing knee joints.
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